ISSN 0031-0204

fJ ~~1i-±~~/.t'_t-!c.t

Transactions and Proceedingsof thePalaeontological Society of Japan
New SeriesNo. 121

Palaeontological Society of Japan
April 30, 1981

Itaru HAY AMI and Ikuwo OBA TA
Co-Editors
Associate editors Teruya UYENO and Tomowo OZAWA

Officers for 1981-1982
Honorary President: Teiichi KOBAYASHI
President: Tetsuro HANAI
Councillors: Kazuo ASAMA, Kiyotaka CHINZEI, Takashi HAMADA, Tetsuro HANAl,
Yoshikazu HASEGAWA, Itaru HAYAMI, Hisayoshi IGO, junji ITOIGAWA, Tadao
KAMEl, Tatsuaki KIMURA, Ikuwo OBATA, Tsunemasa SAITO, Tsugio SHUTO,
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Affairs), Takashi HAMADA (Membership), Itaru HAYAMI (Transactions), Hisayoshi IGO (Foreign Affairs),

Tatsuaki KIMURA (Planning),

Ikuwo OBATA(Transactions), Tsugio SHUTO (Special Papers), Yokichi TAKA YANAGI ("Fossils")
Secretaries: Kazuhiko UEMURA (Finance), TOl:lhiyuki YAMAGUCHI (General Affairs),
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The fossil on the cover is an adult example (T . TAKAHASHI colI.) of

Mikasaites orbicularis MATSUMOTO (subfamily Marshallitinae, family
Kossmaticeratidae) from the Lower Cenomanian (Cretaceous) of theMikasa area, central Hokkaido. (photo by M. NODA, natural size)

All communications relating to this Journal should be addressed to the
PALAEONTOLOGICAL SOCIETY OF JAPAN,
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Yayoi 2-4-16, Bunkyo-ku, Tokyo 113, japan.

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 121, pp. 1-13, pI. 1, April 30, 1981

725. GRASSIGORBISEMA, A NEW SILICOFLAGELLATE GENUS,
FROM THE SOUTHERN OCEANS AND PALEOCENESILICOFLAG ELLATE ZONATION*
HSIN YI LING
Department of Geology, Northern l11inois University, DeKalb, l11inois 60115

Abstract. A new silicoflagellate genus, Crassicorbisema, is proposed from deep·sea sediments of the southern oceans. Unusually thick siliceous skeletal components
bearing a characteristic corrugate surface microstructure permit the specimens to bedifferentiated readily from the related forms. This genus occurs in abundance but islimited to Lower Paleocene sediments, thus enhancing its biostratigraphic significance.
Taxa newly proposed herein are: Crassicorbisema disymmetrica disymmetrica andC. disymmetrica dumitricae. Based on the present analysis, a revised Paleocene sili·
coflagellate zonation is proposed. The newly proposed zones are: Crassicorbisema
disymmetrica dumitricae, C. disymmetrica disymmetrica, Corbisema constricta, andNaviculopsis constricta, in ascending order.

serves special attention because of itsdistinctive skeletal appearance, its limited
biostratigraphic occurrence, and its paleobiogeographic distribution aparently limited only to the middle and high latitudesof the southern oceans. This paper presents the details of this investigation.

Introduction

In the geological history of silicoflagellates, assemblages representing the Paleocene age have not been positively recognized until recently except for brief
descriptions from Russia (SCHULTZ, 1928 ;GLEZER, 1966). Therefore when the documentation of this group of siliceous
micro plank tons was attempted earlier(LING, 1972), the Paleocene interval wasleft completely untouched.
As D/V
Glomar Challenger, under the Deep Sea
Drilling Project (DSDP), continues thedrilling operation throughout the majorparts of the world's oceans, submarine
deposits of various ages have successfully
been recovered including silicoflagellatebearing sediments of a Paleocene age.
One Paleocene silicoflagellate taxon de-Material Studied

Cored submarine sediments analyzed
during the present investigation wererecovered from the following DSDP
Holes:
208: 26°06.61'S; 161°13.27'E; water
depth, 1,545 m.
327 A: 50 52.28'S; 46°47.02'W; water
depth, 2,401 m.
The methods of sample preparation for
microscopic examination, and of description of the location of illustrated specimens in strewn slides are the same as
those given in my earlier investigations.
0* Received June 14, 1980; revised manuscript
received Jan. 27, 1981.

1

Hsin Yi LING

2

Furthermore, morphologic terminology
employed herein was also presented earlier(LING, 1972). All the slides examined forthe present study will be deposited in
the Micropaleontology Collection of the
Department of Geology, Northern Illinois
University.
Systematic Micropaleontology

Phylum Chrysophycophyta
Class Chrysophyceae
Subclass Silicofiagellatophycidae
Order Siphonotestales LEMMERMANN, 1901
Genus Corbisema HANNA, 1928, emend.
FRENGUELLI, 1940
Corbisema inennis inermis (LEMMERMANN)
Plate 1, Figs. 1, 2

Dictyocha triacantha var. inermis LE:VIMERMANN, 1901, p. 259, pI. 10, fig. 21.SCHULTZ, 1928, p. 249, fig. 30a, b (?); p.
281, fig. 75.-GEMEINIIARDT, 1930, p. 43,
fig. 33.-DEFLANDRE, 1932, fig. 31.-TsuMURA, 1963, p. 48, pI. 8, fig. 17.
Corbisema geometrica HANNA, 1928 (in part),
p. 261, pI. 41, fig. 1 (only) .-MANDRA,
1968 (in part), p. 248, fig. 3 (?) (only).LING, 1972 (in part), pp. 153-155.
Corbisema apiculata var. inennis LE:VIMERMAN:--I: DEFLANDRE, 1950 (in part), p.
32/82, fig. 86 (only).
Dictyocha triacantha var. inermis f. inermis
GLEZER, 1966 (in part), p. 230, pI. 8, fig.
1(?), 2(?) (only).
Corbisema inermis inermis (LE:VIMERMANN):BUKRY, 1976, p. 892, pI. 5, figs. 1-3.

Description: Basal body rings, trilobate,with smoothly rounded apices but without
radial spines; three lateral rods, slightly
arched in lateral view, extend straightinward and perpendicularly from middleof basal ring to join in Y at center;

neither apical accessory spine nor apicalbar present; basal accessory spines, relatively long, originate from abapical sideof junction of lateral rods and basal ring,
pointed inward.
Remarks: When HANNA (1928) described
Corbisema geometrica from California, heincluded specimens (1928, pI. 4, fig. 1)
without a hyaline apical plate and wavy
lateral rods, although he regarded themas an irregular form occurring rarely.
As has already been pointed out in myearlier publication (LING, 1972) and in thelater examination of C. geometrica fromthe topotypic material of the California
Academy of Science Collection (MCPHERSON and LING, 1973), no such HANNA'S
irregular specimen was encounted. Resultsof subsequent observations by numerous
authors mainly from DSDP sediments
seem to suggest that it is best to apply
the species, C. geometrica, in its strict
sense to those specimens possessing ahyaline apical plate; thus common geological occurrence of C. geometrica is in
the Late Cretaceous (Maastrichtian), butranges rarely to the Early Paleocene.
As for Corbisema inermis inermis,
LEMMERMANN'S original illustration (1901,
pI. 10, fig. 21) is from Fuur Island of
Denmark, and the· specimens illustrated
here are from my reference samples collected from the same area (S130-135:
sample between ash layer 130 and 135
from Sydklinten, Thy; 514/3, sample fromash layer 11, Knudeklint, Fuur Island) withthe assistance of Dr. Katharina PERCHNIELSEN and Ms. Ella HocH. In her studyof the area, PERCH-NIELSEN (1976) did notreport the presence of this species. The
surface of skeletal components of thisspecies is either smooth (as shown by
LEMMERMANN and DEFLANDRE from Fuur
Island and SCHULTZ from Simbirsk), orbears granulation (as shown by SCHULTZand GEMEINHARDT from Mors Island,

725.

Crassicorbisema, a new silicoflagellate genus

GLEZER from the Urals, and TSUMURA,
from his unspecified locality).
Corbisema naviculoidea (FRENGUELLI)
Plate 1, Fig. 3; Text·figure 1 (left)

Dictyocha navicula EHRENBERG: LEM:vtER:>'1ANN,
1901 (in part), p. 257, pI. 10, fig. 11 (only).
-DEFLANDRE, 1932, fig. 13.
Corbisema apiculata f. naviculoidea FREN·GUELLI, 1940, fig. 12 i.
Corbisema apiculata var. inermis LEMMERMANN: DEFLANDRE, 1950 (in part), fig. 88(only) .
Dictyocha naviculoidea (FRENGUELLI): MARTINI, 1974, p. 528.
Corbisema naviculoidea (FRENGUELLI) : PERCHNIELSEN, 1976, p. 33, figs. 7, 19, 22.
Corbisema navicula navicula (EHRENDERG):
BUSEN and WISE, 1977, p. 712, pI. 2, figs.

7(?), 8, 9.

meet.
Remarks: Thus far all the previous
occurrences for the present taxon fromland outcrops have been limited to Fuur
Island of Denmark and the specimen illustrated (plate 1, figure 3) is from sample(539/1) at about ash layer 15 or 16 of
Holmboes Grav of the island. The specimens with relatively shorter length ofthe major axis show some resemblance
to those of C. constricta, but can be differentiated from the latter by its narrowly
rounded apices and its general appearance(see figure 1 and further remarks underC. constricta).
Corbisema cuspis BUSEN and WISE
Plate 1, Fig. 4

Dictyocha navicula EHRENBERG: SCHULZ, 1928

Description: Basal body ring, naviculoid
with generally narrowly rounded apices;
lateral bar, often thinner than that ofbasal ring, slightly arched in lateral view,
joins the basal ring where a slight construction in outline of basal ring is often
shown; neither apical accessory spine norradial spine present; basal accessory
spines, short, originate from the abapicalside where basal ring and lateral bar

D1&?d1
112 A ~ B

3

1/2A ~ B

Text-fig. 1. Schematic diagram of Corbisema naviculoidea (left) and C. constricta
showing differneces in proportions which areuseful for taxonomic differentiation.

(in part), p. 243, fig. 16a (only) .-MuKHlNA, 1974, pI. 2, fig. 13.-MuKHINA, 1976,
pI. 2, fig. 13.
Corbisema disymmetrica angulata BURKY, 1976,
p. 891, pI. 1, figs. 1-4.
Corbisema cuspis BUSEN and WISE, 1977, p.
711, pI. 1, figs. 4-6.

Description: Basal body ring, bilobate
or naviculoid with distinct acute angle atboth apices on major axis; lateral bar,often thinner than that of basal ring,slightly arched in lateral view, joins thebasal ring where a slight construction in
outline of basal ring is often shown; noapical, basal accessory nor radial spine
present.
Remarks: Geological occurrence of thisspecies is thus far limited only to Late
Paleocene. When BUKRY (1976) raised
DUMITRICA'S Corbisema inermis disymmet rica (1973) to the rank of species as
C. disymmetrica, he recognized threesubspecies: (a) those with skeletal components of smooth, and regular thickness,
C. disymmetrica angulata (=c. cuspis inHsin Yi LING

4

this paper), and C. disymmetrica communis(=C. constricta in this paper); and (b)those possessing a rather thick andunique corrugate microstructure, C. disymmetrica disymmetrica (=Crassicorbisema
disymmetrica disymmetrica in this paper).
Differences in thickness and characteristic
surface microstructure of its skeletalcomponents coupled with a rather limited
geological occurrence of Crassicorbisema
disymmetrica disymmetrica are significant
enough to warrant its taxonomic differentiation from its allied forms which will
be discussed later.
It should be emphasized here that
although BUKRY'S Corbisema disymmetrica
angulata has priority over C. cuspis(BUSEN and WISE, 1977, p. 716) it is apparent from the above discussion thatBUKRY'S C. disymmetrica includes two
distinctly different forms. Furthermore,
the term disymmetrica was originally applied by DUMITRICA (1973) to a subspecies
possessing unusually thick and corrugatedskeletal components, and its biostratigraphic significance is also clearly amplified in this paper (see below). Thus inorder to avoid any further taxonomic
confusion among closely allied forms(LANJOUW et al., 1966, ICBN Art. 24:
Recommendation 24B), an epithet proposed
by BUSEN and WISE is adopted here.

Corbisema navicula constricta BUSEN and WISE,
1976, p. 712, pI. 3, figs. 1, 2.

Description: Basal body ring, oblongor bilobate, with smooth, broadly roundedapices; lateral bar, often thinner thanthat of the basal ring, also slightly arched
in lateral view, joins the basal body ringwhere generally definite constriction in
outline of basal ring occurs; neither
apical accessory spine nor basal radial
spine present; basal accessory spines
either present or absent.
Remarks: The present species is characterized by its broadly rounded apices
and a prolate spheroidal appearance, andgenerally a distinct stracture in its outline.
Some broader specimens of C. naviculoidea
show a resemblance to those of thepresent species, but can be differentiatedfrom each other by the nature of theapices as well as by the proportion ofmajor and minor axes as shown in figure
1. Due to the constriction of the specimen in the middle where the lateral rod
is located, the widest dimension generally
lies in the distal half between apices andthe lateral bar on the major axis.
Holotype:
USNM 241298, specimen
described as Corbisema navicula constricta
by BUSEN and WISE, 1977, pl. 3, fig. 1.
Paratype:
USNM 241229, specimen
described as Corbisema navicula constricta
by BUSEN and WISE, 1977, pl. 3, fig. 2.

Corbisema constricta BUSEN and WISE
Plate 1, Figs. 5-7; Text·figure 1 (right)

Genus Crassicorbisema LING, n. gen.

Dictyocha apiculata var. inermis (LEMMER·:\'IAKN), DEFLAl'1DRE, 1941 (in part), p.
102, figs. 20 (?), 22.
Dictyocha navicula EHRENBERG, TSUMURA,
1963 (in part), pp. 43, 44, pI. 7, fig. 4GLEZER, 1966, pp. 233-234, pI. 9, figs. 4,
5; text·fig. 6(6).
Corbisema disymmetrica communis BUKRY1976 (in part), p. 891, pI. 1, figs. 7-9

Diagnosis: Relatively large silicoflagellates with unusually thick skeletal components with characteristic corrugate
surface microstructure throughout; basal
body ring, either well-shaped trilobate,bilobate or widely irregular outline; lateralrod, equal to or frequently thinner thanthat of basal body ring with corrugate
or smooth surface microstructure; basal(only) .

725.

Crassicorbisema, a new silicoflagellate gem~saccessory spines, also thick and short,originate generally on the abapical side
where the lateral rod joins the basal ring,frequently bifurcate at the distal end orform two divergent spines from the proximal end; apical accessory spine, generally
absent, but if present, short and thick;radial spines absent.
Remarks: Specimens belonging to thepresent genus demonstrate a rather broad
range of irregularities in the outline ofits basal body ring, and the presence of
one or two additional accessory spines on
the basal ring are also common (DUMITRICA, 1973). However, the combinationof unusually thick skeletal components
and distinct corrugate surface microstructure are consistant and thus readily differentiate specimens of the genus fromall the other related forms thus far published even in the lower (e. g. 200 times)
magnification.
It may be argued that their unusually
thick skeleton and corrugated surface
microstructure are due to some environmental conditions, but this is considered
to be unlikely at least at the present
time, because abundant specimens of thepresent species are observed with other"normal" -formed silicoflagellates in thesame slides.
Until now their abundant occurrence(acme) is observed only in Lower Paleocene sediments recovered from middle tohigher latitudes of the southern oceans.
Type species: Crassicorbisema disymmetrica (DUMITRICA) LING, n. comb.
Derivation of generic name: Fromcrassus, (Latin, for thick), referring to theunusually thick and corrugate skeletalcomponents of the specimens belonging
to this genus.
Crassico rbisema disymmetrica(DUMITRICA) LING, n. comb.

5

Crassicorbisema disymmetrica dumitricae

LING, n. subsp.
Dictyoclw triacanth var. inermis f. inermis
GLEZER, 1966 (in part), p. 230, pI. 8, fig.
1(?), 2(?) (only)

Corbisema inermis DUJI,IITRICA (not LBI~IER­
MANN), 1973, p. 845, pI. 12, figs. 7-9.
Corbisema inermis (GLEZER) : BUKRY, 1975, p.
854.
Corbisema inermis crenulata BUKRY, 1976, p.
892.
Corbisema inermis inermis (LEMMERMAi'\N):
BUSEN and WISE, 1977, p. 711, pI. 2, fig. 5.

Description:
Basal ring, commonly
triangular, large, robust or thick, consisting of minute crests or tubercles in transverse or irregular forms showing characteristic rough outline; radial spines
generally absent at rounded corners;
lateral rods, thinner than that of basal
ring, gradually tapering off their thickness
inward where they join in a form of Y;
apical accessory spine absent; basal accessory spine, thick and short, located at
abapical side where lateral rods originate
from basal ring, though completely absent
sometimes.
Remarks: This subspecies was discussed in detail and is well illustrated by
DUMITRICA (1973) based on submarine
deposits, cores 29 through 31 of Site 208,
DSDP Leg 21 from the western flank of
the crest of the northern Lord Howe Riseof the Southwest Pacific. Therefore his
description is largely adopted here. DUMITRICA (1973, p. 846) listed the present
triangular form as constituting 100% for
31 CC, 92% for 30 CC, but its abundance
declines rather sharply to only 2% in
29 CC of the Crassicorbisema specimens.
The present author's examination certainly
conforms this observation of DUMITRICA
noting only a few specimens in sample
30-2. The section, cores 29 through 31,
is considered to be Early to Middle

6

Hsin Yi LING

Paleocene in age by DUMITRICA, whereas
BUKRY (1976, p. 887) assigned it to the
Early Paleocene Cruciplacolithus tenuis(calcarous nannoplankton) Zone.
PERCH-NIELSEN (1975) observed thepresent taxon from the cored sections 11
through 14, of Hole 277 A (Southern Campbell Plateau in the Southwest Pacific,
52° 13'43"S ; 166° 11'48"E ; water depth,
1,214 m) of Leg 29 and assigned to the
Oligocene Dictyocha medusa to Corbisema
hastata-C. apiculata Zones. Reexamination of these Hole 277 A sections, samples
11-2, 12-2, 13-2 and 14-2, all taken at
70-71 cm interval, reveals that only core
13-2 contains a very few specimens of
the present taxon, but age of the assemblage is definitely younger consisting of
Naviculopsis constricta, N. biapiculata, andN. trispinosa. Therefore the occurrenceof the present species in Hole 277 A is
here considered to be reworked specimens
or contaminants. Nevertheless, its occurrence points out that the source area iseither from the Paleocene section of thesame site, cores 44-46 CC consisting of
nannofossil chalk (KENNETT, HOUTZ, etal., 1975), or from a nearby oceanic area.
GLEZER (1966) recognized Paleocene specimens from Russia noting considerable
variations for their skeletal contour, andthey have unusually large dimensions,70-100 pm long (vs. 36-63 pm in Cretaceous forms). Her specimens (pI. 8, figs.
1, Early Paleocene; 2, Late Cretaceous)further show a distinctly rough (crenulate?) surface microstructure. Although
her specimens have pointed abapical accessory spines and a basal body ring having a regular thickness, there is a possibility that the present taxon may occur
in Russian sediments.
Derivation of name: The present subspecies is named after Dr. Paulian DUMITRICA of Romania who first recognized
this characteristic silicoflagellate and who

is contributing much to the field of siliceous microfossils.
Holotype: Plate 12, figure 9 of DUMITRICA, 1973.
Paratypes: Plate 12, figures 7 and 8 of
DUMITRICA, 1973.
Measuremants: Maximum diameter,
93-109 pm (according to BUKRY, 1976, p.
892).
Type locality: Site 208, 31 CC (561 m),
southwestern Pacific Ocean.

Crassicorbise11la disY11l11letrica
disY11lmetrica (DUMITRICA) LING
Plate 1, Figs. 8-12

Corbisema inermis disymmetrica DUMITRICA,
1973 (in part), p. 846, pI. 12, figs. 1, 2,
4-6 (only); plate 13, figs. 1-8.-PERCHNIELSEN, 1975, p. 685, pI. 8, figs. 1, 2.BUSEN and WISE, 1977, p. 711, pI. 2, fig. 6.
Corbisema disymmetrica disymmetrica (DUMITRICA) : BUKRY, 1976 (in part), p. 891, pI. 1.

Description: Basal body ring, generally
elliptical to bilobate, but shows a wide
range of irregularities in the outline withslight constriction in the outline wherelateral rods join; thick skeletal components and corrugate surface microstructure as C. disymmetrica dumitricae ; radial
spine absent; short apical accessory spine
occasionally present; lateral bar, similar
to but often thinner than that of basal
ring, slightly arched upward in lateralview; basal accessory spines either completely absent or thick and short, frequently terminated with blunt end or
bifurcate at the distal end; or two divergent spines.
Remarks: Similar to the above subspecies, the present subspecies has wellbeen documented by DUMITRICA (1973).
The silicoflagellate flora of the oldest(deepest) sample examined during thepresent study, 30-2, 112-114 em (subbot-

725.

Crassicorbisema, a new silicoflagellate genus

tom depth 550.6 m), comprises more than
90% of this subspecies. As noted by
DUMITRICA, there is a sharp microfloral
change from the Corbisema inermis disymmetrica (=Crassicorbisema distymmetrica
disymmetrica, in this paper) rich sediments above to his Corbisema inermis(=Crassicorbisema disymmetrica dumitricae, in this paper) dominant sediments
below, and apparently this change takes
place between section 30-2 and 30 CC.
(551-557 m). It is therefore quite possiblethat this microfloral change corresponds
to that of lithologic change recognizedat 552.5 m (between 30-3 and 30-4) froma radiolarian and sponge spicule rich nannochalk above to the underlying diatom
bearing radiolarian, sponge spicule nannochalk.
The sporadic occurrence with a low
frequency of this taxon as well as theabove type of species from Hole 327 A
samples does not negate their biostratigraphic potential. On the contrary, theirbiostratigraphic value is enhanced byrealizing: (a) their wide geographicaloccurrence in both the Pacific (Site 208)
and Atlantic (Hole 327 A) sectors of southern oceans; (2) the total range of thisspecies is apparently limited only to the
Paleocene; but (3) for a practical biostratigraphic purpose, their common occurrence should limit only the Early Paleocene.
Holotype,' Plate 12, figure 2 of DUMITRICA, 1973.
Paratype,' Plate 12, figures 4-6 of
DUMITRICA, 1973.
Measurements,' Maximum diameter on
major axis, based on 20 specimens, 90115 pm.
Type locality,' Site 208, 29 CC. (557 m),
southwestern Pacific Ocean.

7

Discussion and Paleocene Silicoflagellate
Zonation

The geological occurrence of the aforementioned silicoflagellate taxa can be
discussed by correlating the cores andsections of the two DSDP sites to respective zonations based on other planktonic
microfossils at these sites. The biostratigraphic framework adopted here is thatof the recently improved time scale of
HARDENBOL and BERGGREN (1978, seetable 1). For the following comparisonof different zonations within respective
planktonic groups, readers are referred. to the articles by BUKRY (1978) and
MULLER (1974) for calcareous nannoplankton and to BOLLI and KRASHENINNIKOV(1977) for planktonic foraminifers.
Site 208,'
1. 29-1 (below 50 cm) through 29-3:
Heliolithus kleinpellii (NP 6) Zone
(BURNS, ANDREWS et al., 1973).
2. Top of 29-4: Beginning of Fasciculithus tympani/ormis (NP 5) Zone
(BURNS, ANDREWS et al., 1973).
3. Between 29-6, 53-55 cm and 30-1, 3436 cm: boundary between Globorotalia
pusilla pusilla (P 3) and Globortalia
uncinata (P 2) Zones (WEBB, 1973).
4. Between 30-3, 112-114 cm and 30-4,
29031 cm: boundary between Globigerina uncinata (P 2) and Globigerinapauciloculata (=G. trinidadensis, P 1 d)Zones (WEBB, 1973).
5. Between 21-23 cm and 91-93 cm of 331: boundary between Paleocene Conococcolithus panis Zone and Maastrichtian Nephrolithus /requens Zones (EDWARDS, 1971: BURNS, ANDREWS et al.,1978).
Hole 327 A,'
1. Between 4 CC and 5-1, 3 cm : boundary
between Discoaster multiradiatus (NP9) and Discoaster nobilis (NP 8) (WISEHsin Yi LING

8

Table 1. Paleocene time scale, planktonic zonations (after HARDENBOL
and zontaion of silicoflagellates.
PLANKTONIC
ZONES

t'
0

6~

"0
~6

o •
g:E;

§ .c"u

"0 "
-5::'

~ '"

8

SILICOFLAGELLATE TAXA
DSDP
SITE

.
a
.
. ..
~

~~

~

0

~

~

U"

~'

.-1--515 -

58
59

P6

,nR

-

..

..,

"

P3

~

~ Nl'3
P1

~

"7J

~
5/S
7~2

-g
~

Danian

.~

.;;

0

.Il

. "" .~

,~

~

"~

"

"

0

u

'tI

"~
'tI

~

.~
1:

~

.:l
1:

8

5/3
1

25

Hlf;t-

r- 60

~

"~

]

"
"
.
.
a a
"'" ~l ..

...

~i=! Thanetian P4 ~::i

60 - ~6~
61
62>63 tz7
r:i
64_21
65
2

"" ~" "" "'"n8~ .§""3

~

r---

P5

'"
~5g"

"'~

.~

I-- NP9

au

.
.

"'

Ages

54
55-~3
56
57 24

"~ 'B ~~~ U c:01
n "" "'" u:a'tJ~] oo~~"" ...11

0
0.

~

:IDr
1

29 6

8~1

I

I

~
~
'"
~

.~

1:
13

.~

:::

8"

.:l

t

"~

"'!!!

I

8 3

30/1

~ ~

;¥ti

h"Pl

and WIND, 1977)
2. 7-2, 147 cm: the bottom of Fasciculthus tympani/ormis (NP 5) (WISE and
WIND, 1977).
3. Between 43-44 cm and 70-71 cm of 83: Boundary between silicoflagellate
bearing sediments above (BUKRY, 1976)
and the underlying microfossil poor
sediments of the present investigaiton.
The entire cores are described as azeolite clay (BARKER, DALZIEL, et al.,1977). The absence of Corbisema
inermis crenulata BUKRY (=Crassicorbisema disymmetrica dumitricae, inthis paper) in the sample of 43-44 cm
suggests that the sample is within the
newly proposed Crassicorbisema disymmetrica disymmetrica Zone (see below).
Geological occurrence of the taxa ispresented in table 1 arranged according
to the stratigraphic positions of those
cored sediments as just discussed. It is
immediately evident that silicoflagellate
taxa show a distinct sequence of events
which provide the basis for a proposed
new zonation based on silicoflagellates.

Therefore, a brief review of the silicoflagellate zonation for the Paleocene interval is in order.
The recovery of silicoflagellates fromthe cored sediment, 31-3, 110-111 em (561m) at Site 208, the northern end of theLord Howe Rise, led BUKRY (1973) torecognize the first Paleocene (Danian)silicoflagellate assemblage. In his analysis
the sedimentary section from 29-5
through 31-3 was assigned (but withquestion in his figure 2) to Cruciplacolithus tenuis, calcareous nannofossil, Zone.
In addition, an assemblage of similar age
was recorded from the cores 37-3 through40-2 (343-381 m), Site 214 (11 °20'21/1S,
88°43'08/1E, water depth 1,665 m) fromthe eastern Indian Ocean (BUKRY, 1974).
These findings are the basis for establishing the Corbisema hastata Zone by BUKRY
and FOSTER (1974, Table 1), of whicn baseis defined by the initial apperance of Corbisema hastata, at its top by the first
appearance of Naviculopsis constricta.
Although they cited the first occurrenceof N. constricta in the late Paleocene or725.

Crassicorbisema, a new silicoflagellate genus

and BERGGREN, 1978) geological distribution

SILICOFLAGELLATE ZONES

Buk.y &
Foster(1974)
Bukry,(1975)
Leg 29Bukry(1976)
Leg 36

Busen &
Wise

(1976)

Bukry(1977)
Leg 39

Ling
this
paper

Leg 36Nat'iculop-

Corbisema

sis

Nat'.

Na~·.

constricta

conse.

const.

Nav. const.
C. hastaca

hastatilllaviculop.

constricta
Corbisemaconstricta

Corbisema

Corbisema

Crassicorb.
disymmatr.
Corbisem.l disymmetr.

hastatahastatahastatoJ

Crassicorb.
ciisymmatr.
rlumitricae

possibly in early Eocene time (1974, p.
305), the zone was considered to encompass the entire Paleocene Epoch at thattime. This zonal scheme is followed bylater (BUKRY, 1975, also see figure 4) discussion of Leg 29 samples from the southwest Pacific Ocean, although no Paleocene sediments were recovered during
the cruise. Note here, however, the upperboundary of the zone was drawn within
Late Paleocene in his figure 3 (BUKRY,
1975, p. 847).
It is from Hole 327A of Leg 36 fromthe South Atlantic Ocean that BUKRY(1976) formally lowered the upper limitof the Corbisema hastata Zone to theinitial common occurrence of Naviculopsis
constricta below the Paleocene-Eocene
boundary (1976, 1977). According to him,
this occurs within core 5 and is associated with the coccolith guide species,
Heliolithus riedelii. The zonation of
Paleocene section for Hole 327 A is:
5-1 through 5-4: Naviculopsis constricta
5-5 through 7-2: Naviculopsis constricta
or Corbisema hastata

9

8-1 through 8-3: Corbisema hastata
Zone
This same interval was investigated by
BUSEN and WISE (1977) and their results
are: 5-1 through 6-1 (14-16 cm) :Naviculopsis constricta
6-1 (102-103 cm) through 8-3: Co rbisema hastata
They considered the Corbisema hastata
Zone to range from the beginning ofPaleocene to middle Late Paleocene,
whereas the overlying Naviculopsis constricta Zone extends up to Middle Eocene(see their table 2 on p. 703). An interesting, unexpected point emerges from theabove comparison: increase in abundanceof Naviculopsis constricta did not showa sharp break but rather a steady upward
increase in abundance throughout thezone (BUSEN and WISE, 1977; BUKRY,1976) following its initial appearance atthe beginning of the Corbisema hastata
Zone. Therefore, BUSEN and WISE suggested that the initial appearence of Corbisema cuspis in conjunction with theincrease in abundance of Naviculopsis
constricta delimits the base of the N.
constricta Zone. The initial appearanceof Corbisema cuspis between 14-16 cm
and 102-103 cm of 6-1 from Hole 327 A
by BUSEN and WISE (1977) agrees withthat of BUKRY as well as the present
author's investigation.
The observations that the COl'bisema
hastata Zone thus far defined encompases
from Early to at least a part of Late
Paleocene is well documented. The
results of the present investigation revealthat silicoflagellate taxa discussed above
possess a definite geological range as well
as morphological characteristics which
would be useful for biostratigraphic subdivision of the Paleocene Epoch; consequently a new zonation is proposed asfollows.

Hsin Yi LING

10

Crassicorbisema disymmetrica dumitricae

Zone
Top: Initial common occurrence of
Crassicoribisema disymmetrica disymmetrica
Bottom: Initial appearence of thenominated species
References Section: Cores 30-4 through33-1 of Site 208
Remarks: The zone is characterized
by the predominance of C. disymmetrica
dumitricae as observed by DUMITRICA(1973). During the present investigation
the bottom of this zone was not observed.
It is quite conceivable that Corbisema
hastata is present, and some Cretaceous
index species, such as those belonging toVallacerta and Lyramula may extend
their ranges to early Cenozoic. The zone
is here regarded as coeval to PI Planktonic foraminiferal Zone.
Crassicorbisema disymmetrica disymmetrica Zone
Top: Initial apperance of Corbisema
constricta
Bottom: Initial common occurrence ofthe nominated subspecies.
Refel'ence section: Cores 29-5 through30-3 of Site 208
Remarks: A change of predominancefrom Crassicorbisema disymmetrica dumitricae to the nominated subspecies limit
the base of the zone. The earliest appearance of Corbisema naviculoidea also
occurs at this level or slightly later. The
upper limit of the zone here defined canalso be considered as the top of local
acme zone of the nominated species.
Corbisema apiculata, C. hastata hastata
and C. tricantha are also present.
Corbisema constricta Zone
Top: Initial appearance of Corbisema
cuspis and initial common occurrence of
Naviculopsis constricta
Bottom: Initial appearance of thenominated species
Reference section: Core 5-4, between
100-103 cm and 138 cm through 7-2 ofHole 327A
Remarks: The upper boundary of thezone defined herein based on the results
my investigation is in agreement withthat of BUSEN and WISE (1977). As forthe base, the following observations provide a convenient guide for its recognition: (1) initial appearance of Corbisema?
falklandensis of BUKRY (=Pseudomicromarsupium gombosum of BUSEN and
WISE); (2) the last common occurrenceof Crassicorbisema disymmetrica disymmetrica),. and (3) the only limited occurrence of Naviculopsis dancia in this partof southern ocean. Other members of theassemblage consist of: Corbisema hastata
hastata C. hastata cunicula, C. hastata
glabela, C. glezerae, C. inermis inennis,
C. inermis minor, and C. triacantha.
Naviculopsis constricta Zone
Top: First common occurrence ofDictyocha hexacantha (not observed inthis study)
Bottom: Initial common occurrence of
Naviculopsis constricta and initial appearance of Corbisema cusPis
Reference sections (for the lower part):Cores 5-1 through 5-4, between 100-102
cm and 138 cm of Hole 327 A.
Remarks: The zone is essentially thesame as recognized previously by BUKRY(1976, 1977) except with the modificationof the base as defined above. The local
range of Corbisema cuspis seems to belimited only to the lower part of thiszone.
Acknowledgements

Samples used in the present analysis
were provided from East and West Coastcores repository through the approval of
the Curatorial Office of the Deep Sea

725.

Crassicorbisema, a new silicoflagellate genus

Drilling Project whose operation has been
funded through the National Science
Foundation. Special thanks are due to
Dr. Katharina PERCH-NIELSEN, Zurich,
Switzerland, Ms. Ella HOCH, MineralogiskGeologisk Museum, Kobenhavn, Denmark
who kindly accompanied the author on
visits to several outcrops in Denmark;and to Mr. Kozo TAKAHASHI currently
at Woods Hole Oceanographic Institution
for his able technical assistance throughout the present investigation. The author
has also benefited from critical reviews
and constructive suggestions by Drs. PaulF. CIESIELSKI, York T. MANDRA and Harald S. POELCHAU.

References
BARKER, P., DALZIEL, I. W. D. et al. (1977):
Site 327. In: BARKER, P., DALZIEL, I. W.
D. et al., Initial Reports of the Deep Sea
Drilling Project, vol. 36, Washington (U.
S. Govt. Print. Office), p. 27-86.
BOLLI, H. M. and KRASHENINNIKOV, V. A.
(1977): Problems in Paleogene and Neogene correlations based on planktonic
foraminifera. Micropaleontology, vol. 23,
no. 4, p. 436-452.
BUKRY, D. (1973): Coccolith and silicoflagellate stratigraphy, Tasman Sea and southwestern Pacific Ocean, Deep Sea Drilling
Project, Leg 21. In: BURNS, R. E., ANDREWS, J. E. et al., Initial Reports of the
Deep Sea Drilling Project, vol. 21, Washington (U. S. Govt. Print. Office), p. 885893.
- - (1974): Coccolith and silicoflagellate
stratigraphy, Eastern Indian Ocean, DeepSea Drilling Project, Leg 22. In: vo;-';; DER
BORCH, C. C., and SCLATOR, J. G. et al.,Initial Reports of Deep Sea Drilling Project, vol. 22, Washington (U.S. Govt. Print.
Office), p. 601-605.
- - (1975):
Silicoflagellate and coccolith
stratigraphy, Deep Sea Drilling Project,
Leg 29. In: KENNETT, J. P., HOUTZ, R. E.
et al., Initial Reports of the Deep Sea

11

Drilling Project, vol. 29, Washington (U. S.
Govt. Print. Office), p. 845-872.
- - (1976): Cenozoic silicoflagellate and coccolith stratigraphy, South Atlantic Ocean,
Deep Sea Drilling Project, Leg 36. In:
HOLLISTER, C. D., CRADDOCK, C. et al.,Initial Reports of the Deep Sea Drilling
Project, vol. 35, Washington (U. S. Govt.
Print. Office), p. 885-917.
- - (1977):
Coccolith and silicoflagellate
stratigraphy, South Atlantic Ocean, DeepSea Drilling Project, Leg 39. In: SUPKO,
P. R., PERCH-NIELSEN, K. et al., Initial
Reports of the Deep Sea Drilling Project,
vol. 39, Washington (U. S. Govt. Print.
Office), p. 825-839.
- - (1978):
Biostratigraphy of Cenozoic
marine sediment by calcareous nannofossils. Micropaleontology, vol. 24, no. 1, p.
44-60.
- - and FOSTER, J. H. (1974): Silicoflagellate
zonation of Upper Cretaceous to Lower
Miocene deep-sea sediment. U.S. Ceol.
Surv., Jour. Res., vol. 2, no. 3, p. 303-310.
BURNS, R.E., ANDREWS, J.E. et al. (1973):
Site 208. In: BURNS, R.E., ANDREWS,
J.E. et al., Initial Reports of the DeepSea Drilling Project, vol. 21, Washington(U.S. Govt. Print. Office), p. 271-331.
BUSEN, Karen E. and WISE, S. W., Jr. (1977) :Silicoflagellate stratigraphy, Deep Sea Drilling Project, Leg 36. In: BARKER, P.,
DALZIEL, I. W. D. et al., Initial Reparts of
the Deep Sea Drilling Project, vol. 36,
Washington (U. S. Govt. Print. Office), p.
697-743.
DEFLANDRE, G. (1932): Les Silicoflagelles desterres fossiles
diatomees. Soc. France,
Microsc., Bull., vol. 1, p. 10-20.
- - (1941): Les notions de genre et de gradechez les Silicoflagellidees et la phylogenesedes mutants naviculaires. C.R. Acad. Sci.,
vol. 212, no. 2, p. 100-102, figs. 1-24.
- - (1950): Contribution a i'etude des Silicoflagellides actuels et fossiles. Microscopie, vol. 2, 82 p., figs. 1-24. vol. 2, no.
2, p. 72-108; no. 3, p. 117-142; no. 4, 192210.
DUMITRICA, P. (1973): Paleocene, late Oligocene and post-Oligocene silicoflagellates ina12Hsin Yi LING

southwestern Pacific sediments cored on
DSDP Leg 21. In: BURNS, R. E., ANDREWS, J. E. et al., Initial Reports of the
Deep Sea Drilling Project, vol. 21, Washington (U. S. Govt. Print. Office), p. 837883.
EDWARDS, A. R. (1971): A calcareous nannoplankton zonation of the New Zealand
Paleogene. In: FARINACCI, A. (ed.), Proceedings of the II Planktonic Conference,
Roma, 1970, vol. 1, p. 381-419. Edizioni
Tecnoscienza.
FRENGUELLI, J. (1940): Consideraciones sobre
los Silicoflagelados Fosiles. Rev. Mus. La
Plata, n. s., vol. II, paleont. no. 7, p. 37112.
GEMEINHARDT, K. (1930): Silicoflagellatae.
In: Dr. L. RABENHORST'S KryptogamenFlora von Deutschland, Osterreich und derSchweiz, vol. 10, p. 1-87.
GLEZER, Z. I. (1966): Silicoflagellatophyceae.
In: GOLLERBAKH, M. M. (ed.) , Cryptogamic plants of the U. S. S. R., vol. VII,
Akad_ Nauk SSSR_ Botanicheskii Institut
1m V. A. KOMAROVA. (Translated from Russian by Israel Program for Scientific Translations Ltd., Jerusalem, 1970, IV +363 p.)
HANNA, G. D. (1928): Silicoflagellates fromthe Cretaceous of California. jour. Paleont.,
vol. 1, no. 4, p. 259-264.
HARDENBOL, J. and BERGGREN, W. A. (1978):
A new Paleogene numerical time scale.
In: COl-lEE, G. V., GLAESSNER, M. F. and

HEDBERG, H. D. (eds.), Contribution to
the geologic time scale. Amer. Assoc.
Petrol. Geol., Studies in Geology, no. 6, p.
213-234.
KENNETT, J. P., HOUTS, R. E. et al. (1975):
Site 277. In: KENNETT, J. P., HOUTZ, R. E.
et al., Initial Reports of the Deep Sea
Drilling Project, vol. 29, (U. S. Govt.
Print. Office), p. 45-120.
LANJOUW, J. (chairman), et al. (1966): International Code of Botanical Nomenclature.
Internat. Bureau Plant Taxonomy, Nomenclature, Internat. Assoc. Plant Taxonomy,
70 p.
LEMMERMANN, E. (1901): Silicoflagellatae.
Deutsch. Bot. Ges., Ber., vol. 19, p. 247271.
LING, H. Y. (1972): Upper Cretaceous andCenozoic silicoflagellates and ebridians.
Bull. Amer. Paleont., vol. 62, no. 273, p.
135-229.
MANDRA, Y. T. (1968): Silicoflagellates fromthe Cretaceous, Eocene, and Miocene of
California, U. S. A. Calif. Acad. Sci. Proc.,vol. 36, no. 9, p. 231-277.
MARTINI, E. (1974): Silicoflagellate zones inthe Eocene and Early Oligocene. Senckenberg. Leth., vol. 54, nos. 5/6, p. 527-532.
MCPHERSON, L. M., and LIlXG, H. Y. (1973):
Surface microstructure of selected silicoflagellate. Micropaleontology, vol. 19, no.
4, p. 475-480.
MULLER, C. (1974) : Calcareous nannoplankton,

Explanation of Plate 1
All illustrations are x 400 unless otherwise indicatedFigs. 1-2. Corbisema inermis inermis (LEMMERMANN).
1: S130-135, R-2 (L6/0); 2: 514/3, L-2, (x 23/0), abapical view oblique showing rather long
basal accessory spines.
Fig. 3. Corbisema naviculoidea (FRENGUELLI). 539/1, L-2, (D39/0).
Fig. 4. Corbisema cuspis BUSEN and WISE. 327A, 5-4, 70-71 cm, L-2 (MI9/0).
Figs. 5-7. Corbisema constricta BUSEN and WISE
5,6: 327A, 5-4, 70-71cm, L-2 (S14/1). 7: same specimen as Figs. 5, 6, with higher
magnificantion, x 1020, showing the surface microstructure.
Figs. 8-12. Crassicorbisema disymmetrica disymmetrica LING, n. comb.
8, 9: 208, 30-2, 112-114 cm, L-2 (P 32/0). 208, 30-2, 112-114 cm, L-2 (P43/3). Specimen
as illustrated in Figs. 10, 11, with higher magnification, x 1020, showing the surface microstructure

LING:A new silicoflagellate genus

P late 1

2

3
4

5

6

7

8

9

12

725. Crassicorbisema, a new silicoflagellate genus
Leg 25. (western Indian Ocean). In: SIMP·
SON, E. S. W., SCHLlCH, R. et al., Initial
Reports of the Deep Sea Drilling Project,
vol. 25, Washington (U. S. Govt. Print.
Office), p. 579-633.
PERCH-NIELSEi', K. (1975): Late Cretaceousto Pleistocene silicoflagellates from theSouthwest Pacific, DSDP, Leg 29. In:
KENNETT, J. P., HOUTS, R. E. et al., Initial Reports of the Deep Sea Drilling
Project, vol. 29, Washington (U. S. Govt.
Print. Office), p. 677-721.
- - (1976): New silicoflagellates and a silicoflagellate zonation in North European
Eocene diatomites. Ceol. Soc. Denmark,Bull., vol. 25, pts. 1-2, p. 27-40.
SCHULZ, P. (1928): Beitrage zur Kenntnis fossiler und rezenter Silicoflagellaten. Bot.
Archiv., vol. 21, pt. 2, p. 225-292.
ft~~=B~

13

TSUMURA, K. (1963): A systematic study ofsilicoflagellatae. Yokohama Munic. Univ.,
Jour., ser. C-45, no. 146, p. 1-84.
WEBB, P. N. (1973): Upper Cretaceous-Paleocene foraminifera from Site 208 (LordHowe Rise, Tasman Sea), DSDP, Leg 21.
In: BURNS, R. E., ANDREWS, J. E. et al.,Initial Reports of the Deep Sea Drilling
Project, vol. 21, Washington (U. S. Govt.
Print. Office), p. 541-573.
WISE, S. W., Jr., and WIND, F. H. (1977):
Mesozoic and Cenozoic calcareous nannofossils recovered by DSDP Leg 36 drillingon the Falkland Plateau, southwest Atlantic sector of the southern ocean. In:
BARKER, P., DALZIEL, I. W. D. et al., Initial Reports of the Deep Sea Drilling
Project, vol. 26, Washington (U. S. Govt.
Print. Office), p. 269-491.

(Silicoflagellate) 1D~},m Crassicorbisema c.:t1D I]jt~ti!: ID:$Hif""lD ~1!fU:~#a#aJ[E:tJffiJ1jUH@j (DSDP) *m~~1D 208 c 327 A :tlli,~-C-:l*~L-t-:I!t~ti!:ID:fim4'kJ*il'I?,
l!~~=Bll (Silicoflagellate) ID-~ Crassicorbisema a-~~ L. t-:o ;W:1tt::.JJ~ 'l!~1f~15-

NBc, mi~ts::mHH.': (wtlt L-b) :l*1D~iIiilD{fIU8l:j1U!ilt~~-C%'l!!&B~-C-, fj£m-~-C-M~£t::.
.:tlDfHEil'~:g~ I?h7.>o mtE£ -C-lDffl, ;: 1D~lt-:fi=lm:fiil' I? ts:: I), m~~t::'ID.7,..7};(Pil'/Jt
wg ~h -c~, 7.>il', .:t1D:tlli~U~f;;lt±' c L. -ClF-1tIJ1!t~ti!:t::'ID.7,..~II?h -c~, 7.>$il' I?j,' <c t;: ID:tlli~ID~1\!iiFfID~$ft;E c VL~.ll."?tlD cWl~~h7.>o X;:ID1Vf~IDfi!i*, l!~~=B~il'I?
I!t~ti!:a-ril' I? Crassicorbisema disymmetrica dumitricae, C. disymmetrica disymmetrica, Corbisema constricta, Naviculopsis constricta IDIm"?t::.7}* L-ko:/'-1: -Fa -Trans. Proc. Palaeont. Soc. Japan, N. S., No. 121, pp. 14-28, pis. 2, 3, April 30, 1981

726. CORBICULID MOLLUSCA FROM THE URAHORO GROUP,
KUSHIRO COAL FIELD, EASTERN HOKKAIDO*YUT AKA HONDA
Department of Earth Science, Mie University, Kamihama, Tsu 514

Abstract. Corbicula (Mollusca: Corbiculidae) is one of the most common nonmarine mollusks in the Urahoro Group. A total of three species is recorded: Co rbicula (Batissa) sitakaraensis SUZUKI, C. (Corbicula) tokudai (YOKOYAMA) and C.
(Corbicula) kotakai, n. sp. C. sitakaraensis is considered to be a more saline water
dweller than both C. tokudai and C. kotakai, which are probably brackish or fresh
water species.

Otobe-gawa, etc.
The group ranges in thickness fromabout 400 to 600 m. It is unconformably
overlain by the Omagari Formation of
the Ombetsu Group, and rests unconformably on the Kawaruppu Formation of the
Nemuro Group.
Table 1 shows thestratigraphic classification in the Ombetsu
district.
The Urahoro Group contains molluscan
fossils which are shallow marine orbrackish water dwellers, and are called
the upper Ishikarian fauna (MIZUNO,1964). The fauna includes such species as
Mytilus mabuchii OYAMA and MIZUNO,
Chlam),s shitakaraensis HONDA, Ostrea
eorivularis OYAMA and MIZUNO, C01'bicula(Batissa) sitakaraensis SUZUKI. C. (Corbicula) tokudai (YOKOYAMA), c. (Corbicula)kotakai, n. sp., Nemocardiu111 ezoense
TAKEDA. Hubertschenckia ezoensis (YOKOYAMA), Macoma sejugata (YOKOYAMA),
Mya g1'ewingki MAKIYAMA, Thracia n.
sp., "Ampullina" asagaiensis MAKIYAMA,etc.
Corbicula is one of the most common
non-marine mollusks in the Urahoro

Introduction
The Urahoro Group developed in the
Ombetsu district, in the western part of
the Kushiro coal field, eastern Hokkaido,
can be divided into four formations.
These are the Rushin, Yubetsu, Shitakara
and Shakubetsu Formations in ascendingorder.
All four are in conformably
contact.
The group is composed mainly of conglomerate, poorly sorted sandstone andgray siltstone. The conglomerate consists
predominantly of chert pebbles. Coalseams are well developed in the Yubetsu
and Shakubetsu Formations throughout
the Ombetsu district, but poorly developedin the Rushin Formation at its northwestern extremity in the district along
the Muri-gawa.
The Urahoro Group is distributed in a
NNE-SSW trend in such rivers and valleys
as the Chambetsu-gawa, the Tankonosawa, the Yatatoshino-zawa, the Shakubetsu-gawa, the Chokubetsu-gawa, theRubeshube-zawa, the Sango-zawa, the* Received September 2, 1980.

14

726.

Corbiculids from the Kushiro Coal Field

15

SB-A
I

5 B- B\/

YB-02,03,04,OS

Fig. la.

/SB-C

Map of the northern Ombetsu district indicating fossil localities.

Group of the Kushiro coal field, as wellas that in the Naibuchi Group of southern
Sakhalin, USSR, the Ishikari Group of the

Ishikari coal field and the Uryu Group of
the Rumoi coal field, central Hokkaido.
MIZUNO (1964) reported a total of threeYutaka HONDA

16

o
\

'?

~

C"

'1....

Y 8-09\K m
Fig. lb.

Map of the southern Ombetsu district indicating fossil localities.

726. Corbiculids from the Kushiro Coal Field
Table 1. Stratigraphic classification in
the Ombetsu district (HONDA, 1977MS, partly

revised) .
AGE

GROUP

Holocene

Pleistocene

FORMATION
Alluvium
Terrace deposits
Shiranuka Formation

MioceneAtsunaiGroup
OmbetsuGroup

Oligocene
UrahoroGroup
Late Cret.Paleocene

NemuroGroup

Atsunai Formation

Tokornuro Formation
Nuibetsu Formation
Charo Formation
Omagari Formation
Shakubetsu Formation
Shitakara Formation
Yubetsu Formation
Rushin Formation

Kawaruppu Formation

species of Corbicula from the Urahoro
and Ombetsu Groups in the Kushiro coal
field. The three are Corbicula (Batissa)
sitakaraensis which is found abundantlyin the "Tenneru Formation" in the
Semposhi area at the eastern extremityof the coal field, the So un Coal-bearing
Member of the Teshibetsu Formation, andthe Shitakara Formation; C. (Cyrenobatissa)
sakakibarai (OTATUME) which is also
found abundantly in the upper part of
the Shakubetsu Formation in the Yubetsu
and Akan districts of the central part ofthe coal field; C. (Corbicula) tokudai
which is very rare in the Urahoro Group;and C. (Batissa) sitakaraensis, subsp.
which is found abundantly in the Omagari
Formation of the Ombetsu Group.
The "Tenneru Formation" is a correlative of the upper part of the Rushin
Formation, and the Soun Coal-bearing
Member is a correlative of the upper
part of the Yubetsu Formation in theKushiro coal field.
MIZUNO (1964) mentioned that thestratigraphic occurrence of Corbicula in
the Urahoro Group is similar to that in
the Hiragishi and Ashibetsu Formations

17of the upper part of the Ishikari Groupin the Ishikari coal field, central Hokkaido.
He concluded that C. tokudai represents
his lower and middle Ishikarian faunas,
and C. sitakaraensis and C. sakakibarai
represent the upper Ishikarian fauna.
Corbicula (Corbicula) lives in brackish
water as well as in fresh water in thejapanese Islands (HABE, 1977). On theother hand, Batissa and Cyrenobatissa do
not live in japan at present, but they
live in brackish water, south of thePhilippines, and south of Taiwan or the
Ryukyu Islands, respectively (SUZUKI,
1949).
Corbicula (Corbicula) japonica PRIME,
is one of the most abundant corbiculid
mollusks living in japan, and has beenreported from sandy, muddy and gravelly
bottoms of brackish lakes in Hokkaido(ASAHINA, 1941), and from sand and mud
bottoms of the Lake Shinji-ko on thejapan Sea coast, Southwest japan (MIZUNO, SUMI and SUZUKI, 1966). These
different substrates inhabited by Corbicula
today were apparently also inhabited in
the past, as shown by the various grain
sizes of sedimentary rocks where C.
tokudai and C. sitakaraensis are obtained,
if these are autochthonous and the specimens have not been transported fromhabitats of different grain size. The
lithology from which specimens of C.
tokudai and C. sitakaraensis were collected
is described below.
In this paper, the author describes anddiscusses three species of the genus
Corbicula, among which one is new andwas collected from the Urahoro Groupin the Ombetsu district, in the westernpart of the Kushiro coal field. Maps of
the Ombetsu district indicating fossil
localities are shown in Figs. la, b.

18

Yutaka HONDAOTATUME, 1943a; 3d-e, OTATUME, 1943c;
3g-h, from SUZUKI, 1941a).

Acknowledgments
The author expresses his deep gratitude
to Professor Tamio KOTAKA, Institute ofGeology and Paleontology, Tohoku University, and to Professor Jun YAMADA,
Department of Earth Science, Mie University, for their continuous encouragement
during the course of the present study
and their critical reading of the manuscript. Deep appreciation is also expressed
to Dr. Kenshiro OGASAWARA, Institute ofGeology and Paleontology, Tohoku University, for his valuable advice during thepresent study, and to Dr. Alan G. BEu,
Department of Scientific and Industrial
Research, New Zealand Geological Survey,
for his critical reading of the manuscript.
The author is also indebted to Mr. Shohei
OTOMO of the Tohoku University, for his
aid with photography.
Systematic Description
Family Corbiculidae
Subfamily Corbiculinae
Genus Corbicula MERGELE VONMUHLFELD, 1811
Subgenus Batissa GRAY, 1853
Corbicula (Batissa) sitakaraensis

SUZUKI, 1941
PI. 2, Figs. 11, 19; PI. 3, Figs. 1-8
Corbicula sitakaraensis SUZUKI, 1941a, p. 57,
pI. 4, figs. la-b.
Batissa sitakaraensis (SUZUKI): OTATUME,
1943a, p. 241, pI. 5, figs. 1-10; OTATUME,
1943c, p. 23, pI. 4, figs. 7-9.
Corbicula (Batissa) sitakaraensis (SUZUKI):MINATO, 1950, p. 18, text·figs. 13, 13a-b.
Corbicula (Batissa) sitakarensis SUZUKI: QYA)'1A, MIZUNO and SAKAMOTO, 1960, p. 160,
pI. 48, figs. 31-h (3a-c, f, reproduced from

Dimensions :-Dimensions are shown in

Table 2.
Remarks :-Several hundred more or lessbroken specimens with conjoined or
separated valves were collected. Theyfrequently form beds attaining several
tens of cm in thickness, and occur ingroups in pebbly to granular conglomerate,or poorly sorted fine-grained sandstone
bearing pebbles and granules, at 22 localities of the Rushin, Yubetsu, Shitakara
and Shakubetsu Formations of the Urahoro
Group in the Ombetsu district, in thewestern part of the Kushiro coal field.
This species was originally described
by SUZUKI (1941a, p. 57, pI. 4, figs. la-b)
from the Shitakara Formation at Karisyo,
Shiranuka-machi, Shiranuka-gun, in thecentral part of the Kushiro coal field.
It has also been reported from the
Naibuchi Group of southern Sakhalin
USSR, the Omagari and Charo Formation~of the Ombetsu Group, and the Hiragishi
Formation of the Ishikari Group, Ishikaricoal field, central Hokkaido (l>TATUME,
1943a; MATSUI, 1962; MIZUNO, 1964). It
shows fairly variable outlines; for instance,height/length ratio varies from 77.3 to107.3 percent and width/length ratio
varies from 14.3 to 26.9 percent (Table
2).

The present species is characterized bythree divergent cardinal teeth in eachvalve, two anterior and two posterior
lateral teeth in the right valve, and one
anterior and one posterior lateral in theleft valve. The anterior cardinal toothof the right valve is the shortest andweakest of the three, and continues
anteriorly to the cardinal plate, the middle
one is bifid, the strongest of the three,and shorter than the posterior one. The
anterior cardinal tooth of the left valve

726. Corbiculids from the Kushiro Coal Field
Table 2.

19

Measurements (in mm) of Corbicula (Batissa) sitakaraensis.

IGPS call.
cat. no.

Lac. no.

HeightLengthWidth

H/L(%)

W/L(%)

Valve

96762-1

RN-02

30.9

34.0

5.8

90.9

17.1

Left

96760-1

YB-09

26.5

32.9

6.6

80.5

20.1

Left

96760-2

YB-09

--

37.7

6.6

--

17.5

Right

96760-3

YB-09

35.8

41.0

14.5/2

88.3

17.7

Both

96760-4

YB-09

43.4

8.8

Right

YB-09

41. 8

11. 0

---

--

96760-5

---

--

Right

96760-6

YB-09

--

45.2

6.5

--

14.4

Right

96760-7

YB-09

35.0

37.3

7.5

93.8

20.1

Right

96760-8

YB-09

38.5

41. 0

6.9

93.9

16.8

Right

96760-9

YB-09

41. 0

38.2

16.8/2 107.3

22.0

Both

96760-10

YB-09

39.5

43.1

18.0/2

91.6

20.9

Both

96760-11

YB-09

38.1

--

8.4

--

--

Right

96760-12

YB-09

39.3

41. 0

14.0/2

95.6

17.1

Both

96760-13

YB-09

46.0

--

10.0

--

--

Left

96760-14

YB-09

33.2

38.2

5.8

86.9

15.2

Right

96760-15

YB-09

33.3

--

6.8

--

--

Right

96759-1

SK-56

43.5

48.1

--

90.4

--

Both

96759-2

SK-56

36.8

7.5

--

--

Right

96759-3

SK-56

43.3

-50.9

14.6+/2 85.1

14.3

Both

96765-1

SK-57

32.4

--

6.1

--

--

Right

96765-2

SK-57

17.0

18.6

5.0

91. 3

26.9

Right

96765-3

SK-57

43.9

--

8.1

--

--

Right

96761

SB-01

33.9

44.0

18.0/2

77.0

20.5

Both

96770

SB-03

41.3

49.6

10.0

83.3

20.6

Right

96764-1

SB-A

30.9

37.9

15.3/2

81. 5

20.2

Both

96766

SB-F

6~5

7.2

3.7/2

90.3

25.7

Both

is bifid, the shortest of the three andalmost as strong as the middle one; themiddle one is bifid and shorter than theposterior one; the posterior one is thelongest but the weakest of the three, andcontinues posteriorly to the cardinal
plate. Both the anterior and the posterior
laterals extend to the anterior and posterior muscle scars, respectively; the anterior laterals about two-thirds as long as

the posterior. The lateral teeth arecompressed and serrated.
The present species resembles Corbicula(Batissa) hukayai OTATUME (1943c, p. 26,
pI. 4, figs. 10-17), originally describedfrom the Nayoshi Formation (Naibuchi
Group, vide OYAMA, MIZUNO and SAKAMOTO, 1960), southern Sakhalin, USSR,
but it is distinguished from C. hukayai
by its less inflated and larger shell, and20

Ytttaka HONDA

by the anterior laterals being shorter
than the posterior ones.
It also resembles C. (Corbicula) tokudai(YOKOYAMA, 1932, p. 240, pI. 2, figs. 3-4,
non fig. 2) in outline, but C. sitakaraensis
differs in having; 1) bifurcated cardinalteeth, 2) different relations between thelength and strength of the three cardinals,
3) the anterior laterals shorter than theposterior ones, 4) a much larger and lessinflated shell, 5) much more variable outlines. However, in immature specimens
of one or two centimeters height (orlength) of shell, C. sitakaraensis is hardly
distinguishable from C. tokudai in outline.
Associated fauna:- The present species
is commonly associated with Ostrea eorivularis, My til us mabuchii, Nemocardium
ezoense and/or "Ampullina" asagaiensis,
and rarely with Chlamys shitakaraensis,
Bellamya (Sinotaia) mabutii or Turritellasp.
Locality and Formation :-RN-Ol, RN02, Rushin Formation; YB-09, YB-A,
YB-C, Yubetsu Formation; SK-22, SK-29,
SK-35, SK-56, SK-57, Shitakara Formation; SB-Ol, SB-03, SB-04, SB-A, SB-B,
SB-D, SB-F, SB-G, SB-H, SB-O, SB-P,
SB-R, Shakubetsu Formation.

Subgenus Corbicula s. s.
Corbicula (Corbicula) tokudai(YOKOYAMA, 1932)
PI. 2, Figs. 1-5, 7, 8, 12, 18
Cyrena sp., lnmo, 1890, p. 42, pI. I, fig. 5(fide SUZUKI, 1941d).
Circe tokudai YOKOYAMA, 1932, p. 240, pI. 2,
figs. 3, 4 (non fig. 2).
Corbicula atrata tokudai (YOKOYAMA) : SuzuKI, 1941b, p. 9, text-figs. I, 2 on page 10,
pI. I, figs. 11, 12, pI. 2, figs. 1-26; SUZUKI,
1941c, p. 32, pI. 2, figs. 6-18.
Corbicula atrata tokudai (YOKOYAMA)?: SUZUKI, 1941d, p. 524, text-figs. la, b on

page 521 (reproduced from limbo, 1890).
Corbicula tokudai (YOKOYAMA): NAGAO andOTATUME, 1943, p. 7, pI. 3, figs. 4-9;
OTATUME, 1943b, p. 16, text-fig. 4 on page18; MINATO, 1950, p. 19, text-figs. 16, 16ab; non KAMADA, 1955, p. 21, pI. 4, figs.
4-9.
Corbicula (Corbicula) tokudai (YOKOYAMA):
QyAMA, MIZUNO and SAKAMOTO, 1960, p.
166, pI. 50, figs. 6a-k (6a-c, reproduced
from SUZUKI, 1941c; 6d-k, from SUZUKI,
1941b).

Dimensions :-Dimensions are shown in
Table 3.
Remarks :-Several hundred specimens
were collected, mostly with valves closed.
They frequently form beds attaining
several tens of cm in thickness, andoccur in groups in fine-grained sandstone,gray siltstone and granular conglomerate
at 24 localities of the Yubetsu andShakubetsu Formations of the Urahoro
Group in the Ombetsu district, in thewestern part of the Kushiro coal field.
Some specimens lack umbonal areas, or
have been deformed by pressure after
burial. The specimens are generally one
or two cm in height (or length) of shell,and show less variable outlines than thoseof C.sitakaraensis; for instance, height/
length ratio varies from 76.3 to 93.4 percent and width/length ratio varies from
19.9 to 28.7 percent (Table 3).
The present species was originallydescribed by YOKOYAMA (1932, p. 240, pI.
2, figs. 3, 4, non fig. 2) from the Numata
Formation of the Uryu Group and the
Miocene Okada Formation of the Rumoi
coal field, central Hokkaido. It has also
been reported from: the Yubari, Wakkanabe, Bibai, Akabira, Ikushumbetsu,
Hiragishi and Ashibetsu Formations of
the Ishikari Group (SHIMOKA w ARA, 1963) ;the Tachibetsu Formation of the Uryu
Group (OHARA and KANNO, 1969); andthe Yubetsu, Shitakara and Shakubetsu

726.
Table 3.

Corbiculids from the Kushiro Coal Field

21

Measurements (in mm) of Corbicula (Corbicula) tokudai.

IGPS call.
Lac. no.

HeightLengthWidthcat. no.

H/L(%)

W/L(%)

Valve

96768-1

YB-03

17.1

20.8

10.1/2

82.2

24.3

Both

96768-2

YB-03

17.9

19.6

9.3/2

91. 3

23.7

Both

96772-1

YB-05

19.1

22.5

9.2/2

84.9

20.4

Both

96772-2

YB-05

16.8

18.2

9.1/2

92.3

25.0

Both

96772-3

YB-05

17.5

18.8

10.8/2

93.1

28.7

Both

96772-4

YB-05

14.7

16.3

7.9/2

88.3

24.2

Both
Both

96772-5

YB-05

15.1

17.1

9.1/2

88.3

26.6

96753-1

YB-D

16.8

20.5

9.1/2

82.0

22.2

Both

96753-2

YB-D

17.5

21. 9

8.7/2

79.0

19.9

Both

96753-3

YB-D

15.1

19.8

7.7/2

76.3

25.5

Both

96753-4

YB-D

16.0

19.3

9.0/2

82.9

23.3

Both

96753-5

YB-D

15.2

18.6

9.0/2

81.7

24.2

Both

96753-6

YB-D

15.3

18.9

8.9/2

81. 0

23.5

Both

96753-7

YB-D

15.0

19.1

8.8/2

78.5

23.0

Both

96753-8

YB-D

15.0

18.3

8.9/2

82.0

24.3

Both

96753-9

YB-D

14.5

17.5

8.7/2

82.9

24.9

Both

96753-10

YB-D

13.7

17.2

7.5/2

79.7

21.8

Both

96753-11

YB-D

14.2

16.3

8.1/2

87.1

24.8

Both
Both

96753-12

YB-D

13.9

16.0

8.0/2

86.9

25.0

96753-13

YB-D

13.9

16.3

8.0/2

85.3

24.5

Both

96753-14

YB-D

13.8

15.9

7.9/2

86.8

24.8

Both

96753-15

YB-D

12.2

15.5

7.5/2

78.7

24.2

Both

96753-16

YB-D

13.4

15.3

7.0/2

87.6

22.9

Both

96753-17

YB-D

12.4

14.6

7.7/2

84.9

26.4

Both

96753-18

YB-D

11. 9

15.0

6.5/2

79.3

21.7

Both
Both

96753-19

YB-D

12.3

15.1

7.6/2

81.5

25.2

96753-20

YB-D

12.8

14.5

7.0/2

88.3

24.1

Both

96753-21

YB-D

12.0

14.5

6.9/2

82.8

23.8

Both

96753-22

YB-D

11.5

14.4

7.3/2

Both

YB-D

11. 4

13.9

6.1/2

80.0
82.0

25.2

96753-23

25.5

Both

96753-24

YB-D

11. 0

13.8

6.7/2

79.7

24.3

Both

96753-25

YB-D

11. 5

13.3

6.6/2

86.5

24.8

Both

96753-26

YB-D

11. 6

13.2

6.5/2

87.9

24.6

Both

96753-27

YB-D

10.7

11. 7

6.0/2

91.5

25.6

Both

96753-28

YB-D

10.0

12.5

6.4/2

80.0

25.6

Both

96753-29

YB-D

10.0

11.6

5.8/2

86.2

25.0

Both

96753-30

YB-D

9.9

11.9

5.9/2

83.2

24.8

Both

96753-31

YB-D

9.2

11. 8

4.9/2

78.0

20.8

Both

96753-32

YB-D

9.4

11.0

4.7/2

85.5

21.4

Both

96753-33
96753-34

YB-D

10.8
10.0+

4.5/2

83.3

20.8

YB-D

9.0
9.0

5.0/2

90.0

25.0

Both
Both

96753-35

YB-D

8.5

10.0

4.1/2

85.0

20.5

Both

96753-36

YB-D

7.9

9.0

4.0/2

87.8

22.2

Both

96753-37

YB-D

6.5

7.3

3.0/2

89.0

20.5

Both

96754-1

SB-02

11.3

12.1

6.4/2

93.4

26.4

Both

96754-2

SB-02

10.5

12.1

5.9/2

86.8

24.4

Both

96769

SB-K

19.0

20.6

5.2

92.2

25.2

Right

22

Yutaka HONDANO and SAKAMOTO (1960).
Formations of the Urahoro Group, and
KANNO (1971, p. 83, text-fig. 13 on page
the Omagari Formation of the Ombetsu
83; pI. 17, figs. 13-1~) described C.
Group (MATSUI, 1962).
(Corbicula)sp. from the upper part of the
The present species has three divergent
Kulthieth
Formation(Eocene) of the
cardinal teeth in each valve, two anterior
Yakataga
district,
southern
Alaska, USA,and two posterior lateral teeth in theandconsideredthat
theindeterminable
right valve, and one anterior and one
form is closely related to C. (Corbicula)posterior lateral in the left valve. The
tokudai. But KANNO'S specimens differ
anterior cardinal tooth of the right valve
from C. tokudai in having the posterior
is the shortest and weakest of the three,cardinal tooth of the left valve longer
and continues anteriorly to the cardinal
plate; the middle one is the longest andthan the others.
Associated fauna:- The present species
strongest of the three; the posterior one
is not generally associated with otheris shorter and weaker than the middle
molluscan species, but rarely with Melone. The anterior cardinal tooth of theleft valve is the strongest of the three
anoides? sp. or Mytilus sp.
and nearly as long as the middle one;
MATSUI (1960) reporte(tha~ C. tokudai
the posterior one is the shortest andoccurs together with C. .sitakaraensis in
weakest of the .three, .and continues
the Hiragishi Formation of the Ishikari
posteriorly to the cardinal plate. The
Group, Ishikari coal field, central Hokkaido.
anterior and posterior lateral teeth extend
OTATUME (1943b) also reported that it isto the anterior and posterior muscle scars,
associated with C. (Cyrenobatissa) nisirespectively; the anterior lateral is askawai (OTATUME) in the Uryu Group,
long as the posterior. The lateral teeth
Rumoi coal field, central Hokkaido.
are compressed and serrated.
Locality and Formation:- YB-Ol, YBThe present species resembles Corbicula
03, YB-04, YB-05, YB-06, YB-13, YB-B,(Corbicula) iburica (YOKOYAMA, 1931, p.
YB-D, Yubetsu Formation; SB-02, SB-05,
194, pI. 11, fig. 8), originally described
SB-06, SB-07, SB-C,. SB-E, SB-I, SB-j,from a Neogene bed at Mukawa, YufutsuSB-K, SB-L, SB-M; SB-N, SB-Q, SB-S,gun, central Hokkaido, but C. tokudai is
SB-T, SB-U, Shakubetsu Formation.
distinguished from C. iburica by its lessinflated and more rounded shell.
Corbicula (Corbicula) lzotakai
It is allied also to C. (Corbicula) japonica
HOl\DA, n. sp.
PRIME (1864, p. 68, fig. 15, fide KURODA,
1938, p. 34), living in japan, but it differs
PI. 2, Figs. 6, 9, 10, 13-17
from the latter by its less inflated andDescrpition :-Shell small, subpentagonmore rounded.. shell, and less inflated
ally rounded, moderately inflated, inequiumbonal area.
KAMADA· (1955, p. 21, pI. 4, figs. 4-9)
lateral and rather thick. Antero- andposterodorsal margins broadly arched,described C. tokudai from the Shiramizu
ventral margin well-rounded. Posterior
Formation of the Uchigo Group, joban
margin obliquely sub truncated. Beaks
coal field, Northeast japan, but the species
situated anteriorly. Height a little shorterhe called C. tokudai differs from C.
than length. A weak ridge runs fromtokudai in its more inflated and more
trigonal shell. It is allocated here to C. .:. umbo "tQ. posteroventral corner. Surface
sculptured with numerous, rather fine andiburica, as was treated by OYAMA, Mrzu-

23726. Corbiculids from the Kushiro Coal Field
Table 4.

Measurements (in mm) of Corbicula (Corbicula) kotakai, n. sp.

IGPS colI. cat. no.

Loc. no.

HeightLengthWidth

H/L(%)

W/L(%)

Valve

96758 (Holotype)

YB-I0

20.8

23.8

12.9/2

84.0

27.1

Both

96757-1 (Paratype)

YB-I0

19'.2

21.0

11. 0/2

91.4

26.2

Both

96757-2

YB-I0

16.0

19.0

10.1/2

84.2

26.6

Both

YB-I0

16.9

18.8

11. 0/2

89.9

29.3

Both

(Paratype)96757-8irregular concentric lines of growth.
Hinge plate rather wide and thick, withwidely arched lower margin. Teeth withthree divergent cardinals in each valve,
two anterior and two posterior laterals
in right valve, and one anterior and one
posterior lateral in left valve.
Anterior cardinal tooth of right valve
the shortest and weakest of the three,and continues anteriorly to the cardinal
plate; middle one the longest and strongestof the three; posterior one shorter andweaker than the middle one. Anteriorcardinal tooth of left valve the strongestof the three and nearly as long as the
middle; posterior one the shortest andweakest of the three, and continues
posteriorly to the cardinal plate. Lateral
teeth compressed. Inner surface unknown.
Dimensions :-Dimensions are shown in
Table 4.
Depository:-Holotype (IGPS* colI. cat.
no. 96758) and four paratypes (IGPS colI.
cat. nos. 96757-1, 96757-2,96757-3,967574) in the Institute of Geology andPaleontology, Tohoku University, Sendai,
Japan.
Compa rison :-The new species resembles Corbicula (Corbicula) tohudai (YOKOYAMA. 1932, p. 240, pI. 2, figs. 3, 4, nonfig. 2) in outline and the dentition of the
cardinal teeth. It differs from C. tohudai* Abbreviation for

the Institute of Geology
and Paleontology, Tohoku University, Sendai,
Japan.

in its more inflated shell, more prominentridge running from umbo to posteroventral
corner and somewhat more rounded ventral
margin.
It also resembles C. (Cyrenobatissa)sahahibarai (OTATUME, 1943c, p.24, pI. 4,
figs. 1-6), originally described from the
Naibuchi Group, southern Sakhalin, USSR,
but differs from C. sahallibarai in having
the simple, un bifurcated cardinal teeth in
the hinge plate having a more widely
arched lower margin.
It is allied also to C. (Corbicula) iburica(YOKOYAMA, 1931, p. 194, pI. 11, fig. 8),
but differs in having a more prominentridge running from umbo to posteroventral
corner, and a more rounded shell.
Remarhs :-Several tens of specimens
having well-preserved conjoined valves,
but unfortunately lacking beaks, were
examined. They form beds attaining
several tens of cm in thickness, and also
occur in groups in poorly-sorted finegrained sandstone with granules, at three
localities of the Yubetsu Formation. The
occurrence of the new species is restricted
to the Yubetsu Formation of the Urahoro
Group in the Ombetsu district. The
stratigraphic occurrence of the species
must be further studied in the Urahoro
Group throughout the Kushiro coal field,
together with other corbiculid mollusks
reported from the Kushiro coal field.
Associated fauna :-Only
the new
species was collected from the Yubetsu
Formation, and it is not associated with

Yutaka HONDA

24

other molluscan species.
Locality and Formation:- YB-02, YB10 (Type locality), YB-ll, Yubetsu Forma.tion.

should be investigated further, to determine paleoenvironmental conditions during
the deposition of the Urahoro and Ombetsu
Groups.

Concluding Remarks

List of Localities

Corbicula (Batissa) sitakaraensis is considered to be a brackish water inhabitant,because it is commonly associated withsuch shallow marine or brackish water
species as Ostrea eorivularis, Mytilus
mabuchii, Nemocardium ezoense and/or"Ampullina" asagaiensis, and also because
Corbicula (Batissa) lives in brackish watersof Southwest Asia (SUZUKI, 1949).
On the other hand, C. (Corbicula) tokudai
is not generally associated with othermolluscan species, but rarely occurs withsuch fresh water or shallow marine
inhabitants as Melanoides? sp. or iVIytilussp., and Corbicula (Corbicula) lives now
in brakcish or fresh waters of the JapaneseIslands (HABE, 1977). Therefore, it isconsidered to have inhabited less saline
water than did C. sitakaraensis. C.
(Corbicula) kotakai, n. sp. probably
inhabited the same brackish or a fresh
water as did C. tokudai.
This conclusion is consistent with thefact that C. tokudai was collected fromthe Yubetsu and Shakubetsu Formations,and C. kotakai, n. sp., from the Yubetsu
Formation, in both of which coal seams
are well developed; whereas only C.
sitakaraensis was collected from the
Shitakara Formation, which is not intercalated with coal seams but contains
abundant shallow marine or brackish
water molluscan species such as Mytilus
mabuchii, Chlamys shitakaraensis, Ostrea
eorivularis, Nemocardium ezoense, Macoma
sejugata, Mya grewingki, etc.
The temporal and spatial distributionof corbiculid mollusks in the Urahoro andOmbetsu Groups in the Kushiro coal field,

RN-Ol: roadside cutting along a national roadforest, north of the Rubeshube-zawa, atributary of the Chokubetsu-gawa, Urahoro-machi, Tokachi-gun, Hokkaido (Lat.
42°S3'2"N, Long. 143°46'40"E).
RN-02: ditto (about ISO m SW of RN-Ol) (Lat.
42°S2'S9"N, Long. 143°46'38"E).
YB-Ol: riverside cliff along the Tankono-sawa,a tributary of the Koikata-muri-gawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat.
42°S9'S2"N, Long. 143°4S'S8"E).
YB-02: ditto (about 4 m upper horizon of YB01) (Lat. 42°S9'S2"N, Long. 143°46'0"E).
YB-03: ditto (about 1 m upper horizon of YB02) (Ditto).
YB-04: ditto (about 20 em upper horizon of
YB-03) (Ditto).
YB-OS: ditto (about 120 em upper horizon of
YB-04) (Ditto).
YB-06: riverside cliff along a south-southeastern tributary of the Shibetsu-zawa, atributary of the Muri-gawa, Ombetsumachi, Shiranuka-gun, Hokkaido (Lat.
42°SS'36"N, Long. 143°47'38"E).
YB-09: riverside cliff along the Chokubetsugawa, Urahoro-machi, Tokachi-gun, Hokkaido (Lat. 42°S3'10"N, Long. 143°47'32"E).
YB-lO: riverside cliff along the Rubeshubezawa, a tributary of the Chokubetsu-gawa,
Urahoro-machi, Tokachi-gun, Hokkaido(Lat. 42°S2'4S"N, Long. 143°47'I"E).
YB-ll: ditto (Lat. 42°S2'47"N, Long. 143°47'13"E).
YB-13: roadside cutting along a logging road,north of the Rubeshube-zawa, Urahoromachi, Tokachi-gun, Hokkaido (Lat. 42°
S2'SI"N, Long. 143°47'lS"E).
YB-A: boulder on river bed of the upperstream of the Shibetsu-zawa, a tributaryof the Muri-gawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat. 42°SS'IS"N, Long.
143°47'19"E) .

726.

Corbiculids from the Kushiro Coal Field

YB-B: riverside cliff along the upperstreamof the Shakubetsu-gawa, Ombetsu-machi,
Shiranuka-gun, Hokkaido (Lat. 42°54'29"N,Long. 143°47'26"E).
YB-C: boulder below a roadside cutting along
a logging road, north of the Rubeshubezawa, a tributary of the Chokubetsu-gawa,
Urahoro-machi, Tokachi-gun, Hokkaido(Lat. 42°52'55"N, Long. 143°47'5"E).
YB-D: riverside cliff along the Rubeshubezawa, a tributary of the Chokubetsu-gawa,
Urahoro-machi, Tokachi-gun, Hokkaido(Lat. 42°52'47"N, Long. 143°47'17"E).
SK-22: riverside cliff along the upperstreamof the Shakubetsu-gawa, Ombetsu-machi,
Shiranuka-gun, Hokkaido (Lat. 42°5'34"N,Long. 143°47'52"E).
SK-29: river bed of the upperstream of the
Shakubetsu-gawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat. 42°54'45"N,Long. 143 °48'2"E) .
SK-35: riverside cliff along the Chokubetsugawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (about 100 m NNE of YB-09) (Lat.
42°53'13"N, Long. 143°47'36"E).
SK-56: riverside cliff along the Sango-zawa, atributary of the Chokubetsu-gawa, Urahoro-machi, Tokachi-gun, Hokkaido (Lat.
42°53'8"N, Long. 143°42'32"E).
SK-57: ditto (about 2.5 m upper horizon of
SK-56) (Ditto).
SB-01: riverside cliff along the Chambetsugawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat. 43°0'41"N, Long. 143°48'51"E).
SB-02: ditto (Lat. 43°0'37"N, Long. 143°49'26"E) .
SB-03: riverside cliff along the Shibetsu-zawa,a tributary of the Muri-gawa, Ombetsumachi, Shiranuka-gun, Hokkaido (Lat. 42°
56'14"N, Long. 143°48'23"E).
SB-04: ditto (about 50 m ESE of SB-03) (Lat.
42 °56' 13"N, Long. 143 °48'24"E) .
SB-05: riverside cliff along the Chokubetsugawa, Ombetsu-machi,
Shiranuka-gun,
Hokkaido (Lat. 42°53'3"N, Long. 143°47'58"E).
SB-06: ditto (about 10 m lower horizon of SB05) (Ditto).
SB-07: ditto (about 5.5 m lower horizon of
SB-06) (Ditto).

25

SB-A: riverside cliff along the Chambetsugawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat. 43°0'49"N, Long. 143°48'33"E)
SB-B: boulder on river bed of the Chambetsugawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat. 43°0'45"N, Long. 143°48'39"E).
SB-C: ditto (Lat. 43°0'44"N, Long. 143°48'40"E).
SB-D: ditto (about 100 m SE of SB-C) (Lat.
43°0'42"N, Long. 143°48'43"E).
SB-E: riverside cliff along a logging road
along the Chambetsu-gawa, Ombetsu-machi,
Shiranuka-gun, Hokkaido (Lat. 43°0'44"N,Long. 143°48'50"E).
SB-F: riverside cliff along the Chambetsugawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat. 43°0'36"N, Long. 143°49'11"E).
SB-G: boulder on river bed of the Chambetsugawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (about 50 m E of SB-F) (Lat. 43°0'36"N, Long. 143°49'13"E).
SB-H: boulder on logging road, along the
Chambetsu-gawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (about 70 m NE of SBG) (Lat. 43°0'39"N, Long. 143°49'19"E).
SB-J: boulder on river bed along a small
northern tributary of the Chambetsu-gawa,Ombetsu-machi, Shiranuka-gun, Hokkaido(Lat. 43°0'15"N, Long. 143°50'26"E).
SB- J: ditto (about 100 m E of SB-J) (Lat.
43°0'15"N, Long. 143°50'31"E).
SB-K: ditto (about 25 m SE of SB- J, approximately the same horizon as SB- J) (Lat.
43°0'14"N, Long. 143°50'33"E).
SB-L: riverside cliff along the uppermost
stream of the Yatatoshino-zawa, a tributary of the Muri-gawa, Ombetsu-machi,
Shiranuka-gun, Hokkaido (Lat. 42°58'24"N,Long. 143°48'37"E).
SB-M: riverside cliff along the upperstreamof the Yatatoshino-zawa, a tributary of
the Muri-gawa, Ombetsu-machi, Shiranukagun, Hokkaido (Lat. 42°58'O"N, Long.
143°49'7"E) .
SB-N: ditto (about 10 m lowerstream of SBM) (Ditto).
SB-O: ditto (about 5 m lowerstream of SB-N)(Ditto) .
SB-P: riverside cliff along the Shibetsu-zawa,a tributary of the Muri-gawa, Ombetsu-

Yutaka HONDA

26

machi, Shiranuka-gun, Hokkaido (Lat.
42°56'I1"N, Long. 143°47'6"E).
SB-Q: riverside cliff along a tributary of the
Shakubetsu-ichigo-zawa, a tributary of the
Shakubetsu-gawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (Lat. 42°54'50"N, Long.
143°48'40"E) .
SB-R: riverside cliff along a northern small
valley of the Shakubetsu-gawa, Ombetsumachi, Shiranuka-gun, Hokkaido (Lat.
42°54'15"N, Long. 143°48'28"E).
SB-S: riverside cliff along the Chokubetsugawa, Ombetsu-machi, Shiranuka-gun, Hokkaido (about 0.5 m lower horizon of SB07) (Lat. 42°53'3"N, Long. 143°47'58"E).
SB-T: ditto (about 4 m lower horizon of SBS) (Ditto).
SB-U: riverside cliff along the Otobe-gawa,
Urahoro-machi, Tokachi-gun, Hokkaido(Lat. 42°51'47"N, Long. 143°46'7"E).

References
ASAHINA, E., 1941, An ecological study ofCorbicula japonica group, the brackish
water bivalve, with special reference tothe environmental factors of its habitat in
Hokkaido. Bull. Jap. Soc. Sci. Fish., vol.
10, no. 3, p. 143-152 (in japanese withEnglish synopsis).

HABE, T., 1977, Systematics of Mollusca injapan. Bivalvia and Scaphopoda. 13+372 p.,
Hokuryukan Tokyo, japan (in japanese).
HONDA, Y., 1977MS, [Stratigraphical study
in the western area of Ombetsu, eastern
HokkaidoJ. Master's Thesis, Inst. Ceol.
Paleont., Tohoku Univ., 85+ 15 p., 4 pis.
(in japanese, title translated).
KAMADA, Y., 1955, Non-marine Mollusca fromthe Paleogene Uchigo Group of the joban
coal field, Northeast Honshu, japan. Trans.
Proc. Palaeont. Soc. Japan, n. s., no. 17,
p. 19-22, pI. 4.
KANNO, S., 1971, Tertiary molluscan faunafrom the Yakataga district and adjacentareas of southern Alaska. Palaeont. Soc.
Japan, Spec. Pap., no. 16, p. i-iii, 1-154,
pis. 1-18.
KURODA, T., 1938, Studies on japanese Corbicula. Venus, vol. 8, no. 1, p. 21-36, 1
pI. on page 33 (in japanese with English
summary).
MATSUI, H., 1960, On the Toyosato barrierand Ashibetsu basin in the geo-history ofthe deposition of the upper Ishikari Group,
Hokkaido. Rep. Ceol. Surv. Japan, no.
185, p. 1-22 (in japanese with English
abstract) .
MATSUI, M., 1962, Sedimentological study of
the Paleogene basin of Kushiro in Hok-

Explanation of Plate 2(All figures in natural size, unless otherwise stated)
Figs. 1-5, 7, 8, 12, 18. Corbicula (Corbicula) tokudai (YOKOYAMA)
1a-c, IGPS coli. cat. no. 96753-20, Loc. YB-D; 2a-c, IGPS coil. cat. no. 96753-18, Loc. YBD; 3a-c, IGPS coil. cat. no. 96753-11, Loc. YB-D; 4a-c, IGPS coil. cat. no. 96753-3, Loc.
YB-D; 5a-c, IGPS coli. cat. no. 96753-2, Loc. YB-D; 7, IGPS coli. cat. no. 96756, Loc. SBI; 8a-c, IGPS coil. cat. no. 96753-1, Loc. YB-D; 12, x 2, IGPS coil. cat. no. 96755-1, Loc.
SB-S; 18, x 2, IGPS coil. cat. no. 96755-2, Loc. SB-S.
Figs. 6, 9, 10, 13-17. Corbicula (Corbicula) kotakai HONDA, n. sp.
6a-b, IGPS coil. cat. no. 96757-4 (Paratype), Loc. YB-lO; 9a-c, IGPS coil. cat. no. 96757-2(Paratype), Loc. YB-10; lOa-c, IGPS coli. cat. no. 96757-1 (Paratype), Loc. YB-lO; 13a-c,
IGPS coli. cat. no. 96758 (Holotype), Loc. YB-10; 14a-b, IGPS coil. cat. no. 96757-3 (Paratype), Loc. YB-lO; 15a-c, IGPS coli. cat. no. 96757-5, Loc. YB-lO; 16a-b, IGPS coli. cat.
no. 96757-6, Loc. YB-lO; 17a-c, IGPS coli. cat. no. 96757-7, Loc. YB-lO.
Figs. 11, 19. Corbicula (Batissa) sitakaraensis SUZUKI
11, IGPS coli. cat. no. 96759-2, Loc. SK-56; 19, IGPS coli. cat. no. 96762, Loc. RN-02.

C01'biculids !1'01n the J(~~shiTO Coal Field

HONDA:

1:1

Ib

3a

31l

5b

Bb

l Oa

Plate 2

2,1

2b

3t

4c

5e

Ga

Be

ge

I Oc

12

13 c
14 a

15 a

15 c

17e

14 b

726. Corbiculids from the Kushiro Coal Field
MINATO, M., 1950, Illustrated Cenozoic fossilsof northern japan 4. Cenoz. Res., no. 3,
p. 18-19, 1 pI. (in japanese).
MIZUNO, A., 1964, Summary of the Paleogene
molluscan faunas in North japan. Rep.
Ceol. Surv. japan, no. 207, p. 1-28.
- - , SUMI, Y. and SUZUKI, Y., 1966, A pre·liminary study on the sedimentary environment and bottom fauna of the Lake Shinjiko, a brackish lake on the japan Sea coastof western Honshu, japan. Ibid., no. 214,
p. 1-26, 1-2, pI. 1 (in japanese with English abstract).
NAGAO, T. and ChATUME, K., 1943, Thefossil corbiculids from the Palaeogene Isikari Series in the Isikari coal-field, Hokkaido. jour. Fac. Sci., Hokkaid{j Imp.
Univ., ser. 4, vol. 7, no. 1, p. 1-13, pis.
1-3.
OHARA, T. and KANNO, S., 1969, Mid-Tertiary molluscan faunas of the Uryu coal-field.
Fossils, no. 17, p. 41-49 (in japanese).
OTATUME, K., 1943a, A brief note on fossil
corbiculids from the Kusiro coal field in
Hokkaido. jour. Ceol. Soc. japan, vol. 50,
no. 594, p. 240-242, pI. 5.
- - , 1943b, On two fossil corbiculids fromthe Palaeogene coal-bearing Tertiary of
Obirasibe, Tesio province, Hokkaido. jour.
Fac. Sci., Hokkaid{j Imp. Univ., ser. 4,
vol. 7, no. 1, p. 15-19, text-figs. 1-4.
- - , 1943c, Three species of fossil corbiculids from the Tertiary formation of
Karahuto. Ibid., vol. 7, no. 1, p. 21-28,
pI. 4.
OYAMA, K., MIZU);O, A. and SAKAMOTO, T.,
1960, Illustrated handbook of japanese
kaido, japan. jour. Fac. Sci., Hokkaido
Univ., ser. 4, vol. 11, no. 3, p. 431-480.

Paleogene molluscs. 244p., 71 pis., Ceol.
Surv. japan.
SHIMOKAWARA, T., 1963, [The formation of
the Yubari coal field and the developmentof the geological structure]. Stud. Coal
Geol., no. 5, p. 1-243, Ceol. Sec., Hokkaido
Assoc., Coal Min. Tech. (in japanese, title
translated) .
SUZUKI, K., 1941a, Three new species of
non-marine shells from the Tertiary formations of Hokkaido and Karahuto. jap.
jour. Ceol. Ceogr., vol. 18, nos. 1-2, p.
53-58, pI. 4.
- - , 1941b, Some non-marine shells from the
Oligocene Isikari Series in the Isikari coalfield, Hokkaido. jour. Fac. Sci., Imp.
Univ. Tokyo, sec. 2, vol. 6, pt. 1, p. Ill, pis. 1-2.
- - , 1941c, Notes on the Tertiary non-marine
Mollusca from the coal-field of Uryo., Hokkaido. Ibid., vol. 6, pt. 2, p. 13-37, pis.
1-2.
- - , 1941d, On the three Tertiary non-marine
shells illustrated in K. jIlvIBO'S "Hokkaido
Tisitu Ryakuron (Geological Sketch of
Hokkaido) ", 1890. jour. Ceol. Soc. japan,
vol. 48, no. 578, p. 520-525, text-figs. 1-6.
- - , 1949, Development of the fossil nonmarine molluscan faunas in Eastern Asia.
jap. jour. Ceol. Ceogr., vol. 21, nos. 1-4,
p. 91-133.
YOKOYAMA, M., 1931, Neogene shells from
Karafto and the Hokkaido. jour. Fac. Sci.,
Imp. Univ. Tokyo, sec. 2, vol. 3, pt. 4, p.
185-196, pI. 11.
- - , 1932, Tertiary Mollusca from the coalfield of Uryu, Ishikari. Ibid., vol. 3, pt.
6, p. 221-247, pis. 1-4.

~twili*'€ffimJlI~.ftERE8rmljl)\\mlM-&: y:;; ~ f4 (1f,teJl~) 11::fi: ~11~1I-ERE8ICgeit-t Gi!i~'::::*ft.
~&~~._M-t~&~.~@M-tK~~~hGo~MERE8D'€ffi~.~ • • K~~-tGnljl)\\_fM~&iI' GfgJll;J\'ii, i$7]U_, <§'*F."I, R7]IJ@~lZ9l\?it.::~~~h, ~!6-, 1tP!6-, Y It.- r !G-t.d:'iI' G
nit I), ERJfl'i~~tE-t Go ;g._ii, Gft.~$tJ:~' l...l'~\)J(1:.~ilil:f*1fiJ~fl::fi~37&: l..., ~'€ffi:fi~'niJ~
M- (MIZUXO, 1964) t IIflfh Y :;; ~ f4 (Corbiculidae) 11 f\;~B9tJ:3f~~1:.ilil:f*llW~11::fi~-"?

""C't6G o *1!fft. Corbicula (Batissa) sitakaraensis, C. (Corbicula) tokudai ~=:fiI!~~1IilI;~rrtJ:~',

27

C. (Corbicula) kotakai, n. sp. ~~fl1!t VClc1lill;l...t.: o Corbicula sitakaraensis

It. Ostrea eorivularis, Mytilus mabuchii, Nemocardium ezoense, "Ampullina" asagaiensis tJ: c~ ~$tJ:~' l...R*i1:~:fiI! Ut&:-t Go C. tokudai l'iJiii'it, {t!Hil!~lliIIi*-ltf, c.

28

Yutaka HONDA
kotakai, n. sp. 1i.1!ifi#1it~:f;ft.:tJ:~'o (::h~=1itQ)I!ifi#1it, m1:Q) Batissa 7Jl..rY Corbicula
C. sitakaraensis fi.J'!t7J(t'lQ), C. tokudai 7Jl..rY C. kotakai, n. sp. Ii.

:!II!1.lIiQ)1:.e,~m;ry,~,

J'!t7J(-~7J(M:Q)1itl:~IJ, litr:'i!W:.~=~J:: IJ tJ:: lJiWiJlirl(7J(M:Q)1itc~k..~:h7.>o

*83

m-

Atsunai ~P3, Chambetsu-gawa T.,. /"" 'Y JII, Charo ~lm, Chokubetsu-gawa jj[lIJjJII, Karisyo;lJujflj.!f!;, Kawaruppu JIIVft;(P, Koikata-muri-gawa ::11 7J .?r ~H!.JII, Muri-gawa ~H!.JII, Noyoshi
i5/if, Nuibetsu ~lIJj, Omagari *!Ill, Ombetsu 'tfllJj, Otobe-gawa Z$JII, Rubeshube-zawa Iv""
' / =>. ""iR,
Rushin fB., Sango-zawa =~iR, Semposhi 1J1J.I.~J!:, Shakubetsu RlIJj, Shakubetsuichigo-zawa RlIJj-~iR, Shibetsu-zawa y""'YiR, Shiranuka aM, Shitakara I§"~, Soun ~Jl!!,
Tankono-sawa m~/ iR, Tenneru 3C$, Urahoro iIIlm, Yatatoshino-zawa i'.?r r '/ / iR, Yubetsu MElIJj

Explanation of Plate 3(All figures in natural size)
Figs. 1-8. Corbicula (Batissa) sitakaraensis SUZUKI
1a-b, IGPS colI. cat. no. 96764-2, Loc. S8-A; 2, IGPS colI. cat. no. 96764-3, Loc. S8-A; 3,
IGPS colI. cat. no. 96762-2, Loc. RN-02; 4, IGPS colI. cat. no. 96760-15, Loc. Y8-09; 5a-c,
IGPS colI. cat. no. 96761, Loc. S8-01; 6, IGPS colI. cat. no. 96764-5, Loc. S8-A; 7a-c, IGPS
colI. cat. no. 96759-1; Loc. SK-56; 8, IGPS colI. cat. no. 96760-13, Loc. Y8-09.

HONDA:

Cor'bic~~lids

from the K~~shi1'O Coal Field

Plate 3

Trans. Proc. Palaeont. Soc. Japan. N. S., 121, pp. 29-50, pis. 4, 5, April 30, 1981

727. CENOMANIAN MOLLUSCS IN A SANDSTONE BLOCK FROMTHE SEA BOTTOM OFF THE SOUTHERN COASTOF KUJI, NORTHEAST JAPAN*
ITARO HAYAMI
University Museum, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113

andTOMOKI KASE
National Science Museum, Hyakunin-cho, Shinjuku-ku, Tokyo 160

Abstract_-A block of calcareous fossiliferous sandstone, which was dredged bya fisherman from the sea bottom about 30 km off the southern coast of Kuji, Iwate
Prefecture, was paleontologically examined. Eleven bivalves and three gastropods,
including Inoceramus (Birostrina) sp. cf. I. (B.) concentricus nipponicus, Pterotrigonia (Pterotrigonia) brevicula, Thetis japonica, Goshoraia crenulata, Margarites?
juniculatus and Drepanochilus minimus sp. nov. were identified and are described here.
The specific assemblage is quite similar to the shallow marine fauna in the lower
part of the Mikasa Formation in central Hokkaido, and a Cenomanian age is strongly
suggested. In the Kitakami mountains Miyakoan (Aptian-Albian) and Urakawan(Coniacian-Santonian) deposits are represented by the Miyako and Kuji Groups, respectively, whereas Gyliakian (Cenomanian-Turonian) sediments have not been found.
The present discovery seems to justify the interpretation that the sea retreated tothe east from the Kitakami mountains in Gyliakian times and also to suggest thatthe marginal facies of the large sedimentary basin, called "Yezo Geosyncline", extended southwards for more than 250 km from the south coast of Hokkaido.

lection during a field trip, they generously
donated it to the National Science Museum, Tokyo.
The sandstone is dark grey, fine-grained, more or less stratified and well sortedwith remarkably calcareous cement. The
surface is roundly abraded, but its interior
is fresh and very hard. Numerous individuals of a serpulid and colonies of bryozoans, though it is unknown whether
they were living or dead at the time ofdredging, attach themselves to the eroded
surface. Three species of bryozoans,
namely, Tegela armi/era (HINCKS), Parella

Introduction
A few years ago, Mr. Kozo SASAKI, afisherman of Miyako City, Iwate Prefecture, dredged a sandstone block from thesea bottom at about 30 km east of Cape
Kurosaki, southeast of Kuji City, north
Honshu. He and his relative, Mr. Fukuji
SASAKI, thoughtfully kept the block, because it bears numerous fossils. At therequest of T. KASE who knew their col-* Received September 10, 1980; read January
23, 1981 at Sendai.

29

Itan~ HAY AMI

30

and Tomoki KASE

.S;=;;i.,,=-----.:.:~""+----__\j-------\.__-+-+-'r__t-T 40°10 ' N

PAC

oC E A N

PACIFIC OCEAII

'-+~'

omTO

.,. ---~+-I!--!-------1~---+---+--l--+-\-I 39°50' Nwo~

T ext-fig . 1.

Map showing the loca lit y of the fossi liferous sandstone block.

porife m (HINCKS) and Dalwria dawsoni
were identified.* Molluscan
fossils are contained abundantly in a thinlayer near the surface of the block andsporadically in other part. They are
scarcely deformed and generall y wellpreserved, but their tests are apt to bebroken, when the sandstone is spli t. Observations of surface and internal characters by etching were tried in vain owing
to the ca lcareous cement.
The fossils in th is block show a great
diversity; the fo ll owing eleven bi val ves
and three gastropods were identified, although each species is generally represented by a small number of specimens :(HI NCKS) ,* We express our s incer e thanks to Mr. Shinj i
AR AKAWA of th e Ch iba Univ e rsit y for his
iden tification of th ese br yozoa n specimens.

T ex t·fig . 2. Fossilife rous sa ndstone block(Maximum len gth about 50 cm).

Clyeymeris (Clyeyme ri ta) s p. aff. C. (C. ) hokIwidoensis (Y ABE an d NAGAO)
I noceramus (B irostrina) sp. d . I. (B. ) con eentl'ieus nipponicus NAGAO and MATSU ~IOTO

Entolium sp . d. E. obovatum (STOL ICZKA)

727.

Cenomanian Molluscs off the coast of Kuji

31

Pterotrigonia (Pterotrigonia) brevicula (YE-

Systematic descriptions

HARA)

Pterotrigonia (Acanthotrigonia) sp. d. P. (A.)
longiloba (JnvlBo)
Pterotrigonia (Acanthotrigonia) sp.
Thetis japonica (YABE and NAGAO)
Anthonya sp. d. A. apicalis NAGAO
Cymbophora sp.
Goshoraia crenulata (MATSUMOTO)
Goniomya sp.
Margarites? funiculatus (YOKOYAMA)
Drepanochilus minimus KASE, sp. nov.
Avellana sp.

In addition to them, a nuculid, a nuculanid,
a lucinid and a corbulid, each represented
by one or a few minute specimens, were
found in association, but their genericreferences are uncertain owing to. theinsufficient materials.
In the present article the above listed
molluscan fossils are described and theirfaunal significances are discussed. As tothe systematic descriptions, HAYAMI and
KASE are responsible for the bivalves andthe gastropods, respectively.

All the described specimens occurred ina sandstone block (about 40 kg in total
weight) landed from the sea bottom(about 400 meters in depth) about 30 km
east of Cape Kurosaki (approximately
40"00'N, 142" 17'E). The specimens of
Inoceramus (Birostrina) sp. d. I. (B.) concentricus nipponicus, Pterotrigonia (Acanthotrigonia) sp. d. P. (A.) longiloba and
Thetis japonica were taken out fromvarious parts in the block, whereas most
specimens of other species occurred in
the thin fossiliferous layer near the surface.
Bivalvia[by Itaru HAY AMI]

Order Arcoida STOLICZKA, 1871
Family Glycymerididae NEWTON, 1922
Genus Glycymeris DA COSTA, 1778

Repository
All the specimens described in thispaper as well as the remaining materialof this block are preserved in the Department of Geology, National Science Museum, Tokyo, with the abbreviation NSM.
Comparative studies are also based on
the specimens kept in the following institutions:
GMH: Department of Geology and Mineralogy,
Faculty of Science, Hokkaido University,
Sapporo.
IGPS: Institute of Geology and Palaeontology,
Faculty of Science, Tohoku University,
Sendai.
UMUT: Department of Historical Geology andPalaeontology, University Museum, University of Tokyo, Tokyo.
GK: Department of Geology, Faculty of
Science, Kyushu University, Fukuoka.

Subgenus Glycymerita FINLAY
and MARWICK, 1937
Glycyme1'is (Glycymerita) sp.
aff. G. (G.) hokkaidoensis(Y ABE and NAGAO)
Plate 4, Figs. 1, 2

Only two left valves are at hand. The
smaller specimen (NSM-PM 15097, 13.2 mm
long, 11.7 mm high, ca. 4.5 mm thick) is
nearly complete, showing external characters. The larger specimen (NSM-PM 15098,
22.5+mm long, 19.9+mm high, 7.0+mm
thick) is composed of incomplete internaland external moulds with broken shellfragments.
These specimens look similar to Glycymeris (Glycymerita) hokkaidoensis (YABE32

Itaru HAY AMI and Tomoki KASE

and NAGAO, 1928), but the shell is seemingly more elongated transversely andthe umbonal area may be narrower. In
the original description of Pectunculus
hokkaidoensis, Y ABE and NAGAO (1928, pI.
17, fig. 22) illustrated only one specimen(lGPS no. 22613) from the "Trigonia sandstone" at Ponhorokabets of Yubari, central Hokkaido. Although the illustrated
specimen was treated as "holotype bymonotypy" in my previous article (HAy AMI, 1975, p. 33), it should be regarded
as lectotype, because two different localities were indicated in the original des:ription.
The smaller specimen also resembles
some young specimens of Glycymeris(Glycymerita) multicostata NAGAO, 1932,
from the Upper Yezo Group of Teshio(e. g. TASHIRO, 1971, pI. 27, figs. 31, 32),
but the larger specimen shows less orbicular outline and weaker convexity thanits adult specimens. The present specimens may be also similar to some specimens of Glycymeris (Glycymerita) amakusensis NAGAO, 1930, from the Himenoura Group of Kyushu in the relatively
low shell form. The radial ribs on thesurface, however, are much weaker thanthose of the Himenoura species.
Order Pterioida NEWELL, 1965
Family Inoceramidae GIEBEL, 1852
Genus Inoceramus J. SOWERBY, 1814
Subgenus Birostrina J. SOWERBY, 1821
Inoceramus (Birostrina) sp. cf. I. (B.)
concentricus nipponicus NAGAO
and MATSUMOTO
Plate 4, Figs. 3-6
Compare.?l928. Inoceramus sp.: YABE and NAGAO, Sci.

Rep. Tohoku Imp. Univ., ser. 2, vol. 9,
no. 3, p. 84, pI. 16, fig. 13, a, b.
1939. Inoceramus concentricus var. nipponicus
NAGAO and MATSUMOTO, jour. Fac. Sci.
Hokkaido Imp. Univ., ser. 4, vol. 4, nos.
3-4, p. 267, pI. 24, fig. 2a-c, pI. 25, figs.
1a-c, 2a, b, 3-5, 6a-c.
1959. Inoceramus concentricus nipponicus NAGAO and MATSUMOTO: MATSUMOTO,
Mem. Fac. Sci. Kyushu Univ., ser. D,
vol. 9, no. 2, p. 84, pI. 11, fig. a.
1971. Inoceramus concentricus nipponicus NAGAO and MATSUMOTO: NODA, KagakuQita, no. 24, p. 28, pI. 1, figs. 1, 2.
1974. Inoceramus concentricus nipponicus NAGAO and MATSUMOTO: TAMURA and
MATSUMURA, Mem. Fac. Educ. Kumamoto Univ., no. 23, sec. 1, p. 49.
1975. Inoceramus (Birostrina) concentricus
nipponicus NAGAO and MATSUMOTO:
HAYAMI, Bull. Univ. Mus. Univ. Tokyo,
no. 10, p. 51.
1976. Inoceramus concentricus nipponicus NAGAO and MATSUMOTO: NODA and MATSUMOTO, Atlas of japanese Fossils, no. 45265, pI. Cr-31, figs. 1, b, 2.
1977. Birostrina nipponica (NAGAO and MATSUMOTO): KAUFFMAN, Palaeont. Soc.
japan, Spec. Papers, no. 21, p. 175.

Type of Inoceramus concentricus nipponicus.-A left valve (GMH no. 7167)
from Hakkinzawa of Oyubari, central
Hokkaido, which was originally listed andillustrated as one of the syntypes (NAGAO
and MATSUMOTO, 1939, p.267, pI. 25, fig.
6a-c), is here designated as the lectotype.
NAGAO and MATSUMOTO (1939, p. 297)
regarded this specimen as belonging to"the typical form", and TAMURA and
MATSUMOTO in TAMURA and MATSUMURA(1974, p. 49) also considered that it shows"typical characters of I. concentricus nipponicus". These procedures, however, are
not regarded here as constituting any
valid type designation.
Material.-Three right valves (NSMPM 15071-15073) and one left valve (PM15074).

727.

33

Cenomanian Molluscs off the coast of Kuji

Table 1. Measurements in mm [Inoceramus (Eirostrina) sp. d. I. (E.)
concentricus nipponicus NAGAO and MATSUMOTO]
Specimen

LengthHeightThickness

Right valve (NSM-PM 15071)
Right valve (NSM-PM 15072)
Right valve (NSM-PM 15073)
Left valve (NSM-PM 15074)

24.4
21. 0+
11.1+
10.4+

21. 9+
26.4+
13.0
7.9+

7.0
7.0
3. 7
4.2

Description.-Shell relatively small for
genus, highly inequivalve, roundly subtrapezoidal but somewhat irregular inoutline; test thin; left valve strongly
convex, with extremely prominent andincurved umbo and slightly concave anterior and dorsal margins; right valve
only moderately convex, mytiliform, withterminal and pointed umbo and nearlystraight anterior and dorsal margins;apical angle of right valve ranging from70 to 90 degrees; hinge line moderate inlength; surface of two valves nearlysmooth except for weak concentric ringsof irregular interval and fine growthlamellae.
Remarks.-All the present specimens
are incomplete, but their umbonal areas
are well exhibited and scarcely deformed.
The shell is partly preserved in the left
valve (PM 15074) but almost entirely exfoliated away in other specimens.
These specimens are comparable with
Inoceramus (Birostrina) concentricus nipponicus by the highly inequivalve outline
and weak and irregular concentric rings,
though there is a shortage of good material showing the specific and subspecificcharacters.
As pointed out by TAMURA and MATSUMURA (1974, p. 49) and KAUFFMAN (1977,
p. 174), the original specimens of I. concentricus var. nipponicus may be a heterogeneous mixture of two or more species
from various localities and horizons, but
specific separation may be difficult unlessa more extensive survey on the morpho-

logy and stratigraphic occurrence is carried out at the population level. At present I think that the subspecific distinction of most of these specimens from theEuropean ones of I. concentricus (s. s.) isappropriate, because the left valve in theformer has generally less prominent umbo.
Incidentally, the occurrence of this species
is restricted to the Albian in Europe(WOODS, 1911; etc.), while in Japan I.
concentricus nipponicus and I. concenticus
costatus seems to characterize K4a 2 (upper
Lower Cenomanian) and K4a 3 (lower Upper
Cenomanian), respectively.
As mentioned by NAGAO and MATSUMOTO (1939), the outline of I. concentricus
nipponicus is considerably variable; theoriginal specimens were classified into
three forms; namely, typical form, higher
form and lower form. The present left
valve (PM 15074), though very small andincomplete, is similar to one of the paralectotype (IGPS no. 22783; NAGAO and
MATSUMOTO, 1939, pI. 25, fig. 4) from
Bibai, which was included in lower form,in the outline, especially in the broadly
concave dorsal margin and comparatively
large apical angle. A small right valve(PM 15073) looks similar to the specimen(GK H4; NODA, 1971, pI. 1, fig. 2) from
Abeshinai in the relatively large apicalangle and the presence of a shallow diagonal sulcus extending from the umbonal
area to the postero-ventral margin.

Itaru HAY AMI and Tomoki KA.SE

34

Family Entoliidae KOROBKOV, 1960

Order Trigonioida DALL, 1889

Genus Entolium MEEK, 1865

Family Trigoniidae LAMARCK, 1819
Genus Pterotrigonia VAN HOEPEN, 1929

Entolium sp. d. E. obovatum (STOLICZKA)
Subgenus Pterotrigonia VAN HOEPEN, 1929
Plate 4, Fig. 71928. Pecten(Syncyclonema)

obovatus
Rep.
Tohoku Imp. Univ., ser. 2, vol. 9, no.
3, p. 87, pI. 17, figs. 3-6.
1938. Pecten (Syncyclonema?) aff. obovatus
STOLICZKA: NAGAo, Jour. Fac. Sci.
Hokkaido Imp. Univ., ser. 4, vol. 4, nos.
1-2, p. 128, pI. 16, figs. 1, 2.
1975. Entolium sp. cf. E. obovatum (STOLICZKA) : HAYAMI, Bull. Univ. Mus. Univ.
Tokyo, no. 10, p. 73.
1975. Entolium sp. cf. E. obovatus [sic] (STOLICZKA): TAMURA, Mem. Fac. Educ.
Kumamoto Univ., no. 24, sec. 1, pI. 3,
fig. 9.
cf.

STOLICZKA: YABE and NAGAo, Sci.

Only one right valve (NSM-PM 15075,
17.2 mm long, 18.0+mm high, ca. 3.0 mm
thick) was obtained. The shell is almost
entirely exfoliated from the internal mould.
judging from the relatively tall outline
and internal characters, the present specimen is referable to Pecten (Syncyclonema)d. obovatus by YABE and NAGAO (1928)
from the Mikasa Formation in central
Hokkaido. The generic validity of Syncyclonema and its distinction from Entolium
and other related pectinacean genera weremuch clarified by SPEDEN (1967). The
present species as well as its comparable
species, Pecten obovatus STOLICZKA, 1871,
from the Upper Cretaceous of India, isreferable to Entolium instead of Syncyclonema, as was already treated by HAYAM I (1975) and TAMURA (1975). Further
comparative studies between the present
Japanese form and the Indian species
should be done on the basis of better
preserved specimens from Hokkaido.

Pterotrigonia (Pterotrigonia) brevicula(YEHARA)
Plate 4, Figs. 8-14
1915. Trigonia brevicula YEHARA, Sci. Rep.
Tohoku Imp. Univ., ser. 2, vol. 2, no.
2, p. 42, pI. 2, figs. 18, 19.
1954. Pterotrigonia brevicula (YEHARA): KoBAYASHI, Japan. Jour. Geol. Geogr., vol.
25, nos. 1-2, p. 76.
1961. Pterotrigonia brevicula (YEHARA) : NAKANO and NUMANO, Trans. Proc. Palaeont. Soc. Japan, n. s., no. 43, p. 91, pI.
13, figs. 4-8.
1975. Pterotrigonia (Pterotrigonia) brevicula(YEHARA): HAYAMI, Bull. Univ. Mus.
Univ. Tokyo, no. 10, p. 118.
1976. Pterotrigonia brevicula (YEHARA) : T AMURA, Atlas of Japanese Fossils, no. 44264, pI. Cr-30, fig. 16.

Type.-An incomplete left valve (IGPS
no. 4329; YEHARA, 1915, pI. 2, fig. 18)
from the Ikushumbets River, about 3 km
above the Ikushumbets Coal Mine, Mikasa
City, central Hokkaido, was designated by
NAKANO and NUMANO (1961, p. 91) as thelectotype.
Material.-Seven right valves (NSM-PM
15077-15083) and three left valves (NSMPM 15084-15086).
Description.-Shell small- or mediumsized for genus, crescentic, rostra ted
posteriorly, much longer than high, moderately inflated; test comparatively thick;anterior margin rounded, passing gradually into venter; ventral margin a little
concave below posterior rostrum; postrodorsal margin rounded and moderate in727. Cenomanian Molluscs off the coast of Kuji

35

Table 2. Measurements in mm [Pterotrigonia (Pterotrigonia) brevicula (YEHARA) ]Specimen
Right valve (NSM-PM 15077)
Right valve (NSM-PM 15078)
Right in. mould (NSM-PM 15079)
Right valve (NSM-PM 15080)
Right valve (NSM-PM 15083)
Left in. mould (NSM-PM 15084)
Left valve (NSM-PM 15086)

length; umbo rather low, opisthogyrous,
situated at about one-third of length fromfront; flank ornamented with a dozen or
more (if adult), widely spaced, subequidistant oblique costae, which are slightly
sinuous, weakly tuberculated, somewhat
abruptly strengthened toward anteroventral side, not impressed on internalsurface and separated from posteriorcarina by a shallow ante-carinal sulcus;
posterior carina sharp near umbo but gradually becoming obscure toward posterior
end; area (posterior area) undeveloped,
very narrow even in adult, nearly smooth
except for a sharp and narrow medianfurrow; escutcheon considerably wide,
deeply excavated, steeply inclined to commissure plane, ornamented with coarse
transverse costae; sharp internal ridge
running subhorizontally on posterior rostrum; adductor muscle scars strongly impressed; pallial line simple; umbonal
cavity narrow but conically and profoundly
excavated.
Remarks.-Of the ten specimens athand, the test is, though not completely,preserved in one left valve (PM 15086)
and four right valves (PM 15077, 15078,
15080, 15083). The outline is best shownby two specimens (PM 15079, 15084). The
mode of weakly tuberculated oblique costae on the flank is well observed in theleft valve (PM 15086) and two rightvalves (PM 15077, 15078), while the narrowand smooth area and excavated escut-

LengthHeightThickness

36.9
25.9+
44.0
16.5
22.4+
19. 7
21. 6+

25.4
19.8+
33.6
10.9
24.3
13. 7
15.6

10.2
7.0+
11. 0+
4.5
9.3
3.8+
7.2

cheon with coarse transverse costae arerecognized only in the left valve (PM15086) and the immature right valve (PM15080). The muscle structure is partly
observed in a broken right valve (PM15083),As originally described by YEHARA(1915) and subsequently studied by NAKANO and NUMANO (1961) on the basis ofmany specimens from the Mikasa Formation in central Hokkaido, the present species
seems ot be characterized by the thick test,
very narrow and unornamented area witha distinct median furrow, slightly sinuous
and weakly tuberculated oblique costae
on the flank and deeply excavated andsteeply inclined escutcheon. The unusually narrow and profound umbonal cavity
seems to constitute another diagnostic
character of this species. The lectotype
and paralectotype of Trigonia brevicula(YEHARA, 1915, pI. 2, figs. 18, 19) show
at a glance relatively short outline, but
it is probably because the posterior marginal part is incomplete like one of thepresent specimens (PM 15086). NAKANO
and NUMANO (1961) studied the ontogenetic transformation of P. brevicula, describing that the outline changes fromsubtrigonal to crescentic and that theform ratio (length/height) gradually increases with growth. Such a tendencyof allometric growth is also recognized in
the present material.
The slightly sinuous and antero-ven-

36

Itaru HAY AMI and Tomoki KASE

trally thickened costae on the flank are
not much different from those in certain
species of the subgenus Acanthotrigonia,
especially P. (A.) mashikensis (TAMURA
and TASHIRO, 1967) and P. (A.) higoensis(TAMURA and TASHIRO, 1967) from the
Cenomanian Mifune Group of central Kyushu. The present specimens, however,differ from them in the much narrowerarea and steeply inclined escutcheon.
Another problem arises about the relation
between P. (P.) brevicula and Pte rot rigonia (Acanthotrigonia) longiloba (jIMBO,
1894), since the present specimens looks
similar to the para lectotype of the latter
species (UMUT MM4465; JIMBO, 1894,
pI. 8, fig. 3; KOBAYASHI and NAKANO,
1957, pI. 17, fig. 5). However, the two
species are regarded as distinct, even if
the paralectotype is conspecific with thepresent specimens (See also the taxonomic
remarks on P. (A.) sp. cf. P. (A.) longiloba).
Subgenus Acanthotrigonia
VAN HOEPEN, 1929
Pterotrigonia (Acanthotrigonia) sp. cf.
P. (A.) longiloba (jIMBO)
Plate 4, Fig. 15

Only a left valve (NSM-PM 15088, 28.9mm long, 23.5 mm high, ca. 6.0 mm thick)is available for this study. The test ispreserved but mostly attached to the external mould. The outline is nearly complete, and the oblique costae on the flankare clearly impressed on the internalmould.
It is clearly distinguishable from thespecimens of P. (P.) brevicula from thesame block by the much thinner test,
slender and somewhat flattened posterior
rostrum, highly prominent umbo, longer
internal ridge and steep anterior slope.

Clearly impressed oblique costae andweakly impressed adductor muscle scars
on the internal surface are also distinct
characters from those specimens.
The present specimen is probably conspecific with the lectotype of P. (A.)
longiloba from Ponhorokabets of Yubari(jIMBO, 1894, pI. 8, figs. 2,4), because theoutline and flank ornamentation are quite
similar. KOBAYASHI and NAKANO (1957,
p. 235) indicated a specimen (jIMBO, 1894,
pI. 8, fig. 3) as the lectotype, but the"fig. 3" is interpreted to be a misprint offig. 2, as pointed out by MATSUMOTO(1963. p. 45). The specific characters ofP. (P.) longiloba are, however, still debatable, because the paralectotype (jIMBO,
1894, pI. 8, fig. 3) and most of subsequently described specimens (YEHARA, 1915,
1923; KOBAYASHI and NAKANO, 1957) areconsiderably different from the lectotype
in the less prominent umbo and broader
posterior rostrum. Unfortunately, thelectotype specimen, which is to be preserved in the University Museum, University of Tokyo, is now missing (ICHIKAWA
and HAYAMI, 1978, p. 52). Although MATSUMOTO (1963, p. 45) regarded the wax
cast (UMUT MM4466), which was illustrated by KOBAYASHI and NAKANO (1957,
pI. 17, fig. 6) as "the type left valve", astaken from the lectotype, it is quite different from the original figure of thelectotype in the outline and mode of oblique costae. judging from the old label
annexed to the wax cast, its original
specimen (in Preuss ian Geological Survey
at that time) came from the Sorachi district of Hokkaido and was possibly treated
by JIMBO, but it is certainly unrelated to
the lectotype, because their dimensions
and recorded localities are quite different.
There are much uncertainty about themorphological variatIOn and specificcharacters of P. (A.) longiloba, but thepresent specimen is tentatively compared7~7.

Cenomanian Molluscs off the coast of Kuji

with this species owing to the close resemblance with the figure of its lectotype.

Pterotrigonia (Acanthotrigonia) sp.
Plate 4, Fig. 16

Only internal and external moulds of asmall (probably immature) right valve(NSM-PM 15087, 9.3 mm long, 7.8 mm high,2.5+mm thick) are available for thisstudy. The characteristic chevron-shaped
oblique costae on the flank and area areclearly observed on the external mould,
while the general outline is better shownby the internal mould. The ornamentation seems to indicate that the present
specimen belongs to Acanthotrigonia. It
looks especially similar to the small trigoniid specimen from the Mikasa Formation of Ikushumbets, which was illustrated
by YEHARA (1915, pI. 2, fig. 11) as ayoung individual of "Trigonia longiloba",
though his specific identification is notwarranted here by the reason stated before. It is actually possible that the present specimen is conspecific with thespecimen of P. (A.) sp. d. P. (A.) longiloba from the same block, but further
comparison is now difficult owing to thedifferent ontogenetic stages. The present
specimen shows somewhat similar outline
to the coexistent specimens of P. (P.)
brevicula, but is clearly different fromthem in the densely spaced oblique costae
on the flank, wide and costa ted area andprobably much narrower escutcheon.

Order Veneroida ADAMS and ADAMS, 1856
Family Mactromyidae Cox, 1929
Genus Thetis J. de C. SOWERBY, 1826

Thetis japonica (YABE and NAGAO)

37

Plate 5, Figs. 2-4
1927. Thetironia affinis (WHITEAVES) var.
japonica YABE and NAGAO in YABE, Sci.
Rep. Tohoku Imp. Univ., ser.2, vol. 11,
no. 1, pI. 5, fig. 7a-d. [no written des·cription]
1928. Thetironia affinis (WJ-IITEAVES) var.
japonica YABE and NAGAO: Y ABE andNAGAO, Sci. Rep. Tohoku Imp. Univ.,
ser. 2, vol. 9, no. 3, p. 89, pI. 17, figs.
14, a, b, 15, a.
1975. Thetis japonica (Y ABE and NAGAO):HAYAMI, Bull. Univ. Mus. Univ. Tokyo,
no. 10, p. 122.
1976. Thetis affinis japonica (Y ABE and NAGAO) : TAMURA and TASHIRO, Atlas ofJapanese Fossils, no. 43-258, pI. Cr-24,
figs. 17, 18.

Type.- YABE (1927) illustrated only one
specimen (IGPS no. 22602) under the nameof T. affinis var. japonica Y ABE and NAGAO. Although the verbal description ofthis variety was first made by YABE andNAGAO (1928), the name seems to beavailable since 1927 according to ICZN
(Articles 12 and 16 (vii)). Because YABE
and NAGAO (1928) noted "Numerous specimens were examined", the illustrated
specimen (Y ABE, 1927, pI. 5, fig. 7a-d;
YABE and NAGAO, 1928, pI. 17, fig. 14,a, b)
is here designated as'the lectotype. It
was obtained from the Trigonia Sandstone [=Mikasa Formation] at the middle
course of the Ikushumbets River, Mikasa
City, central Hokkaido.
Material.- Three right valves (NSMPM 15089-15091).
Description.-Shell small- or mediumsized for genus, globose, slightly inequilateral, a little longer than high, strongly
inflated; test very thin; antero-dorsal
margin a little concave in front of umbo,
but valve margin of other parts roundly
arcuate and not differentiated; umbo prominent, incurved, slightly prosogyrous,
placed subcentrally; lunule and escutcheon

38

Itaru HAY AMI and Tomoki KASE
Table 3. Measurements in mm [Thetis japonica (Y ABE and NAGAO) ]Specimen
Right in. mould (NSM-PM 15089)
Right in. mould (NSM-PM 15090)
Right valve (NSM-PM 15091)

not clearly impressed; surface smooth
except for fine growth lines and weakradial threads on anterior and posterior
peripheral areas; internal surface whollymarked with numerous faint radial striae,
which suggest the presence of radial
structure of shell; anterior adductor scarsomewhat larger than posterior; pallial
line simple; umbonal cavity deep.
Remarks.-The first specimen (PM15089) consists of internal and externalmoulds of a right valve, and the second(PM 15090) is represented only by a rightinternal mould. The test is partly preserved in the third specimen (PM 15091).
The shell material is fragile, and the surface is commonly tinged with green bysome unknown reason. This state ofpreservation is very similar to that of
the specimens of the same species in the
Mikasa Formation. The hinge structure
is difficult to observe both in the Mikasa
and present speciinens, because the hinge
plate is very narrow.
As described by YABE and NAGAO(1928), a curiously inflected "rib" runs on
the surface of two valves in the lectotype specimen. Somewhat similar structure, especially a tongue-shaped relief
between two inflections on the posterodorsal surface, is clearly observed in someparalectotype specimens and also in oneof the present specimens (PM 15089). It
is, however, unknown whether the relief
is of primary origin or not.
It is an interesting but unsolved problem how intimately the present form isrelated to Thetis afjinis (WHITEAVES) from

LengthHeightThickness

20.5
19.8
16.0

19.6
18.3
14.9

8.1
6.9
6.0

the Upper Cretaceous of Queen Charlotte
Islands. They are tentatively regarded
as specifically distinct, because the Japanese specimens show less prominent
umbo and more developed anterior partof shell.
Family Crassatellidae FERUSSAC, 1822
Genus Anthonya GABB, 1864
Anthonya sp. d. A. apicalis NAGAO
Plate 4, Fig. 17

Only an external mould of right valve(NSM-PM 15069, 36.5+mm long, 16.5+mm
high, 3.0+mm thick) was obtained. Its
anterior part is broken, but the external
characters of post-umbonal part are well
exhibited. Its original outline is roughly
recognizable from the impressed growthlines, but the apical angle is actually notmeasurable. Though the hinge and ligament structures are unknown, it is referable to Anthonya by the blade-shaped,
elongated and compressed outline. The
weak and rounded diagonal carina extending from the umbo to the postero-ventral
angle is also characteristic of this genus.
As listed by TAMURA and PACKARD(1972) and additionally described by T AMURA (1977), there are four species andone subspecies of Anthonya in the Cretaceous of Japan (more than 16 species in
the world). The present specimen is, if
not identical with, closely similar to Anthonya apical is apicalis NAGAO, 1938, from

727. Cenomanian Molluscs off the coast of Ku:ji
the Mikasa Formation of central Hokkaido
in the general outline, especially in thetruncated posterior margin and irregular
growth-lamellae on the surface. On thisoccasion a left internal mould (GMH no.
8203) illustrated by NAGAO (1938, pI. 15,
fig. 1, la) from the Trigonia Sandstone(=Mikasa Formation) at Ponhorokabetszawa of Poronai near Ikushumbets is designated as the lectotype of A. apical is.
In comparison with the lectotype andparalectotypes, the present specimen issomewhat larger and has more or lessbroader posterior part. Its identification
with A. apicalis apical is, however, might
be confirmed in the future, if the morphological variation of this subspecies
were examined on adequate material fromthe type area.
Anthonya apicalis shishijimensis AMANO,
1956, from the Goshonoura Group at Shishijima of west Kyushu may be alsosimilar in the outline, but the concentriclines on the surface are seemingly regularand more prominent in comparison withthe present specimen. Anthonya mi/unensis TAMURA, 1977, from the lower partof the Mifune Group of central Kyushu
is probably a closely related species to A.
apical is. Although further comparative
studies may be needed, the Mifune species
seems to be distinguishable from A. apicalis by the more rounded posterior margin. Moreover, the present specimen has
slightly larger and broader shell than A.
mi/unensis. Anthonya subcantiana NAGAO,
1934, from the Aptian-Albian Miyako
Group in north Honshu (HAY AMI, 1965b)
has decidedly a smaller and shorter shelland more conspicuous regular concentricribs on the surface.
Family Mactridae LAMARCK, 1809
Genus Cymbophora GABB, 1869

39

Cymbophora sp.
Plate 5, Fig. 1

This species is here represented only
by a right valve (NSM-PM 15070, 12.7 mm
long, 10.4 mm high, ca. 3.5 mm thick). It
is nearly complete, but nothing is known
about the internal characters. Its subtrigonal outline and densely spaced concentric lamellae on the surface remind me
those of Cymbophora ezoensis (Y ABE andNAGAO) from the Mikasa Formation ofcentral Hokkaido. HANZA W A, ASANO andT AKAI (1961) listed one of the original
specimens of Spisula (Cymbophora) ezoensis(IGPS no. 22614; Y ABE and NAGAO, 1928,
pI. 16, fig. 5) as the "holotype". This
procedure is regarded here as constituting
a valid lectotype designation. In comparison with the lectotype and paralectotypes, the present specimen seems to havesomewhat longer antero-dorsal margin.
TAMURA (1977) also described C. ezoensis
from the Mifune Group of central Kyushu, but the Mifune specimens have astronger posterior carina than the present
specimen and probably also than the Mikasa specimens of C. ezoensis.
Family Veneridae RAFINESQUE, 1815
Genus Goshoraia TAMURA, 1977
Goshoraia crmulata (MATSUMOTO)
Plate 5, Figs. 5-8
1938. "Callista"(Pseudamiantis) crenulatus[sic] MATSUMOTO, jour. Ceol. Soc.
japan, vol. 45, no. 532, p. 19, text-figs.
12, 13, pI. 1, figs. 5, 6.
1956. Pseudamiantis crenulatus(MATSl'l\10TO) :AMANO, Kumamoto jour. Sci., ser. B,
sec. 1, vol. 2, no. 1, p.78, pI. 1, fig. 26,
pI. 2, figs. 13-19.
1963. "Callista" (Pseudamiantis) crenulatus[sic] MATSUMOTO: IWASAKI, Trans.

40

Itaru HAY AMI and Tomoki KASE

Proc. Palaeont. Soc. Japan, n. S., no. 51,
p. 94, pI. 15, figs. 4-7.
1975. Pseudamiantis? crenulata (MATSUMOTO) :HAYAMI, Bull. Univ. Mus. Univ. Tokyo,
no. 10, p. 144.
1976. "Callista" (Pseudamiantis) crenulatus[sic] MATSUMOTO: TAMURA and TASHIRO, Atlas of Japanese Fossils, no.
43-257, pI. Cr-23, figs. 19-22.
1977. Goshoraia crenulata (MATSUMOTO):TAMURA, Mem. Fac. Educ. Kumamoto
Univ., no. 26, p. 139, pI. 9, figs. 9-16.

Type.-A right valve (UMUT MM7751)
illustrated by MATSUMOTO (1938, pI. 1, fig.
5) from the Goshonoura Group at Kobunenosako, northeast of Enokuchi, Goshonoura (=Goshora) Island, Kumamoto Prefecture of Kyushu, was designated by
IWASAKI (1963) as the "holotype". This
procedure is here regarded as constituting
a valid lectotype designation.
Material.- Three right valves (NSM-PM
15092-15094) and two left valves (NSMPM 15095, 15096).
Deseription.-Shell medium in size, equivalve, inequilateral, subovate, about 1.3
times longer than high, moderately inflated, not carinated; test moderate in thickness; antero-dorsal margin a little concavein front of umbo, while other part ofvalve margin is continuously arcuate
without any angulation; umbo moderate
in prominence, incurved, prosogyrous,
placed at about two-fifths of length fromfront; lunule moderate in width, distinct,
deeply excavated; surface marked withirregularly spaced growth-lamellae and also
Table 4.

numerous (more than 80) sub internal radial
riblets which correspond with fine crenulations along inner ventral margin;adductor muscle scars subequal in size,
clearly impressed; pallial line deeply andangularly sinuated; umbonal cavity moderate in depth.
Remarks.-The largest specimen (PM15092) consists of right internal and external moulds exhibiting the surface andmuscle characters. The hinge is only
partly observable in the same specimen;
the presence of three cardinal teeth ofveneroid type is recognized. The subinternal radial riblets were probably not
exposed on the exterior of the original
shell, and their limited distribution on thepresent external moulds is regarded as
due to the partly preserved shell material
or slightly eroded surface of shells. These
specimens are variable in size, but every
essential character is quite the same.
The present specimens are undoubtedlyreferable to Callista (Pseudamiantis) erenulata MATSUMOTO, 1938, from the Goshonoura Group of Kyushu, on which T AMURA (1977) established the genus Goshoraia.
This species was redescribed by him insome detail on the basis of many specimens from the Mifune Group. All theimportant characters of the present specimens agree well with those of TAMURA'S
specimens as well as the type material.
Order Pholadomyoida NEWELL, 1965
Family Pholadomyidae GRAY, 1846

Measurements in mm [Goshoraia crenulata (MATSUMOTO)]

Specimen
Right in. mould (NSM-PM 15092)
Right ex. mould (NSM-PM 15093)
Right ex. mould (NSM-PM 15094)
Left ex. mould (NSM-PM 15095)
Left in. mould (NSM-PM 15096)

LengthHeightThickness

34.5
23.0+
20.0+
25.9+
19.3

25. 7
19. 7
15.9
21.6+
15.4

8.5
5.6
4.7+
6.4
4.0

727. Cenomanian Molluscs off the coast of Kuji
Genus Goniomya AGASSIZ, 1841
Subgenus Goniomya AGASSIZ, 1841
Goniomya (Goniomya) sp.
Plate 5, Fig. 9

Only an external mould of a fragmentary right valve (NSM-PM 15076) was
obtained. The characteristic U-shaped
ornament impressed on the mould indicates that it certainly belongs to Goniomya.
The considerably long and persistent
median horizontal ribs may remind oneof those of Goniomya (Goniomya) subarchiaci NAGAO, 1934, from the AptianAlbian Miyako Group in north Honshu(HA YAMI, 1966), but the triangular partwith the median ribs is more prosoclinally
inclined in comparison with that species.
This is the first occurrence of Goniomya in
the Upper Cretaceous of Japan, but thematerial is too poor to be specificallydetermined.
Gastropoda[by Tomoki KASE]

Order Archaeogastropoda THIELE, 1925
Family Trochidae RAFINESQUE, 1815
Genus Margarites GRAY, 1847
Margarites? /uniculatus (YOKOYAMA)
Plate 5, Fig. 101890. Margarita funiculata YOKOYAMA, Palaeontographica, vol. 36, p. 197, pI. 20,
fig. 13a-d.
1963. Margarites funiculatus (YOKOYANIA):
MATSUMOTO, HAYAMI and ASANO, A
Survey of Fossils from Japan illustrated
in Classical Monographs, p. 30, pI. 46,
fig. 13a-d.
1977. Margarites funiculatus (YOKOYAMA):
HAYAMI and KASE, Bull. Univ. Mus.

41

Univ. Tokyo, no. 13, p. 35.

Type.-Holotype by monotypy (Bayerische Staatsammlung fUr Palaontologie
und Historische Geologie, Munchen ;YOKOYAMA, 1890, pI. 20, fig. 13a-d). As
interpreted by NAGAO (1939, p. 216), it
probably came from the Trigonia Sandstone (Mikasa Formation) near Poronai,
central Hokkaido.
Material.-Only one small specimen(NSM-PM 15099) and a few fragments(NSM-PM 15108).
Description.-Shell very small, broadly
phaneromphalous, thin-tested, turbiniformwith height slightly smaller than width.
Incremental angle in neighbourhood of
penultimate whorl about 90 degrees.
Spire comprising at least two volutions
and occupying slightly less than a halfof total shell height. Spire whorls slightly
shouldered, angularly inflated and separated by weakly impressed sutures.
Protoconch mlsslllg. Body whorl large,
shouldered and rather flat-sided. Its side
nearly vertical and delimited above andbelow by weak angulations. Base weakly
convex with broad umbilicus. Umbilicalmargin covered by well delimited heavy
callus. Ornamentation of spire whorls
unknown. On body whorl, surface ornamentation consisting of closely spaced
round-topped spiral threads and collabral
ribs. Spiral threads wider than their interspaces, becoming obscure toward whorl
side. Collabral ribs low and strong nearsuture, dying out on side but again
strengthened near umbilical margin.
Below suture, two prominent spiralgrooves intersected by collabral ribs.
Growth-lines steeply prosocline. Aperture
incompletely known, subcircular in outline.
Remarks.-This species seems to be
represented by several specimens in thiscollection, but they are mostly incomplete.
The width of the largest specimen may

42

Itan~ H AYAMI and To?noki KASE

attain 10 mm in view of the fragmentar y
specimen (PM 15108), and, therefore, thedescribed specimen (PM 15099, 3.5+ mm
high, 4.4 mm wide) is considered to be
juvenile.
The present specimen is probably
conspec ific with the specimen once described by YOKOYAMA (1890) as Mal'garita
funiculata, w hich is the most common
gastropod in the Mikasa Formation.
YOKOY AMA' S description on the umbilicalstructure is somewhat incomplete, but
he stated " Die Basis ist gewblbt, wei t
genabelt". Several well preserved specimens from the Mikasa Formation near
the t ype locality deposited in the National
Science Museum, Tokyo, agree well withthe description and ill ustration of YOKOYAMA'S specimen. The umbilical margin
in these specimens is covered by thick
and we ll delimited callus as in the caseof the present specimen. By the ge nera lshell outline the present species seems to
be referable to N/argarites or Atim,
though such thick umbili cal callus is un familiar in these genera.
Ord er Caenogastropoda Cox, 1959
Famil y Aporrhaidae ADAMS, 1858
Genus DrejJanochilus MEEK, 1864

Drepanochilus minimus
KASE, sp. nov.
Plate 5, Figs. 13- 17, T ext·fig . 3

Type and material. - The holot ype (NSMPM 15100) is the largest specimen whichlacks the shell of spi re whorls. The
parat ypes (NSM-PM 15101- 15105) are allincomplete specimens.
Diagnosis .-A very small species of
Drepanochilus with only one spiral keel
on body whorl. Spire whorls five in

Text·fig. 3.

Drepanochilus minimus

K ASE, sp. no v. (restored ) . ca. x 8

number including protoconch. About adozen of axial ribs weak, moderately
incli ned and obscure below sutures.
Anterior siphonal canal short.
Description.-Very small aporrhaid shellwith he igh t s li g htl y larger than w id th .
Spi re turr iculate, about five in w horl
number including protoconch and sligh tly
cyrtoconoid as a w hole, occupying about
two-fifths of total shell height. Sutures
impressed.
Protoconch cons lstll1g ofsmooth naticiform w horl s with about one
vo lution and separated from teleoconch
by a sigmoidal groove . A pical angle
about 60 degrees but incremental angle
in neighbourhood of penu ltimate whorI
about 45 degrees .
First and second
whorls of teleoconch smooth w ith a weakspiral keel slight ly above suture. Thirdand fourt h \vhorIs of teleoconch wellrounded w ith w idth more th an 1.5 timesof height and surface ornamentation
compr ising ax ial ribs and spira l cords.
Axial ribs about a dozen in number pera whorl, rather weak, opisthoclinallyopisthocyrt and most prominent at middle
but obscure below sutures. Spiral cords
fine and regu larly spaced. Body w horl
angu larly inflated above and abruptly

727. Cenomanian Molluscs off the coast of Kuji
becoming narrower anteriorly, forming ashort, pointed and nearly straight siphonal
canal, and prominently unicarinated at
two-thirds from anterior end.
Body
whorl sculptured by fine spiral cords,
sometimes with weak axial rugae on
basal area near aperture. Axial ribs
abruptly appearing near boundary between penultimate and body whorls,
where a spiral ridge exists. Spiral cords
on body whorl about seven and fifteen
above and below spiral keel, respectively,
and gradually becoming stronger towards
anterior end. Outer lip forming a simply
tapered and gently upturned spike.
Measurements.-No specimen is perfectly preserved. The holotype is atleast 7.3 mm in height and 6.3 mm inwidth including the extended outer lip
spike.
Remarks.- The dredged sandstone blockcontains a large number of specimens of
this species. Owing to the very small
shell size and fragility of shell, only six
imperfect specimens were prepared forthis study. The holotype shows perfectly
the simple and upturned short outer lip
spike and the surface ornamentation ofbody whorl. The early teleoconch whorls
are best observed in a silicone rubber
cast of a paratype (PI. 5, Fig. 13). The
delicate ornamentation of early whorls inthis specimen is somewhat obliterated,
but it reveals two post-embryonic whorls
which possess a distinct spiral keelslightly above the anterior sutures.
Similar characteristics of the earlyteleoconch whorls are found in somespecies from the Gault of Englanddescribed by GARDNER (1875), such as
Dimorphosoma calcarata (SOWER BY), D.
toxochila GARDNER and D. doratochila
GARDNER, whereas such Uppermost
Cretaceous species from North America
as Drepanochilus evansi COSSMANN, D.
scotti SOHL and D. nebrascensis (EVANS

43

and SHUMARD) described by SOHL (1967)
possess different kind of sculptures.
D. minimus is one of the smallest
species of the genus and is easily distinguishable from other species by thesmaller size, smaller number of whorls
and simple outer lip spike. It resembles
Drepanochilus muleti (D'ORBIGNY, 1850)
sensu DE LORIOL (1882, pI. 4, figs. 1-3)[=Drepanocheilus sp. in KOLLMANN, 1978,
p, 184J from the Gault of Cosne inFrance, but differs decidedly in thesmaller shell size, short and simple outer
lip spike, shorter anterior siphonal canal,
more numerous axial ribs on the spire
whorls and smaller number of whorls.
Compared with D. calcaratus (SOWERBY,1823) (GARDNER, 1875; KOLLMANN, 1978)
from the Gault of England and theUpper Albian of Austria, the present
species is smaller and has larger apicalangle, only one spiral keel on the bodywhorl, short and simple outer lip spikeand less prominent axial ribs on the spire
whorls.
Order Cephalaspidea FISCHER, 1883
Family Ringiculidae MEEK, 1863
Genus Avellana D'ORBIGNY, 1842
Avellana sp.
Plate 5, Figs. 11, 12

Two incomplete specimens are available
for this study. One specimen (NSM-PM
15106; 4.3 mm high, 3.8+mm wide) well
exhibits the surface ornamentation andtwo folds on columellar lip, but it lacks
the outer lip and parietal region. The
other specimen (NSM-PM 15107; 4.2 mm
high, 4.3 mm wide), on the other hand,
has poorly preserved outer lip and parietal
region. The shell is small for this groupand has height nearly equal to width.

44

Itar1,~ HAYAMI and

The volution is two and a half including
the protoconch. The surface ornamentation consists of 23 spiral rows of punctat ion on the body whorl. The outer lip
is reinforced, much thickened by callus
and denticulated internally. The parietal
area is much thickened by callus andhas an obtuse denticle. The columellar
lip has two simple folds.
The outer and inner lip characteristics
suggest that these specimens can probably be assigned to the genus Avellana,
but the fragmentary material preventsme from their comparison with hitherto
known species of this genus.

Concluding remarks
The sandstone block, which happened
to be dredged from the sea bottom off
the east coast of north Kitakami mountains, seems' to be significant for theconsideration of geologic history as wellas palaeobiogeography, because it contains a number of characteristic molluscan
fossils. Of the fourteen molluscs described here, six species are actuallycommon with and three species arecomparable with the fauna of the Mikasa
Formation (formerly called "Trigonia
Sandstone") of the Middle Yezo Group in
central Hokkaido. On the other hand,
there is no common species with themolluscan fauna of the Miyako Groupdescribed by NAGAO (1934), HAY AMI(1965a, b, 1966) and others.
According to up-to-date biostratigraphic
scheme (e. g. MATSUMOTO, 1977), Inoceramus (Birostrina) concentricus nipponicus can be treated as a zone fossil
indicating the upper part of Lower
Cenomanian (K4a z). Pterotrigonia (Pterotrigonia) brevicula and Thetis japonica
also seems to be important, because theirknown occurrences are restricted to the
Mantelliceras japonicum Zone- Eucalyco-

Tomoki KASE

ceras pentagonum Zone, which corresponds
to the lower part of the Mikasa Formation.
Along the classical standard
section of the Ikushumbets valley (easternwing) of central Hokkaido, such amolluscan assemblage is found in thelower part, especially IIb Member by
MATSUMOTO (1959) and OKADA (1965), of
this formation. Goshoraia crenulata isa characteristic venerid species originally described from the Goshonoura
Group (later also from the Mifune Group)of central Kyushu, but, as noted by
MATSUMOTO (1938, 1954) and also confirmed by us, it also occurs commonly inthe lower part of the Mikasa Formationin the Ikushumbets area. judging fromthe assemblage of these fossils, a Cenomanian age as well as some shallow
marine sedimentary environment is conclusive for this sandstone block.
Petrographically, the present sandstone
may be called calcareous lithic arenite.
It actually looks similar to some calcitecemented sandstone of the Mikasa Formation, which was studied in detail by
OKADA (1965). Subangular quartz andsubrounded chert grains of various colours
are characteristically abundant, and feldspars and other rock fragments are notrare. These grains are well sorted andalmost entirely cemented with sparrycalcite (more than 40 percent in weight)
instead of clay matrix. The present
sandstone block is more calcareous thanmost examples of the Mikasa Sandstonetreated by OKADA (1965, Table 2), but it
is highly probable that the present blockis as a whole a large concretion in a lesscalcareous sandstone, since such a fossiliferous part is often nodular in the Mikasa
Formation.
In the Kitakami mountains Miyakoan(Aptian-Albian) and Urakawan (ConiacianSantonian) marine deposits are represented
by the Miyako Group and the Kuji Group,727.

Ceno?nanian Molluscs off' the coast of J(~~J'i

A

45

B

T ex t-fig . 4 . Thin section of the sa ndston e block: calcite-cemented fine-gra ined lithic arenit ew ith abundant chert gra in s , x 25. A : und e r open nicol, B: und er crossed nicol.

respecti vely, whereas Gyliakian (Cenomanian-Turonian ) sediments ha ve notbeen found . The strata of the twogroups, which are separate ly distributed
along the coasta l reg ion of the mountains,abut against the basement complex on
the west and t ilt gently to the east
w ithout any strong fo lding. Since the
Gyl iakian is generall y regarded as a
reg ressive stage in this region, the distribution of mari ne sediments of this stage,
if present, may be well ant icipated off
the coast of the mountains. The present
discover y seems to substantiate thisexpectation.
The submarine geology off the coast ofnorthern Kitakami mountains was recent ly

in vesti ga ted by the staff of the Geological
Survey of Japan. According to the submarine geologic map published by the
Geo logica l Survey of Japan (T AMA KI,
1975), which was made main ly on thebasis of the resu lts of seismic reflection
profi ling sur vey, Cretaceous and Paleogene
sedimentary rocks are distri buted on theupper (western ) part of t he continental
she lf in this sea area. Some samples offine-grained sandstone dredged from t hesea bottom (39°50.2'N, 141°07.4'- OS.1 'E,
depth 134-137 m) off the coast of Omotowere pa lynologica ll y correlated to theKu ji Group. On the other hand, thelower part of the shelf and the continenta l slope aresaid to be covered by

46

Itaru HAY AMi and Tomoki KASE

Neogene and Quaternary sediments.
Since the locality of the present block issituated in the distributed area of theseyounger sediments, our conclusion is apparently inconsistent with the seismic
result. We are, however, putting belief
in the fishermen's information about the
locality, which is supported by theoperational record of the fishing boat,
although it is, of course, by no means
scientifically accurate. Judging from theoutline and lithology of the block, we
presume that it is actually a nodular
mass which was washed out from themother rock on the sea floor.
In the meridional backbone range of
Hokkaido, the sandstones of the Mikasa
Formation merge eastwards into muddy
sediments (MATSUMOTO and OKADA, 1973;
etc.) and have been regarded as representing the western marginal facies, at the
Gyliakian times, of a large sedimentarybasin called "Yezo Geosyncline". Althoughmuch should be done about the submarine
geology off the Kitakami mountains, thepresent find of Mikasa-type sandstone
seems to suggest that the marginal faciesof this basin extended southwards at thattime for more than 250 km from thepresent southern coast of Hokkaido.
Acknowledgments. - We are deeply
grateful to Mr. Kozo SASAKI and Mr.
Fukuji SASAKI, a fisherman and his
relative of Miyako City, for the privilegeof describing their collection which was
generously donated to the National
Science Museum, Tokyo. We also express
our sincere thanks to Professor Emeritus
Tatsuro MATSUMOTO of the Kyushu
University and Professor Minoru TAMURAof the Kumamoto University for theirkind advice about the identification ofsome molluscan species.

References
AMANO, M. (1956): Some Upper Cretaceous
fossils from southwestern japan (Part 1).
Kumamoto Jour. Sci., ser. B, sec. 1, vol.
1, no. 1, p. 63-86, pis. 1, 2.
GARDNER, j. S. (1875): On the Gault Aporrhaidae. Geol. Mag., ser. 2, vol. 2, p. 4956, 124-130, 198-203, 291-298,392-400, pis.
3, 5-7, 12.
HANZAWA, S., ASANO, K. and TAKAI, F.
(1961): Catalogue of Type-specimens ofFossils in Japan. Palaeont. Soc. japan,
25th Anniv. Vol. 422p.
HAY AMI, I. (1965a): Lower Cretaceous marine
pelecypods of japan. Part 1. Mem. Fac.
Sci. Kyushu Univ., ser. D, vol. 15, no. 2,
p. 221-349, pis. 27-52.
- - (1965b): Lower Cretaceous marine pelecypods of japan. Part II. Mem. Fac. Sci.
Kyushu Univ., ser. D, vol. 17, no. 2, p.
73-150, pis. 7-21.
- - (1966): Lower Cretaceous marine pelecyds of japan. Part III. Mem. Fac. Sci.
Kyushu Univ., ser. D, vol. 17, no. 3, p.
151-249, pis. 22-26.
- - (1975): A systematic survey of the
Mesozoic Bivalvia from japan. Bull. Univ.
Mus. Univ. Tokyo, no. 10, p. 1-249 (10pis. incl.).
- - and KASE, T. (1977): A systematic survey of the Paleozoic and Mesozoic Gastropoda and Paleozoic Bivalvia from japan.
Bull. Univ. Mus. Univ. Tokyo, no. 13, p.
1-155 (11 pis. incl.).
icHIKAWA, T. and HAYAl\II, 1. (1978): Catalogue of type and illustrated specimens in
the Department of Historical Geology andPalaeontology of the University Museum,
University of Tokyo. Part 1. Paleozoic andMesozoic fossils. Univ. Mus. Univ. Tokyo,
Material Reports, no. 2, p. 1-396.
IWASAKI, Y. (1963): Pseudamiantis, a pelecypod genus. Trans. Proc. Palaeont. Soc.
Japan, n. s., no. 51, p. 91-101, pis. 14, 15.
JIMBO, K. (1894): Beitrage zur Kenntnis derFauna der Kreideformation von Hokkaido.
Paliiont. Abhandl., N. F., Bd. 2, Ht. 3, p.
149-194, pis. 17-25.
KAUFFMAN, E. G. (1977): Systematic, bio-

727. Cenomanian Molluscs off the coast of Kuji
stratigraphic, and biogeographic relationships between Middle Cretaceous Euramerican and north Pacific Inoceramidae. In
MATSUMOTO, T. (ed.): Mid-Cretaceous
events-Hokkaido Symposium, 1976. Palaeont. Soc. japan, Spec. Papers, no. 21, p.
169-212.
KOBAYASl-ll, T. (1954): Studies on the jurassic trigonians in japan. Part 1. Preliminary
notes. japan. jour. Ceol. Ceogr., vol. 25,
nos. 1-2, p. 61-80.
- - and NAKANO, M. (1957): On the Pterotrigoniinae. japan. jour. Ceol. Ceogr.,
vol. 28, no. 4, p. 219-238, pIs. 16, 17.
KOLLMANN, H. A. (1978): Gastropoden aus
den Losensteiner Schichten der Umgedungvon Losenstein (Oberosterreich). 2 Teil:
Naticidae, Colombellinidae, Aporrhaidae,
Ceritellidae, Epitoniidae (Mesogastropoda).
Ann. Naturhistor. Mus. Wien, vol. 81, p.
173-201, pIs. 1-5.
LORIOL, P. DE (1882): Etudes sur la faunades couches du Gault de Cosne (Nievre).
Mem. Soc. Pateont. Suisse, tom. 9, p. 1118, pIs. 1-13.
MATUMOTO [MATSUMOTOJ, T. (1938): Preliminary notes on some of the more im·portant fossils among the Gosyonoura
fauna. jour. Ceol. Soc. japan, vol. 45, no.
532, p. 13-26, pIs. 1, 2.
MATSUMOTO, T. (1954): The Cretaceous System in the japanese Islands. japan. Soc.
Prom. Sci. Res., Tokyo, 324p., 20pls. [for1953J
- - (1959): Zonation of the Upper Cretaceousin japan. Mem. Fac. Sci. Kyushu Univ.,
ser. D, vol. 9, no. 2, p. 55-93, pIs. 6-11.
- - (1963): Part X. K. jIMBO: Beitrage zur
Kenntnis der Fauna der Kreideformation
von Hokkaido. In MATSUMOTO, T. (ed.) :A Survey of Fossils from japan Illustrated
in Classical Monographs. Palaeont. Soc.
japan, 25th Anniv. Vol., p. 41-48, pIs. 6068.
- - (1977): Zonal correlation of the Upper
Cretaceous in japan. In MATSUMOTO, T.
(ed.): Mid-Cretaceous events-Hokkaido
Symposium, 1976. Palaeont. Soc. japan,
SPec. Papers, no. 21, p. 63-74.
- - , HAYAMI, I. and ASANO, K. (1963): Part

47

VII. M. YOKOYAMA: Versteinerungen aus
der japanischen Kreide. In MATSUMOTO,
T. (ed.): A Survey of Fossils from japan
Illustrated in Classical Monographs. Palaeont. Soc. japan, 25th Anniv. Vol., p. 2732, pIs. 44-51.
- - and OKADA, H. (1973): Saku Formationof the Yezo geosyncline. Sci. Repts. Dept.
Ceol. Kyushu Univ., vol. 11, no. 2, p. 275309. [in japanese with English abstractJ
NAGAO, T. (1930): On some Cretaceous fossils from the islands of Amakusa, Kyushu,
japan. jour. Fac. Sci. Hokkaido Imp.
Univ., ser. 4, vol. 1, no. 1, p. 1-25, pIs.
1-3.
- - (1932): Some Cretaceous Mollusca fromjapanese Saghalin and Hokkaido (Lamellibranchiata and Gastropoda). jour. Fac.
Sci. Hokkaido Imp. Univ., ser. 4, vol. 2,
no. 1, p. 23-50, pIs. 5-8.
- - (1934): Cretaceous Mollusca from the
Miyako district, Honshu, japan. jour. Fac.
Sci. Hokkaido Imp. Univ., sel". 4, vol. 2,
no. 3, p. 177-277, pIs. 23-39.
- - (1938): Some molluscan fossils from theCretaceous deposits of Hokkaido and japanese Saghalien. Part 1. Lamellibranchia
and Scaphopoda. jour. Fac. Sci. Hokkaido
Imp. Univ., ser. 4, vol. 4, nos. 1-2, p.
117-142, pIs. 14-16.
- - (1939): Some molluscan fossils from theCretaceous deposits of Hokkaido and japanese Saghalien. Part 2. Gastropoda. jour.
Fac. Sci. Hokkaido Imp. Univ., ser. 4,
vol. 4, nos. 3-4, p. 213-239, pIs. 20-22.
- - and MATUMOTO [MATSUMOTOJ, T.
(1939): A monograph of the Cretaceous
Inoceramus of japan. Part 1. jour. Fac.
Sci. Hokkaido Imp. Univ., ser. 4, vol. 4,
nos. 3-4, p. 241-299, pIs. 23-34.
NAKANO, M. and NUMANO, K. (1961): On
some Gyliakian Pterotrigoniae from Kyushu
and Hokkaido. Trans. PI'OC. Palaeont. Soc.
japan, n. s., no. 43, p. 89-98, pI. 13.
NODA, M. (1971): The Cretaceous Inoceramus
from the Onogawa Group and the Tano
Formation, central Kyushu. Kagaku-Oita,
no. 24, p. 24-34, pIs. 1-3. [in japaneseJ- - and MATSU:VIOTO, T. (1976): Mesozoic
molluscan fossils of japan 4 (Cretaceous

48

Itaru HAY AMI and Tomoki KASE

Inoceramus 1). Atlas of japanese Fossils,
no. 45-265, pI. Cr-31. Tsukiji Shokan
Pub I. Co., Tokyo. [in japanese]
OKADA, H. (1965): Sedimentology of the Cretaceous Mikasa Formation. Mem. Fac. Sci.
Kyushu Univ., ser. D, vol. 16, no. 1, p.
81-111, pis. 19-24.
SOHL, N. F. (1967): Upper Cretaceous gastropods from the Pierre shale at Red 8ird,
Wyoming. U.S. Geol. Surv., Prof. Paper,
393-8, p. 81-846, pis. 1-11.
SPEDEK, 1. G. (1967): Revision of Syncyclonema(Upper Cretaceous) and comparison withother small pectinid bivalves and Entolium.
Peabody Mus. Nat. Hist., Yale Univ.,
Postilla, no. 110, p. 1-36, pis. 1-7.
T AMAKI, K. (1978): Geological map off Hachinohe (with explanatory notes). Geol.
Surv. japan, Marine Geology Map Series,
10, p. 1-22, 4 maps.

TAMURA, M. (1975): On the bivalvian faunas
from the Gyliakian of japan. Mem. Fac.
Educ. Kumamoto Univ., no. 24, sec. 1, p.
59-62, pI. 3, [in japanese with English
abstract]- - (1976): Mesozoic molluscan fossils ofjapan 3 (Late Cretaceous trigonid bivalves).
Atlas of japanese Fossils, no. 44-264, pI.
Cr-30. Tsukiji Shokan Publ. Co. Tokyo.
[in japanese]- - (1977): Cenomanian bivalves from the
Mifune Group, japan. Part 2. Mem. Fac.
Educ. Kumamoto Univ., no. 26, sec. 1, p.
107-144, pis. 1-13.
- - and MATSUMURA, M. (1974): On theage of the Mifune Group, central Kyushu
Japan. Mem. Fac. Educ. Kumamoto Univ.,
no. 23, sec. 1, p. 47-55, pI. 1.
- - and PACKARD, E. L. (1972): The genotype species of Anthonya GABB. Mem.

Explanation of Plate 4
Figs. 1, 2. Glycymeris (Glycymerita) sp. aff. G. (G.) hokkaidoensis (YABE and NAGAO) .... p. 31
1. Left valve (NSM-PM 15097) x2.
2. Left valve (NSM-PM 15098) x 1.2.
Figs. 3-6. Inoceramus (Birostrina) sp. cf. I. (B.) concentricus nipponicus NAGAO
and MATSUMOTO .................................................................... p. 32
3. Left valve (NSM-PM 15074) x2.
4. Right internal mould (NSM-PM 15073) x 2.
5. Right internal mould (NSM-PM 15071) x 1.2.
6. Right internal mould (NSM-PM 15072) x 1.2.
Fig. 7. Entolium sp. cf. E. obovatum (STOLICZKA) ........................................ p. 34
7. Right internal mould (NSM-PM 15075) x 1.2.
Figs. 8-14. Pterotrigonia (Pterotrigonia) brevicula (YEHARA) ............................ p. 34
8. Left valve (NSM-PM 15086) x2. 8a: left side view, 8b: upper view.
9. Immature right valve (NSM-PM 15080) x 1.2.
10. Immature left internal mould (NSM-PM 15084) x 1.2.
11. Right valve (NSM-PM 15078) x 1.2.
12. Right valve (NSM-PM 15077) x 1.2.
13. Right valve (NSM-PM 15083) x 1.2.
14. Right internal mould (NSM-PM 15079) x 1.2.
Fig. 15. Pterotrigonia (Acanthotrigonia) sp. cf. P. (A.) longiloba (lIMBO) ................ p. 36
15. Left internal mould (NSM-PM 15088) x 1.2.
Fig. 16. Pterotrigonia (Acanthotrigonia) sp ............................................... p. 37
16. Right valve (NSM-PM 15087) x 2. 16a: internal mould, 16b: silicone rubber castfrom external mould.
Fig. 17. Anthonya sp. cf' A. apicalis NAGAO ............................................ p. 38
17. Silicone rubber cast from right external mould (NSM-PM 15069) x 1.2.

HAY AM I and J(ASE:

Ceno1nanian molluscs

Plate 4

727. Cenomanian Molluscs off the coast of Kuji
Fac. Educ. Kumamoto Univ., no. 20, sec.
1, p. 22-30, pI. 1.
- - and TASHIRO, M. (1967): Cretaceous trio
goniids from the Mifune Group. Mem.
Fac. Educ. Kumamoto Univ., no. 15, sec.
1, p. 13-22, pI. 1.
- - and - - (1976): Mesozoic molluscan fos·sils of japan 2 (Late Cretaceous bivaives
from Kyushu and Hokkaido). Atlas ofJapanese Fossils, no. 43-257, 258, pis. Cr23, 24. Tsukiji Shokan Publ. Co., Tokyo.
[in japanese]
TASI-IIRO, M. (1971): Upper Cretaceous giycy.
merids in japan. Trans. Proc. Palaeont.
Soc. Japan, n. S., no. 84, p. 225-242, pis.
27, 28.
WOODS, H. (1911): A Monograph of the Cre.
taceous Lamellibranchia of England. Vol.
2, Part 7. Inoceramus. p. 261-284, pis. 4550. Paiaeontogr. Soc. London.

49

YABE, H. (1927): Cretaceous stratigraphy of
the japanese isiands. Sci. Rep. Tohoku
Imp. Univ., ser. 2, vol. 11, no. 1, p. 27100, pis. 3-9.
- - and NAGAO, T. (1928): Cretaceous fossils
from Hokkaido: Annelida, Gastropoda andLamellibranchiata. Sci. Rep. Tohoku Imp.
Univ., ser. 2, vol. 9, no. 3, p. 77-96, pis.
16, 17.
YEI-IARA, S. (1915): The Cretaceous trigoniae
from Miyako and Hokkaido. Sci. Rep. To·
hoku Imp. Univ., ser. 2, vol. 2, no. 2, p.
35-44, pis. 1, 2.
- - (1923): Cretaceous trigoniae from south·
west japan. Japan. Jour. Ceol. Ceogr., vol.
2, no. 3, p. 59-84, pis. 8-13.
YOKOYAMA, M. (1890): Versteinerungen aus
der japanischen Kreide. Palaeontographica,
Bd. 36, p. 159-202, pis. 18-25.

Abeshinai 7 ~ '/'71, Bibai ~1]l',I. Enokuchi iTQ) 1=1. Goshonoura (Gosyonoura, Goshora) f,l1Jr9f
fIlj, Hakkinzawa B~tR, Ikushumbets ~~5JJj, Kobunenosako 'HltQ)~, Kuji ~~, Kurosaki~~, Mifune f,l1J~·a. Mikasa =.32:. Miyako 'Elti, Omoto IJ'*,;f-:/
p 71 ~ '7, Poronai ~P'.I, Sorachi ~9;D. Yubari :&iJft*

Oyubari *:&~~, Ponhorokabetsu~~nl¥,"Q)#aJ!EiJ' 1?l*1& ~nt.:1iP!5*Q)~ / ~ =- 7 :/iliI\f*!lJiJ~f~:fi: !5=F~~~nHyJ:nQ)"~~r$*9 30 km, i*It*9 400 m" Q)#aJ!EiJ'I?i«\~:1lft;:: J: '0 -C~~tf~nt,:-E;-f~:fi1iP!5!lf!.~~~t
L..t.:~t~, Inoceramus (Birostrina) sp. d. I. (B.) concentricus nipponicus, Pterotrigonia (Pterotrigonia) brevicula, Thetis japonica, Coshoraia crenulata. Margarites?
funiculatus, Drepanochilus minimus sp. nov. ~-E;-tr 11 fil!Q)=l':\cJ'J. • 3 :fjQ)JUUE~~~~

L-t.:Q)'"C"~ttt Go ;: Q)fil!Wi.Ql(Ji~t#aJR*if"!Ib$Q)*$.:<:. '/JffHWQ)='32:~ (=.~J'J.1iP!5) r$t;::
9;Dl?nGiliI\f*lIltJtJfft;::/MiW L.., ~ / ~ =- 7 :/Q)lIifftc~Wi1:Q):It~:rJlt!fliJ'%i <~~~nG. ~t
J: l1I:tt1!'"C" Ii.. 'Eltit!!: (7 -j' 77 :/-7 Iv 'C 7:/) c i'mfoIt!!: (::2 =- 7 '/'7 :/--1}-:/ J-. =- 7:/) Q)
WJil(;:ltfl~Ii.~n.:fn'EltiM7ffc~~~ff'"C"ft~~nGiJ'. *r,,'Q)=¥ P 7-!lt!!: (~/ ~ =- 7:/-7,,- - p =- 7:/) Q)#aJil(;~Ii.9;D I?n -C~ ,t"'-~'o 4-@IQ)JeJ!Ii.. ;: Q)lIifftt;::#aW~iJ,~u:l1I:ttI!iJ' I?*:nt;::}g~,·n't.:;: c ~TI:WEi" Gee 'h t;::. ".:<:. '/:ttI!(ti]f4" Q)~~miJ,m,:(:EQ)~tWJRm
WiJ'l? 250 km J;AJ: 'h m:nt;:: ~ '"C"7r1fl L.. -C~ ,t.:;: C ~~~i" G 'h Q)"('~ Go
1!7.IC f!. ;/JDrJi~tf

50

Itaru HAY AMI and Tomoki KASE

Explanation of Plate 5
Fig. 1. Cymbophora sp ................................................................... p. 39
1. Right valve (NSM-PM 15070) x2.
Figs. 2-4. Thetis japonica (YABE and NAGAO) ............................................ p. 37
2. Right internal mould (NSM-PM 15090) x 1.2.
3. Silicone rubber cast from right external mould (NSM-PM 15089) x 1.2.
4. Right valve (NSM-PM 15091) x 1.2.
Figs. 5-8. Goshoraia crenulata (MATSUMOTO) ............................................ p. 39
5. Right valve (NSM-PM 15092) x 1.2. 5a: internal mould, 5b: silicone rubber castfrom external mould.
6. Left internal mould (NSM-PM 15096) x 1.2.
7. Silicone rubber cast from right external mould (NSM-PM 15093) x 1.2.
8. Silicone rubber cast from right external mould (NSM-PM 15094) x 1.2.
Fig. 9. Goniomya (Goniomya) sp ......................................................... p. 41
9. Silicone rubber cast from fragmentary right external mould (NSM-PM 15076) x 2.
Fig. 10. Margarites? funiculatus (yOKOyAMA) ............................................ p. 41
lOa-c. Back, apical and basal views of an immature specimen (NSM-PM 15099) x 5.
Figs. 11, 12. Avellana sp ................................................................. p. 43
lla, b. Back and front views of a specimen (NSM-PM 15106) x 5.
12a, b. Back and front views of a specimen (NSM-PM 15107) x 5.
Figs. 13-17. Drepanochilus minimus KASE, sp. nov ....................................... p. 42
13. Silicone rubber cast from external mould, back view of a para type (NSM-PM
15101) x5.
14. Back view of a paratype (NSM-PM 15102) x 5.
15. Back view of a paratype (NSM-PM 15103) x5.
16. Back view of the holotype (NSM-PM 15100) x 5.
17. Back view of two paratypes; left (NSM-PM 15104), right (NSM-PM 15105) x 5.

HAY AMI and KASE:

Cenomanian molluscs

Plate 5

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 121, pp. 51-73, pis. 6-8, April 30, 1981

728. SOME CONIACIAN AMMONITES FROM HOKKAIDO*(STUDIES OF THE CRETACEOUS AMMONITES FROM HOKKAIDO**-XL)
T ATSURO MATSUMOTO
c/o Department of Geology, Kyushu University, Fukuoka 812

KIKUWO MURAMOTO
Mikasa Museum, Mikasa 068-22

HIROMICHI HIRANO
Department of Geology, Waseda University, Tokyo 160

and
TAKEMITAKAHASHI
28-109, Yayoi, Mikasa 068-22

Abstract. In this paper four species of Coniacian ammonites are described tosupplement previously published monographs (MATSUMOTO, 1965-1971). They are
two new species of Peroniceras, which are allied to P. stefaninii VENZO and P.
besairiei VAN HOEPEN respectively, Sornayceras ct. proteus MATSUMOTO, which isbased on a large specimen, and Barroisiceras onilahyense BASSE. The localities andstratigraphic positions of the described specimens are explained at length.
As an appendix, remarks are given by one of us (T. M.) on the Coniacian biostratigraphy in western Europe and other selected regions and also on the zonationand correlation of the Coniacian equivalent in Japan.

on the Cretaceous Stratigraphy (Chairman
Professor Tove BIRKELUND), one of us(T. M.) has been studying ammonites fromthe Japanese province to compare themwith those from northwest Europe andother well studied regions. For the purpose of inter-regional correlation, ammonites of the Collignoniceratidae are themost useful.
One of us has already published amonograph of that family in series (MATSUMOTO, 1965a, b, 1969, 1970a, 1971).

Introduction
To cooperate with the Coniacian to
Maastrichtian Working Group (Leader Dr.
F. SCHMID) of the lUGS Subcommission* Received Sept. 14, 1980; read Jan. 26,
1980 at Tsukuba Univ. (Part I) ; June 30, 1980
at Kochi Univ. (Part II) ; April 2, 1980 at Shimane Univ. (Appendix).
** Numbering follows that of the title"Studies of the Cretaceous ammonites from
Hokkaido & Saghalien".
51

Tatsuro MATSUMOTO et al.

52

Recently some additional ammonites havebeen obtained by several persons who
have worked in cooperation with T. M.
One of them, a Santonian species of
Texanitinae, has been described by MATSUMOTO and HARAGUCHI (1978), in the
appendix of which the problem of Santonian zonation has been discussed. In thispaper some Coniacian ammonites aredescribed by coauthorship of relevant
persons in two parts and the problem ofConiacian zonation is discussed by oneof us (T. M.) as an appendix.
Acknowledgements :-Before going further, we thank Mr. Hisayoshi TANIGUCHI
and Mr. Fumio SUZUKI, who have kindly
provided fine specimens for our study,
and also Drs. Kazushige TANABE and
Masayuki NODA, who have friendly helped
us. Thanks are extended to Drs. H.
SUMMESBERGER (Vienna), E. SEIBERTZ, S.
KELLER (both Hannover), J. WIEDMANN(Tiibingen) and W. J. KENNEDY (Oxford)
for their kind replies to the inquiries
from one of us (T. M.). Miss Kazuko HARA
has assisted us in preparing the typescript.
This is a contribution to the "International Correlation of the Cretaceous
System" which has been supported by the
Science Research Fund (No. 334043) of
the Ministry of Education, Science andCulture [MonbushoJ.

one of us (MATSUMOTO, 1965b), in which
ten species were described. Among thesubsequent collections there are threelarge interesting specimens. We describe
them below. Although one of us (T. M.)
is mainly responsible for the palaeontological description, coauthorship is taken
because the other of us (K. M.) is responsible for collecting and cleaning thespecimens.
Family Collignoniceratidae WRIGHT, 1952
Subfamily Peroniceratinae HYATT, 1900
Remar/?s :-Pending the issue of thepaper by KENNEDY and KLINGER (1975)
on the Peroniceratinae from South Africa,
we would not discuss too much on therelationships between the genera andsubgenera proposed or redefined by VAN
HOE PEN (1965) with those of MATSUMOTO(1965b).
Genus Peroniceras DE GROSSOUVRE, 1894
Type species :-Peroniceras moureti DE
GROSSOUVRE, 1894 (original designation).
Remarks:-The two species to be described below are certainly referred toPeroniceras.
Peroniceras latum sp. nov.
PI. 6, Fig. 1; PI. 7, Fig. 1; Text-fig. 1

Palaeontogical Description
Part I
Additional Ammonites of thePeroniceratinae from Hokkaido
T. MATSUMOTO and K. MURAMOTO
The ammonites belonging to the subfamily Peroniceratinae from the Cretaceous of Hokkaido were monographed byMaterial :-Holotype, "HCS. 73", obtained from loco Ik 1540, main stream of the
Ikushumbets, by H. TANIGUCHI and K.
MURAMOTO in July 1965.
Description :-The shell is very large
in the adult stage, somewhat over 300 mm
in diameter. It is much evolute, consisting of slowly enlarging polygyral whorls
with little overlap. The diameter of theumbilicus is about 63 per ct. of that of

53728. Coniacian Ammonites from Hokkaido
the entire shell. The. body-chamber isvery long, occupying somewhat more than
one full volution, although the very apertural margin is not preserved.
The whorl is nearly as high as broadin the intercostal section; thickest at
some distance from the abruptly roundedumbilical shoulder in its lower part (accordingly between the umbilical tubercles
in the costal section); the umbilical wall
is low but nearly vertical. The venter isbroadly arched and weakly to moderately
tricarinate; the ventrolateral shoulders
are sloping on the intercostal parts, but
subangular along the costae.
The ribs are moderately broad. fairly

distant, but numerous, numbering 28 on
the outer whorl and 24 on the next inner
one and about 20 on the still inner one.
They are mostly simple on the outer two
whorls but occasionally bifurcate on the
inner ones. They are nearly rectiradiateon the septate whorls and slightly prorsiradiate or gently flexuous on the bodywhorl. Each of them has a bullate tubercle around the umbilical margin and arather clavate one at the ventrolateralshoulder; the former is highest slightly
above the umbilical shoulder; the latteris typically clavate on the inner whorls
but obliquely rounded and thickened on
the body-whorl.

-----

\
\

------Text.fig. 1.

J

Peroniceras latum sp. nov. Diagrammatic sketch of the holotype.
Lateral view and whorl·section at Q.
Bar: 30 mm.
(T. M. delin.)\Tatsuro MATSUMOTO et al.

54

Measurements (in mm) of Peroniceras latum:Specimen

DiameterUmbilicus

Height

HCS. 73
323.0(1)206.0(.64)
For comparison: P. stefaninii
VENZO'S
240.0(1)134.0(.56)

B/H

B'/H

62.0(.19)

Breadth Breadth[B'](costal) (intercostal)
70.0(.22)
62.0(.19)

1.1

1.0

62.0(.26)

60.0(.25)

0.97

0.8

The suture follows the general patternof Peroniceras suture (as explained by
MATSUMOTO, 1965b, p.212), but the stemof its lateral lobe (L) has some breadthand is not so extremely narrowed as in
Peroniceras aff. platicostatum VAN HOEPEN(see MATSUMOTO, 1965b, pI. 36, fig. 1;
text-fig. 2), or in P. westphalicum var.
australis VENZO (1936, pI. 11, fig. 8).
Compa rison and discussion:-This specimen . resembles the holotype of Peroniceras stephaninii VENZO (1936, p. 102, pI.
9, fig. 8; pI. 10, fig. 10; pI. 12, fig. 6),
from the Coniacian of Zulu land (South
Africa) in many respects. The latter is
240 mm in diameter, but the body-chamber
seems to be incompletely preserved. Should
its body-chamber completely preserved, itwould be 310 mm or so in diameter, thatis nearly the same size as the present
specimen.
The specimen from Hokkaido is likewise similar to the illustrated specimen
from the Coniacian of Armenia, which
was identified with Peroniceras haasi
YOUNG by ATABEKIAN and AKOPIN (1972,
p. 8, pI. 2, fig. 4a; pI. 3, fig. 1b). That
Armenian form has coarser, stronger andmore rounded ribs than P. haasi YOUNG(1963, p. 72, pI. 34, figs. 3, 4; pI. 35, figs.
1-3), from the Lower Coniacian of Texas,
and is closer to or possibly identical with
P. ste/aninii.
In the holotype of P. stephaninii, as in
the specimen from Armenia, the umbilicus
is about 55 per ct. of the shell diameterand the ribs number about 20-22 perwhorl. The specimen from Hokkaido has

50.0(.21)

much wider umbilicus, i. e. about 63 per
ct. of the shell diameter, more slowly
enlarging whorl and more numerous ribs,
numbering 28 on the outer whorl despite
their fairly wide intervals.
YOUNG (1963, p. 75) thought that P.
stephaninii would be placed in synonymy
with P. westphalicum of SCHLUTER (1867,
1872). As YOUNG himself mentioned, thefigured examples from Texas describedunder P. westphalicum closely resemble
the holotype of P. stephaninii.
Unless examining the original specimens (syntypes) of Ammonites westphalicus VON STROMBECK (1859, p. 56), and its
topotypes from the "Grauer Mergel"(Coniacian) of Westphalia (West Germany),
it seems me difficult to understand definitely this "famous" species. SCHLUTER'S
earlier paper (1867, p. 30, pI. 6, fig. 2) isalso ambiguous in that he did not illustrate the lateral view of his specimen.
He described, however, that the ribs
number 19 around the umbilicus and 24
at the ventrolateral part. STROMBECK
recognized "rarely and irregularly intercalated ribs in the late growth-stage" ofhis specimen. According to SCHLUTER'S
later paper (1872, p. 45, pI. 13, figs. 5, 6),Ammonites westphalicus has fairly frequently intercalated or bifurcated secondary ribs, with the result to have more
numerous ventrolateral tubercles thanthe umbilical ones (e. g. the former
counted 27 in contrast to 19 or 21 of thelatter). In this and other respects, oneof the illustrated specimens of DE GROSSOUVRE (1894, p. 98, pI. 12, fig. 4), from

728. Coniacian Ammonites from Hokkaido
the Coniacian of France, is a good example of P. westphalicum in the sense of
SCHLUTER, but the other (DE GROSSOUVRE,
1894, pi. 12, fig. 1) differs from "the type",
as GROSSOUVRE himself mentioned. We
hesitate to identify the latter to the same
species.
If the above discussion is warranted,
then it follows that "Peroniceras westphalicum" of YOUNG (1963, p. 74, pi. 28,
figs. 2-4; pi. 29, figs. 1, 2; text-fig. 15d),from Division A of the Austin Chalk(Texas), may not be the named species.
We suggest that YOUNG'S P. westphalicum
is probably P. stefaninii and that P. stefaninii and P. westphalicum are distinguishable.
Coming back to the specimen from
Hokkaido, we hesitate to decide conclusively whether the described differences
deserve specific or subspecific distinction
from P. stefaninii. If we consider theresemblance in essential points but for theextremely wide umbilicus and the consequent increase of rib numbers, the
Hokkaido specimen could possibly regarded
as representing a subspecies of P. stefaninii in the Japanese province. YOUNG(1963, p. 74), however, has shown thatthe umbilicus size ranges from 43 to 58
per ct. of the diameter in the Texas
specimens (of his P. westphalicum). Thisvariation is of large extent, but the
Hokkaido form (63 per ct.) distinctly exceeds that range. Therefore, at least for
the time being, we describe it as representing a new species.
Should the extent of variation in our
province be made clear on more specimens to overlap slightly with that of the
Texas or South African form, then the
new name latum might be ranked down
to subspecific. Be that as it may, itcannot be denied that there is a discrepancy in geological age (i. e. Late Coniacianof our species as compared with Early

55

Coniacian of Texas or South African
species) as well as the difference in geographical distribution.
Occurrence :-Loc. Ik 1540, dark grey
mudstone of the Upper Yezo Group exposed on the left bank of the main streamof the River Ikushumbets, about 100 m
downstream from the confluence with thetributary Samatazawa (Text-fig. 4). In
the same mudstone unit Inoceramus(Platyceramus) yubarensis NAGAO et MATSUMOTO occurs and this part is assigned
to the upper part of Lower Urakawan[K5a2], approximately Upper Coniacian.
Peroniceras yubarense sp. nov.
PI. 6, Fig. 2; PI. 7, Fig. 2; Text·fig. 2

Material :-Holotype, Yb5152 of K.
MURAMOTO'S Collection in a calcareous
nodule from the River Shiyubari.
Description :-The shell is 197 mm indiameter at the last septum. The bodychamber is only partly and poorly preserved and its actual length is unknown.
Should it be assumed to occupy two
thirds whorl, the entire shell diameter
would be about 350 mm, which can besaid very large. It is fairly evolute, consisting of moderately enlarging whorls
with a slight overlap. The umbilicus isabout 52 per ct. of the entire shell diameter.
The whorl is somewhat higher thanbroad in the intercostal section but
broader than high in the costal section,
being broadest between the umbilicaltubercles. The venter is tricarinate, withthe highest keel in the middle. It is
broadly arched in the intercostal section.
On the interspaces of the ribs the flanks
are nearly parallel and only gently convex,
with the maximum breadth at about the
middle of the flank. The umbilical shoulder
is abruptly rounded; the umbilical wall is

56

Tatsuro MATSUMOTO et al.

Text-fig. 2. Peroniceras yubarense sp.
nov. Diagrammatic sketch of the ho!otype.
Latera! view and whorl-section at Q.
Bar: 20 mm.
(T. M. delin.)

low but almost vertical.
Ribs are all simple, long and nearlyrectiradiate or sometimes slightly rursiradiate, so far as the observable parts areconcerned. They are broadly rounded
and distant on the outer whorl, numbering 8 in a half whorl of the last septate
stage; on the inner whorl of an earlier
stage, about 100 mm or so in diameter,
they are less distant, being separated by
the interspaces nearly as wide as or only
slightly broader than the ribs.
The umbilical tubercles are more orless bullate and highest at a point slightly

below the middle of the flank instead ofnear the umbilical shoulder. The ventrolateral tubercles are clavate at their baseand on the outer whorl moderately elevated and rounded.
The suture is of the Peroniceras pattern (see MATSUMOTO, 1965b, p. 212) (also
DE GROSSOUVRE, 1894, figs. 37-39). The
second lateral lobe [U2J is rather gently
oblique. In the late stage the branches(lobules) of the first lateral lobe (L) aredeep and much narrowed.
Comparison and discussion :-With respect to the shell-form and the strengthof the ornamentation, this specimen resembles one of the illustrated specimensof Peroniceras westphalicum of SCHLUTER(1872, pI. 13, fig. 6), but that specimen
has more frequently intercalated orbranched ribs, as has been mentioned in
the foregoing page.
Taking account of the predominant
simple ribs, without or with only occasional intercalation of the secondary ribs,
and the highest elevation of the umbilicaltubercles slightly below the middle ofthe flank, we consider that the present
specimen is closer to the holotype from
Zulu land (South Africa) and another example from Madagascar of Peroniceras
besairiei VAN HOEPEN (1965, p. 4, pI. 1;
text-fig. 1a) (COLLIGNON, 1965, p. 54, pI.
437-438, fig. 1803). These specimens fromSouth Africa and Madagascar differ fromthe Hokkaido specimen in their wider
umbilicus, slower rate of whorl-growthand more numerous ribs.
Again it might be possible to regard

Measurements (in mm) of Peroniceras yubarense:Diameter
Umbilicus
Yb 5152
197.0(1)102.0(.52)
For comparison: P. besairiei
HOEPEN'S
132(1)
73 (.55)COLLIGNON'S 220(1)135 (.61)

Height56.0(.28)
34
52

(.26)
(.24)

Breadth (c.)
58.0(.29)
37
55

(.28)
(.25)

B' (ic.)48(.24)

B/H
1. 05
1. 07
1. 05

B'/H
0.86

728. Coniacian Ammonites from Hokkaido
the present form as representing a subspecies of P. besairiei in the Japaneseprovince, if the extents of variation wereoverlapped between the forms from Japanand South Africa-Madagascar. So far as
the available material is concerned, thedistrict ion is so clear that we regard, atleast provisionally, the Hokkaido specimen
as representing a new species which is
closely allied to P. besairiei.
Incidentally, the ammonite from Madagascar, which was described under Peroniceras subtricarinatum (D'ORBIGNY) by
BESAIRIE (1930, p. 634, pI. 66, figs. 4-6),
was regarded as another example of P.
besairiei by VAN HOEPEN (1965). We arein favour of BESAIRIE, because it has
more frequently intercalated or branchedsecondary ribs and because its umbilicalnodes are highest at or near the umbilicalshoulder.
Occurrence :-The calcareous nodule
containing this ammonite was obtainedby one of us (K. M.) as one of the transported boulders on the gravel of the mainstream of the Shiyubari, at a point close
to loco YI02 of MATSUMOTO (1942, route
map of pI. 15). For a considerable distance upstream from this point along theriver, Coniacian strata consisting of theZone of Inoceramus uwajimensis and theZone of Inoceramus mihoensis are exposed
repeatedly on account of minor thrusts(see geological map and profile of MA TSUMOTO, 1942, pIs. 13, 14 and map of
MATSUMOTO and HARAGUCHI, 1978, fig.
1). Therefore this nodule is presumed
to have been derived from either of thesetwo zones. We should confirm the precise
stratigraphic position of this species
through further field work.
Genus Sornayceras MATSUMOTO, 1965
Type-species :-Sornayceras proteus MATSUMOTO, 1965 (original designation).

57

Remarks :-This genus was establishedwith a clear definition by MATSUMOTO(Nov. 20, 1965b, p. 226), as a relative of
Gauthiericeras and Peroniceras. Nomenclaturally, however, it may be synonymouswith one of the genera (or subgenera)
established independently by VAN HOEPEN(july, 1965). Further discussion about
this point will be given by KENNEDY and
KLI!'lGER. I use for the time being the-generic name Sornayceras until the issueof their forthcoming paper.
Sornayceras sp. d. S. proteus MATSUMOTO
PI. 7, Fig. 3; Text·fig. 3
1960. Sornayceras proteus MATSUMOTO, Mem.
Fac. Sci., Kyushu Univ., [D], vol. 16,
no. 3, p. 227, pI. 40, fig. 1; pI. 41, fig.
1; text·fig. 11, 12.

Material :-A large specimen of K.
MURAMOTO'S Collection, figured in thispaper, is concerned with the present description.
Description :-The specimen is somewhat deformed into an elliptical form
and its right side is dissolved into therock matrix. The measurements (in mm)
at about 90· behind the preserved end
are as follows in the deformed state:
DiameterUmbilicus
HeightBreadth (costal)B'. (interc.)

340 (1)170(.50)100(.29)ca. 58 x 2
ca. 50 x 2The shell is large, rather evolute andwidely umbilicate. The whorl is nearlyas high as broad in the intercostal section, but the proportion of B/H cannot
be accurately measured on account of
the half dissolved condition. It is broadest
in its lower part and its flank is gently
inflated. The venter is broad and low
roof-shaped. The keel at the middle ofthe venter is low and there is a smooth

58

Tatsuro MATSUMOTO et al.

Text-fig. 3. Sornayceras sp. cf. S. proteus MATSUMOTO, from loco Ik 1509,
diagrammatic sketch. Lateral view and whorl-section at Q.
Bar: 30 mm.
(T. M. delin.)zone on either side of it instead of agroove.
The radial ribs are distant, coarse,
mostly simple and provided with an umbilical and a ventrolateral rows of tubercles. They are nearly rectiradiate on themain part of the flank, but on the bodywhorl they show a backward curvaturearound the umbilical margin. The umbilical tubercles are bullate and on the bodychamber they are thickened and highest
at some distance from the umbilicalmargin. The ventrolateral tubercles arerounded to somewhat clavate and also
thickened on the body-chamber.
There are 9 ribs on the preserved partof the body-whorl, that is a half volution.
On the preceding septate whorl there are
24 ribs, of which only two are shorter
than others. Still inner whorls are notwell shown.
The l?uture is as complex as that ofS. proteus (MATSUMOTO, 1965b, text-fig.
12). The last suture is at about 280 mm
in diameter.
Comparison:- This specimen essentiallyresembles the holotype of So rnayceras
proteus MATSUMOTO (cited above), but ismuch larger and its ribs are mostly
simple, without intercalated shorter ribon the outer whorl. On the inner whorl
there are a few shorter ones. In theoriginal description (MATSUMOTO, 1965b),
another large fragmentary whorl was
described, on which no shorter rib isshown. It was called Sornayceras sp. d.
S. proteus. The present specimen isbetter preserved than that fragmentary
one and seems to show the change inthe mode of ribbing with growth. Unfortunately, its inner whorl as large as
the holotype, about 95 mm in diameter, is
not well preserved. Therefore we call it
for the time being Sornayceras sp. d. S.

59728. Coniacian Ammonites from Hokkaido
N

+
o

lkm
!

Iu

Im

Text-fig. 4. Route map of the River Ikushumbets around the localites of Peroniceras tatum (Ik-1540) and Sornayceras d. proteus (Ik-1509). Ik: main stream of
the Ikushumbets, In: Inari-zawa, K. L.: Katsura-zawa Lake, Sam: Samata-zawa. Ia:
Zone of Inoceramus amakusensis (lower Santonian), 1m: Zone of I. mihoensis, Iu:
Zone of I. uwajimensis, Im+Iu: Coniacian, . : mega-fossil locality, broken thickline: fault. Inset at the upper right corner is the index map of Hokkaido. (Geol.
Surv. by T. MATSU:vJOTO)

proteus MATSUMOTO.
Occurrence ;-Loc. Ik 1509, mudstone ina small stream running to the right sideof the main stream of the River Ikushumbets, immediately above the artificial lakeof the Katsura- zawa dam (see Text-fig.
4). In the mudstone and contained calcareous nodules there are Inoceramus d.
mihoensis MATSUMOTO and I. (Platyceramus) d. yubarensis NAGAO et MATSUMOTO. Therefore, the host bed is certainly
assignable to the Zone of I. mihoensis, asin the case of the holotype. It is upper
part of the Lower Urakawan [K5a2],
approximately Upper Coniacian.

Part IIA New Record of Barroisicems
from Hokkaido

T. MATSUMOTO, H. HIRANO
and T. TAKAHASHI
When one of us (MATSUMOTO, 1969)
mono graphed the Barroisiceratinae, no
example of Barroisiceras in a strict sense
was known from Hokkaido and only B.
(Basseoceras) inornatum MATSUMOTO wasdescribed. On the basis of recent acquisitions, we now can describe a species of60

Tatsuro MATSUMOTO et al.

B. (Barroisiceras) from our province.

Subfamily Barroisiceratinae BASSE, 1947
Genus Barroisiceras DE GROSSOUVRE, 1894
Type-species :-Ammonites haberfellneri
HAUER, 1866 (subsequent designation by
SOLGER, 1904).
Remarks :-Pending the issue of the revision of Ammonites haberfellneri HAUER
by KENNEDY and SUMMESBERGER now in
preparation, we temporarily follow MATSUMOTO (1969) for the generic diagnosis
and the subdivision into the subgenera,
Barroisiceras and Basseoceras COLLIGNON,
1965.
Barroisiceras (Barroisiceras)
onilahyense BASSE

Text-fig. 5. Barroisiceras onilahyense
BASSE. Diagrammatic sketch of GK. H5733.
Right side and frontal views and external
suture at S (on left side). Bar: 10 mm.
(T. M. delin.)

PI. 8, Figs. 1-3; Text·figs. 5, 6

1907. Schloenbachia (Barroisiceras) haberfellneri et var., BOULE, LEMOINE & THEVENIN, Ann. Paleont., vol. 2, p. 43-45, pI.
11, figs. 2-4.
1947. Barroisiceras onilahyense BASSE, Ann.
Paleont., vol. 33, p. 100-109, pIs. 1-5;
pI. 6, figs. 1-4; pI. 7, fig. 1, la; pI. 8,
figs. 1, 2; text-figs. 1-3.
1965. Barroisiceras onilahyense, COLLlG"'ON,
Atlas de Fossiles Caracteristi ques deMadagascar (Ammonites), fasc. 13, p.
68, pI. 444, figs. 1815-1817; p. 69, pI.
445, fig. 1819.

iVIaterial :-GK. H5733, obtained by H.
HIRANO, in a field-work with K. TANABE,
from loco R2638j, now kept at GeologicalType Collections of Kyushu University,
and T. TAKAHASHI'S Collection (TTC.
79-7-1) obtained by Fumio SUZUKI in afield-work with T. TAKAHASHI, from another exposure along the main course of
the River Obirashibe, Rumoi district,
Hokkaido.
Description :-The two specimens look

so dissimilar that the individual characters are described at first.
GK. H5733 (PI. 8, Fig. 2; Text-fig. 5)
has a tight involution (i. e., the growthratio of the umbilical radius to the spiralis very small), a narrow umbilicus, muchcompressed whorl, weak and gently flexuous and somewhat prorsiradiate ribs andweak umbilical bullae.
The whorl is broadest at a point slightly
outward from the umbilical margin andthe flanks are convergent toward theshouldered, roof shaped venter. The
ventral keel is serrated and provided
with narrow clavae which correspond to
the ribs. The long ribs start from low,slightly rursiradiate bullae, which number
7 or 8 per half whorl. At a short distance from the umbilical margin, the ribs
are curved forward and then gently
prorsiradiate on the main part of theflank, sometimes showing a gentle flexuosity. As a rule, the long ribs are alternated with shorter ribs on the outer partof the flank. The ribs are low and some-61728. Coniacian Ammonites from Hokkaido
what broad, being separated by narrowerinterspaces. At the ventrolateral shoulder
all the ribs have distinct, somewhat
clavate tubercles, from which they run
forward toward the ventral clavae, showing chevrons. The ventrolateral tubercles
are 13 or 14 per half whorl.
The suture, exposed on the part at
whorl-height of about 16 mm, has rather
massive saddles, irregularly subdivided
lobes and rather shallow minor incisions.
The specimen has the incompletely
preserved body-chamber and is only 56
mm in diameter. On the body-chamber
the ribs become broader and lower andthe umbilical bullae and ventrolateral
tubercles are much weakened. Lirae andstriae may be discernible on the surface.
They run in parallel with the ribs. Theyshow some irregularity at about the ocularsinus on the preserved last part of theleft side (PI. 8, Fig. 3). This is probably
an injury.
The other specimen (PI. 8, Fig. 1 ; Textfig. 6) is stouter in shell-form and ornamentation than GK. H5733. It is also
fairly involute and narrowly umbilicate,but U/D is 0.14-0.15 as compared with
0.12 of the latter. The umbilical wall isnearly vertical or somewhat overhanging.
The whorl is higher than broad, but
broader than in GK. H5733, showing B/H=0.77 as compared with 0.53 in the latter.
It is broadest a little outside the subrounded or abruptly rounded umbilicalshoulder and the flanks are convergent
toward the shouldered and keeled venter.
The ribs are moderately coarse andstrong. Strong umbilical tubercles are
only 3 or 4 per half whorl. Some of theribs arise from those umbilical tubercles
but others start from near the umbilicalmargin without tubercles or from a weakbulla. The ribs are normally bifurcatedat or near the umbilical margin andoccasionally still shorter ones are intercalated on the outer half.
The ribs are gently flexuous on theflank of the outer whorl and projected
forward on the venter, forming chevrons.
The ribs are gradually broadened outward. The clavate tubercles at theventrolateral shoulder and on the ventral
keel are moderately strong. They number
12-13 per half whorl.

:V,
\

}

",

,:

"

.:

...

,

Text-fig. 6. Barroisiceras onilahyense
BASSE. Diagrammatic sketch of TTC. 797-1. Lateral view and cross-section. Bar:
10 mm.
(T. M. delin.)This specimen also has the incompletely
preserved body-chamber. The ornament
tends to be somewhat weakened on thebody-chamber, if not so remarkably weakened as in GK. H5733. Lirae and striae
are in places discernible on the ribs andthe interspaces in parallel with the ribs.
Again, there is a slight injury at about
the last portion of the phragmocone on
the middle of the left flank. This is soon
recovered on the body-chamber.

62

Tatsuro MATSUMOTO et al.

Measurements (in mm) of Barroisiceras (Barroisiceras) onilahyense:(last)1/( -90°)
TTC. 79-7-1 (last)1/( -30°)
GK. H5733

Diameter
55.6(1)45.0(1)69.0(1)59.0(1)

Umbilicus
6.7(.12)5.2(.12)10.0(.14)
9.2(.15)Comparison:-The two specimens look
so dissimilar to each other that theymight be regarded as representing distinct species. However, in view of thegreat variability of B. onilahyense demonstrated by BASSE (1947) on the material
from Madagascar, careful comparison isrequired. In fact, GK. H5733 is fairly
similar to certain very involute, muchcompressed and weakly ornamented examples from Madagascar (e. g., BASSE,
1947, pI. 5, figs. 3, 3a; pI. 3, fig. 3, 3a).
Although the umbilical tubercles of GK.
H5733 are weaker than those of BASSE'S
pI. 5, fig. 3, those of BASSE'S pI. 3, fig. 3
are as weak as ours. Therefore, GK.
H5733 can well be regarded as an extreme
variant along the same line.
On the other hand, TTC. 79-7-1 closely
resembles another example from Madagascar (i. e., BASSE, 1947, pI. 2, fig. 6).
Although the former is somewhat lesscompressed than the latter, there are examples from Madagascar (e. g., BASSE,
1947, pI. 2, figs. 4, 4a; 5, 5a; 1, 1a) whose
whorls are as broad as or somewhat
broader than ours.
There could be a possibility of subspecific separation between Madagascar
and Japan, seeing that some of the ribs
in our two examples are slightly more
flexuous than those in many Madagascar
examples. To examine this possibility weneed more specimens from our province.
At the moment this is left undecided and
we regard the two specimens at our disposal as being within the extent of variation of B. onilahyense.

Height29.8(.54)
24.4(.54)
38.0(.55)
32.4(.55)

BreadthB/H

13.0(.29)
28.6+a25.0(.42)

0.53
0.75+aO. 77

In addition to Madagascar, B. onilahyense has recently been reported from theConiacian of the Middle East (LEWY and
RAAB, 1978), although it is only listed
without detailed description.
Occurrence :-GK. H5733, from a nodule
contained in the sandy siltstone of loco
R2638 j, exposed on the left bank of theRiver Obirashibe (point A in Text-fig. 7).
This siltstone is assignable either to theupper part of Unit Ub or to the lower
part of Unit Uc in the TANAKA'S (1963)
lithostratigraphic subdivision. From thesame bed Damesites damesi (lIMBO), Gaudryceras denseplicatum (lIMBO), Otoscaphites (Hyposcaphites) matsumotoi TANABE,
Inoceramus uwajimensis YEHARA, Didymotis akamatsui (YEHARA), etc. have beenobtained.
TTC. 79-7-1 was in a calcareous nodule
contained in a bed of siltstone exposedon the floor of the main stream of River
Obirashibe at a point (indicated as B in
Text-fig. 7), 8 m upstream from the bridge,
about 150 m downstream from the confluence with the tributary Okufutamatagawa. This siltstone is probably assigned
to the lower part of Unit Uc, close to
the Uc-Ub boundary. From the same
nodule, Inoceramus d. uwajimensis was
obtained.
In short, the two specimens came fromthe middle part of the Lower Urakawan[K5aJ of the Obira area.
In Madagascar B. onilahyense is characteristic of the "Middle Coniacian" (COLLIGNON, 1965).

728.

63

Coniacian Ammonites from Hokkaido

M
I
"

T

.~.:'

.,

I

~,/"""/- - --::.:;"- - ......::.:",

o

500rn

Text-fig. 7. Geological map of the Obira area (part) (adapted from TANAKA,
1963 and TANABE et aI., 1977). Ak: Akano-sawa, Ob: main stream of the Obirashibe,
Ok: Okufutamata-gawa, M: Middle Yezo Group, Ua-Uk: subdivided units of Upper
Yezo Group, T: Tertiary, • (A, B): locality of Barroisiceras onilahyense, thickbroken line: fault. Inset at the upper left corner is the index map of Hokkaido.

Appendix
Notes on the Coniacian Biostratigraphy
Tatsuro MATSUMOTO
The nomenclatural type locality of theConiacian stage is at Cognac in the northern part of the Aquitaine basin of southwestern France. The stage was proposedand defined by COQUAND (1856, 1857) as
the lowest unit of the quadripartite Senonian in this area. He subdivided theConiacian of this area into two parts,
A (lower) and B (upper). Subsequently

ARNAUD (1877) described the stratigraphy
comprehensively, but essentially kept
COQUAND'S idea.
For a long time the type Coniacian had
been little studied, until SERONIE-VIVIEN(1960, 1972) restudied it. According to
SERONIE-VIVIEN, the type Coniacian ismade up of glauconitic sandstone (6 m)in the lower part (i. e. A of COQUAND)
and sandy limestone (8 m) in the upper
part (i. e. B of COQUAND). The former
lies unconformably on the Turonian Hippurites limestone. Recently VAN HINTE(1979) has stated that the fossil contents

64

Tatsuro MATSUMOTO et al.

and the sections in the type Coniacianare fully satisfactory for a definition of
the stage and that they deserve standard
for inter-regional correlation. This statement may be adequate for the microfossils, but the lower unit (A) at Cognac
has no fossils of correlative value andthe mega-fossil fauna from the upper unit(B) has few species which are useful forinter-regional correlation. Moreover, there
is some difficulty as to Micraster coranguinum (KLEIN), which otherwise may be
a valuable index species of a certain level(see LEWY, 1975, p. 22; RAWSON et aI.,
1978, p. 25).
The subdivison of the Coniacian stage
into the lower Zone A, i. e., "Zone ofBarroisiceras haberfellneri" and the upper
Zone B, i. e. "Zone of Paratexanites emscheris" was proposed by GROSSOUVRE(1894, 1901) on the basis of the ammonites
from "Craie de Villedieur (Touraine)" on
the southwestern side of the Paris basin.
This place is about 230 km distant from
Cognac, but the sequence represents thelower part of D'ORBIGNY'S Senonian in a
general sense. The scheme of ammonite
zonation by GROSS OUVRE for the Senonian
were cited frequently by many subsequentauthors up to RAWSON et aI., (1978) andthe sequence of Craie de Villedieur has
become practically a standard reference
section of the Coniacian for mega-fossil
biostratigraphy.
It should be pointed out that the namesof the above two zones are misleading, if
not entirely incorrect. The reasons are
as follows: (1) The ammonites which
GROSSOUVRE (1894) called B. haberfellneri are mostly other species, such as
Forresteria (Reesideoceras) galica (BASSE),
Harleites harlei (GROSSOUVRE) etc., as
pointed out by BASSE (1947) and otherauthors. (2) The exact stratigraphic position of the holotype of B. haberfellneri(HAUER) in the Gosau basin (the East

Alps) is not clear (H. SUMMESBERGER inlit., 1980-2-15). (3) GROSS OUVRE (1894, p.
69) regarded Ammonites emscheris SCHLUTER, 1867 as a synonym of Ammonites
serratomarginatus REDTENBACHER, 1873,
although I do not agree with his conclusion (MATSUMOTO, 1970, p.262). (4) The
original locality (Glanegg) of A. serratomarginatus, which species is now referred
to Paratexanites (Parabevahites), is notin a sequence and isolated from the otherGosau localities (SUMMESBERGER in lit.
1980-2-15), although the species is ofConiacian age from the evidence of associated ammonites and its occurrence inother regions. (5) The stratigraphic rangeof P. (Parabevahites) emscheris in Germany
is not very clear, although it is presumed
to be Middle to Upper Coniacian (E. SEIBERTZ in lit., 1980-4-16).
If I were admitted to select other species from the assemblages of the GROSSOUVRE'S zones, I would.propose to callas follows:
Zone of Protexanites bourgeoisi (upper)
Zone of Peroniceras subtricarinatum(lower)As to the Coniacian in the British Isles,
RAWSON et a1. (1978) have given adequate
remarks. Ammonites are very few there
and inoceramid species are preliminarily
allocated stratigraphically (KAUFFMAN,
1978).
The Coniacian equivalent in Germany
is defined and subdivided clearly by several species of Inoceramus, although thelower part of the Coniacian had long
been erroneously called "Oberturon", until
SEIBERTZ (1979a) gave correction. According to SEITZ (1959), TROGER and HALLER(1966), SEIBERTZ (1979b also in lit. 19804-16) and TROGER (oral comm. at Dresden
1980, through S. KELLER in lit., 1980-425), the following zones are recognized:
Above: Zone of 1. (Platyceramus) undulatoplicatus (Lower Santonian)

728.

Coniacian Ammonites from Hokkaido(3) Zone of Gonioteuthis praewest/alica(2b) Z. of I. (Volviceramus) involutus(2a) Z. of I. (V olviceramus) koeneni(1) Zone of I. schloenbachi
Below: Z. of Mytiloides striatoconcentricus (Upper Turonian)The subdivisions (1), (2a+2b) and (3)are called the Lower, Middle and Upper
Coniacian in the revised German scheme.
Besides the zonal indices, I. (Magadiceramus) subquadratus SCHLUTER occurs in
the Zone of G. praewest/alica, thoughless abundantly. I. (1.) kleini MULLER and
I. (Platyceramus) mantelli MERCEY (BARROIS) occur along with I. (V.) koeneni
MULLER and I. (V.) involutus SOWER BY
may range slightly upward. The true
ranges of ammonite species in terms of
the above zones are not exactly determined, because ammonites are mostly ofolder collections. According to WIEDMANN(1979) and SEIBERTZ (1979 and in lit.,
1980-4-16), Peroniceas subtricarinatum and
P. westphalicum (VON STROMBECK) seemto occur in the Lower to Middle Coniacian, whereas Gauthiericeras margae(SCHLUTER), Paratexanites (Parabevahites)emscheris (SCHLUTER) and P. (Paratexanites) pseudotexanus (ANDERT) seem tooccur in the Middle and/or Upper Coniacian.
Incidentally, I. schloenbachi BOHM, 1912
could either be synonym of I. de/ormis
MEEK, 1876 (see SEITZ, 1959) or a later
descendant of the latter (SEIBERTZ, 1979b).
I. rotundatus FIEGE seems to be theearliest form of the same lineage. The
last form is at or near the TuronianConiacian boundary and its age may besaid as either the basal Coniacian or topof the Turonian or the transition ofTuronian-Coniacian, depending on thedefinition of the stage boundary. For
the definition of the stage boundary thesequence in the type Cognac area lacks

65

sufficient evidence, because there is an
unconformity and because the basal sandstone is poor in fossil contents. The
succession of inoceramid species in the
Senonian of France does not seem to havebeen well correlated with that of Germany.
Turning to the North American Interior
province, the succession of inoceramid
species is well studied (but not yet fully
described) by KAUFFMAN (in KAUFFMAN
et aI., 1978) and can be approximately
correlated with that of Germany. To citefrom him, with some simplification, thezones in the Coniacian are as follows:
Upper Coniacian: Zone of Scaphites
ventricosus(7) Zone of I. (Magadiceramus) subquadratus (with I. (V.) involutus
in the upper part of its range)
Middle Coniacian: Zone of Scaphites
preventricosus, upper half(6) Zone of "I." wandereri (with I.
(V.) koeneni in the middle partof its range)(5) Zone' of "I." schloenbachi (with
I. (V.) koeneni and I. (V.) tnvolutus in the early part oftheir ranges)(4) Zone of "I." browni CRAGIN
Lower Coniacian: Zone of Scaphites
preventricosus, lower half(3) Zone of "I." de/ormis (which canbe subdivided into two subzones
by subspecies)(2) Zone of "I." erectus (which again
can be subdivided into two subzones by subspecies)(1) Zone of "I." l'otundatus
KAUFFMAN et al. (1978, p. 15) discussed
at length about the Turonian-Coniacianboundary. Their opinion is acceptable inprinciple.
The ammonite zones of the Coniacianthrough Maastrichtian in the Interior
province of North America are indeed
very fine, but the zonal indices are mostly

66

Tatsuro MATSUMOTO et al.

endemic species, with occasional intermingling of more widespread species. The
top of the Turonian in this province may
be defined by the extinction of Prionocyclus and the base of the Coniacian by
the first appearance of the genera of Barroisiceratinae. KAUFFMAN et al. (1978)
record the lowest occurrence of Forresteria sp. in the Zone of "f." rotundatus,
although without palaeontological description and illustration.
In the Gulf Coast province, ammonites
of wider geographical distribution occur
more commonly. According to YOUNG(1963) the equivalent of the Coniacian in
Texas is biostratigraphically subdivided
as follows:(3) Zone of Prionocycloceras gabrielense(2) Zone of Peroniceras westphalicum(1) Zone of Peroniceras haasi
Peroniceras haasi YOUNG resembles P.
platycostatum VAN HOEPEN from South
Africa. As has been discussed in themain text of this paper "Peroniceras westphalicum" from Texas is better transferred to P. stefaninii. In the second zone
Peroniceras moureti GROSS OUVRE occurs
and in the third zone Protexanites planatus(LAS SWITZ), Paratexanites sellardsi YOUNG
and Prionocycloceras hazzardi YOUNG are
associated. YOUNG correlated the first
and the second zones to the Lower Coniacian and the third to the Upper Coniacian of GROSS OUVRE.
Tripartite biostratigraphic subdivision
is proposed by COLLIGNON (1965) for theConiacian of Madagascar as follows:
Upper: Zone of Prionocycioceras guyabanum-Gauthiericeras margae
Middle: Zone of Kossmaticeras theobaldianum-Barroisiceras onilahyense
Lower: Zone of Pel'oniceas dravidicum
The Coniacian ammonite fauna of Madagascar contains many species which are
identical or closely allied to those fromJapan.
The biostratigraphic records for theConiacian of Natal and Zululand (South
Africa) have been described by KENNEDY
and KLINGER (1975) and KENNEDY (1978).
The sequences seem to yield some species
which are identical or allied to those fromthe Japanese province. I omit, however,to review them here, because their palaeontological monographs have not yet been
completed.
In the epicontinental shallow sea of the
Tethys realm the Coniacian is finely subdivided by ammonites but the predominantfaunal elements are different from thoseof the north temperate region. An example in the west is the zonation innorthern Spain by WIEDMANN (1960, 1979 ;also in WIEDMANN and KAUFFMAN, 1978):(5) Zone of H emitissotia lenticeratiformis WIEDMANN(4) Zone of Hemitissotia turzoi KARRENBERG(3) Zone of Gauthiericeras valleri CIRY
(2) Zone of Reymentoceras hispanicum
WIEDMANN(1) Zone of Tissotioides haplophyllus(REDTENBACHER)
The first three zones were grouped into
the Lower Coniacian and the rest into
the Upper Coniacian in WIEDMANN'S
earlier paper but later the third zone was
assigned to the Middle Coniacian.
Tissotia (Metatissotia) ewaldi (BUCH)
occurs in the first zone, Barroisiceras spp.
in the second, Protexanites bourgeoisi(D'ORBIGNY) in the second and the third,
and Paratexanites (Parabevahites) emscheris in the fourth (WIEDMAMM, 1979).
Another example in the central Tethys
is the zonal succession of ammonites in
the Middle East reported by LEWY andRAAB (1978) as follows:(5) Tissotia (Metatissotia) ewaldi-T.
(M.) fourneli (BAYLE)(4) Heterotissotia neoceratites PERON-

728.

Coniacian Ammonites from Hokkaido

Buchiceras bilobatum HYATT(3) Allotissotia galeppei (PERVINQUIERE)-Barroisiceras onilahyense BASSE(2) Plesiotissotia sinaitica LEwY-Roemeroceras parnesi LEWY
(1) Placenticeras tamulicum (BLANFORD)-Proplacenticeras eboroense COLLIGNON
The authors grouped units (1)-(3) into theLower Coniacian and units (4) and (5)into the Upper Coniacian, without using
the Middle Coniacian. I am rather surprised to see the great difference in thestratigraphic occurrence of T. (M.) ewaldi
between Spain and the Middle-East.
Now in Japan what we call the Lower
Urakawan is the approximate equivalentof the Coniacian. It is biostratigraphicallybipartite on the basis of several wellstudied sections in Hokkaido, Futaba areaof Northeast Japan, Onogawa basin of
Kyushu and Uwajima area of Shikoku.
They are called(2) Zone of Inoceramus mihoensis(1) Zone of Inoceramus uwajimensis
In some sections, such as those in the
Ikushumbets, Futaba and On ogawa areas,
the two species are stratigraphically
clearly separated, with I. uwajimensis YEHARA below and I. mihoensis MATSUMOTO
above, as in the Naibuchi district of South
Saghalien (where the type locality of I.
mihoensis is situated). In some other sections, as in the Obira area of Hokkaido,
the ranges of the two species are overlapping, with later appearance of I. mihoens is.
It should be noted that I. uwajimensis
is similar to I. kleini and I. stan toni
SOKOLOW (=1. acuteplicatus STANTON)
and that I. mihoensis is allied to, if not
identical with I. de/ormis and I. erectus.
Consequently, there is discrepancy in thezonal succession of these allied species
between Japan and Euramerica.
I. (Platyceramus) yubarensis NAGAO et
MATSUMOTO occurs commonly in the Zone

67

of I. mihoensis but appears already in theZone of I. uwajimensis. This species is,in my opinion, allied to I. (P.) mantelli,which occurs in the Middle to Upper
Coniacian of Germany. KAUFFMAN (1977,
p. 182) holds the view that I. yubarensis
is a subspecies of I. walterdor/ensis ANDERT from the highest Turonian andLower Coniacian of Germany and North
America. If this is correct, the age discrepancy is again distinct. I do not, however, agree with KAUFFMAN'S taxonomic
assignment, because in I. (P.) yubarensis
the growth-axis is not so oblique as in I.
walterdor/ensis but upright in the late
growth-stage and the hinge-line is shorter.
Likewise, an ancestral form (species orsubspecies) of I. (Cordiceramus) cordi/ormis SOWER BY (s. 1.), with shallower
sulcae than in the typical form, occurs
fairly commonly in the Zone of I. mihoensis and is occasionally found together
with I. uwajimensis. The typical representatives of I. (G.) cordi/ormis occurs in
the Santonian of Japan as in Euramerica.
Dr. NODA has coworked with me for thispreliminary knowledge of the cordi/ormis
group and will eventually give full descriptions of these forms from Japan.
Sphenoceramus yokoyamai (NAGAO et
MATSUMOTO) begins to appear in theConiacian.
Among long-ranging ammonites, Anagaudryceras limatum (Y ABE) marks thelater half of its range in the Coniacianand Gaudrycems tenuiliratum Y ABE begins to appear in the same stage. Baculites
yokoyamai TOKUNAGA et SHIMIZU arecommon in the Coniacian of Japan, but
B. d. yokoyamai is reported from theTuronian of North America (COBBAN and
SCOTT, 1972). B. schencki MATSUMOTO,
whose original locality is in the Coniacianof California, occurs also in Japan, thoughless frequently (MATSUMOTO and OBATA,
1963). TANABE (1977) has recently made

68

Tatsuro Matsumoto et al.

clear that the scaphitid species of theConiacian of japan are distinct from thoseof the Turonian. The Coniacian group isrepresented by Scaphites' pseudoaequalis
Y ABE, S. formosus Y ABE, Otoscaphites
klamathensis (ANDERSON), O. (Hyposcaphites) matsumotoi TANABE and Clioscaphites (?) sp. The last species looks similar to S. arnaudiformis COLLIGNON from
the Middle Coniacian of Madagascar (COLLIGNON, 1965), whereas the first species(S. pseudoaequalis) is reported from theUpper Turonian Chalk Rock of England(WRIGHT, 1979).
An aberrant ammonite species Nipponites
bacchus MATSUMOTO et MURAMOTO
ranges from the Upper Turonian to thelower part of the Coniacian (see MATSUMOTO and MURAMOTO, 1967). I have notyet confirmed an unmistakable exampleof Eubostrychocems indicu112 (STOLICZKA)
in japan, but E. indopacificum MATSUMOTO is fairly common in the Coniacianof japan, southern India and Madagascar(see MATSUMOTO, 1967, p. 333). Anotherspecies, E. mummotoi MATSUMOTO isallied to E. saxonicum (SCHLUTER) fromthe English Chalk Rock but occurs in theZone of I. uwajimensis.
Yezoceras nodosu112 MATSUMOTO andY. miotuberculatu17l MATSUMOTO, among
other nostoceratids, occurs in the Zone ofI. uwajimensis and range somewhat upwards within the Coniacian (see MATSUMOTO . 1977).
Another species which characterizes theConiacian of southern India and Madagascar is /(ossmaticems theobaldianum(STOLICZKA), which occurs also in theZone of I. uwajimensis. There are someother species of /(ossmaticeras (see MATSUMOTO, 1955, 54). Several species of
Yokoyamaoceras, bituberculate microforms, range from the Upper Turonian
to Coniacian or even to Lower Santonian.
Similarly Mesopuzosia yubarensis (JIMBO)
ranges from the Turonian to the Coniacian. More long-ranging species Gaudrycems denseplicatum (JIMBO), Tetragonites
glabrus (JIMBO), Hypophylloceras (Neophylloceras) subramosum (SPATH) occur commonly in the Coniacian of japan.
Among species of less frequent or rareoccurrence, there are following species
which are useful for inter-regional correlation. In the list (1) means the Zone ofI. uwajimensis and (2) that of I. mihoensis;
allied species are also indicated.
Lewesicems kawashitai MATSUMOTO (1or 2) (allied to L. elmii COLLIGNON,
from the Middle Coniacian of Madagascar)
Nowakites mikasaensis MATSUMOTO (1)(allied to N. tallavignesi (D'ORBIGNY)
from the Coniacian of France)
Prionocycloceras wrighti MATSUMOTO(1) (allied to P. guayabanum (STEINMANN), from the Coniacian of Colombia and Venezuela)
Prionocycloceras sigmoidale MATSUMOTO (1) (allied to P. maarfiaense
SORNA Y, from the Coniacian of Algeria)
Prionocycloceras sp. aff. P. lenti (GERHARDT) (1) (Coniacian of Venezuela)
Niceforoceras japonicum(?) MATSUMOTO

Explanation of Plate 6
Fig. 1. Peroniceras tatum MATSUMOTO et MURAMOTO, sp. nov ......................... Page 52
Holotype, lateral view, x 1/3.
Fig. 2. Peroniceras yubal"enSe MATSUMOTO et MURAMOTO, sp. nov ........ "........ " ... Page 55
Holotype, lateral view, x 1/2.
Kyushu Univ. (K. TA!'1AI3E) photos, without whitening.

MATSUMOTO et al.,'Coniacian Ammonites

Plate 6

728. Coniacian Ammonites from Hokkaido(2 ?)Peroniceras latum sp. nov. (2) (allied to
P. stefaninii VENZO, from the Lower
Coniacian of South Africa and Texas)
Peroniceras yubarense sp. nov. (lor 2)(allied to P. besairiei VAN HOEPEN
from the Lower Coniacian of South
Africa)Peroniceras sp. aff. P. Platycostatum
VAN HOEPEN (lor 2) (Coniacian ofSouth Africa)
Sornayceras proteus MATSUMOTO (2)Sornayceras omorii MATSUMOTO (2)(allied to S. bajuvaricwn (REDTENBACHER), from the Gosau beds and S.
aff. isamberti (F ALLOT) from theLower Coniacian of France)
Sornayceras d. propoetidum (REDTENBACHER) (2 ?) (Coniacian of the East
Alps)
Ishikariceras binodosum MATSUMOTO (1)(allied to I. schneeblii (BOULE, LEMOINE et THE VENIN) from the Coniacianof Madagascar)
Paratexanites (Paratexanites) orientalis(Y ABE) (2) (allied to P. (P.) zeilleri(GROSSOUVRE), from the Lower Coniacian of France and P. (P.) umkwelanensis (CRICK) from the Senonian ofSouth Africa)
Paratexanites (Paratexanites) mikasaensis MATSUMOTO (2 ?) (allied to P. (P.)
canaensis (GERHARDT), from the Lower
Senonian of Venezuela)
Paratexanites (Parabevahites) serratomarginatus (REDTENBACHER) (1)Pseudobarroisiceras nagaoi SHIMIZU (1)Barroisiceras onilahyense BASSE (upper
part of 1) (Middle Coniacian of Madagascar)
Barroisiceras (Baseoceras) inornatum
MATSUMOTO (1) (allied to B. (B.) colcanapi COLLIGNON from the Upper
Coniacian of Madagascar.)Forresteria(Forresteria)
alluaudi
BOULE, LEMOINE et THEVENIN) (1)69(Middle Coniacian of Madagascar;
Coniacian of South Africa, Peru, Utah)
Forresteria (Forresteria) armata MATSUMOTO (1)Forresteria (Muramotoa) yezoensis MATSUMOTO (1) (allied to F. (M.) ampozaloakensis (BASSE), from the Coniacian of Madagascar)
Forresteria (Muramotoa) 11lummotoi
MATSUMOTO (1)Yabeiceras orientale TOKUNAGA et SHIMIZU (1) (allied to Y. bituberculatum
COLLIGNON, from the Middle Coniacianof Madagscar)
Harleites d. harlei (GROSSOUVRE) (1)Hourquia hataii HASHIMOTO (1 and 2)(Readers may refer to MATSUMOTO,
1965a, 1965b, 1969, 1970a, 1971, 1979 and
HASHIMOTO, 1973 for the descriptions of
the species listed above.)
As is clearly shown in the above list,
some species occur in Japan in an unit
which corresponds approximately to thatof the extra-Japanese province(s) where
the same or allied species occur, whereas
others show disharmony in stratigraphic
occurrences. Therefore, the zone by zone
correlation is fairly difficult between Japanand other remote provinces. It may begenerally concluded from the comprehensive viewpoint that the Zone of I. uwajimensis is approximately correlated with
the Lower and Middle Coniacian of Madagascar and the Zone of I. mihoensis is sowith the Upper Coniacian of the same
area. Anyhow, the Lower Urakawan ofJapan is certainly correlated with theConiacian stage of Europe and other wellstudied areas by means of diagnostic
species. Therefore, we can use the stage
name Coniacian in the Japanese province.

References cited
H. (1877): Memoire sur Ie terrain
Cretace du sud·ouest de la France. Mem.

ARNAUD,

70

Tatsuro Matsumoto et al.

Soc. Ceol. Fr., ser. 2, vol. 10, no. 4, p. 1110.
ATABEKIAN, A. A. and AKOPIN, V. T. (1972):
Late Cretaceous ammonites from Armenya
SSR (Collignoniceratinae, Peroniceratinae).
Bull. AN Aremenya SSR, Earth Sci., 1972,
no. 2, p. 3-12, pis. 1-3 (in Russian).
BASSE, de Menorval EHane (1947): Les peu·
plements malgachen de Barroisiceras (Re·vision du genre Barroisiceras DE GROSS.).
Ann. Paleont., vol. 33, p. 100-190, 9 pis.
BESAIRIE, H. (1930): Les rapports du Cretace
malgache avec Ie Cretace de I' Afriqueaustrale. Bull. Soc. Ceol. Fr., ser.4, vol.
30, p. 613-643.
BOHM, J. (1912): Uber Inoceramus cuvieri
Sow. Zeitschr. Deutsch. Ceol. Cess., vol.
63 (for 1911), p. 569-570.
BOULE, M. LEMOINE, P. and THEVENIN, A.
(1906-7): Paleontologie de Madagascar,
Ill· Cephalopodes cretacees des environs
de Diego·Suarez. Ann. Paleont., vol. 1, p.
173-192, pis. 14-20 (1906) ; vol. 2, p. 1-56,
pis. 1-8 (1907).
COBBA:->, W. A. and SCOTT, G. (1972): Strati·
graphy and ammonite fauna of the Gra·
neros Shale and Greenhorn Limestone near
Pueblo, Colorado. U. S. Ceol. Surv. Prof.
Paper 645, p. 1-108, pis. 1-39.
COLLIG:->ON, M. (1965): Atlas des Fossiles
Caracteristiques de Madagascar (Ammonites), fasc. 13 (Coniacien), p. 1-88, pis.
414-454, Servo Geol., Rep. Malgache.
COQUA"D, H. (1856): Notice sur la formation
cretacee du departement de la Charente.
Bull. Soc. Ceol. Fr., Ser. 2, vol. 14, p. 5598.
- - (1857): Position des Ostrea columba etbiauriculata dans Ie groupe de la craie

inferieure. Ibid., vol. 14, p. 55-98.
GROSSOUVRE, A. DE (1894): Recherches surla Craie superieur II: Paleontologie. Lesammonites de la Craie superieur. Mem.
Carte Ceol. Det. Fr. [1893J, 264 p., 39 pis.
- - (1901): Recherches sur la Craie superieur I: Stratigraphie general. Ibid., 1013 p.
HASHIMOTO, W. (1973): Hourcquia hataii HASHIMOTO, a new species of ammonite fromthe Upper Cretaceous System of theAbeshinai region, Teshio province, Hokkaido, Japan. Tohoku Univ., Sci. Rep.,
2nd ser. (Geol.), Special Vol. no. 6, p. 315318, pI. 35.
HINTE, J. E. VAN (1979): The Coniacian, Santonian and Campanian stratotypes. Lethaia,
vol. 12, p. 183-187.
HOEPEN, E. C. N. VAN (1965): The Peron iceratinae and allied forms of Zululand.
Ceol. Surv. S. Afr., Mem. 55, p. 1-70 (incl.
pis. 1-27).
KAUFFMAN, E. G. (1977): Systematic, biostratigraphie and biostratigraphie relationships between middle Cretaceous Eurameriean and North Pacific Inoceramidae.
Pal. Soc. Japan, Spec. Pap., no. 21, p. 169212.
- - (1978): British middle Cretaceous inoceramid biostratigraphy. Ann. Mus.
d' Hist. Nat. Nice., vol. 4 (for 1976),
chapt. 4, p. 1-12.
KAUFFMAN, E. G., COBBAN, W. A. and EICHER,
D. L. (1978): Albian through Lower Coniacian strata, biostratigraphy and principal
events, Western Interior United States.
Ibid., vol. 4 (for 1976), chapt. 23, p. 1-52.
KENNEDY, W. J. (1978): The middle Cretaceous of Zululand and Natal, easternSouth Africa. Ibid.. vol. 4 (for 1974),

Explanation of Plate 7
Fig. 1. Peroniceras latum MATSUMOTO et MURAMOTO, sp. nov ......................... Page 52
Holotype, ventral view, x 3/8.
Fig. 2. Peroniceras yubarense MATSUMOTO et MURAMOTO, sp. nov ..................... Page 55
Holotype, ventral view, x 1/2.
Fig. 3. Sornayceras sp. cf. S. proteus MATSUMOTO .................................... Page 57
Muramoto Coli., from loco Ik 1509, lateral view, x 1/4.
Kyushu Univ. (K. TANABE) (1, 2) and Mikasa Museum (3) photos, without whitening.

MATSUMOTO et al.:Coniacian Ammonites

Plate 7

728.

Coniacian Ammonites from Hokkaido

chapt. 18, p. 1-29.
KENNEDY, W. J. and KLINGER, H. C. (1975):
Cretaceous faunas from Zululand andNatal, South Africa. Introduction, Stratigraphy. Bull. Brit. Mus. (Nat. Hist.) ,Geol., vol. 25, no. 4, p. 265-315, 1 pI.
LEWY, Z. (1975): The geological history of
Israel and Sinai during the Coniacian.
Israel Jour. Earth-Sci., vol. 24, p. 19-43.
LEWY, Z. and RAAB, M. (1978): Mid-Cretaceous stratigraphy in the Middle East.
Ann. Mus. d' Hist. Nat. Nice, vol. 4 (for1976), chapt. 32, p. 1-20.
MATSUMOTO, T. (1942): Fundamentals in the
Cretaceous stratigraphy of Japan. Part I.
Mem. Fac. Sci. Kyushu Imp. Univ., ser.
D, vol. 1, p. 129-280, pis. 5-20.
- - (1954): Family Kossmaticeratidae from
Hokkaido and Saghalien. Japan. Jour. Geol.
Geogr., vol. 26, nos. 1-2, p. 115-164, pis.
8-10.
- - (1955): Further notes on the kossmaticeratids from Hokkaido. Ibid., vol. 27. nos.
2-4, p. 173-187, pI. 14-16.
- - (1965a): A monograph of the Collignon iceratidae from Hokkaido. Part I. Mem.
Fac. Sci. Kyushu Univ., ser. D, vol. 16,
no. 1, p. 1-80, pis. 1-18.
(1965b): Ditto. Part II. Ibid., vol. 16,
no. 3, p. 209-234, pis. 36-43.
- - (1967): Evolution of the Nostoceratidae(Cretaceous heteromorph ammonoids).
Ibid., vol. 18, no. 2, p. 331-347, pis. 18-19.
- - (1969): A monograph of the Collignoniceratidae from Hokkaido. Part 111. Ibid.,
vol. 19, no. 3, p. 297-330, pis. 39-45.
(1970a): Ditto. Part IV. Ibid., vol. 20,
no. 2, p. 225-304, pis. 30-47.
- - (1970b): Uncommon keeled ammonites
from the Upper Cretaceous of Hokkaido
and Saghalien. Ibid., vol. 20, no. 2, p.
305-317, pis. 48-49.
- - (1971): A monograph of the Collignoniceratidae from Hokkaido. Part V. Ibid.,
vol. 21, no. 1, p. 129-162, pis. 21-24.
- - (1977): Some heteromorph ammonites
from the Cretaceous of Hokkaido. Ibid.,
vol. 23, no. 3, p. 306-366, pis. 43-61.
- - (1979): Notes on Lewesiceras and Nowakites (Pachydiscid ammonites) from the71

Cretaceous of Hokkaido. Trans. Proc.
Palaeont. Soc. Japan, n. s., no. 113, p. 3044, pis. 4-7.
MATSUMOTO, T. and HARAGUCHI, Y. (1978):
A new texanitine ammonite from Hokkaido.
Ibid., no. 110, p. 306-318, pI. 42.
MATSUMOTO, T. and MURAMOTO, T. (1967):
Two interesting heteromorph ammonoids
from Hokkaido. Mem. Fac. Sci. Kyushu
Univ. ser. D, vol. 18, no. 2, p. 361-366,
pis. 22-24.
MATSUMOTO, T. and OBATA, I. (1963): A
monograph of the Baculitidae from Japan.
Ibid., vol. 13, no. 1, p. 1-116, pis. 1-27.
MEEK, F. B. (1871): Preliminary palaeontological report, consisting of lists of fossils,with descriptions of some new types, etc.
U. S. Geol. Surv., Wyoming and Portionsof Contiguous Territories, Ann. Rept.,
vol. 4, p. 287-318.
RAWSON, P. F., CURRY, D., DILLEY, F. C.,
HANCOCK, J. M., KENNEDY, W. J., NEALE,
J. W., WOOD, C. J. and WORSSAM, B. C.
(1978): A correlation of Cretaceous rocks
in the British Isles. Geol. Soc. Lond.,Special Report, no. 9, p. 1-70.
REDTENBACHER, A. (1873): Die Cephalopodenfauna der Gosauschichten in den nordostlichen Alpen. Abh. k. k. Geol. Reichsanst.
(Wien), vol. 5, p. 91-149, pis. 22-30.
SCHLUTER, C. (1867): Beitrag zur Kenntniss
der jungsten Ammoneen Norddeutschlands,
36 p., 6 pis., Bonn.
- - (1872): Die Cephalopoden der oberen
deutschen Kreide (part). Palaeontographica, vol. 21, p. 25-120, pis. 9-35.
SEIBERTZ, E. (1979a): Probleme der TuronGliederung Nordeuropas (Oberkreide) im
iiberregionalen Vergleich. Newsl. Stratigr.,
vol. 7, p. 166-170.
- - (1979b): Biostratigraphie im Turon desSE-Miinsterlandes und Anpassung an dieinternationale Gliederung aufgrund vonVergleichen mit anderen Oberkreide-Gebieten. Ibid., vol. 8, p. 111-123.
SEITZ, O. (1959): Vergleichende stratigraphie
der Oberkreide in Deutschland und in
Nordamerika mit Hilfe der Inoceramen.
Congr. Geol. Intern., xx sesi6n, Mexico,1956, Symposium del Cretacico, p. 113-129.

72

Tatsuro Matsumoto et al.

SERONIE·VIVIE"I, M. (1960) : Les localites-types
du Senonien dans les environs de Cognac
et de Barbezieux (Charente) in Colloque
sur Ie Cretace superieur francais. 84 e
Congr. Soc. Sav., Dijon, 1959, p. 579-589.
- - (1972): Contribution a I'etude de senonien en Aquitaine septentrionale, ses
stratotypes: Coniacien, Santonien, Campanien. Les Stratotypes Franfais vol. 2,
1-195, Edit. Centre Natl. Res. Sci., Paris.
SOLGER. F. (1904): Die Fossilien der Mungokreide in Kamerun und ihre geologische
Bedeutung. Beitr. Ceol. Kamerun, p. 85242, 3 pis.
STRO~IBECK, A. VON (1859): Beitrag zur Kenntniss der Planers tiber der Westphalischen
Steinkohlenformation. Zeitschr. Deutsch.
Ceol. Cess., vol. 11, p. 27-77.
TANABE, K. (1977): Mid-Cretaceous scaphitid
ammonites from Hokkaido. Palaeont. Soc.
Japan, Special Papers, no. 21, p. 11-22,
pI. 1.
TANABE, K., HIRANO, H.; MATSUMOTO, T.
and MIYATA, Y. (1977): Stratigraphy of
the Upper Cretaceous deposits in the Obiraarea, northwestern Hokkaido. Sci. Rept.
Dept. Ceol. Kyushu Univ., vol. 12, no. 3,
p. 181-202 (in Japanese with Engl. abstract) .
TANAKA, K. (1963): A study of the Cretaceous sedimentation in Hokkaido, Japan.
Ceol. Surv. Japan, Rep. no. 197, 122 p., 2maps, 3 pis.

TROGER, K.-A. and HALLER, W. (1966): Biostratigraphie der Inoceramen und einiger
ausgewahlter Ammoniten, Belemniten und
Echinodermaten des Unter-Coniac bis
Unter-Campan in der DDR. Abh. zentr.
geol. Inst., Heft 5, p. 84-91, tables 6-9.
VENZO, S. (1936): Cefalopodi del Cretaceo
medio-superiore dello Zululand. Palaeont.
Italica, vol. 36, p. 59-133, pis. 5-12.
WIEDMANN, J. (1960): Le Cretace superieur
de l'Espagne et du portugal et ses cephalopodes. 84 e Congr. Soc. Sav., Dijon, 1959,
p. 709-764.
- - (1979): Die Ammoniten der NW-deutschen, Regensburger und Ostalpinen Oberkreide im Vergleich mit den Oberkreidefaunen des West lichen Mediterrangebietes.
In WIEDMANN, J. (ed.) : Aspekte der Kreide
Europas. lUGS ser. A, no. 6, p. 335-350,
Stuttgart.
WIEDMANN, J. and KAUFFMAN, E. G. (1978):Mid-Cretaceous biostratigraphy of northern
Spain. Ann. Mus. d'Hist. Nat. Nice, vol.
4 (for 1976), chapt. 3, p. 1-34.
WRIGHT, C. W. (1979): The ammonites of the
English Chalk Rock (Upper Turonian).
Bull. Brit. Mus. (Nat. Hist.) , Ceol., vol.
31, no. 4, p. 281-332 (incl. pis. 1-7).
YOUNG, K. (1963): Upper Cretaceous ammonites from the Gulf Coast of the UnitedStates. Univ. Texas Publ., 6304, ix+142
p., 82 pis.

Akano-sawa iJi; / iR, Futaba ~~, Ikushumbets [=IkushunbetsuJ ~$~Ij, Inari-zawa fIll1i1fiR,
Katsura-zawa ~iR, Mikasa .::::~, Obira 'J':lJZ, Obirashibe ,}:lJZ~, Okufutamata-gawa ~=JBtJII,
Onogawa *!l!fJ/l, Rumoi {jilJj, Samata-zawa tc~iR, Shiyubari Y.::L-/~!J [±'~~J, Uwajima~fIl~

Explanation of Plate 8
Figs. 1-3. Barroisiceras onilahyense BASSE ............................................ Page 60
1. TTC. 79-7-1 (hypotype), two lateral (a, b), ventral (c) and frontal (d) view, xL
2. GK. H5733 (hypotype), right lateral (a), frontal (b) and ventral (c) view, xL
3. Ditto, part of left side, showing an injury, enlarged (x 2.8).
4. Inoceramus cf. uwajimensis YEHARA, which occurred with TTC. 79-7-1. Waseda Univ.
(H. HIRANO) photos, without whitening.

MATSUMOTO et 01.:

Coniacian Ammonites

Plate 8

lc

ld

4

728.

73

Coniacian Ammonites from Hokkaido~twj1[iJ'~!¥:U'::J=-7-/7/WJ7/-c:T1

J-Q);5T: ~twj1[Er!IE*!¥:Q)7/-c:T1 J--e

:J =- 7 -/ 7 /~4'If~-?~ G±:JffllH'i, -j--eIC Collignoniceratidae ~Q)-c / !f '77(MATSU'1965-1971) ,*,tc1iCtI; U.:iJ', ;:: ;::tctIfj,@c VC 4 :ff!~g~tI; U': o ..'f:-Q),*,Q) 2 :ff!f'i~:ff!
-e, ..'f:-.h.:fn Peroniceras stefaninii VENZO C P. besairiei VAN HOE PEN Icliji{W,-j-G o~3f'i Sornayceras d. proteus MATSUMOTO -e, ;::.h{,litr2:ff!cli'U~*~-c'a;Go ~4f'iBarroisiceras onilahyense BASSE -Co, JJli:~:ttl!-;>'~';li;t,;iJlv-c'~.lb~.ht.:~~Q)fIlI!lIDtcAG.
MOTO,;::.h~ Q)!¥::ttl!

c ~&IC "':;)\, '-C Q)~fflB!tf.E* {, #t~ Lt.:ot~*~~~ . M*:a:R$ • f!l!fiU,~ • iWi~ji;l;;~#~c L-Cfl9I!k..'f:-Q)ft!!.Q) J:<W.Il~~.h -C\"Gw7'i-Q)::l =- 7 -/7 /Q)~~:ttl!:lgl(lc"':)\,,-C, ..'f:-Q){r.15@Ff (.;( ;iJ'{r.15) Q)mtEQ)~o~Hgfr UJ:iJ- ~~IfU~ L, B *Icto~ G ::l =- 7 -/ 7 /;ffi~mQ){r.15*IK7j- c ~~M.ltQ)rp~mlc"':)\"-C~IfU;iffi U': o:f~*~~~

Postscript: After the manuscript of this paper was received by theeditor, Dr. H. G. KLINGER (from Tiibingen) sent me a photograph of
SCHLUTER'S Ammonites westphalicus in lateral view, which shows that
SCHLUTER'S description cited in p. 54 of this paper is correct. Dr. KLINGER
was unable to trace VON STROMBECK'S original material. I thank Dr.
KLINGER for his kind help,

74
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75
IP A, 26 th IGC, :to J:: L1 RCPNS (Paris) ....
... " .. " .. " ..................... il1Ii:WU~S'
~

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Coelenterate affinity of stromatoporoids ....

.................................. ~*1!i1=.:W-{l::fiB5l:/ii(.!t!.C7)1=.~~C7)m:tk c rp'Jifi.~. • . . . . . . . . . . . . . . . . . . . . . . . . . . ..

..

~*t!!:I!i:¥t?kt!~~:lit ~ ;~~:Jjtii1*~. . . . . . . . . . . . . . . . . . . . . . . . . . .. rej:j:trt!~
OOA~;~

il1Ii;:D~:f\.\t~llI(7)I!i1=.~B5l:/ii(.!t!.{l::fi ...... I!i~ra

Mid-Carboniferous ammonoids from the Akiyoshi Limestone Group (Molluscan Paleontology of the Akiyoshi Limestone GroupVI) ............ NISHIDA, T. and KYUMA, Y.
Paleontological study on HeterocoraIIia fromthe Akiyoshi Limestone Group, Southwest
Japan ...................... SUGIYAMA, T.
fti1tffi'(7) ~/v.b. *i1' 1?i£:l:illA-:. AlbaiIIellidae f.lt
I;::"'?~'-C ............ ¥rtt}!ji:Rj· *t!!:I!i:¥t?kt!~
Peculiar spirothecal structure of schwagerinid
from east of Wang Saphung, Central North
Thailand .................... TORIY AMA, R.
Notes on the Permian brachiopod genus
Cryptospirifer ......................... .
........ NAKAMURA, K. and GOLSHANI, F.
A distinctive brachiopod Pennianella fromthe Permian of Japan ...... NAKAMURA, K.
Upper Permian nautiloids from Abadeh,Central Iran .................... BANDO, Y.
On the occurrence of Procarnites, latest
Scythian ammonite, from the Osawa
Formation at Asadanuki, Towa-cho, Miyagi
Prefecture ...... BANDO, Y. and EHlRO, M.
n~+IRRMllI:I!!! (:f'k5C1il'itHii') I;:::toft 0 *1=.:W-~~
CB5l:1lt.!t!.{l::fitlF!$(7) WI ~7t;(P ............. .
.......... ggrnll:¥t?-.· *t!!:"i!l:¥t?k~~ • ;j;;jlBlE)c
Early Jurassic plants in Japan, Part 4 ..... .
. .. .. .. .. .. ... KIMURA, T. and TSUJII, M.
'ltrlll~~*,~~tlFftl!1E~!iTI i£:tt{l::fiIC ",?~, -C ....
. . . . . . . . . • . . . . . . . . . . . . .. llIi1ffifMi~' jl!1B:¥tRj
Araucarioxylon from Khorat, Thailand ....
............. ...... ...... .... ... ASAMA, K.
Permian plants from Akasaka, Japan ..... .
................................ ASAMA, K.
Upper Jurassic and Lower Cretaceousammonites from Sarawak, Borneo, East

Malaysia .................... ISHIBASI-lI, T •:;kWi:l!!!J!.iI(m{t,:I!iJli\1C7)B5l:/ii(.!t!. {l::fi(7) ~{ftl¥.17t;{ff •.
*lI!f~=' ~tt :Jl;. lB~lEz:;kWi:l!!!J!.iI(m{t,:I!iJli\1 (7)B5l:/ii(.!t!. {l::fi ............. .
. . . . . . . . . . . . . . . . . . .. *t!!:I!i:¥t?kt!~. ~tt :Jl;
Some cephalopods from the Lower
Cretaceous of the Odochi area, Shikoku ..
............ MATSUMOTO, T. and OBATA, 1.

..............

~~M?-..#J::~.!$~ht¥U7-9W.~

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Steinmanella (Yeharella)japonica obsoleta (7)i£:l:ilc-t:-C7)~~~l¥.1m~........................ jiI!j~7Jt!~. lB~lEZ~t~njj¥jml(7)*m~i1'1? lobed oak (7)3B~ ....

....... " ......................... Wilj:j:~:li~t1fa~~IDJ{t)t[C7)J:ml*m~C7) 7J =LT ffJ.

•.•...

....... " ............... Wilj:j:~:n:· *lltfr§$
A Miocene flora from the Fuego Island,
southern Chile .................. T ANAl, T.
~tW:~:fJljJWJmJ!.il( :to J:: L13(~t:l!!!J!.iI(C7) ~=:'*1'r::fL.!t!.
{l::fiI\i'l~-!ffIC I!i~=:'* c m~=:'*(7)!tlW-lc"'?~'-C ............. . *~!j£1.~t!~ '1!i1B±~1<:~t1fa~1il'JA:I!!!J!.iI(C7) ~=:'*1'r::fL.!t!.{l::fi@~ C fE~{l::fi~~ .............. -(7)I*I£U~ • f;k~)c$
Molluscan fossils from the Urahoro Group in
the Kushiro coal field, eastern Hokkaido ..
. ............................... HONDA, Y.
.JV.J1:JJIi\1 c=:'=§5JIj)fgiC7):fi&<:'Gl -r;/ / {l::fiI;::J:: 0 ~~ ................................ ~IBj'lijj\

An early Miocene (Aquitanian) planktonic
foraminiferal fauna from the Muroto
Formation, Shikoku, Japan ........ SAITO, T.
The evolution and taxonomy of the foraminiferal genus Candeina D'ORBIGNY ...... .
.......... SAITO, T. and THOMPSON. R. R.
t-Uiti1'r::fL.!t!.iC J:: 0 7;;t -:I -iT"'" 9"-r m~=:.*(7):I!!!'GllRff-l;; ................ ~*~ftT • ± ~.iMT#-~~'l~-W:.(7)~~eB5l:/ii(.!t!..~ ..

................................ i@j:j::Ill!:=:'~~
7J U 7 ,.. Iv =- 7f.?J(7)~~*c1'r::fL.!t!.tlF-DSDP

Leg 64 •...•... EI'g~f*~· ;e.1B*~· 1lIr::l 00"Phleger Collection"-mt!!:J!f~1'r::fL.!R~*-lc"'?~'-C ............................ B':J~f*~*:9C$~*:if~(7) J!f1=.1'r::fL.!t!.tlFlc ",?~, -C ..... .
...................... ;£t~}II~t!~· il1Ii:WlI~a~~ Iv r 1fai£: dinoflagellate {l::filc ",?~, -C ..... .
. ................................. }Jj(1B~J!f1=.1'r::fL.!t!.~(7)rr!IYJ c1=.m~;;:!:; ... ..... ~tm.

~*~:fiW(~J1:Jlc1iNt 0:fit(7)~*lC7)~*................................ ~tt*zij;l]76:Ilt:E-fl:~:ilt.~- ry-1 =-;( AO)MWH;::!JZil'-ltt.c~'· ............................... 1MltJ":Iltzl!iJ*~i!t7;/'/;f.Ji:

Balanus sendaicus HATAI,MASUDA and NODA t;::"?~,-C ...... ilIr:J~Z

B*~~=,:*cO)7.K1\!ifl::::fi Kewia t;::"?~,-C....

.................................. ~r ~'fi.. TANABE, K., FUKUDA, Y. and OBATA, I .
Ultrastructure of siphuncular epithelium inmodern Nautilus: its paleobiological implications ..................... " .......... .
.. FUKUDA, Y., TANABE, K. and OBATA, 1.
7- g -J:$B1Il!*~~ Pacitrigonia t;::"?~'-C................................ iitrEBggn~·

A Miocene Cetothere from the Ashiya
Group, Kitakyushu City ...... OKAZAKI, Y.
~~~O)~~:::fi~:E-~.~~~ifr~~~iliLk-\,""?;f. :2fl::::fi .......... :Ilt1§'-JII~;fIl. *~~M

Cyclemys miyatai 0)7t;{Ji C I!;!jf"l;;t;:: ,,?~, -C ....

................................ :Ilt1§'-JII~;fIl..
........................ t~OOFa§· ~1fIlB=
1iii1Ml9i'<*~!t!!~0)~gg*c~~ ............... .
~t~!t!rjH;:::fO~o=, =':O)f"'f1t~~t;::"?~'-C· . . . . . . . . . . . . . . . . . . . . . .. rilllE-· ~~~!J3
Palynological aspects of the late Quaternary
deposits from the coastal plain along
Hakata Bay .................. KURODA, T.,
SHUTO, T. and MUKAIYAMA, H.
Late Pleistocene Ostracoda from the Boso
Peninsula, central Japan ........ YAJIMA, M.
Ostracode biofacies in Southern Boso during
Jomon transgression ............. FRYDL, P.
Ultrastructure of the ostracod carapace, III.
Sensory setae and pores ........ OKADA, Y.
Ultrastructure of the ostracod carapace, IV.
So-called normal pore canals ........... .
................................ OKADA, Y,
f&.Z~ ".lf~" (~~:::fi~:E-) ~fl::::fi"'" /' :2"0)

2s0Th ~~ •..........•..•....•.••• *tJ"Ij,EJ~
71 A~) 0) "exposed reef" 0)1ij(

i¥J.!w~ (""? -M~f\;c..'f:"O)~~....................... .

JIIill~ijl/;,

Carlos RUIS, F. and CORVALAN J.

;f. g ~7 J:$B1Il!*~ Charophytes I;::"?~'-C ..
................................ Jllill~ijl/;·iitrEBggR~ • Jose PONCE, V. and Angel ESCOBAR
t.c:fO,

M;\:~~T~ 1i!i~!I1IJ~Q)liJf'9EPfiJ ~ 2 @]lm~~il~ rrbtL,~~~~O)?iJf~mrriOO/H~jt~

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W~il't.c~tLt.:: (i!t~tA.: i'iIimt$-a·)t* ., ~~.36~)0

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fl*il~~oot:fL~+I*~~ltt!c&ffi*~n~jt~It.:Ilt~ t;::bt.:: ~~~~~O)?iJf~-Mt;:: 7/,-'E-T-1;!iU:' ;l;\f,

1E~ff9t;::i'iIi~' *1\!iO)?iJf~~rr~',~tL£ Lt.::o 1lB;fIl19~t;::i19B*Jtfl:1t, 1lB;fIl35~
t;::iWl BJtfl:1t, 1lB;fIl44~t;:: ~±I!iC1t~ ~1t~tL,..'f:"O)~fiDilt.IEP3?1-t;::M'-C 1E7H;:::!E~L,............ EB ifrJEt!J3 • 'J'i1'sll=............. .

........................
71=f~=~~0)~rr;;~~~{±g.~*li'f-..............•i19li'fil1li=f...,.~Ji:O).*.-MK?~gff=-Ji:K~o.
1tt;::"?~'-C-..................... .INRtp~=f...,.~Ji:O)~$~~c1t~t;::"?~'-C ... .INJ~tp~
i'iIi*EErt;:::fO~ 0
ry A 71- -1 O)rrllilJ c liI1i~~Mi*'" ..................... l¥1I}jjtJ'(;· 8IHm~!J3
Function of pellicle, de-coupling space andseptal prismatic zone in ammonites:
comparison with modern Nautilus ....... .
· .OBATA, 1., TANABE, K. and FUKUDA, Y.
Adaptive morphology of siphuncular system
in Cephalopoda ......................... .

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83

B*i!i§::!jWJ!'F~!M=~IJ% No. 23

KOBAYASHI, T. and HAMADA, T.: Carboniferous Trilobites of japan

in Comparison with Asian, Pacific and other Faunas (132~ - :;, 22~Jlli(, 19801f.12JJ 15 B§efT) iJ~X
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NISHIYAMA, Syozo: The Echinoid Fauna from japan and Adjacent Regions. Part

1. .•.•...••••....•.......................•........•..••..•........•..... 8, 400Pl (=r300Pl)

No. 12 (1966)

SHIKAMA, Tokio:

Postcranial Skeletons of japanese Desmostylia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3, 600Pl (=r250Pl)
No. 13 (1968) NISHIYAMA, Syozo: The Echinoid Fauna from Japan and Adjacent Regions. Part
II .................................................... , .................. 6, OOOPl (=r300Pl)
No. 15 (1971)

HAMADA, Takashi: Early Devonian Brachiopods from the Lesser Khingan Districtof Northeast China ...................................................... 3, OOOPl (=r200Pl)
No. 16 (1971)

KANNO, Saburo: Tertiary Molluscan Fauna from the Yakataga District andAdjacent Areas of Southern Alaska. . .................................. .4, 200Pl (=r250Pl)
No. 17 (1973)OYAMA, Katsura: Revision of Matajiro YOKOYAMA'S Type Mollusca from the

Tertiary and Quaternary of the Kanto Area ............................ .4, 700Pl (=r300Pl)
No. 18 (1974)

KOBAYASHI, Teiichi and HAMADA, Takashi: Silurian Trilobites of japan in

Comparison with Asian, Pacific and other Faunas ........................ 3, 700Pl (=r350Pl)
No. 19 (1976)TASHIRO, Masayuki: Bivalve Faunas of the Cretaceous Himenoura Group in

Kyushu ................................................................. 3, 300Pl (=r250Pl)
No. 20 (1977)

KOllA YASHI, Teiichi and HAMADA, Takashi: Devonian Trilobites of japan incomparison with Asian, Pacific and other faunas ......................... 5, 500Pl (=r300Pl)
No. 21 (1977)

MATSUMOTO, Tatsuro (org.): Mid-Cretaceous Events-Hokkaido Symposium,

1976.......................................................... , ......... .4,400Pl (=r300Pl)
KANMERA, Kametoshi and UJIIE, Hiroshi: Bibliography of Palaeontology in

No. 22 (1978)

japan, 1961-1975 ......................................................... 5, 500Pl (=r300Pl)~.~~~J:!J

o 19801f.JJE t;:.t9:ff.ljO) tlCM t;:.g.1J ~.nt-:~5Lt;:.~WL ~i" (1l11I~;gli${?;b-ttt;:. J: IJ 1::~~ ,t-: L ~-ttA.,)o84

Palaeontologica Society of Japan Special Papers No. 23
Carboniferous Trilobites of Japan in Comparison
with Asian, Pacific and other Faunas
By Teiichi KOBAYASHI and Takashi HAMADA
Issued December 15, 1980, vii + 132 pp., 22 pis.

Price (postage and handling incl.) ¥6,400 or equivalent US dollars

This is the third monograph in the series of studies on the Japanese trilobites,
following "Silurian Trilobites of Japan" (Spec. Papers No. 18, 1974, ¥5,100) and "Devonian Trilobites of Japan" (Spec. Papers No. 20, 1977, ¥6,900) by the same authors.
In the present paper Carboniferous trilobites of Japan are considerably enriched asmuch as 41 species belonging to 21 genera in the Brachymetopidae and Proetidae. 28
species are new, and Schizophillipsis and Parvidumus are two new genera.
The Carboniferous trilobites of Japan reveal their intimate relationship to other
Eurasian faunas. Their affinities are evidently closer to the Australian trilobites thanthe North American ones, though a few American genera occur exceptionally in west
Japan. In adding some 20 species of China and Southeast Asia to the Japanese species
the Oriental trilobites attain more than sixty species which are distributed in about
thirty genera including some indigenous ones. As the result of comparative study of
the Oriental trilobites the Carboniferous provinciality is clarified to distinguish two
realms and five provinces.
This volume as well as two preceding ones would be indispensable for geologicaland paleontological libraries as well as persons who may have interests in trilobitology
and Paleozoic historical geology.

*

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*

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*

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The following Back Numbers of the Special Papers are also on sale at the Society.
Orders must be accompanied by remittance made payable to Dr. Tsugio SHUTO, Editorof the Special Papers of the Palaeontological Society of Japan, c/o Department ofof Geology, Faculty of Science, Kyushu University, Hakozaki, Fukuoka 812, Japan.
Standing orders for future issues, both private and official, are also invited.

85
Number 11 (Feb. 20, 1966): The Echinoid Fauna from Japan and Adjacent Regions. Part J.
By Syozo NISHIYAMA .................................... ¥9, 800 or equivalent US dollars
Number 12 (Sept.20, 1966): Postcranial Skeletons of Japanese Desmostylia.
By Tokio SHIKAMA ...................................................... ¥5, 000 or ditto
Number 13 (March 16, 1968): The Echinoid Fauna from Japan and Adjacent Regions.
Part II.

By Syozo NISHIyAMA ............................................ ¥7, 400 or ditto

Number 15 (Feb.25, 1971): Early Devonian Brachiopods from the Lesser Khingan
District of Northeast China. By Takashi HAMADA ........................ ¥ 4,400 or ditto
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and Adjacent Areas of Southern Alaska. By Saburo KANNO .............. ¥5, 600 or ditto
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Type Mollusca from the Tertiary and Quaternary of the Kanto Area.
By Katsura Qy AMA ...................................................... ¥6, 100 or ditto
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Number 19 (Feb. 10, 1976): Bivalve Faunas of the Cretaceous Himenoura Group in Kyushu.
By Masayuki TASHIRO .................................................... ¥ 4,700 or ditto
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By Tatsuro MATSUMOTO (org.) .......................................... ¥5, 800 or ditto
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By Kametoshi KANMERA and Hiroshi UJIIE (ed.) .......................... ¥6, 900 or dittottt5i!O)d~!JW~~O)15m
OO~d~!JW~$~"t"~~, mmtJO)~~c: UL, ttt5i!O)d~!JW~~O)15m~~~~~~c:~~~*u~o~O)15m~H~~~~~~~~,~~O).
F~~~::r 1::'- uL;?€~"t"~AO)l::,*fF*~<:~~~<:to~~ ~~lt' 0

Vivianne Berg-Madsen, Department of Palaeobiology,
Box 56~, S-75~, 22, Uppsala, Sweden
INTERNATIONAL' PALAEONTOLOGICAL ASSOCIAnONWorld Directory of Palaeontologists
QUESTIONNAIRE (complete in typescript or block letters)
Entry name (family or other surname, tl>aMHJlHl!, etc.):
,

~,

,

Individual name (at least one 'first' name in full, HMl! H OHeCTBO nOJlHOCTblO, etc.):,15_ _ _ _ _-'-'--'-'-'--'--'--'--'--'-'-~~_~_ _ _ _~~_ (F/M). Year of birth _ _ __Address (institution ifany, street number or post office box, city, state/country; add 'zip' or other postal
code at the appropriate place):lIifla%Maximum of three specializations on fossil groups, with stratigraphical range and geographical area ofinterest:(1) _ _ _ _ _ _ _ _ _ Range: _ _ _ _ _ _ _ _ _ Area: _ _ _ _ _ _ _ __(2) _ _ _ _ _ _ _ _ _ Range: _ _ _ _ _ _ _ _ _ Area: _ _ _ _ _ _ _ __(3) _ _ _ _ _ _ _ _ _ Range: _ _ _ _ _ _ _ _ _ Area: _ _ _ _ _ _ _ __Approaches (taxonomy, ecology, biostratigraphy, etc.)::7tlffOffices of interest to international palaeontology an,d related sciences, held in 1981 or at least part of theperiod 1981-1985: OO~d~!JW~~1*~=

Example of entry (abbreviation and punctuation system yet to be finally decided):

IVANOVA, ELENA ANDREEVNA (F), 15, Institut geologii i geofiziki SO AN SSSR, SU-630090
NOVOSIBIRSK, USSR; Arthropoda, cam, Siberia; Trilobita, cam, Eurasia; Agnostidea, cam-ord,world. Biostratigraphy, palaeoecology. Chairman, IGCP Project Black Shales, 1980-.

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Transactions and Proceedings of the PalaeontologicalSociety of Japan

April 30, 1981

New Series No. 121

CONTENTS
TRANSACTIONS
725. LING, Hsin Yi: Crassicorbisema, a new Silicoflagellate Genus, from theSouthern Oceans and Paleocene Silicoflagellate Zonation ........ . . . . . . . .

1726. HONDA, Yutaka: Corbiculid Mollusca from the Urahoro Group, Kushiro Coal
Field, Eastern Hokkaido ..............................................

14

727. HAYAMI, Itaru and KASE, Tomoki: Cenomanian Molluscs in a Sandstone
Block from the Sea Bottom off the Southern Coast of Kuji, Northeast
Japan ................................................................

29

728. MATSUMOTO, Tatsuro, MURAMOTO, Kikuo, HIRANO, Hiromichi and TAKAHASHI, Takemi: Some Coniacian Ammonites from Hokkaido...... .. .... 51
PROCEEDINGS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

74