Editor: Hiroshi UJIlE
Associate editors : Ikuwo OBATA, Yasuji SAITO

Officers for 1973 - 1974
Honorary President:
President:

Teiichi KOBAYASHI

Tatsuro MATSUMOTO

Councillors (*Executive): *Kazuo ASAMA, K iyoshi ASANO, *Kiyotaka CHINZEI, *Takashi HAMADA, *Tetsuro HA NAI, Kotora HATAI, *Itaru HAYAMI, *Kametoshi
KANMERA, Tamio KOTAKA, *Tatsuro MATSUMOTO, Tokio SHIKAMA, Tsugio
SHUTO, *Yokichi TAKAY ANAGI, Toshimasa TANAI, *Hiroshi U]IIE
Executive Committee:
General Affairs:
Membership:

Itaru HAY AMI, Yasuhide IWASAKI

Kazuo ASAMA, Kazuhiko UEMURA

Finance:

Takashi HAMADA, N aoaki AOKI

Planning:

Tetsuro HANAI, Saburo KANNO

Pu blica tions
Transactions:

Hiroshi UJIlE, Ikuwo OBATA, Yasuji SAITO

Special Papers:"Fossils":

Kametoshi KANMERA, Ienori FUJIY AMA, Tomowo OZAWA

Yokichi TAKAYANAGI, Toshiaki TAKAYAMA

All communications r elating to this journal should be addressed to the
PALAEONTOLOGICAL SOCIETY OF J AP AN
c/ o Business Center for Academic Societies, Japan.
Yayoi 2-4- 16, Bunkyo-ku, Tokyo 113, Japan
Sole agent:

University of Tokyo Press, Hongo, Tokyo

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 95, pp. 341-352, pI. 47, September 20, 1974

634. MIOCENE MOLLUSCS FROM THE BIHOKU GROUP ATMIYAUCHI-CHO, SHOBARA CITY, SOUTHWEST JAPAN*
KAZUO OKAMOTO and MASAMI TERACHI
Geological Laboratory, Shinonome School, Faculty of Education,
Hiroshima University, Hiroshima .734

iNi¥i f3 *EEJJRrtf'§i*l/IIJIi::.Blt QVm~t~af;6' 1?:>001'j:l~i!tJUJBc "?1t,"C : EEJJRm'§I*J/IIJ (18ft~rr~/IIJ) 0) OTUKA (1938) 0) Loc. 2 IcaI±\TQI'j:lJtJjI'j:l~i!tfjfll~t~f,fTff~li'J>*~IC~;t;f1,Q
ffi:!JiMt;p"~~~~t L. t:.o k"O)~*. Crassostrea-Cyclina-Geloina .B J: '(f. Batillaria-Crassostrea 0) 21r.;p"lW~ii!~t&ZIJt!:~1,t:.o t.;f1,l?:>lW~f'J: "rv tRmllliJJ~lW" O)~~ii'l?:>t.flfJjl(;t!:;f1,Qii', iVr~f'J:1~11f0)r'Ulm$I:';Ii, Q c 1\lJ~IC, iilU1lff'J:jiil5tW,lf* IC;Ii, Q
Geloina yamanei ~llcil& L. t:.o0

i1lT11fIC"?v'"C 7lf* L.,~J*fll;k . 1f:ttl!i!E~

Crassostrea-Cyclina-Geloina assemblages

Introduction and Acknowledgements

are recognized in this member. The
former is found in the most part of themember, and the latter is restricted inits distribution within a part of the basal
horizon. The Crassostrea-Cyciina-Geloina
assemblage is comparable with theTelescopium-Geloina assemblage of the
Miocene Kadonosawa-type fauna foundin the other areas of Japan, and is very
interesting to us because of its peculiar
combination of species.
We wish to express our sincere
thanks to Dr. Katura OYAMA of theGeological Survey of Japan at Kawasaki
for help to discriminate some fossils
and Dr. Tadashige HABE of the National
Science Museum at Tokyo for suggestion
on the taxonomy of Recent geloinas.
We are indebted to Associate Professor
Kiyotaka CHINZEI of the University ofTokyo for reading the manuscript.
Acknowledgements are due to Dr.
Yasuhide IWASAKI of the University ofTokyo for suggestion and permission to
study the specimens stored at the

Miyauchi-cho (formerly shinchiku-cho)of ShObara City, Southwest Japan has
been well known as a locality of the
Miocene· fossil molluscs, since OTUKA(1938) reported Ostrea, Soletellina,
Cyclina, Batillaria, and other well preserved shells. OYAMA (1967) mentionedthat the fossil molluscs from the locality
may be regarded as one of the typicalexamples of the tidal zone communities
in the inner bay facies of the transgressive phase. We have restudied the
Miocene molluscs occurred in the Shobara area from the paleoecological pointof view, and as a result of our research,
we will report here on the fossil molluscan assemblages of the Lower
Sandstone member of the Bihoku group(IMAMURA, 1953) at Miyauchi-cho. Twotypes of combination of molluscan
species, i. e. Batillaria-Crassostrea and* Received Aug. 1, 1973; read Oct. 28,
1972, at Matsuyama.

341

Kazuo OKAMOTO and Masami TERACHI"342

University Museum. Thanks are also
due to Professor C.C. RIN of the National
Taiwan University at Taipei and Dr.
Tunyow HUANG of the Chinese Petroleum
Corporation at Miaoli for information:about the formations yielding geloinas.
Appreciation is expressed to Mr. Shige:haru IRISA w A at Miyauchi-chO, ShObara
City and Mr. Osamu IRISE of the Hakushima Primary School of Hiroshima City
for collecting and supply of specimens.
This study was supported in part by
the Grant in Aid for Science Researches
from the Ministry of Education.

~

Kadonosawa

Nishitagawa~)

MUrakamio 8TanegaShima

Text-fig. 1. Locality map.

Notes on Geology

According to IMAMURA (1953), theMiocene formations distributed in theSh6bara, Miyoshi, and Mirasaka areas()f Hiroshima Prefecture are divided into
the Shiomachi formation in the lower

and the Bihoku group in the upper, andtheir stratigraphic relation is recognized
as a parallel unconformity. The nonmarine Shiomachi formation, 10-45 m
thick, is composed of conglomerate,
sandstone, shale, and tuff. It yields
fossil plants, such as Trapa yokoyamae
NATHORST, T. cf. borealis HEER, andLiquidamber jormosana HANCE.
The marine Bihoku group is subdivided into the Lower Sandstone andUpper Shale members (IMAMURA, 1953).
The Lower Sandstone member, 15-45 m
thick, is made up of conglomerate,
sandstone, and alternation of sandstoneand shale. It contains larger foraminifera and various molluscs.
Thecharacteristic fossils are as follows:
Larger foraminifera:
Miogypsina"kotoi HANZAWA ", Operculina complanata japonica HANZA w A.
Molluscs:
Anadara daitokudoensis(MAKIY AMA), Vepricardium ogurai (OTUKA), Dosinia suketoensis OTUKA, Tapes
siratoriensis (OTUKA), Vicarya callosa
japonica Y ABE and HAT AI, Batillaria
yamanarii MAKIY AMA.
The Upper Shale member, about 50 m
thick, is composed of shale containing asmall number of molluscs, such as Acila
submirabilis MAKIY AMA, Propeamussium
d. tateiwai KANEHARA, Fissidentaliumsp., etc. The study of smaller foraminifera from this group was carried out
by TAl (1953). The geologic age of theLower Sandstone member of the Bihoku
group is assigned to the Early to Middle
Miocene, or in other words tothe Zones
N. 8 to N. 9 of BLOW'S planktonic foraminiferal zonation (IKEBE et aI., 1972).
The geologic columns of the Lower
Sandstone member of the Bihoku groupshown in Text-fig. 2 is observed at asmall valley of Miyauchi-ch6 (Loc. 2 ofOTUKA, p. 23, text-fig. 1, 1938) in Textfig. 1. The Lower Sandstone member

634. Miocene molluscs from Miyauchi-chO, ShObara-covers unconformably the undulated-surface of the basement rock, i. e. tuff
of rhyolite or rhyodacite of Late Cretaceous. This member, approximately
23 m thick, is made up of angular343

pebble to cobble conglomerate, graymudstone with thin coal layers, mediumto coarse-grained sandstone, gray mudstone to fine-grained sandstone, andbluish gray fine- to medium-grained

10m

(f)
Q
::J

5

~
(I)

o

::J

CD

0

19 ':.A':\'i A
~ B

....

o

IS

C

..
D
III]

.I'
.I'

2

m

E

1t~:i@M F
G

H

Text-fig. 2. Geologic columns of the Miocene Bihoku groupin Miyauchi-chO, ShObara City.
A: Molluscs, B: Nodules, C: Coaly shale, D: Mudstone to fine-grainedsandstone, E: Sandstone, F: Pebble-bearing Sandstone, G: Conglomerate,
H: Rhyolite tuff.

344

Kazuo OKAMOTO and Masami TERACHI

sandstone in upward succession. The
lithofacies of the member seems to bevariable laterally, and the member contains coaly laminae and drifts of plantfragments besides molluscs.
Molluscan Assemblages

The fossil molluscs were collectedfrom the 7 horizons of different localities in the Lower Sandstone memberof the Bihoku group at Miyauchi-ch6(Text-figs. 1, 2 and Table 1). The shells
are abundantly found at Horizons 2, 4,
5, 6, and 7, but rare at Horizons 1 and 3.
Accordingly, the relative abundance ofeach species at each of the former
horizons is noted in Table 1, whereasthat of the latter ones is not shown.
The molluscs reported by OTUKA (1938)
might be obtained from the middle partof the columns (Horizons 5 and 6 in
Text-fig. 2). The brief description oflithology, modes of molluscan occurrence. and species composition of molluscs at e~ch horizon are as follows:
Hor. 1 :-Light brown mudstone tomedium-grained sandstone. A few fragmental molluscs are found with plantremains. They are Crassostrea sp.,
Cyciina sp., Batiliaria tateiwai, B. yamanarii, etc.
Hor. 2 :-Purplish gray mudstone tofine-grained sandstone withcoaly
laminae. Shells are clustered or sporadic.
The shells of oysters are not articulated.
A large number of specimens of Crassostrea sp. were collected with a few
individuals of Cyciina takeyamai.
Hor. 3 :-Light to moderate brownfine-grained sandstone. A few fragments
of molluscs occur sporadically. Amongthem, Batiliaria yamanarii is noticeable.,Hor. 4 :-Yellowish brown, muddy,
medium-, to coarse-grained sandstone.
Most shells are obtained from a disconti-

nuous fossil layer, and crassostreas:
occur as the nodules of fossil clusters.
Some geloinas are articulated, but theother bivalves are scarcely jointed ..
Cyciina takeyamai is very abundant ..
Crassostrea gravitesta, Geloina yamanei,.
and Anadara daitokudoensis are common ..
Few or rare species are Saxolucina khataii, Soletellina minoensis, Vicaryacallosa japonica, Batillaria tateiwai, etc.
The species association is peculiar to,this horizon.
Hors. 5 and 6 :-Dark gray mudstone·
to fine-grained sandstone. Most molluscs·
are scattered, but the lens at Hor. 6 is.
made up of densely aggregated oyster
shells. Batillaria tateiwai, B. yamanarii
and Crassostrea gravitesta are thedominant species, and Cyciina takeyamai
and Vicarya callosa japonica arecommonly found. The rare forms are
Anadara daitokudoensis, Lunatia meisensis, etc.
Hor. 7 :-Medium gray mudstone to,fine-grained sandstone. Molluscs occur
sporadically or clusteringly, and some
nodules are composed of clusteredshells. Some bivalves remain intact.
Batillaria yamanarii and Crassostrea
gravitesta are abundant as well as at
Hors. 5 and 6. Cyciina takeyamai andVicarya callosa japonica are associatedcommonly.
The rare species are
Anadara daitokudoensis, Saxolucina khataii, Meretrix sp., Trapezium sp.,
Cardilia d. toyamaensis, Soletellina
minoensis, etc. The number of rare'
species are more than those of Hors. 5
and 6.
The molluscan species listed in Table
1 are all common constituents of the
Early to Middle Miocene Kadonosawa(Kurosedani)-type fauna (CHINZEI and
IWASAKI, 1967;. IWASAKI, 1970; TSUDA.
1960) which was distributed widely inJapan and Korea at that time.

Judging634.
Table 1.

Miocene molluscs from Miyauchi-chO, Shobara

345

Fossil molluscs from the Miocene Bihoku group at Miyauchi-cho,Shobara City (Loc. 2 of OTUKA, 1938).

-Fossil- -Name- - - -. ---- Horizon__ _ ___ 1

I2

3

4

-=-B-a-rb-a-t-ia-s-p-.- - - - - - - - - - ' = : 1 - - 1- - - - - Anadara (Hataiarca) daitokudoensis(MAKIYAMA)
A. sp.
Crassostrea gravitesta (YOKOYAMA).C. sp.
-Geloina yamanei (OYAMA)

Meretrix sp.
·Cyclina takeyamai OYAMA·C. sp.
Nipponomarcia sp.
-Tapes (Siratoria) siratoriensis(OTUKA)
Trapezium (Neotrapezium) sp.
Cardilia d. toyamaensis TSUDA
Soletellina minoensis YOKOYAMA
S. ? sp.
Tellina notoensis MASUDA
T. sp.
Solen sp.
Nerita sp.
Vicarya callosa japonica Y ABE andHATAIV. sp.

6

Horizonunknown

7

OTUAD(1938)-;------'---x---'------

C

R

R

R

R

X
-1----;----1----:'---x VA

~

I-

C

·G. sp.

Felaniella ? sp.
.saxolucina k-hataii (OTUKA)
S.? sp.

5

x

R}A

R

x
R
F
--------1-----1-----

R

x

F

R

x

R

R

R

F

A

x

R

R

x

R

--------R-R-'---x--II-----1--: :

~

R

x

x

1

--I-R-I----I---R

R

R

C

F

R
-----1-1--1--

Vicaryella bacula (YOKOYAMA)·Cerithidea tokun-agai OTUKA*-C. ? sp.
Batillaria (Tateiwaia) tateiwai
MAKIYAMA
B. (T.) yamanarii MAKIYAMA

1

i
xi

Ix

~

R
C

R
A,R

I

_X_!_I__J~~I~

B. sp.

Lunatia meisensis (MAKIYAMA)
Pseudomurex ? tukiyoshiensis
OYAMA and SAKA
Trigonaphera sp.
Nekewis ? sp.

R

R

xi i

x

1

x

'I

____

nYI~'

,I _

x
_

x_

; I I ~!

R <5%, F 5-10, C 10-20, A 20-30, VA>30. 1,3,5,6,7: Batillaria-Crassostrea assemblage,
2,4 : Crassostrea-Cyclina-Geloina assemblage.
* OTUKA (1938) indicated that the type locality of Cerithidea tokunagai is Loc. 1 (atSuketo) of Text-fig. 1 on p. 40 of his article. On the other hand he marked the occurrence of C. tokunagai only at Loc. 2 (in Shinchiku.cho) in his Table 1, and he also
noted that the locality is Shinchiku.chO (Loc. 2) on the label of the type specimen
stored in the University Museum, University of Tokyo. Accordingly, the type locality.of C. tokunagai seems to be OTUK A'S Loc. 2 at Miyauchi-chO (formerly Shinchiku-chO).

Kazuo OKAMOTO and Masami TERACHI

346

from the species composition at eachhorizon, the molluscan fauna found in
the Lower Sandstone member can bedivided into the following two assemblages, namely Batillaria-Crassostrea
assemblage (Hors. 1, 3, 5, 6 and 7) andCrassostrea-Cyclina-Geloina assemblage(Hors. 2 and 4).
The former assemblage is distributed
in most parts of the member, but
the occurrence of the latter is restrictedwithin a part of the basal horizon of
the member. The idealized relationshipof both assemblages to the other
Kadonosawan assemblages is shown in
Table 2. These molluscan habitats
might not be so far from the place ofburial, judging from the observation ofmodes of fossil occurrence and sed i-ments enclosing fossils.
OTUKA (1938) concluded that themarine fauna of the Lower Sandstone
member of the Bihoku group is rich ingenera that are common with the inhabitants of estuaries or shallow inlandseas. In addition to OTUKA's conclusion.the mangrove coast (SHEPARD, 1963)or the estuarine mangrove swamp·(EMERY et al., 1957) of tropical or subtropical regions is possibly inferred asa depositional environment of the Lower
Sandstone member of the group, judging
from the generic composition of the
Crassostrea-Cyclina-Geloina assemblage
and lithofacies as OYAMA (1950) inferredon the Kurosedani fauna of the Toyama
basin.

Table 2. Correlation table of the bay head assemblages
in the Kadonosawa-type fauna.
Shobara
OKAMOTO e.
TERACHI (1973)

Bafil/aria Crassostrea~:raSSOSfr6'QCyclina-

Eastern Setouchi
RegionITOIGAWA (1971)

ToyamaTSUDA (1965)

Idealized Kadonosawatype Fauna
IWASAKI (1970)

OstreaCrassostreaBatil/aria

Geloina

Remarks on the Molluscan
Assemblages
The Batillaria-Crassostrea assemblage
at Miyauchi-chO is equivalent with
Crassostrea-Batillaria assemblage whichis commonly found at the basal part ofthe Bihoku group distributed in theeastern Setouchi region (ITOIGAWA,
1971).
It also corresponds to the
Batillaria and Ostrea assemblages of
the Kadonosawa area in Northeast
Japan where the typical Kadonosawa

Arcid-Potamid
fauna

Batil/aria
Te/es c opiumGe/oina

fauna is developed (CHINZEI and Iw ASAKI, 1967). At Miyauchi-chO, it isimpossible to divide the BatillariaCrassostrea assemblage into two assemblages, since batillarias are usuallyassociated with crassostreas at the basaL
part of the Bihoku group, as pointed by
ITOIGAWA (1971). The Batillaria andOstrea assemblages, however, weres~paratedfrom each other in the
Kadonosawa area (CHINZEI and IWASAKI,.
1967).
The combination of Crassostrea-

634. Miocene molluscs from Miyauchi-chO, 8hObara
Cyclina-Geloina is new to science andmuch interesting to us. Up to now,
geloinas have been reported from the
Eocene of Hokkaido (NAGAO and l>TATUME, 1943; MINATO, 1950), and fromthe Early to Middle Miocene of the area
near Toyama City (OYAMA, 1950) andtwo other areas in Japan. The Early to
Middle Miocene geloinas were found in
the Arcid-potamid fauna (TSUDA, 1965)of the Kurosedani fauna (TSUDA, 1960).
The Arcid-potamid fauna, also belonging
to the Kadonosawa-type fauna, wascollected from the lower part of theKurosedani formation of the Yatsuo
group near Toyama City of the Hokuriku
district. According to TSUDA (1965),
the characteristic and abundant speciesof the fauna are as follows: Anadara
kakehataensis, A. kurosedaniensis,Striarea
uetsukiensis, Cueulaea toyamaensis, Ostrea
gravitesta, Geloina staehi, G. yamanei,
Cyclina mitsuehii, Phaxas izumoensis,
Protorotella yuantaniensis, Cerithidea
kanpokuensis, C. yatsuoensis, Viearya
yokoyamai, Viearyella notoensis, Chieoreus
asanoi, and C. notoensis.
Judging
fromtheconstituents
mentioned above as well as from thespecies list of the Kurosedani fauna(TSUDA, 1960), the Arcid-potamid fauna
is considered to be the mixture of theOstrea, Batillaria, and TeleseopiumGeloina assemblages in the idealized
Kadonosawa-type fauna (IWASAKI, 1970),
or of the Batillaria-Crassostrea andCrassostrea-Cyclina-Geloina assemblages
at Miyauchi-cho.
The TeleseopiumGeloina assemblage was named at firstas the Teleseopium-Geloina biocoenosis
by OYAMA (1950), and was regarded as
the fauna proper to mangrove swampsof tropical and subtropical regions. In
this assemblage (Assemblage I of the'Kurosedani fauna by TSUDA, 1960), theforms of mangrove swamps proper,

347

such as Geloina and Teleseopium, areassociated with Anadara, Ostrea, Viearya,
Viearyella, Cerithidea, etc., which are
the constituents of the Batillaria andOstrea assemblages of the Kadonosawatype fauna.
Comparing the Crassostrea-CyclinaGeloina assemblage with the TeleseopiumGeloina assemblage, Crassostrea, Cyclina.
Geloina, and, Anadara are common inboth assemblages, but the former lacks.
the other characteristic elements ofmangrove swamps, such as Littorinopsis
miodelieatula and Teleseopium sehenekiof the latter assemblage. However, theCrassostrea-Cyclina-Geloina assemblage
is certainly comparable with the Teleseopium-Geloina assemblage in the
Kadonosawa-type fauna, since theprincipal constituents are common witheach other.
TSUDA (1965) reported Geloina yamanei,
Littorinopsis miodelieatula, and Terebratulina spp. from the Miocene Iwafune
formation near Murakami of Niigata
Prefecture, Northeast Japan. NISHIDA
and CHIHARA (1966) listed the following
molluscs from the Miocene l>yama formation of the Kamigo group in the
Nishitagawa coal-field area of Yamagata
Prefecture, Northeast Japan, besides
the molluscus reported by T ANAl (1951) :Anadara kakehataensis, Area spp., Clementia papyraeea, Cultellus sp., Geloina
yamanei, Joanisiella takeyamai, andViearya yokoyamai (discriminated by
TSUDA).
Of the other characteristic form ofTeleseopium from the Miocene formationsin Japan, SHUTO (1963) reported Teleseopium sp. with Anadara? daitokudoensis
and Traehyeardium shiobaraensis from
the Miocene l>yatori formation of the
Sakatani subgroup of the Nichinangroup in the Nichinan area, Miyazaki
Prefecture, Kyushu. IWASAKI (1970)

348

Kazuo OKAMOTO and Masami TERACHI

found Telescopium telescopium along with
Anadara "kakehataensis ", Ostrea gravitesta, Batillaria yamanarii, Joanisiellacumingi, Cyclina japonica, Clementia
papyracea, Polinices meisensis, etc. in the
Miocene Sakai formation of Tanegashima Island, Kagoshima Prefecture,
Kyushu. OKAMOTO, TAKAHASHI and
TERACHI (1971) also found a specimenof Telescopium schencki in the ModiolusCyclina-Turritella- Patinopecten assemblage from the Miocene Kawai formation of
Nima-cho, Shimane Prefecture, San in
district.
These Miocene assemblages containing
Geloina and Telescopium, except the
Modiolus- Cyclina- Turritella- Patinopecten
assemblage in Nima-cho, can be compared with the Telescopium-Geloina assemblage. Accordingly, it is concluded
that Telescopium, Geloina, and the other·elements of mangrove swamps proper
are usually associated with the constituents of the Batillaria and Ostrea.assemblages or the Arcid-potamid faunain the Kadonosawa-type fauna. The·occurrence of the Telescopium-Geloina.assemblage may be expected from the
Early to Middle Miocene formations.containing the Arcid-potamid fauna inJapan when the collection of fossils ismade carefully.
TAN (1938) studied the TelescopiumGeloina fossil biocoenosis from theT'ouk'oshan (Tokazan) group in Taiwan.
The association of his Loc. B in theUpper Pliocene to Lower Pleistocene"Konglin (Kyfirin)" formation at Saokeng,Kuanhsi-chen,
Hsinchu-Hsien(Soko, Kansai-syo, Sintiku Prefecture) is·characterized by the occurrence offollowing common or abundant species:
Cyclina sinensis, Assiminea kansaiensis,
Melanoides
subscabroides,
Cerithidea
ornata, C. cingulata, Telescopium tele.scopium, and Ellobium aurisjudae.

In this association Ostrea gigas, Polymesoda (Geloina) luchuana, and Cyclina
sinensis are more or less rare constituents. Comparing this with the Crassostrea-Cyclina-Geloina assemblage from
Miyauchi-cho,
however, Crassostrea
gravitesta, Geloina yamanei, and Cyclina
takeyamai are rather abundant and main
constituents at Miyauchi-cho. MARTENS(1897) listed the recent brackish watermolluscs from Indonesia. In genericlevel, the molluscs of Miyauchi-chO arein some common with those of Indonesia.
Description of Geloina Species

Family Corbiculidae GRAY, 1847
Genus Geloina GRAY, 1842
Geloina yamanei OYAMA, 1950
PI. 47, figs. 1, 2, 3, and 4

1950. Geloina yamanei OYAMA, Rep. Geol.
Surv. Japan, No. 132, pp. 13-14, pI. III,
figs. 3a and 3b .

Material:-Twenty five specimens ofGeloina were collected; most of them
are ill-preserved. A few specimens(GSEH-OK-HOOl-H003) are fairly wellpreserved and enough to identify with
G. yamanei. The specimens are kept at
the Geological Laboratory, Shinonome
School, Faculty of Education, Hiroshima
University.
Description :-Shell medium to large
in size for the genus, quadrangularlyor subtrigonally oval, inequilateral andmoderately thick; umbo at about athird from the anterior end, blunt, prosogyrous, and somewhat below thesummit of valve; antero-dorsal margin
straight and steeply sloped; anterior
end roundly angulated; postero-dorsal
margin almost straight or slightly
convex, posterior margin sightly convex,
subvertical; posterior end sub truncated,

634.

Miocene molluscs from Miyauchi-chO, ShObara

making blunt angles with the posterodorsal and -ventral margins; antero- topostero-ventral margin forms a largearc. Surface ornamented with concentricfine growth-lines and low wrincles; andwith weak furrows running from theumbo to the postero-ventral extremity.
Internal margin smooth; ligamental
suture distinct; ligamental groove longand excavated; nymph also long;post-ligamental cutting deeply V-shaped;

349

hinge broad and solid; dentition of left
valve three cardinal and an anterolateral and a postero-lateral teeth;
anterior cardinal tooth short and subvertical, middle one medium and oblique,and posterior one long and very oblique;bifurcation observable only on the
middle cardinal; anterior lateral tooth
short and very strong like cuspid, posterior one long and weak.

Measurements (in mm):Specimen

LengthHeight

Depth

----

-

,

I

I

H/L

I

D/L

I

1

Sh6baraPI. 47, fig. 1

73.0

65.4

(1/2) 19.3

2

Sh6baraPI. 47, fig. 3

57.2

50.5+

(1/2) 12.8

3

Topotype
PI. 47, fig. 4

60.2

53.4

4

Holotype
Oy AMA (1950)

57.5

52

I

0.90

I

0.53

0.88+

0.45

0.89

0.58

---

Remarks:-The present specimens aremorphologically quite similar to theholotype of Geloina yamanei (OYAMA,
pi. 3, figs. 3a, b, 1950) and the topotype{pi. 47, fig. 4), which were collected fromthe Kurosedani formation of the Yatsuo
group in the Hokuriku district. The
topotype is more or less trigonal thanthe holotype and the present specimens,
and has furrows running from the umbo
to the postero-ventral end. The lengthheight proportion among the specimensof yamanei is fairly constant, i. e. 0.88+
to 0.90, but the length-depth proportionof them is more variable, i. e. 0.45 to
0.58 as seen on the table of measurements.
Geloina stachi COy AMA, pi. 3, figs. 123., b, 1950) is found in association with
G. yamanei from the Kurosedani formation, but G. stachi is discriminated from

34.8
0/2)14

0.90

I

0.49

I

the latter in having laterally elongatedand more oval shell form (Length-height
proportion is 0.80 to 0.85).
Geloina yamanei differs from Geloina
hokkaidoensis (NAGAO and OTATUME, pi.
1, figs. 1-4; pi. 2, figs. 1-7, 1943; MINATO,
fig. 10, 1950), which occurred in the
Eocene of Hokkaido, in having larger
and lower shell form. The present
specimens are distinctive from Geloina
bibaiensis (NAGAO and OTATUME, pi. 1,
fig. 5, 1943; MINATO, fig. 11, 1950), which
was collected also from the Eocene of
Hokkaido, in having not protruded umbo
and truncated posterior end.
The present species has a close resemblance in the shell form to the recent
Geloina sinuosa (DESHAYES)* (CLESSIN,
pi. 45, fig. 1, 1879; OYAMA and ISHIYAMA, in fig. 6, 1963; SHIKAMA, pi. 40, fig.
6, 1964), which includes Geloina fissidens

Kazuo OKAMOTO and Masami TERACHI350(PILSBRY, pI. 8, figs. 5-6, 1895) as thesynonym, distributed in the southwest·
ern Pacific region and Okinawa. but it
has rather angulated and trapezoidal
outline and weaker furrows on the posterior surface than those of C. sinuosa.
The present form is less similar to
the recent Celoina papua (LESSON)(CLESSIN, pI. 14, figs. 7-8, 1879; KURODA
and HABE, fig. 943, 1965), which includes
Celoina luchuana (PILSBRY, pI. 9, figs. 45, 1895; HABE, fig. 233, 1951-'53; HABE,
pI. 55, fig. 5, 1961) and Celoina yaeyamaensis (PILSBRY, pI. 8, fig. 7; pI. 9, fig.
6, 1895) as the synonym, found in Okinawa and the southwestern Pacificregion. It is distinguished from C. papua
in having more rounded and higher
shell outline and furrows on the posterior area.
Locality:- Miyauchi-ch6, ShObara City,
Hiroshima Prefecture (Loc. 4 in Textfig. 1).
Lithology:- Yellowish brown (ormedium gray) medium- to coarse-grainedsandstone.
References
CHINZEI, K. and IWASAKI, Y. (1967): Paleoecology of shallow sea molluscan
faunae in the Neogene deposits of Northeast Honshu, Japan.
Trans. Proc.
Palaeont. Soc. Japan. N.S., No. 67, p. 93113.

CLESSIN, S. (1879): Die FamiIie der Cycla.
deen. 282 p., 46 Taf. 1m Systematisches
Conchylien-Cabinet von MARTINI und
CHEMNITZ. Bauer & Raspe, Nurnberg.
EMERY, K.O., STEVENSON, R. E. and HEDGPETH, J. W. (1957): Estuaries and la-* The name of Geloina sinuosa is generally
used for the geloinas having furrows on theposterior area, but G. sinuosa (DESHAYES)
1854 is regarded as a synonym of Geloina
coaxans (GMELIN) 1791 according to Dr. HABE
(personal communication).

goons.
In HEDGPETH, J. W. (ed.):Treatise on Marine Ecology and Paleoecology. Geol. Soc. Amer., Mem. 67,
Vol. 1, p. 673-750.
HABE, T. (1951-53): Genera of Japanese
Shells Pelecypoda and Scaphopoda 326 p.,
770 text-figs. Kairui-Bunken-Kankokai,
Kyoto (in Japanese).
(1961): Coloured lIIustrations of the
Shells of Japan (II). 183 p., 66 pIs.
Hoikusha, Osaka (in Japanese).
IKEBE, N., TAKAYANAGI, Y., CHIJI, M. and
CHINZEI, K. (1972): Neogene biostratigraphy and radiometric time scale ofJapan-An attempt at intercontinental
correlation. Pacific Gealogy, Vol. 4, p.
39-78.
IMAMURA, S. (1953): In IMAMURA et al.:
Guide Book of Geological Excursion,
Kamine, Funasa, Miyoshi, Mirasaka,
Sh6bara and ShOkozan, 50 p. Inst. GeoI.
Min., Fac. Sci., Hiroshima Univ., Hiroshima (in Japanese).
ITOIGAWA, J. (1971): Miocene molluscan
fauna from the eastern district of
Chugoku,Southwest
Japan, Kaseki(Fossils), No. 22, p. 29-36 (in Japanese).
IWASAKI, Y. (1970): A Miocene molluscan
fauna in the Philippines. Trans. Proc.
Palaeont. Soc. Japan, N.S., No. 17, p.
205-228, text-figs. 1-6, pI. 23.
KURODA, T. and HABE, T. (1965): In
OKADA, K. et al. (ed.): New lIIustrated
Encyclopedia of the Fauna of Japan (II).
803 p., 1462 text-figs.
Hokuryukan,
Tokyo (in Japanese).
MARTENS, E. VON (1897):
Suss- undBrackwasser-Mollusken des indischen
Archipels. Zool. Ergebn. einer Reise in
Nied. O. Indien v. DR. MAX WEBER, Bd.
IV, 331 p., 12 Taf.
MINATO, M. (1950): Fossil corbiculids from
Hokkaido. Shinseidai-no-Kenkyu (Cenozoic Research), No.3, p. 18-19, 1 pI. (inJapanese) .
NAGAO, T. and OTATUME, K. (1943): The
fossil corbiculids from the Palaeogene
Isikari Series in the Ishikari Coal-fields,
Hokkaid6. Jour. Fac. Sci. Hakkaid6 Imp.
Univ., Ser. IV, Vol. 7, No.1, p. 1-13,

634.

Miocene molluscs from Miyauchi-cho, ShObara

text-fig. 1, pis. 1-3.
NISHIDA, S. and CHIHARA, K. (1966) : Neogene
Tertiary stratigraphy in the Nishitagawa
Coal-field, Yamagata-Niigata Prefecture,
North Japan. Contr. Dept. Geol. & Min.,
Niigata Univ., No.1, p. 31-57 (inJapanese).
OKAMOTO, K., TAKAHASHI, Y. and TERACHI,
M. (1971): Molluscan assemblages from
the Miocene Kawai Formation in Nimach6, Shimane Prefecture. Mem. Vol.
Prof. H. MATSUSHITA, p. 179-185, pI. 14(in Japanese).
OTUKA, Y. (1938): Mollusca from the
Miocene of Tyugoku, Japan. Jour. Fac.
Sci., Imp. Univ. Tokyo, Sec. II, Vol. 5,
Pt. 2, p. 21-46, pis. 1-4.
OYAMA, K. (1950): Studies of fossil molluscan biocoenosis, No. 1. Biocoenological studies on the mangrove swamps,
with descriptions of new species from
Yatuo Group. Rep. Geol. Surv. Japan,
No. 132, p. 1-16, pis. 1-3.
- - (1967): Paleoecological problems of thedevelopment of coastal waters. Jub.
Publ. Comm. Prof. Y. SASA 60th Birthday,
p. 267-278 (in Japanese).
- - and ISHIY AMA, S. (1963): Molluscan
fossils and paleoecology. Chishitsu-news(Geological News), No. 104, p. 4-8, 6 textfigs (in Japanese).
PILSBRY, H. A. (1895): Catalogue of the
Marine Mollusks of Japan. 196 p., 10 pIs.
Frederic Sterns, Detroit.
SAKAMOTO, T. and NOZAWA, T. (1960):
Geological Map of Yatsuo (Scale 1:

BihokuKadonosawa
Kurosedani
Miyauchi
Murakami
Nichinan
Nima
Nishitagawa

~t.

{;UJ

r,

/

lR

~ i~TI ~

'8
tl
13

P'l
J:.
J¥j

f=

J!t

j§

83 JII

351

50,000) and its Explanatory Text. Geol.
Surv. Japan, Kawasaki (in Japanese).
SHEPARD, F. P. (1963): Submarine Geology
2nd ed. 557 p. Harper & Row, New York.
SHIKAMA, T. (1964): Sellected Shells of theWorld Illustrated in Colours (II). 212
p., 245 text·fig., 70 pIs. Hokuryu-kan,
Tokyo (in Japanese).
SHUTO, T. (1963): Geology of the Nichinan
area with special reference to the Takachiho disturbance. Sci. Reps. Fac. Sci.,
Kyushu Univ., Geol., Vol. 6, No.2, p.
135-166 (in Japanese).
TAl, Y. (1953): Miocene Foraminifera fromthe Sh6bara Basin, Hiroshima Prefecture.
Jaur. Sci. Hiroshima Univ., Ser. C, Vol.
1, No.3, p. 1-9.
TAN, K. (1938): Some Miocene fossils of
the Syokk6zan Formation. Japan. Jour.
Geol. Geogr., Vol. 15, Nos. 1-2, p. 17-30,
text-figs. 1-2, pis. 2-3.
TANAI, T. (1951): La structure geologiquede la partie septentrionale du gite ducharbon de Nishitaga wa, prefecture de
Yamagata. Jour. Geol. Soc. Japan, Vol.
57, No. 668, p. 157-170 (in Japauese).
TSUDA, K. (1960):
Paleo-ecology of theKurosedani fauna.
Jour. Fac. Sci.,
Niigata Univ., Ser. II, Vol. 3, No.4,
p. 171-203.
- - (1965) : Neogene Molluscan assemblages
in the inner zone of Northeast Japan
with special reference to the Middle
Miocene assemblages. Kaseki (Fossils),
No. 10, p. 20-30 (in Japanese).

SetouchiShinchiku
Shiomachi
Sh6baraSuketoTanegashima
ToyamaYatsuoi*Ji pi P'l
wrr
~
J:1.[
[f.

11IT
)]f.

Jl))

ii.<#

fill .:r ~

ill

JlJ

i\.

~

352

Kazuo OKAMOTO and Masami TERACHI

Explanation of Plate 47(All figures in about natural size, unless otherwise stated)

Figs. 1-4. Geloina yamanei OYAMA. 1. Reg. No. GSEH-OK-H001 x 0.9; 2. Reg. No. GSEHOK-H002; 3. Reg. No. GSEH-OK-H003; Loc. No.4. 4. Topotype, Reg. No. GSEH-OKT002 x 0.9; Loc. Kakebata, Yatsuo-chO, Toyama Prefecture (Loc. No. 206 on Geological
Map of Yatsuo (1/50,000) (SAKAMOTO and NozAwA, 1960)).
Figs. 5a, b-7a, b. Anadara (Hataiarca) daitokudoensis (MAKIYAMA). 5a, b. Reg. No. GSEHOK-H004; Loc. No.4. 6a, b. Reg. No. GSEH-OK-H0005; 7a, b. Reg. No. GSEH-OKH006; Loc. No.7.
Figs. 8a, b. Cardilia cf. toyamaensis TSUDA. Reg. No. GSEH-OK-H007; Loc. No.7.
Fig. 9. Soletellina minoensis YOKOYAMA. Reg. No. GSEH-OK-H008; Loc. No.7.
Fig. 10. Vicaryella bacula (YOKOYAMA). Reg. No. GSEH-OK-H009; Loc. No.6.
Fig. 11. Vicarya callosa japonica YABE and HATAI. Reg. No. GSEH-OK-HOlO; Loc. No.7.
Fig. 12. Batillaria (Tateiwaia) yamanarii MAKIYAl\IA. Reg. No. GSEH-OK-HOll; Loc. No.6.

OKAMOTO and TERACHI:

Miocene molluscs from Miyauchi-chO, Shobara Plate 47

2

5a

7a

Trans. Proc. Palaeont. Soc. Japan, N. S .• No. 95. pp. 353-363. pis. 48,49. September 20. 1974

635.

ONTOGENIES OF TWO MIDDLE ORDOVICIAN TRILOBITESFROM THE EDINBURG FORMATION. VIRGINIACHUNG-HUNG. HU
Department of Earth Science. Cheng Kung University, Taiwan. . ~ - -:/ =-71+1;1:.7 -( :/. . ~ - ?"P.iii:I'j:tWj;;t Iv f I:: A*2=~!i!. 2ftO)flE1*9E~: RAYMOND
Ie. J:: -:> L:ft.L i?t1t-: 2 till. Raymondaspis gregarius .to J:: rf. Amphilichas cf. prominulus0) ~{r.f~lt*le. -:JV'L licifJlGT Q c. c. b Ie..
-t-t1i?0) 9E~i®,&~ 1iJf3t L- t: *!
M"ft 0) kb!i!. IJ:
Illaenus valvulus. Isotelus sp .• Remopleurides caelatus. Phaseolaspis canus t. . cO)kb!i!. Ie.. "! t-: t~ftO)-t-t1fJ: Diacanthaspis. Apianurus .to J:: rf. "Lichas" 0) Y;iJ!i!.1e.!ffif.CJ.T Q ::.
c. ~a~ 12:,zple. L- t-:o ::. 0) ::. c. IJ:, J::tc 2 *JM='!l!i!.!lJiil;-t-t1:ft1O) Fa91:.'"][v , 1e.J1I~t... OOf,.3~Ie. <b*,

Q::' c. ~~~TQ bo)1:.'"<bQo

M

,~,

'Ig

species of trilobites with complete
growth sequence are recognizable fromthe original material. These are Remopleuride!i caelatus WHITTINGTON, Illaenus
valvulus RAYMOND, Otarion trilobus, n.
sp. (MS), Lonchodomas carinatus COOPER,
Acanthoparypha perforata WHITTINGTON
and EVITT, Ceraurinella typa COOPER,
Diacanthaspis lepidus WHITTINGTON, Amphilichas cf. prominulus (RAYMOND), Raymondaspis gregarius (RAYMOND), Isotelussp., Mesotaphraspis acris, n. sp. (MS),Dimero- pyge virginiensis WHITTINGTON
and EVITT, " Proetus" strasburgensis COOPER, Ceratocephala laciniata WHITTINGTON and EVITT, Apianurus barbatus
WHITTINGTON, Ceratocephala (Ceratocephalina) tridens WHITTINGTON, and Trinodus elspethi (RAYMOND). All are withvery well preserved ontogenic sequences.
The present report is a part of ontogenic research of these species, and therest species will be continuously described during the coming period.
The early ontogenies of Raymondaspis
gregarius is closely similar to those ofIllaenus valvulus, Isotelus sp., Remopleur-Introduction
The ontogenies of two species ofMiddle Ordovician trilobites are described. They are Raymondaspis gregarius (RAYMOND) and Amphilichas cf.
prominulus (RAYMOND). The growthsequences of the two species are incompletely known. both lack their early
developmental stage: either of anaprotaspid and/or metaprotaspid stages.
The studied material of the present
report is in black colored fine-grained
limestone, containing very abundantsilicified trilobites, bryozoans, ostracodes, a few brachiopods and conodonts
skeletons, and was collected from the
Edinburg Formation, 1.5 mile southeastof Strasburg Junction, Virginia by Dr.
F. RASETTI some years ago. The described specimens are all etched fromthe limestone in the 5-10% diluted glacial acetic acid as employed by WHITTINGTON and EVITT (1953). About 17* Received August 1, 1973; read Oct. 19.
1974, at Nagoya.
353

Chung-Hung Hu.:354

ides caelatus (WHITTINGTON, 1959; WHITTINGTON and EVITT, 1953), and Phaseolupis canus (Hu, 1971). Thus, they
possibly have the closely related phylogenetic development. The Amphilichas·cf. prominulus is similar to those of
Diacanthaspis, Apianurus (WHITTINGTON,
1956c), and "Lie has" (BEECHER, 1895;
WHITTINGTON, 1956a), except that the'skeletal surface of A. prominulus bears
no stout spines. However, they possibly shows the similar phylogenetic relationship as that of the former group.
The writer wishes to thank to Dr.
K. E. CASTER, University of Cincinnati,'Ohio, for his supervision and kindly
reading over the present manuscript.
The writer also gives his thanks to Dr.
F. RASETTI, Universita Degli Studi,
Roma, for a permission to study his·collections. The figured specimens are.all stored in the Geology Museum, Uni'versity of Cincinnati, Ohio (U. C. G. M.).

Systematic Description
Family Styginidae VOGDES, 1890
Genus Raymondaspis PRIBYL, 1948
Raymondaspis gregarius (RAYMOND)
PI. 48, figs. 1-34; Text-fig. 1.Bronteopsis gregaria RAYMOND, 1920, p. 283294; 1925, p. 69-70, pI. 3, figs. 12-14; B. N.
COOPER, 1953, pI. 9, figs. 1-7, 12-16, p. 24.
Raymondaspis gregarius (RAYMOND), WHITTINGTON, 1965, p. 402.

Remarks:-The present species is represented by more than one hundred
immature and mature specimens, whichshow a very good growth sequence.
WHITTINGTON's (1965) generic and spe·cific identification is followed. The·characteristics of the present species

during its ontogenetic development arethat the glabella expands forwardly; thepalpebral lobe is located posteriorly; therear fixigena becomes narrower; thelibrigena increases in width, and its
anterior facial suture is longer than theposterior one; the distal side of thepygidium made up of thoracic segments,
and the proximal side shows a reductionof the marginal spines.
The early protaspis is closely similar tothat of Illaenus valvulus RAYMOND, Isotelus sp., Remopleurides eaelatus WHITTINGTON (WHITTINGTON, 1953, 1959), andPhaseolupis eanus Hu (Hu, 1971), butdiffers ·in having an elongate skeleton,
less convexity, and three pairs of slender marginal spines.
Figured speeimens:-Cranidia, U.C.G.M.
40419n-q. Librigenae, U.C.G.M. 40419s-w.
Hypostoma, U.C.G.M. 40419r, x. pygidia,
U.C.G.M. 40419d'-f'.
Raymondaspis gregarius (RAYMOND),
ontogeny: - The ontogenetic development of the present species is subdivided into four stages: the early protaspid,
paraprotaspid, early meraspid, and latemeraspid. The" early protaspid" stage
is an informal division, which belongs
either to the anaprotaspid or the metaprotaspid stage, but since it is so rare,
its stage is indefinitely known.
Early protaspid stage (PI. 48, figs. 1-3,
and text-figs. 1 A, B).-The convex shield
is about 0.4-0.45 mm in length (sag.),elongate, oval, and has three pairs ofvery slender and short marginal spines;
these marginal spines are about equally
spaced and radiate from the shield margin; the axial lobe is well defined by adorsal furrow; it is elongate fusiform,
and no transverse segmental furrows
are recognizable; a pair of superciloid
ridges is indented lateral from the sidesof the anterior axial lobe, and run a
short distance to terminate in front of635.

Middle Ordovician trilobites

A

8

G

F

c

Text-fig. 1.

o

o

J

H

L

K

N

355

p

Q

An ontogenetic sequence of Raymondaspis gregarius (RAYMOND).

A, B, dorsal and ventral views of an early protaspid shield, x 45; C, D, two paraprotaspid'shields, x 25; F, G, two early meraspid cranidia, x 25, x 10; H, a late meraspid cranidium,x 22; I, an holaspid cranidium, x 9; J, M, two late meraspid pygidia, x 8, x 10; K, hypo'stoma, x 5; L, an early meraspid pygidium, x 20; N, an holaspid librigena, x 10; 0, P, alate and an early meraspid librigenae, x 18; Q, an holaspid pygidium, x 10. (All drawings
were made from photographs.)

356

Ch~tng-Hungthe first pair of marginal spines. The
surface is covered by very faint granules.
Paraprotaspid stage (Pl. 48, figs. 4-6,
and text-figs. Ie, D.).-The shield is rectangular in outline, rounded both anteriorly and posteriorly, moderately convex, and is about 0.5-0.8 mm in sagittal
length; the glabella is well dilimited bydorsal furrows, slenderly cylindrical,
with anterior end strongly expanded
forward; three pairs of glabellar furrows are recognizable, all across thecentral axis shallowly and deepen laterally; the occipital ring is smaller than
the glabellar segments, transverse elliptical and situated slightly behind the
mid-line of the shield (tr.); no anteriorborder and the preglabellar field areseen, except for a pair of superciloid
ridges which extend laterally from theside of the anterior glabella; the posterior fixigenal border has not been ob·
served; the cranidial and the protopygidial shield are indistinctly separated
by a segmental furrow; the protopygidium is transversely obovate, and without distinct dorsal and pleural furrows;
the posterior margin is broad, decorated
by three or four pairs of serrate spines.
The skeletal surface is covered by faintgranules.
This stage is differentiated from theprevious one in having the shield welldifferentiated into axial and pleurallobes, the facial suture now appears on
the dorsal surface, and the protopygidium is well developed.
Early meraspid stage (Pl. 48, figs. 7-11,
27, 28, and text-figs. IL, F, P.).-The
cranidium is trapezoidal in outline, convex, and about 0.7-0.9 mm in length(sag.); the glabella is about the same
width as the fi'xigena, expanding anteriorly' from th~ occipital furrow, anddivided into four incomplete glabellar

Husegments; the occipital ring is distinctly
impressed by the occipital furro\Y', elliptical-transverse to crescentic, convex,
and bearing a minute median granule;the anterior border is rather narrow,and gently arching forward; there is no
preglabellar field, but a deeply marked
frontal furrow. The fixigena is slightly
wider than or of the same width as
the glabella, and convex; the posterior
fixigena is triangular, convex, and sloping downward; the posterior border isabout twice as wide as the occipital ring(tr.), narrow, convex, and gently arches
forward; the crescentic palpebral lobe
is small, indistinctly delimited by thepalpebral furrow, and is located on the
mid-line of the cranidium; the anteriorfacial suture is gently divergent-convex,
and the posterior one is divergentstraight or slightly convex at the extreme lateral end. The librigena is crescentic, moderately convex, with a small
ring located on the mid-line of the facial
suture; the lateral border is faintly delimited by a furrow, narrow, and convex; the ocular platform is more than
twice as wide as the lateral border, andgently convex; the genal spine is short,stout, and with the distal portion broad
and the proximal end slender.
The pygidium is semicircular in outline, convex, and contains more thanseven non-ankylosed segments; the axis
is convex above the pleural lobe, it isslenderly cylindrical, tapering backward,
and not extending the full length of thepygidium; each pleural band is distinctly impressed by an intrapleural furrow,and ending into a short and broad spine;
the inner marginal furrow is faint but
well impressed at the terminal portion.
The skeletal surface is covered by faintgranules.
The present stage is differentiatedfrom the previous one in having the635.

Middle Ordovician trilobites

cranidium appearing of the anteriorborder, the palpebral lobe is located on
the mid-line of the glabella, the fixigena
becomes narrower, and the pygidium
has freely articulated thoracic segments.
Late meraspid stage (PI. 48, figs. 12-15,
22, 23, 30,31, and text-figs. lB, J, M, 0.).The cranidium is trapezoidal in outline,
convex, about 0.9-1.2 mm in length; theglabella is strongly expanded forward,
convex, well delimited by deep andbroad furrows, and two pair of glabellar
furrows are faintly impressed behindthe mid-line of the glabella; the crescentic occipital ring is convex, well set
off from the glabellar base by the occipital furrow and bearing a tiny mediantubercle; the narrow anterior border isseparated by a deeply impressed frontal
furrow, and arches forward without any
preglabellar field; the fixigena is about
the same width as the glabella, convex,
turning upward from the deep dorsal
furrow, and occupied by a pair of rounded palpebral lobes at ·the lateral freemargin; the medium-sized palpebral lobe
is situated behind the mid-line of theglabella (tr.), convex, with the palpebral
furrow faintly marked; the posterior
fixigena is subtriangular, convex, withthe posterior border about the same
width as the occipital ring (tr.); bothanterior and posterior facial suture arestrongly devergent-convex. The librigena is short and broad, and its broad
lateral border is fiat; the ocular platform is convex; the genal spine is shortand stout; the broad fiat doublure islocated ·along the lateral margin andwith the obtuse projection directed
anteriorly.
The pygidium is semicircular in outline, convex, with the dorsal furrows
well impressed; the axis is slenderly
conical, tapering posteriorly and has aposterior axial ridge directed to the357

marginal furrow; one or two free articulated thoracic segments. The skeletal
surface is generally granulated; wrinkles are faintly impressed on the cranidial surface.
The distinct features of the present
stage are that the palpebral lobe becomesrounded, and located posteriorly fromthe mid-line of the glabella, that the posterior fixigena is narrower, and that themarginal spines of the thoracic segments.
and of the pygidium are reduced in size.
Figured specimens:-Early protaspides,
U.C.G.M. 40419, 40419a. Paraprotaspides,
U.C.G.M. 40419b-d. Early meraspides,
U.C.G.M. 4041ge-i, y, z, a/ . Late meraspides, U.C.G.M. 40419j-m, b', c'.
Family Lichidae HA WLE
and CORDA, 1847
Genus Amphilichas RAYMOND, 1905
Amphilichas d. prominulus (RAYMOND)
PI. 49, figs. 1-31 and text-fig. 2
d. Acrolichas priminulus RAYMOND, 1925, p.
126, pI. 8, figs. 11, 12; TRIPP, 1958, p. 577,
table 1.

Diagnosis: - Cranidium trapezoidal,
strongly convex; glabella broadly rounded, divided into three lobes by deep
furrows; anterior brim narrow without
preglabellar field; fixigena narrow, triangular, located behind of the crescentic
palpebral lobe, and about the same width
as the occipital ring (tr.). Librigena
narrow blade-like, concave laterally;
lateral border narrow, delimited without
lateral furrow; genal spine broad,Pygidium triangular;
medium-sized.
axis broader than pleural lobe, divided
by one or two rings and a terminal
portion. Four pairs of different sized
marginal spines present. Surface cover-

:358

Chung-Hung Hu-covered by fine and coarse pustules.
Description :-The cranidium is regu1arly trapezoidal in outline, strongly,convex, and with the anterior glabellar
rather prominent; the glabella is divided
into three lobes by deeply impressed
10ngitudinal furrows; the median lobe
is expanded antero-laterally and arches
forward; the lateral lobes are elongate·oval; the paired longitudinal glabellar
furrow is deeply marked at nearly the'base of the central lobe, and ends with.a pair of rounded pits; the anterior.glabellar furrows are shallow, and somewhat more prominent laterally along the·side of the glabellar lobe; the occipital:ring is transverse-triangular, convex,
up-turned from the well-marked occipital furrow and with the posterior mar.gin bearing tiny indentations; a rather.large granule occurs on the center ofthe occipital ring; the anterior borderis rather narrow, convex, and surrounds
the anterior glabellar margin directly,
without any preglabellar field. The
fixigena is well demarked by deep dorsal.and pleural furrows, it is narrow trian.gular and located behind the lateral,glabella and the palpebral lebes; no.anterior fixigena is recognizable; the_postero-lateral border is narrower than.occipital ring (tr.), and turned upwardfrom the well-developed border furrow.
The librigena is a narrow blade withboth ends curving laterally; the lateralborder is narrow, vertical, without dis-tinct border furrow; the ocular platform
is of medium width and gently convex;
the rounded eye-ring occupies the inner
free margin; the genal spine is broadly
ilat, with the posterior end obtusely:pointed. The underside of the librigena
is furnished with a broad doublure.lateral and posterior to the genal spine.
The hypostoma is hexagonal in outline, convex, and with the posterior

margin curving inward; the broadly
subquadrate median body is well delimited by deeply impressed furrows,
and is divided into an anterior andposterior half by a pair of macular furrows; the inner margin is broad andsorrounds the posterior median bodywith nearly equal width; it is convex
along the axis (sag.) and depressed
laterally; the marginal border is rather
narrow, elevated along the antero-lateral
median body with a pair of rather short,
downward sloping lateral wings .
The thoracic segment is of medium
width and convex; the pleural lobes archpestero-laterally, and are of almost equal
width from the dorsal furrow to thelateral ends; the axial ring is convex
above the pleuron, and it is divided intoa small anterior half-ring and a large
posterior one by a narrow but deeply
incised furrow; the axial furrow is
distinct; the pleural lobe is extended
laterally and posteriorly, and has three
short spines directed forward from theanterior margin; the intrapleural grooveis fine and distinct, and runs from theanterior end of the axial furrow posterolaterally to end at the mid-length of thepleuron.
The pygidium is triangular in outline,
convex, and has the axis broader thanthe pleural lobe; the axial lobe is convex above the pleuron, well set off by
dorsal furrows, and is divided into one
or two axial rings and a terminal portion, which is convex, triangular, andwith the posterior end pointed to therear pygidial margin. The pleural lobe
consists of three or three and a half
segments, and is well divided by theinterpleural furrows; the intrapleuralfurrow is shallow but distinct; each of
the pleural segments ends with a pairof blunt spines, which are directed
postero-laterally; no marginal furrow or635.

Middle Ordovician trilobites

359

A

B

c

o

£

F

G

H

J

K

N

Text-fig. 2.

LoA growth sequence of Amphilichas cf. prominulus (RAYMOND) •. A-C, three different sized paraprotaspides, x 30; D-E, two early meraspid cranidia, x 20 ;.F, H, two late meraspid cranidia, x 14, x 10; G, a meraspid pygidium, x 9; I, J, K, threedifferent sized hypostomata, x 20, x 15, x 10; L, a large sized cranidium, x 9; M, a large".sized pygidum, x 7; N, a thoracic segment, x 4, an adult librigena, x 2. (All drawings'\Were made from photographs,)

360

Chung-Hung Hu

border are known.
The surface of the skeleton is coveredby fine- and medium-sized granules,
among which the large-sized pustules
are sparsely scattered. The lateral margin of the librigena is marked by parallel ridges and the hypostoma is with
granules anteriorly and ridges laterally.
Remarks:-According to TRIPP (1958)
about 23 species of Amphilichas havebeen described from North America.
They belong to both the Middle andUpper Ordovician. The present material
conforms to RAYMOND's (1925) report.
The narrow anterior border and theprominent anterior glabella are thesame, although RAYMOND's specimens
are much larger and may represent fullygrown forms. RAYMOND'S material was:collected from McNutt Quarry, near·
Sharon Spring, and from the Hoge farm,in Bland County, Virginia. This is thesame general locality as that from which
the present material came.
Figured specimens:-Cranidia, U.C.G.M_
40420u, z, a'-d'. Librigenae, U. C. G. M.
40420n, o. Hypostoma, U.C.G.M. 40420km. Thoracic segments. U.C.G.M. 40420p,.
q. Pygidia, U.C.G.M. 40420v-y.
Amphilichas cf. prominulus (RAYMOND),.
ontogeny :- Paraprotaspid stage (Pl. 49,.
figs. 1-8, and text-figs. 2 A-C.).-The,shield is composed of the cranidium and.
the pygidium; it is about 0.5-1.0 mm insagittal length, oval and convex; theglabella is cylindrical, without glabellar- - - - .. - - - - - - - - - - - - - - - - -Explanation of Plate 48
Figs. 1-34. Raymondaspis gregarius (RAYMOND).
1-3. Two early protaspid shield, showing the three pairs of marginal spines and the weIr
differentiated axial and pleural lobes; 1, x 45, U. C. G. M. 40419; 2, 3, dorsal and ventral.
views of two shields, x 45, U. C. G. M. 40419a.
4-6. Three paraprotaspid shields, showing the appearence of the protopygidium; 4, x 25,.
U. C. G. M. 40419b; 5, x 25, U. C. G. M. 40419c; 6, x 25, 40419d.
7-11. Five early meraspid cranidia, showing the palpebral lobes, located on the mid-lineof the cranidium (tr.); 7, x 25, U. C. G. M. 4041ge; 8, x 25, U. C. G. M. 40419f; 9, x 25,
U. C. G. M. 40419g; 10, x 22, U. C. G. M. 40419h; 11, x 29, U. C. G. M. 40419i.
12-15. Dorsal and ventral views of four late meraspid cranidia, showing the palpebral lobes,.
situated behind the mid-length of the cranidium, and the great expansion of the anterior·glabella; 12, x 18, U. C. G. M. 40419j; 13, x 16, U. C. G. M. 40419k; 14, x 22, U. C. G. M ..
404191; 15, x 22, U. C. G. M. 40419m.
16-19. Four holaspid cranidia; notice the rounded palpebral lobes, narrow fixigenae, and the,postero-Iaterally directed fixigenal region; 16, x 16, U. C. G. M. 40419n; 17, x 16, U. C. G. M.
404190; 18, x 9, U. C. G. M. 40419p 19, x 9, U. C. G. M. 40419q.
21-25. A growth series of librigenae, showing the change of the ocular position during thedifferent growth stages; 21, 22, two possible early meraspid librigenae; x 18, U. C. G. M.
40419s; x 18, U. C. G. M. 40419t; 23, a possible late meraspid librigena; x 15, U. C. G. M ..
40419u; 24, an incomplete librigena, x 10, U. C. G. M. 40419v; 25, x 10, U. C. G. M. 40419w.
20,26. Two large hypostomata; x 7.5, U. C. G. M. 40419r, x.
27-29. Three early meraspid pygidia; notice the marginal spines and the distinct segments;.
27, x 15, U. C. G. M. 40419y; 28, x 20, U. C. G. M. 40419z; 29, x 20, U. C. G. M. 40419a'.
30,31. Two late meraspid pygidia, each associated with one or two thoracic segments; x 10,.
U.C.G.M. 40419b'; x8, 40419c'.
32-34. Three mature pygidia, showing the absence of the distinct pleural bands or furrows;:
32, x 10, U. C. G. M. 40419d'; 33, x 5, U. C. G. M. 4041!?e'; 34, x 6, U. C. G. M. 40419f'.

Hu:

Middle Ordovician trilobites

Plate 48

635.

Middle Ordovician trilobites

furrows; instead four pairs of tubercles·exist; the occipital ring is convex,
well divided by an occipital furrow andthe posterior cranidial suture; the anterior border is narrow, horizontal, elevated, and bearing a row of granules;
the fixigena is triangular, broad posteriorly and narrower forward, with thewidth slightly narrower than the glabella between the palpebral and thedorsal furrows; the small, well elevatedpalpebral lobe is located in front of the
mid-length of the glabella, and its anterior end is continuous with the elevated ocular ridge; the posterior fixi.gena is broad, with the elevated posterolateral border well demarked by a borderfurrow; the lateral end of the posterior
fixigenal border is extended posterolaterally, and ends in a pair of projections. The protopygidium is triangular,-convex, and possibly composed of threeindistinct pygidial segments; the axis
is conical, tapering posteriorly, and iswell delimited by dorsal furrows; thepleural segments end with a pair ofmarginal spines; no marginal furrow orborder is known.
The surface of the small skeleton iscovered by both small- and large-sized,granules, of which the larger ones aremostly regularly arranged. The large.granules are markedly developed along
the anterior border; eight pairs occur
on both of the glabella and the fixigenae,
one row of tubercles on the occipitalring, and seven or eight pairs on boththe pygidial axis and the pleural lobes.
Early meraspid stage (PI. 49, figs. 9-11,
19,23, and text-figs. 2D, E, I.).-The cran:idium is trapezoidal in outline, convex,
about 0.8-1.0 mm in length (sag.); the.glabella is deeply and broadly delimited.by dorsal furrows, it is oblong or nearlytruncato-conical, convex, and without
glabellar furrows, except for a pair of361

A-shaped ridges which extend from theglabellar base to the fixigenal regions.
These suggest the initiations of thelateral glabellar lobes. The occipitalring is convex and well separated by
the occipital furrow. The anterior border is convex, arching forward, about
one-third the length of the glabella.
The triangular fixigena is medium-wide,
convex, at about the same level as theglabella; the medium-sized palpebral
lobe is situated in front of the mid-lineof the glabella (tr.). It is crescentic,
convex, and extends continuously forward to the antero-Iateral glabellar margin; the postero-Iateral border is broader
than the occipital ring (tr.), convex, andhas its lateral end directed slightly
posteriorly.
The triangular pygidium is convex,
divided into two segments and a terminal portion, no marginal furrow orborder is seen; the axial lobe is slightly
wider than the pleuron, convex above
the axis, and divided into two axial
rings and a triangular terminal portion
by distinct furrows; the anterior pygidial segment ends with a pair of
medium-sized marginal spine; and thatthe terminal spines are large and stouter than the rest.
The hypostoma is elongate, hexagonal,
convex, and divided into three sections
by the macular and the median body
furrows; the posterior margin curves
slightly inward, and the lateral wings
are small.
The skeletal surface is covered by fineand large-sized pustules; the pygidial
segment has two rows of granules along
the anterior and the posterior pleural
bands .
The present stage differs from theprevious one in having the oblong or
truncato-conical glabella, the anteriorborder is wider, and the fixigena be-362

Chung-Hung Hu

comes narrower.
Late meraspid stage (PI. 49, figs. 13, 20,
21,24, and text-figs. 2F, G, J.).-The cranidium is trapezoidal in outline, convex,
and about 1.0-1.5 mm in length (sag.);
the glabella is oval and divided into alarge central lobe and a pair of small
lateral nodes by a deep furrow; thecentral glabellar lobe is convex, broadly
expanded antero-Iaterally, and the lateral lobes are elongate oval, small, andlocated behind of the anterior glabellar
expansion; the longitudinal furrows do
not extend to the occipital furrow; theoccipital lobe is crescentic, convex,
bearing a median tubercle; the anteriorborder is medium wide, convex, archingslightly forward and presents no preglabellar field. The fixigena is narrow,triangular, convex, has the posterolateral border slightly narrower thanthe occipital ring (tr.) ; the medium sized

palpebral lobe is crescentic, located on
the mid-line of the glabella (tr.), its.
anterior end is continuous with the wellelevated ocular ridge, and end at the'side of the antero-Iateral margin of theglabella.
The hypostoma is nearly hexagonal,
convex along the axis, and divided into
three sections; the anterior section islarge and transverse oval; the posterior
two sections are about the same width(sag.); the margin of the hypostoma issurrounded by a narrow elevated marginal border.
The pygidium is triangular in outline,
convex; the axial lobe is convex above
the pleural lobe, and divided into two
narrow axial rings and a triangularterminal portion by the indistinct ring
furrow; the posterior terminal portionis short and sharply pointed; no marginal border or furrow is seen; four or

Explanation of Plate 49
Figs. 1-31. Amphilichas d. prominulus (RAYMOND).
l-S. Ventral and dorsal views of eight paraprotaspid shields; notice the cylindrical glabella
and the appearence of the anterior border. I, x 30, U. C. G. M. 40420; 2, x 30, U. C. G. M.
40420a; 3, x 30, U. C. G. M. 40420b; 4, X 30, U. C. G. M. 40420c; 5, x 25, U. C. G. M. 40420d;.
6, x25, U.C.G.M. 40420e; 7, x25, U.C.G.M. 40420f; S, x25, U.C.G.M. 40420g.
9-11,19. Dorsal view of four incomplete early meraspid cranidia; notice the subquadrate
glabella, and the presence of the glabellar nodes. 9, x 20, U. C. G. M. 40420h; 10, x 20,.
U.C.G.M. 40420i; 11, x20, U.C.G.M. 40420j; 19, x20, U.C.G.M. 40420r.
12-14. Three different sized hypostomata, showing the morphologic changes of the median.
body. 12, x 20, U. C. G. M. 40420k; 13, x 15, U. C. G. M. 404201; 14, x 10, U. C. G. M. 40420m.
15,16. Ventral and dorsal views of two librigenae. x 7, U. C. G. M. 40420n; x 21, U. C. G. M ..
404200.
17, IS. A large and a small thoracic segments. x 4, U. C. G. M. 40420p; x 6, U. C. G. M. 40420q ..
20,21. Dorsal view of two incomplete late meraspid cranidia. x 14, U. C. G. M. 40420s; x 10,.
U.C.G.M.40420t.
23-26. Four small and large sized pygidia, showing the differentiations of the pleural spines.
23, x9, U.C.G.M. 40420v; 24, x6, U.C.G.M. 40420w; 25, x6, U.C.G.M. 40420x; 26, x7,.
U.C.G.M.40420y.
22,27-31. Five different sized holaspid cranidia; notice the enlarging of the second glabellar'
node and the reduction of the anterior border. 22, x 14, U. C. G. M. 40420u; 27, x 9,_
U.C.G.M. 40420z; 2S, U.C.G.M. 40420a'; 29, x10, U.C.G.M. 40420b'; 30, x9, U.C.G.M ..
40420c'; 31, x 6, U. C. G. M. 40420d'.

Hu:Middle Ordovician trilobites

Plate 49

635. Middle Ordovician trilobites
five pairs of marginal spines run continuously from the pleural bands; thefirst and the third pairs of spines arelarge and stouter, and the second, fourth,and fifth pairs are short and slender.
The present stage is differentiatedfrom the early meraspid stage by thepresence of the lateral glabellar lobes,
the narrower anterior border, and thepresence of the fixigena, the shorterand broader hypostoma, and three pairsof short pygidial spines. It is differentiated from the holaspid stage by its
wider anterior border, small lateral glabellar lobes, narrower hypostoma, andthe slender terminal spines.
Remarks;- A well-preserved immature
specimens of " Lichas ", which were recovered by BEECHER (1895) from theLower Devonian New Scotland limestone,
Albany Co., New York, and restudied
by WHITTINGTON (1956b), show similar
structure to that here examined, but
BEECHER'S specimen is rounder, and thepalpebral lobe is broader, whereas thepresent specimens are oval, and thepalpebral lobe is elongate as comparedwith specimens of the same age.
Figured specimens; - Para protaspides,
U. C. G. M. 40420, 40420a-g. Early meraspides, U. C. G. M. 40420h-j, r. Late meraspides, U. C. G. M. 40420s, t.
References
BEECHER, C. E. (1893): Larval forms of
trilobites from the Lower Helderberg
group. Am. Jour. Sci., ser. 3, v. 46, p.
142-147, pI. 2.
- - (1895): The larval stages of trilobites:
Am. Geol., v. 16, p. 166-197, pI. 8-10.
COOPER, B. N. (1953): Trilobites from theLower Champlainian formation of the

363

Appalachian Valley. Geol. Soc. America,.
Mem. 55, 66 p, pis. 1-19, 2 text-figs., 1
table.
Hu, C. H. (1971): Ontogeny and sexual dimorphism of Lower Paleozoic Trilobita.
Palaeontogr. Americana, v. 7, no. 44,.
p. 31-125, pis. 8-26, 58 text-figs.
RA YMOND, P. E. (1920): Some new Ordo-·
vician trilobites.
Mus. Compo Zool.,.
Bull., v. 64, no. 2, p. 273-286.
(1925): Some trilobites of the Lower
Middle Ordovician of eastern North
America. Ibid., v. 67, no. 1, 180 p., pis.
1-10.
TRIPP, R. P. (1958): Stratigraphical andge·ographical distribution of the named
species of the trilobites Superfamily
Lichacea. Jour. Paleont., v. 32, no. 3,
pp. 574-582, pI. 85.
WHITTINGTON, H. B. (1941): Silicified trendon trilobites. Jour. Paleont., vo. 15, no.
1, p. 492-522, pIs. 72-75, 13 text-figs.
(1956a): BEECHER'S supposed odontopleuried protaspis is a phacopid. Ibid.,
v.30, no. 1, p. 104-109, pI. 24, 2 text-figs.
(1956b): BEECHER'S Iichid protaspis
and Acanthopyge consanguinea (Trilobites). Ibid., v. 30, no. 5, p. 1200-1204,
pI. 131, 1 text-fig.
(1956c): Silicified Middle Ordovician
trilobites (the Odontopleuridae). Mus.
Compo Zool., Bull., v. 114, no. 5, p. 159289, pis. 1-24, 25 text-figs.
(1959): Silicified Middle Ordovician
trilobites (Remopleurididae, TrinucIeidae, Raphiophuridae, Endymioniidae).
Ibid., v. 121, no. 8, p. 373-496, pis. 1-36,
8 text-figs.
(1965): Trilobites of the Ordovician
Table Head Formation, western Newfoundland. Ibid., v. 132, no. 4, pp. 281441, 68 pIs.
WHITTINGTON, H.B. and EVITT, W.P. (1953) :Silicified Middle Ordovician trilobites.
Geol. Soc. America, Mem. 59, 135 p. pIs.
1-33, 27, text-figs. 2 tables.

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 95, pp. 364-370, pI. 50, September 20, 1974

·636. MARINE FOSSILS FROM THE MONIW A FORMATION ALONG
THE NATORI RIVER, SEND AI, NORTHEAST HONSHU,
JAPAN, PART 2. PROBLEMATIC A FROM
THE MONIW A FORMATION*
KOTORA HATAI
Tohoku University

KOICHIRO MASUDA
Department of Geology, Miyagi University of Education

HIROSHI NODA
Institute of Geology and Paleontology, Facultyof Science, Tohoku University

fllli':l"mi5J&JllmU~~~JiJ}EfflJm1r.:p, {"O) 2. ~IliJiJ}E7·P 7'V"'?T -1 iJ : lJl1i':l"m1¥ij!§tf~O)~~Ji~Jitfil\J:. !J, 1;t1~7t~11M1*0);j}\i&.""t'J}E1±\ L. 'k. *m;j~J~Jr%~1r.:p~~H L. t::.o {"0)~j.Ji!lJ
i11i~0):fiER~""t'~:b~1",{"O)~~~iJijlr.I'j:fiiJ £?:'~~J . tn;*.)('b tJ:<, ffi"1i) £?:,i.J.""t', jiIjj~ffiji.J;~ l>.

~~~.~~~m."O)M.~~~'bO)""t'~~o ftO)G~r.:fi~*~~~~~, ~<~<~'b*Ji'~ftIC~lt ~llG~JRI'j:~<tJ: <, 1r.:P0)J}E;j}\ ~1r.:fi . '!Jl~fll!0)lli:w.0)~i&.~ c !J1~~ 'bO) ~O)JU.J(~iM~1=rtJ:",,f-=~:lltMoniopterus japonicus tJ:~fJi'~· fJi'fll!~ L., i4ii~~mm'7 ~"~O)E~~.L.'k.o~#~~·~W.-M·.wmm

at several centimeters above the baseof the marine Moniwa Formation inassociation with such fossils as pelecypods, gastropods, brachiopods, bryozoans and foraminifers.
Of thementioned fossils, the brachiopods from
the Moniwa Formation distributed along
the Natori River are described in Part
1 of the series of the articles planned
to be published on the marine fauna of
the formation.
A review of the fossils publishedpreviously from the Moniwa Formation,
the stratigraphic position of the formation in the geological column of the
Sendai area, and remarks on the

Introduction
From the basal part of the marine
Moniwa Formation exposed in a cliff
facing the Natori River at Moniwa,
Sendai City, several peculiar shaped
fossils were discovered. The description
and discussion of the problematica of
unknown systematic position and natureforms the scope of the present article.
The peculiar shaped fossils were found* Received Sept. 20, 1973, read Oct. 20,
1973 at Tokyo. The present work was supported by a grant from the Saito Ho-on Kai.Foundation.

364

636.

Problematica from Moniwa Formation

lithology were given in Part 1 of theseries and repetition will be omitted at
this place. The peculiar shaped fossils
are from two localities. each of thebasal part of the Moniwa Formation.
One locality is the basal part of theformation exposed in the cliff facing
the Natori River, south of the Oide
Bridge crossing the Natori River andabout 250 meters south of the type
locality of the formation. This locality
yielded three specimens, one complete
and two with only half preserved. The
complete one is taken as the typespecimen. The fourth specimen is fromthe second locality, which is the basal
part of the Moniwa Formation cropping,out in the southern cliff of the Aoba
Golf Links (under construction), north,of Osawa, Sendai City and situated at,about 2 kilometers southeast of the locality mentioned above. At both localities, the specimens were found,embedded in brownish colored mediumgrained sandstone sporadically with
granules or pebbles.
The invertebrate fauna found 111
association with the four specimens
mentioned above consisted of Kotora-

pecten kagamianus (YOKOYAMA), Nanaochlamys notoensis (YOKOYAMA), Vasticardium ogurai (OTUKA), Crassatellites
sp., Dosinia sp., Panope ct. nomurae
KAMADA, Coptothyris grayi (DAVIDSON),
Terebratalia sp., Flabellum sp., abundantbalanid specimens and also with gastropods, scaphopods and echinoid spines.
Benthonic and planktonic foraminifers,and ostracodes were also found in association with the specimens forming
the scope of the present article.
The fossils upon which this article isbased were evidently exposed on thesea-bottom for some period of time as
is judged from the surface of one of
the fossils having adhered to it several

365

specimens of bryozoans resembling the
genus Actinopora. The bryozoan specimens are somewhat worn, and thissuggests that after the bryozoans adhered to the surface of the fossil, it wasrolled by aqueous agencies which caused
erosion of the surface before burial.
The peculiar-shaped fossil is confusing
for several reasons, first, forms identicalwith the present one have not beenfound through a research of literature
bearing on organisms of probable similarity, second, the systematic position of
the fossil is difficult to determine because
shapes as the present one among marineorganisms are not known to the writers,
and third, the present record seems tobe the first of its kind from the Cenozoic
rocks of Japan. For the reasons justmentioned, it seems worthy to describe
and discuss the present fossil from theviewpoint of its systematic position andsignificance in the Moniwa marine fauna.

The Peculiar-shaped Fossil

Occurrence:- Two of the peculiar
shaped fossil of elongate narrowly oval
outline. and well inflated thin calcareousshell were found in a position parallelwith the bedding plane of the Moniwa
Formation and two others at an obliqueangle. They were found in a mediumgrained sandy patch with sporadic
granules and pebbles intercalated in theconglomerate facies.
As mentioned
above they were found in association
with pelecypods, gastropods, bryozoans,foraminifers, balanids, echinoid spines,
ostracodes and br achiopods, the latterof which formed the first part of theseries of articles on the fossil marine
fauna. Of these fossils mentioned, themajority of the pelecypods (including
all of the scallops) and some of gastro-

366

Kotora HATAl, Koichiro MASUDA and Hiroshi NODA

pods are thought to have been drifted
into the area of their burial. On theother hand, the bryozoans, foraminifers
and brachiopods probably lived in or atleast very near to the place where wereburied. Thus the fossil fauna represents
in part both thanatocoenosis and biocoenosis.· From the mode of occurrenceof the peculiar-shaped fossil it issuggested that they may have beendrifted to the place of their burial
either by aqueous or eolian agencies.
Their mode of transportation to theirplace of burial if they did not actually
live in the environment where they
were found depends upon the nature of
the fossil, as will be stated later.
Comparison: The present specimens
which are characterized by their elongated shell, thin and smooth calcareous
covering, rounded ends and in being
well inflated, can be distinguished fromsuch pelecypods as Musculus (RyeneUa)
cupreus (GOULD), Lithophaga (s. s.) straminea (REEVE), and Lithophaga (Leisolen us) curta (LISCHKE) all described andillustrated by T AKI (1960, p. 90, pI. 45,
figs. 2, 7, 8, respectively), and all whichhave rounded anterior margin, elongate
outline, rather bluntly rounded posteriorside and inflated shells, by lacking
growth lines or other kinds of external
sculpture, not having two valves orshells, more uniform outline, thinnercovering and more uniformly inflatedshell. Other pelecypods with outline
similar to the present fossil can also be
distinguished from the fossil by thefeatures mentioned above. Comparedwith the coprolites described and illustrated by HANTZSCHEL, EL-BAZ and
AMSTUTZ (1968), the present specimens
differ in several important features,such as having no external sculpture socharacteristic of the coprolites, more
uniform outline and inflation, no note-

worthy interior structure of the sediments possessing a thin covering, andshowing no evidence of having been.
sausaged.
Although the eggs of certain Pisces.
can probably be preserved as fossil,.
there seem to be none that can becompared in shape, size and external
morphology with the present specimen.
Most preservable as fossil are probably
the eggs of the 5elachians (MCCORMICK,.
ALLEN and YOUNG, 1963) but their shapes
are different from the present specimens.
and thus need not be brought into·
comparison.
50 far as the general shape is.
concerned, the present specimens showa remote resemblance with such echinoid
genera as Echinometra, Fibularia, Lovenia
and Brissopsis (NISIY AMA, 1968), but thevery thin ectoderm or covering andcomplete lack of echinoderm structures,serve to easily distinguish the present
fossil from the echinoids.
The Aves are well known to haveoval shaped eggs with a thin covering
and without sculpture on the outersurface although different color patterns
exist. The sizes and oval-shaped eggs.
of the Aves vary with genus andspecies, and show a remote resemblancewith the present specimen now underconsideration. If the shape of thepresent specimen is the original one,.
then it can be distinguished from theeggs of Aves by being much moreelongated and with more narrowly
rounded ends. Also since the present
specimen was found embedded in sediments in association with Coptothyris
grayi miyagiensis HATAI, MASUDA andNOD A (1973), pelecypods, gastropods andcirri peds as well as with small bryozoans, such an environment may not be
natural for Aves eggs, although there
remains of possibility of their being636. Problematica from Moniwa Formation
preserved in marine deposits by accident.
Another possibility for the origin of
the elongate-oval fossil under consideration may be that they are nothing but
the eggs of the sea turtle. It is wellknown that sea-turtles crawl up upon
the beach to lay their eggs in holes dug
in the sand. The eggs are whitish with
soft and elastic cover, without noteworthy sculpture. The number of eggs
laid by the turtle is numerous as manyas about 30-50, and it is quite possiblethat they could be reworked by aqueousor other agencies to be transported anddeposited in the nearshore deposits.
By such undertakings it could be possible or probable that fracturing or
cracking during the drying and hardening egg-cover would permit penetration or impregnation of sediments
into the shell and at the same time, by
burial, the shell would be subjected tocompression which would result in thefracturing and elongation of the partially elastic calcareous covering. Although the above mentioned process isquite possible, there is no positive data
to uphold the view. Another possibility
is that the present elongate-oval fossil
is a fossilized sea-snake-egg that waseither drowned, fractured and impregnated with sandy sediment at the timeof continued rise of the sea-level during
the transgressive phase that resulted in
the deposition of the Moniwa Formation.
Also it may be that the snake-egg rolled
down from a higher relief to the seashore, and by continued drying the thinand elastic covering gradually hardened
and became fractured at several parts,
through which sediment flowed-in andfilled the chamber. Subsequently therounded or oval snake eggs by thefilling sediments expanded to become
elongate-oval in shape and then after
became buried in the sediments deposited361'

by the transgressing sea. The sea-snake
is known for its strong poison, rising tothe surface to breathe by its lung, isnot a member of the Pisces but that of
the Reptile that once lived on the land
but latter took to life in water. Thus,
just as the land snake, the sea-snakealso lays eggs with thin, soft, calcarous,_
elastic covering of whitish color and.
probably at or near the shore-line.
Therefore, the burial of the snake egg
in the shallow water sediments of thebasal part of the Moniwa Formation canbe expected. Also it is known that thesea-snake lives in warm and shallow
water, that is to say, in areas where
coral reefs and reef corals exist, thus
it is a tropical to subtropical eel-shaped
reptile. The thermal conditions during
deposition of the Moniwa Formation is
judged to have been about subtropicalas may be interpreted from the fossil
occuring from the formation.
The warm water condition during
deposition of the Moniwa Formation is
documented by the occurrence of tropical to su btropical foraminifers as
Lepidocyclina (Nephrolepidina), molluscs
as Trochus, Xenophora, Morum, Cypraea,
Conus, Bursa and others among thegastropods, Vasticardium, Venus among
the pelecypods, corals as Dendrophyllia
and bryozoans besides other fossils.
A comparison of the fossil egg-likespecimens under consideration was madewith the eggs of the land snake, Elaphe
climacophora (BOlE), which was captured
in July 1937 in the environs of Sendai
City. The eggs of the land snake are
not spherical or rounded and of pingpong size as those of the turtle, notovoid in shape like those of the Aves,
but are elongate oval with well rounded
ends and equidistantly separated parallelsides, smooth surface of whitish color
and with no noteworthy sculpture on

368

Kotara HATAI, Koichiro MASUDA and Hiroshi NODA

the surface of the thin shell or covering.
The snake eggs just mentioned andshown in the annexed illustrations
closely resemble the fossil specimens
decribed in the present article, and areof similar size, almost the same shape,
have the same or very similar kind ofwhitish coloration of the shell covering,and have thin covering. Also the orientation of the eggs of Elaphe climacophora seem to be at random, some havethe longer axis parallel with the groundsurface, whereas in others the longer
axis may be oblique to nearly verticalto the ground surface, and it seems thatthe direction of the longer axis of theeggs depends upon ground configurationand degree of coiling of the snake
because the eggs are protected in thecoils. This remarkable resemblance ofthe fossil specimens to the Recent ones
just mentioned strongly points toor suggests that the fossil ones are theeggs of a snake, and being marine inorigin, they are considered to be of asea-snake of which bones have not yet
been discovered from the Moniwa Formation, although they are expected to
be found, and in a state quite dismembered because their bones are very
thin, weak and easily destroyed byaqueous or other physical and chemical
agencies.
Although some assumptions on thenature of the fossil can be given there
seems to be no positive evidence for.adopting one of the views given above.
Regardless of the different views con·cerning the peculiar fossil, it can be said
that a description and illustrations of
the fossil should be given as a contribution to the study of problematicalfossils. Further, it seems best to givea name to the fossil, which is thought
to be the eggs of a sea-snake and thus
belongs to the Reptilia, but to what

genus or family it belongs is a question
should be reserved for another opportunity. Under such consideration, thewriters propose the generic and specificname of Moniopterus japonicus, n. gen.
et n. sp.
Class Reptilia
Order Apodes
Suborder Enchelycephali
Series Congoidei
Family Ophichthyidae
Genus Moniopterus, HATAI, MASUDA
and NODA, n. gen.

Type species :-J'vfoniopterus japonicus
HATAI, MASUDA and NODA, n. sp.
Diagnosis: - Elongate-oval, ends
rounded, covering thin, calcareous,semi polished, with no external sculpture.

Moniopterus japonicus HAT AI,
MASUDA and NODA, n. sp.
PI. 50, figs. 2-6

Type locality and Formation :-Cliff of
the Natori River, south of the Oide
Bridge, Moniwa, Sendai City, Miyagi
Prefecture, Early Mizuho To, Moniwa. Formation (Moniwan). Three specimens,
the best is chosen as the type specimen.
Desription :-Shell elongate-ovate, one
end bluntly rounded, other end morenarrowly rounded, measuring about 51
mm in length and 20 mm in diameter(Holotype specimen), shell coveringthin, calcareous, smooth, semipolished,without external sculpture. The fourth
specimen is well preserved except forlacking the very thin and semi polishedcovering. It measures about 43 mm inlength and 21 mm in diamter (Para type

636. Problematica from Moniwa Formation
specimen), of the same shape as theHolotype, with bluntly rounded ends
and apparently with smooth surface.
Remarks:- The shell is fractured
both longitudinally and transversally atseveral places and on the surface
several worn bryozoans are attached.
The bryozoans resemble somewhat thegenus Actinopora D'ORBIGNY, which issaid to range from the Cretaceous to
Recent (BASSLER, 1953, p. 57). The
bryozoans in being worn suggest thatafter becoming attached to the surface
covering, and growing to an adult, thehost was subjected to rolling on the seabottom probably by aqueous agencies,
thus explaining the worn condition of
the bryozoans. From the fractured thincalcareous shell, it may be assumed
that after the yolk and white part ofthe egg died, the covering graduallyhardened and by fracturing due to theoverlying sediments during burial andimpaction due to transportation fromthe shell, which may have aided inelongating the originally more globular
shape. This process may explain the
shape of the fossil, if it was originallyglobular or rounded during life and thesediments filling the shell.
A comparison with organisms capableof making structures similar to thepresent fossil have been given in
earlier lines of this article and here it
may be added that whatever the true
nature of the fossil, it is of interest
because it forms the first discovery ofa probable sea-snake egg from the Cenozoic rocks of Japan.

Acknowledgments

The writers thank Dr. Yoshio SUGAw ARA of the Department of Fisheries,
Faculty of Agriculture of the Tohoku

369

University, for his information on thesea-snake, Mr. Kenshiro OGASAWARA of
the Institute of Geology and Paleontology, Faculty of Science, Tohoku
University for his many supports inthe field and Mr. Kimiji KUMAGAI of
the same Institute for taking the necessary photographs.
References Cited
BASSLER, R. S. (1953): Bryozoa. in Treatiseon Invertebrate Paleontology, Part G. p.
1-253, figs. 1-175, CeDi. Soc. America andUniv. Kansas Press, edited by R. C.
Moore.
HATAI, K., MASUDA, K. and NODA, H.
(1973) :Marine fossils
fromtheMoniwa Formation distributed along theNatori River, Sendai, Northeast Honshu,
Japan. Part 1. Brachiopoda from the
Moniwa Formation.
Satio Ho-on Kai
Mus., Res. Bull., no. 42, p. 9-18, pIs. 2, 3.
HANTZCI-IEL, W., EL-BAZ, F. and AMSTUTZ,
G. C. (1968): Coprolites. An annotatedbibliography. Ceoi. Soc. Amer., Mem.
108, p. 1-132, pIs. 1-11, figs. 1-6.
JORDAN, D. S. (1963): The genera of fishes
and a classification of fishes. p. 1-800,
Stanford Univ. Press.
MCCORMICK, H.
ALLEN, T. and YOUNG,
E. (1963): Shadows in the sea. p. 1-415,
with numerous illustrations, Chilton Co.,New York.
NISIYAMA, S. (1968): The echinoid faunafrom Japan and adjacent regions.
Paiaeont. Soc. Japan, SPec. Pap., no. 13,
p. 1-491, pIs. 19-30.
NOMURA, S. (1940): Molluscan fauna of the
Moniwa shell bed exposed along theNatori-gawa in the vicinity of Sendai,
Miyagi Prefecture, Japan.
Sci. Rep.,
Tohoku Imp. Univ., Ser. 2, vol. 21, no.
1, p. 1-46, pIs. 1-3.
T AKI, 1. (1960): Mollusca. in Encycl. Zool.
Illust. Colors, vol. 3, edited by OKADA,
K. and T AKI, 1., Hokuryukan Book Co.
Inc., Tokyo.

w..,

-.370

Kotora HATAI, Koichiro MASUDA and Hiroshi NODA
MoniwaNatoriOide

Osawa
Takadate

Explanation of Plate 50::Fig. 1. View of the type locality of Moniopterus japonicus. The massive lower part consistsof the Takadate Andesite. This is superposed by the conglomeratic facies with mediumgrained sandy patches of the basal part of the Moniwa' Formation. Note the very irregular boundary between the Takadate Andesite and Moniwa Formation. The seasnake egg specimens were obtained from the lower part of the Moniwa Formation,
about 10 centimeters above the base. Cliff south of the Oide Bridge crossing the Natori
River, Sendai City .
. Fig. 2. Two broken specimens in situ. Locality same as above.
Fig. 3. Moniopterus japonicus, n. gen. et n. sp., (x 1), Holotype, (IGPS coIl. cat. no. 92956),
Note fractured parts, thin covering, elongated shape, and adhering bryozoans. Locality
same as above.
: Figs. 4-6. Moniopterus japonicus, n. gen. et. n. sp., (x 1), Paratype, (IGPS coIl. cat. no.
92957), 4, lateral view of entire specimen. 5, view of rounded end. 6, view of otherrounded end. Locality: Southern cliff of the Aoba Golf Links, north of Osawa, Sendai
City.
:'-Fig. 7. Photograph of Elaphe climacophora (BolE) captured in the environs of Sendai Cityand placed in a broken beer bottle of which rim can be seen vaguely. This photograph
was taken of the snake where it laid eggs during capture. The photograph is slightly
enlarged and the morphology of the eggs, their orientation enclosed by the snake andthe number laid at a time can be seen. The snake was captured in July 1937.

HAT AI, MASUDA and NO DA:

Proble?natica !1"01n Moniwa

Plate 505

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 92, pp. 371-394, pis. 51-53, September 20, 1973

637. PROFUSULINELLA ASSEMBLAGE IN THE OMI LIMESTONE,NIIGATA PREFECTURE, CENTRAL JAPAN(STUDIES OF CARBONIFEROUS FUSULINACEAN OF OMI, PART I)
KOZO WAT ANA BE
Noda Senior Highschool, Noda 278~i'4ir6Jj(EJ1fO) Profusulinella C ~O);Jtffl!l! (1fi4irEJj(E::5}j)B~O)*,Ij~!R, ~O) 1):
fJi(?-~ttB~O)1ftm::5Jj(E$ Ii:: 1t':b~.Q Profusulinella 11\-0) fftET ~ L. C ~ a~ ;i.pIC L.,
1!l=v'i, ""f{IT0) Profusulinella omiensis n. sp.·P. daiyamensis 11\-, J:{ITO) Akiyoshiellaozawai 1*0) 211\-L'~~-:5lt;:/1.,.Q L. C ~O)A.t.:. 211\-~mJj)(;T.Ql!I!v'i, Profusulinella 2~
l!I!, Fusulinella 1 ~l!I!, Akiyoshiella 2l!1!~~tJ' 7 ~ 16l!1!L', L.:/1.,;O)*,Ij~!RIC.t"? "(~i~-:5lt ;:/1.,.Q1!ftm::5Jj(EO) Pl'ofusulinella 11\-v'i~J;a::5Jj(EO) Profusulinella beppensis;w,:,
yJ!!!:O) Verei-Kashir ~!$ Cflol~.:c A::r ~7!/) 0) Profusulinella 1t.::5j}J~tP,HcMlt~:/1.,.Q •ill ill ;m ;:§*structure were elucidated by KAWADA(1954) and FUJITA (1958). Recently,
HASEGAWA (1969) has divided the PermoCarboniferous limestone distributed in
the Itagamine district, Kurohime-yama,
and the adjacent regions into nine zones
on the basis of fusulinacean and endothyracean foraminifers. These biostratigraphic studies of the Omi Limestone
are summarized in Table 1.
The author has studied rich fusulinaceans of the Limestone and theirstratigraphic distribution since 1967.
As a result, he recognized eight fusulinacean zones in the Carboniferous
part. In the present paper, the author
described some interesting species fromthe zone of Profusulinella of HASEGAWA(1969).
The author expresses his most sincere
gratitude to Professor Mosaburo KANUMA of Tokyo Gakugei University,
Associate Professor Hisayoshi IGO of
University of Tsukuba, and Dr. Toshio

Introduction and Acknowledgements
The Carboniferous and Permian Omi
Limestone Group distributed in the Omi-district, Niigata Prefecture, has beenstudied by many workers since the-classical paleontological investigation of
HAYASAKA (1924). ISHII (1934), KATO
.and IISAKA (1934) worked out general,geology of this district. OZAWA (1925),
KAWADA (1954), FUJITA (1958), IGO (1960)'and HASEGAWA (1969) contributed tofusulinacean biostratigraphy. Compre,hensive study on fossil bryozoa was:published by SAKAGAMI (1962). IGO and
KOIKE (1964) described some Pennsylvanian conodonts, and ROWETT and MINATO (1969) and others studied rugose-corals.
Of these studies, rather detailed fusulinacean biostratigraphy and geological* Received Jan. 10, 1974; read Sep. 22, 1968
:at Kanazawa.
371

372

Kozo WATANABE

KOIKE of Tokyo University of Education for their suggestion, criticism andcontinuous encouragement. Deep thanks
are also extended to Associate Professor
Atsushi ISHII, Mr. Hisaharu IGO, and
Mr. Fumio KOBAY ASH! of Tokyo Gakugei
University for their kind help and advice in various ways.
Faunal composition of the Zoneof PrOfUSlllillella

Fusulinacean fossils are extraordinalily abundant in various levels of the Omi
Limestone Group in Itagamine district.
There have been recognized eight assemblage zones of Carboniferous fusulinacea in decending order as follows:
Gzhelian ....

Triticites (M ontiparus)
montiparus Zone (T)Fusulinella pulchra
Zone (F 3)Fusulinella biconica
Zone (F 2)Fusulinella simplicataMoscovian ..
F. itoi Zone (F ,)Akiyoshiella ozawai
Zone (Pr 2 )Profusulinella omiensis-P. daiyamensis
Zone (Pr,)
Pseudostaffella antiqua
Bashikirian- {Zone (M 2)
NamurianEostaffeila kanmerai
Visean?
Zone (M,)

In this paper, the author describes
fusulinaceans from two assemblage zones
of Profusulinella omiensis-P. daiyamensis(Pr,) and Akiyoshiella ozawai (Pr2 ). The
two " zones" comprise the zone of Profusulinella of HASEGAWA (1969). This
Zone comformably overlies the Pseudostaffella antiqua Zone, and is overlain
by the Fusulinella simplicata-F. itoi

Zone.
The most complete faunal assemblagesof "Profusulinella Zone" are recognizedin the northern and southern cliffs of
Itagamine district (Text-fig. 1). The
limestone in these localities is lightgrey to white massive biosparite, biooosparite and oomicrite.
Profusulinella omiensis-P. daiyamensis
Zone: The fauna of this zone consistsof Profusulinella omiensis WATANABE,
n. sp., P. daiyamensis HASEGAWA, P. sp.
A, Pseudostaffella kanumai IGO, Eostaffeila postmosquensis KIREEV A, Nankinella
yokoyamai SADA and Ozawainella vozhgalica SAFONOV A.
Profusulinella daiyamensis HASEGAWA
is one of most representative fusulinaceans in the Omi Limestone, and it
was originally described from the Zoneof Profusulinella beppensis in the Akiyoshi Limestone Group, Yamaguchi Prefecture, Japan. Profusulinella taishakuensis SADA and P. toriyamai SADA described from the Zone of Profusulineilaof the Taishaku Limestone, Hiroshima
Prefecture, seem to be fall within thespecific variation of this species. Profusulinella sp. B described by SADA
(1965) from the Profusulinella Zone in
the middle part of the Kodani formationof the Atetsu Limestone, is closely allied
to this species. The similarity between
these two species indicates that they
are apparently conspecific each other_
Profusulinella biconiformis KIREEVA, P_
prolibrovichi RAUSER and its related
species, which were known from thelower to middle Kashir horizon of theRussian Platform, are very similar tothis species.
Profusulinella omiensis WATANABE n.
sp. is yielded only from ScI-G and isclosely related to Aljutovella arissionis
LEONTOVICH and A. arissionis molotovensis SAFONOV A which were described

637.

Profusulinella of Omi Limestone

373:

Table 1. Historical review of the Carboniferous to Lower Permian
Fusulinacean Biostratigraphy.
"C

.;::0

C1l

bO

C1l

c:

.....c.s 0
iJ...
en N
-- - - =Z z -S~
C1l~....~...:I
....

~
~

r:tl

iJ...

r:tl OJ "'I
en~~
en tl..~~-- -p:i Z
~

~

U

r:tl

~

iJ...

:;J

"'~

<:).-

"1:jl-

....
...:I

l!1
N
0

KA WADA (1954)

FUJITA (1958)

HASEGAWA (1969)

P 1 Formation

Zone

Zone

PseudoschwagerinaofPseudofusulina
Zone
Pseudoschwagerina'"

C 3 Formation

Zone

:~

Triticites
Zone

of

~

.i:
Eo..

of

Present Paper

Triticites
simplex Zone PSI

PseudoschwagerinaI

J. . . . . . . .

Triticites

Triticites (M.)
montiparus
Zone

T............. J ..

-- --Fusulinella
pulchra Zone Fa
<:l

en
:;J

0
~

r:tl

rr..

....
Z
0
p::)

.~

Z
~

;;
'"OJ

....

k-

0

;;
'"OJ

:> ~'"

U

en

.!:k-

0

~

Zone
of
C2 Formation

Fusulinellabiconica Zone F2

Fusulinella

Zone
of

Fusulinella
Zone

Fusulinella

Fusulinella
simplicataF. itoi Zone

FI

Akiyoshiellaozawai Zone

Pr2

~

~

--

U

r:tl

~

...:I

.~

Q
Q

....
~

'"

;;

~
....
~
....
~
....

p::)

~
'"l~

I~ ~ ~'"~Z

I

Profusulinella

tl...

-- ~
Z
~
~
....
~
:;J

I~

of

-?- '"OJ
Z ~
l-

ffi~

1-:

Zone

'"

<:).

~

C1 Formation
Coral·
Brachiopods
Zone

Zone
of
MillerellaCoral,Brachiopod

,.

Zone
of
EostaffellaMillerella.Profusulinellaomiensis-P.
Prldaiyamensis
Zone
PS'eudostaffella
antiqua Zone M2

Eostaffellakanmerai
Zone

MI

:374

Kozo W AT ANABEfrom the middle Verei horizon of theRussian Platform (RAUSER-CHERNOUSsov A et aI., 1951).
Pseudostaffella kanumai IGO was
known from the uppermost Millerella.higemm icula-Pseudostaffella kanuma i
Subzone (IGo, 1957) in the Ichinotani
Formation of Fukuji, Gifu Prefecture.
Nankinella yokoyamai SADA is less common in the Omi Limestone. This species
was reported from the Profusulinella
Zone (SADA, 1972) in the Taishaku
Limestone.
o zawainella vozhgalica SAFONOV A isabundant but limited in distribution inthis area. This species was known fromthe upper Verei to lower Kashir horizons of the Russian Platform, and also
described by SHENG (1958) from theFusulina konnoi Subzone to the Fusulina.cylindlica-F. quasicylindrica Subzone in
the Taitzeho Valley region. Northeast
China.
Eostaffella postmosquensis RAUSERoCHERNOUSSOV A is common in the Omi
Limestone. This species was describedfrom the Bashikirian to the middle Verei
horizons of the Russian Platform{RAUSER-CHERNOUSSOV A, 1951).
According to the above mentioned·evidence, the Profusulinella omiensis-P.
.daiyamensis Zone is characterized by
the species described previously fromthe Zone of Profusulinella in the Omi
Limestone Group. Profusulinella {Jmi.ensis is similar to the species of Aljuto.vella which was confined into the middle
Verei in Russia. Therefore, Profusu.linella omiensis-P. daiyamensis Zone established in the Omi Limestone is evi.dently correlated to the Verean to
Kashirian in the Russian Platform andto the Profusulinella beppensis-P. toriyamai Zone or the Atetsuan in Japan.
Akiyoshiella ozawai Zone: This zone
overlies the Profusulinella omiensis-P.

daiyamensis Zone, but the stratigraphic
relationship to the Fusulinella simplicataF. itoi Zone is obscure yet. The following fusulinacean species makes up thiszone: Akiyoshiella ozawai TORIY AMA,
A. toriyamai THOMPSON, PITRAT and
SANDERSON, Staffella akagoensis TORIYAM A, Profusulinella probiconica W AT ANABE n. sp., P. pseudorhomboidea PUTRJA, P. sp. B, Fusulinella hayasakai
W AT AN ABE, n. sp. and F. jamesensis
THOMPSON, PITRAT and SANDERSON.
Akiyoshiella ozawai was describedfrom the Profusulinella beppensis Zone
in the Akiyoshi Limestone Group, where
it is associated with Profusulinella toriyamai SADA and Staffella akagoensis
TORIYAMA.
Fusulinella hayasakai WATANABE, n.
sp. includes Fusulinella sp. Band F. sp .
C which were originally described by
TORIY AMA (1958) from the Profusulinella
beppensis Zone.
The other associations are Akiyoshiella toriyamai THOMPSON, PITRAT and
SANDERSON and Profusulinella pseudorhomboidea PUTIUA. The former is originally described by THOMPSON (1953)
from the Cache Creek area in British
Columbia, Canada. This species is closely related to Palaeofusulina trianguliform is PUTRJA described from Northeast Greenland (DUNBAR et al. 1962), andVerella postspicata BENSH described fromthe Tashikent area in Russia (BENSH,
1969). These species were also describedfrom the Kashir horizon in the Russian
Platform. The Canadian and Japanese
species are related to the genera Eofusulina RAUSER, 1951 and Palaeofusulina PUTRJA, 1956. The author is of theopinion that Akiyoshiella and Eofusulina(s. s.) are not distinct genetically, although he tentatively treated Akiyoshiella as a valid genus herein.
Profusulinella pseudorhomboidea PUT-

637.

Profusulinella of Omi Limestone

RJA was originally described from the
Verei to Kashir horizons of the Russian
Platform (RAUSER·CHERNOUSSOV A 1951).
Profusulinella probiconica WATANABE,
n. sp. has a large subellipsoidal or shortfusiform shell and seems to be a bio·
logically advanced type. This species
is associated with Alziyoshiella ozawai
TORIYAMA.
Based on the faunal evidence, Akiyoshiella ozawai Zone can be correlated
to the Profusulinella beppensis Zone of
the Akiyoshi Limestone (ToRIY AM A,
1958) and the Kashirian of the Russian
Platform.

Collecting Locality
Fusulinacean treated in this paper
were obtained from the following sites
in Itagamine district.
ScI-2: White to light grey oosparitic
limestone. Scattered specimens of Profusulinella sp. Band Staffella akagoensis
TORIY AMA were found.
ScI-5: White brownish massive oosparitic limestone, including rarely Akiyoshi·
ella ozawai TORIY AMA, Profusulinella
probiconica n. sp., Fusulinella hayasakain. sp ..
ScI-7: Black to dark grey, massive biomicritic limestone, yielding Profuslllinella probiconica n. sp. and Fllsulinella
hayasakai n. sp ..
ScI-14: White to light grey massive
bio'oosparitic limestone, including commonly Akiyoshiella toriyamai THOMPSON,PITRAT and SANDERSON, Profusulinella
pseudorhomboidea PUTR]A and P. spp.
ScI-18: Dark grey bio-oomicritic massive limestone, including many Profusulinella daiyamensis HASEGAWA, Pseudostaffella kanumai IGO and Nankinella
yokoyamai SADA.
ScI-18u: Grey massive bio-oomicritic
limestone. The limestone yields a num-375

ber of Ozawainella vozhgalica SAFONOVA
and Eostaffella postmosquensis KIREEV A.
ScI-21: White to grey oosparitic massive limestone. Scattered specimens ofProfusulinella pselldor homboidea PUTRJ A
were found.
ScI-G: White oosparitic limestone,
yielding Profusulinella omiensis n. sp.
and Eostaffella sp ..
IT-I and IT -2: Light grey to whitemassive bio-sparitic limestone. Scattered specimens of Profusulinella daiyamensis HASEGAWA were found.
IT-3: Light grey to white bio-oosparitic bedded limestone, including many
specimens of Akiyoshiella toriyamai
THOMPSON, PITRAT and SANDERSON.
G-l : White oosparitic limestone, including rarely Akiyoshiella toriyamai.
ScII-5: Light grey massive bio-sparitic
limestone. Scattered specimens of Profusulinella sp. A, Ozawainella sp. andEostaffella sp. were found. SAKAGAMI(1962) seems to have found first Profllsulinella sp. from the same locality.
ScII-7: White massive oosparitic limestone. Scattered specimens of Akiyoshiella? sp. and Eoschubertella obscure (LEEet CHEN) were found.
UT -1 and UT -2: Dark to light brownbios pari tic limestone, including a number of Fusulinella hayasakai n. sp., F.
jamesensis THOMPSON, PITRAT and SANDERSON and Akiyoshiella? sp.
Collections NG-l and NG-2 were obtained from the Gojunko-dori of the
Nishiyama Quarry.
NG-l and NG-2: Dark to light grey
sparitic limestone. Scattered specimensof Profusulinella sp., Akiyoshiella sp.
were found.

Systematic Description
Genus Eostaffella RAUSERCHERNOUSSOV A, 1948

c..:>-::J~

JAPAN SEAPRIJFUSULINELLA{ ..... .
......

,,::.,.::::/,:.:..... :~......... \.

~c.. ' .. :/........

/.. :.... .

:~.'" : .........:" :.~

'

.

..

'.

'.

:r····::: ....

...
500

45p

{. ....: .....

........ i,oo....

0.5 kmI

Text·fig. 1, Topographic Map of the Omi area

... .

~

~

to
ttJ

.\":........

.......: ....

o;>~3 . ··<~;.;>

~'"-3

.'

'.

637. Profusulinella of Omi Limestone
Eostaffella postmosquensis KIREEVA

377

Form ratios of four volutions 0.33-0.52.
Proloculus minute, with outside diameter
12-24 microns. Shell expanded slowly
and uniformly. Heights of volutions rapidly increase, last one about two times
larger than proceeding one. Chomata
low and poorly developed. Tunnel very
low, rather broad and path slightly irregular.
Remarks:-The present specimens resemble the Russian materials in the sizeand shape of shell, weak chomata andother biocharacters. This species ismore or less related to Eostaffella etoi

PI. 51, figs. 9-14

1951. Eostaffella postmosquensis KIREEV A in
RAusER-CHERNoussovA et aI., p. 48,
pI. 1, figs. 1-2.

Description: - Shell minute, discoidal-with short axis of coiling, narrowly-rounded periphery and convex lateralslopes. Shell involute throughout growth-in most specimens. Mature specimens:have 4 volutions measuring 0.12-0.19 mm
in length and 0.36-0.42 mm in width.

Table 2. Measurements of species of Eostaffella and Staffella in mm.

S. akagoensis

Eostaffella postmosquensis
Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14'I Fig. 16 Fig. 17

Length

0.172

O. 192

O. 120

0.168

0.180

0.152

I

0.672

0.624

Width

0.420

0.372

0.364

0.360

0.372

0.400

I 1.152

l. 008--Form Ratio

0.41

0.52

0.33

0.47

0.48

0.38

0.58

0.62

Proloculus

0.024

0.012

0.012

0.020

0.020

0.020

0.048

0.052

1
2
3
4
5
6

0.036
0.080
0.136
0.232

0.036
0.084
0.140
0.240

0.036
0.076
0.120
0.212

0.020
0.048
0.100
0.200

0.048
0.084
0.140
0.204

-

-

-

-

-

-

0.052
0.096
0.156
0.240
-

-

-

0.060
0.144
0.192
0.262
0.432
0.600

0.072
O. 144
0.240
0.360
0.528
-

1
2
3
4
5
6

0.016
0.034
0.060
0.086

-

-

-

0.036
0.056
0.094

0.034
0.049
0.060

0.034
0.042
0.086

0.024
0.040
0.060
0.090

0.022
0.042
0.068
-

-

-

-

-

0.024
0.072
0.096
0.216
0.288

-

-

-

-

-

0.024
0.048
0.120
0.144
0.216
0.336
0.40
0.33
0.63
0.55
0.50
0.56

0.34
0.50
0.40
0.60
0.55
-

Vol.

RadiusVectorHalf
Length

Form
Ratio

1
2
3
4
5
6

- - - - - - - ---

0.44
0.43
0.44
0.37

-

-

-

0.43
0.40
0.39

0.45
0.41
0.28

0.71
0.42
0.43

0.50
0.48
0.43
0.44

0.42
0.44
0.44
0.28

-

-

-

-

-

-

-

-

-

~

--_._-- . - - - - --- -------

i
I

II

i
!
I

i
!

i

I

:

-

Kozo WATANABE

378

OTA but differs from it in more rounded periphery.
Occurrence: - Common in collection
ScI-18u, associated with Ozawainellavozhgalica SAFONOV A and O. angulata(COLANI).
Reg. Nos.:-TGU-72001-72006
Genus Nankinella LEE, 1931
Nankinella yokoyamai SADA
PI. 51, figs. 6-8
1972. Nankinella yokoyamai SADA, p. 441-443,

pI. 53, figs. 1-2.

Description:-Shell small, inflated lenticular, with bluntly pointed or archedperiphery and convex or straight lateralslopes. Shell involute throughout growth~
Mature individuals 5 to 6 volutions and0.39-0.55 mm in length and 0.87-1.00 mm
in width. Form ratios of three volutions.
0.43-0.55. Proloculus minute, its outside'
diameter 20-50 microns.
Spirotheca relatively thick for size ofshell due to secondary mineralization,.
but showing four-layered structure in apart of shell. Chomata low and poorly
developed. Tunnel angles of the fourth
to fifth volutions 14 and 15 degrees, res-

Table 3. Measurements of Nankinella yokoyamai in mm.
Fig. 6

Fig. 7

Fig. 8

0.48

0.55

0.46

0.43

3

0.45

0.55

0.40

0.39

Width

3

0.92

1. 00

0.87

0.90

Pro loculus

3

0.04

0.02

0.04

0.05

3
3
3
3

0.02
0.04
0.08
0.12
0.22
0.35

0.05
0.12
0.17
0.25
0.37
0.50

0.05
0.10
0.18
0.32
0.50
0.05
0.06
0.08

N

MEAN

Form Ratio

3

Length

SD

Vol.

6

2

0.04
0.09
0.14
0.23
0.36
0.43

1
2
3

3
3
3
3
3
2

0.04
0.05
0.07
0.12
0.18
0.26

0.03
0.05
0.07
0.13
0.15
0.26

0.04
0.05
0.07
0.13
0.20
0.25

3
3
3

1. 10
0.67
o 58
0.64
0.53
0.62

1. 50
1. 00

0.80
0.42
0.41
0.52
0.54
0.50

1

RadiusVectorHalf
Length

2
3
4
5

4
5
6
1

Form
Ratio

2
3
4

5
6

3

3
3
2

0.88
1. 08
0.68
O. 74

0.11

0.18
1. 00

0.60
0.44
0.34
0.36

379

637. Profusulinella of Omi Limestone
pectively.
Remarks:-The present specimens arevery similar to Nankinella yokoyamai
SADA described from the Zone of Profusulinella of the Taishaku Limestone,
Hiroshima Prefecture, but differ slightly
from the latters in the shape of shell.
Besides, the Omi specimens have arather inflated lenticular shell comparedwith a lenticular shape of the latters.
Occurrence :-Rare in collection Sci -18,
associated with Profusulinella daiyamensis HASEGAWA and Pseudostaffella kanumai IGo.
Reg. Nos.:-TGU-72007-72009
Genus Staffella OZAWA, 1925
Staffella akagoensis TORIY AMA
PI. 51, figs. 15-20

1958. Staffella akagoensis TORIYAMA, p. 2224, pI. 1, figs. 6-8.
1972. Staffella akagoensis SADA, p. 443-444,
pI. 53, fig. 3.

Description :-Shell small, subsphericaland planispiral, with broadly rounded
periphery. The axis of coiling straight.
Mature specimens 5 to 6 volutions and0.62-0.67 mm in length and 1.01-1.15 mm
in width. Form ratios from 0.58 to 0.62.
Proloculus small, its outside diameter
about 50 microns. Shell expanded slowly
in inner two volutions, but somewhat
rapidly and uniformly in outer ones.
Spirotheca thick, consisting of four
layers of tectum, diaphanotheca andinner and outer tectoria. However, detailed spirothecal structure obscure in
inner volutions.
Chomata low andpoorly developed. Tunnel low and rather
narrow. Tunnel angles of the forth andfifth volutions 12 and 15 degrees, respectively.
Measurement:-See Table 2.
Remarks:-The present specimens re-semble closely Staffella akagoensis TORIYAMA from the Profusulinella beppensis
Zone of the Akiyoshi Limestone.
Occurrence: - Common in collections
ScI-2, 5, 7,14 and IT-3, associated with
Akiyoshiella ozawai TORIY AMA and A_
toriyamai THOMPSON, PITRAT & SANDERSON and Profusulinella sp. B.
Reg. Nos.:-TGU-72010-72015
Genus Ozawainella THOMPSON, 1935
Ozawainella vozhgalica SAFONOVA
PI. 51, figs. 21-24
1951. Ozawainella vozhgalica
RAUSER-CHERNOUSSOV A

in
et a!., pI. 11,.

SAFONOVA

p. 138-139, figs. 3-4.
1958. Ozawainella vozhgalica SHENG, p. 73-74,.
pI. 1, figs. 30-34, pI. 2, fig. 1.

Description :-Shell minute, lenticular
in shape with slightly convex lateralslopes and rather bluntly pointed poles.
Mature specimens 6 to 7 volutions, 0.280.37 mm in length and 0.58-1.10 mm inwidth. Form ratios from 0.35 to 0.47,
averaging 0.36 for the fifth volution.
Proloculus small, its outside diameter
about 50 microns.
Spirotheca composed of tectum andless dense upper and lower layers. Inner tectorium partly appeared in thelast volution. Tunnel angle essentiallyequal throughout growth, mostly 9 to 11
degrees. Chomata well developed, asymmetrical; massive and continue to poles.
Tunnel path regular, narrow and low.
Measurement :-See Table 4.
Remar ks :-0 za wainella vozhgalicaSAFONOV A was originally described fromthe Russian Platform, and then was fromthe Taitzeho Valley region in Northeast
China (SHENG, 1956). These specimens.
closely resemble the Chinese ones.
Occurrence:-Abundant in collection

Kozo WATANABE:380

112-113, pI. 2, figs. 4, 7-14, 16-18, 20-21,
34-35, 41.
.
(For further synonyms see IGo, 1957)

Scl-18u, and rare in Scll-5, associatedwith Profusulinella sp. A., Ozawainella
angulata (COLANI) and Eostaffella post,mosquensis KIREEV A.
Reg. Nos.:-TGU-72016-72019

Remarks:-The Omi specimens arevery similar to the previously described
specimens. Ozawainella vozhgalica SAFONOV A is similar to this species in many
respects, but the polar regions of theformer one is more inflated and withmore rounded periphery.

Ozawainella angulata (COLANI)
PI. 51, figs. 25-26
1924. Ozawainella angulata COLAN!, p. 74-75,

Table 4. Measurements of species of Ozawainella in mm.
O. angulata

Oz. voghgalica

N

MEAN

SD

Fig. 21 Fig. 22 Fig. 23 Fig. 24

Length

16

0.368

0.09

0.375

0.350

0.330

0.280

0.300

0.300

Width

16

0.896

0.15

1.100

1. 000

0.875

0.575

0.975

1. 025

Form Ratio 16

0.36

-

0.38

0.35

0.38

0.47

0.31

0.29

Proloculus

16

0.050

0.01

0.020

0.040

0.050

0.040

0.030

0.0::30Vol.
1
2
Radius 3
Vector 4
5
6
7

15
16
15
16
16
16
1

0.05
0.10
0.16
0.26
0.39
0.50

0.01
0.02
0.04
0.05
0.09
0.08

0.05
0.08
0.13
0.21
0.43

0.05
0.10
0.19
0.28
0.43

0.05
0.08
0.13
0.20
0.30

0.05
0.09
0.24
0.34
0.53

-

-

-

-

0.03
0.06
0.12
0.18
0.28
0.48
0.55

-

-

-

-

0.03
0.04
0.07
0.12
0.16
0.15

0.01
0.01
0.02
0.03
0.03

-

-

-

0.02
0.05
0.07
0.10

0.03
0.05
0.08
O. 18

0.05
0.10
0.13
0.18

-

-

-

7

7
15
16
15
16
4
1

-

-

-

0.19

0.07
0.13
0.18
0.28
0.45
0.58
- _ ...0.03
0.06
0.08
0.10
0.13
-

1
2
3
4
5
6
7

8
15
15
15
15
4
1

0.61
0.45
0.48
0.46
0.41
0.33

0.12
0.13
0.13
0.12
0.16
0.09

-

0.33
0.42
0.39
0.36
0.42
0.35

1
2
Half
3
Length. 4
5
6

-

0.04
0.08
0.11
0.14

-

0.03
0.04
0.06
0.11
0.14
-

-

-

-

-

-

0.38
0.38
0.38
0.42

0.50
0.53
0.46
0.42

0.60
0.50
0.46
0.55
0.42

.. -

Forni.
·RatioFig. 25 Fig. 26--.---

0.44
0.33
0.32
0.26

I

~----

0.43
0.38
0.33
0.29
0.22
0.22

Table 5. Measurements of Pro/usulinella omiensis n. sp. in mm.

_ _---- - - - - -----.------- ....
....

-~~--

Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10
SD-----------------Length
1. 000
1.350
1.525
1.500
1. 3501. 375
23
1. 43
0.20
1. 125
1. 925-----------------------------------------Width
0.725
0.925
0.850
1.000
0.910
0.825
0.810
0.750
1.025
0.960
26
0.19
0.09
N

Form Ratio

5
1. 63
---25
0.08

Proloculus

RadiusVectorHalf

Length

Form
Ratio

MEAN

1.55

2.08

1.59

1.53

1.65

1.64

1.70

1.33

0.01

0.075

0.075

0.038

0.100

0.070

0.075

0.063

0.088

0.060

0.100

0.08
o. 13
O. 18
0.33
0.48

0.06
O. 10
O. 16
0.28
0.41

0.08
0.15
0.25
0.40

0.08
O. 10
O. 18
0.28
0.43

0.07
0.13
O. 18
0.30
0.43

0.08
0.16
0.26
0.40

0.08
O. 10
O. 16
0.25
0.38

0.10
0.18
0.28
0.45

0.51

0.06
0.12
O. 19
o 33
0.47

0.05

0.08
o. 15
0.30
0.53
0.80

0.40
O. 13
0.23
0.43
0.78

0.05

0.05
0.10
0.20
0.50
O. 73

0.08
o. 15
0.35
0.50

Vol.
1
2
3
4
5
6

26
26
26
26
21
3

0.08
0.13
0.21
0.34
0.46
0.57

0.02
0.02
0.04
0.06
0.05

0.07
0.12
O. 16
0.28
0.38

1
2
3
4
5
6

19
22
23
23
21
2

0.06
0.13
0.26
0.45
0.70
O. 77

0.02
0.02
o 06
0.06
0.08

0.05
o. 10
0.13
0.28
0.53

1
2
3
4

19
22
23
23

0.66
1. 03
1. 24
1. 37

5

19
3

1. 49
1. 41

0.29
0.23
0.21
O. 19
0.20

10
10
10
10
8

.010
.015
.021
.033
.031

6
1

2
Thickness

3

of

4

Spirotheca

56~-----.---- - - - ---

~

~

~

~
~

<:I>

~

.,0.

0.11

0.25
0.48
0.80

0.08
o. 19
0.35
0.63

0.11

0.25
0.40
0.65

;;2

~
.-.
~

~

a
~

.,0.

O. 71
0.83
0.81
1. 00
1. 40

0.63
0.85
1. 25
1. 46
1. 67

1. 19
1. 35
1. 47
1. 44

.012
.020
.024
.043
.024

.010
.012
.024
.048
.043

.012
.019
019
.022
.024

0.89
0.94
1. 35
1. 25
1. 57

o 67

.007
.012
.019

.048
.036

1. 08
1. 21
1. 30
1. 66

0.63
1. 10
1. 39
1. 43
1. 51

O. 71
O. 77

.010
.014
.017
.026
. 048

.005
.012
.019
.024
. 020

.007
.012
.017
.024
. 020

1.11
1. 67
1. 70

t-<

1. 00

~.

0.94
1. 35
1. 25

.012
0.17
.024
.024

~

<:I>

""'o;;2"
~

.007
.012
.019
.024
.029

.019
.024
.024
.044
C;:I

00
....

382

Kozo WATANABE

Occurrence :-ScI-18u.
Reg. Nos.:-TGU-72020-72021

Genus Profusulinella RAuSER·CHERNOUSSOVA and BELJAEV, 1936
Profusulinella omiensis
WATANABE, n. sp.

ers have shape and size of shell andseptal fluting similar to those of thisnew species, but they have more strongly fluted septa in the polar regions anddifferent structure of spirotheca.
Occurrence :-Found only in collection
ScI-G.
Reg. Nos.:-TGU-72022-72032 (Holotype 72021)

PI. 52, figs. 1-10

Profusulinella daiyamensis HASEGAWA
Description :-Shell small, short fusiform, with bluntly pointed poles. Mature
specimens 5 to 6 volutions and 1.13-1.93
mm in length and 0.73-1.00 mm in width.
Form ratios of the first to sixth volutions of mean values 0.66, 1.03, 1.24, 1.37,
1.49 and 1.41, respectively. Proloculus
small, its outside diameter from 40 to
100 microns, averaging 80 microns for
25 specimens.
Spirotheca composed of three layers,
dense tectum, upper tectorium and diaphanotheca. Fine porous structure
rather distinct in outer volutions. Thicknesses of spirotheca rather variable, attaining 31 microns in outer volutions.
Septa weakly fluted in polar regions,but almost flat in other parts of shell.
Septal counts increased very slowly
toward ou ter regions, 8, 11, 13, 15 and
16 in some well-oriented saggital specimens. Tunnel path almost straight ormore or less irregular. Tunnel angle intypical specimens: 10, 19, 30, 29 and 24
degrees. Chomata well developed, narrow and high, massive in outer volutions
with steep sides.
Remarks:- The present new species
differs from the previously described
species of Profusulinella in its shell
shape. Aljutovella arrisionis LEONTOVICH
and A. arrislonis molotovensis SAFONOVA
described from the upper Verei horizonof the Russian Platform are related toProfusulinella omiensis n. sp. The form-

PI. 52, figs. 11-16

1967. Profusulinella daiyamensis HASEGAW AT
p. 9-15, pis. 1-3, figs. 1-38.
1972. Profusulinella fusiform is SADA, p. 439440, pI. 52, figs. 5-12.
1965. Profusulinella sp. B. SADA, p. 107, pI.
10, figs. 4-8, 12-13.

Description: - Shell small, short fusiform, with slightly concave lateralslopes and rather bluntly pointed poles.
Mature specimens 5 volutions and 0.841.60 mm in length and 0.58-0.80 mm inwidth. Form ratios from 1.37 to 2.00,
averaging 1.72 for 5 specimens. Proloculus small, its outside diameter varing
from 40 to 70 microns, averaging 50
microns for 18 specimens.
Spirotheca thin, composed of tectum,
outer tectorium and diaphanotheca. Septa numerous, almost unfluted throughout. Chomata well developed and massive in outer volution. Tunnel path almost straight. Tunnel angle in typical
specimens: 29, 21 and 23 degrees. Axial
filling weakly developed polar regions.
Remarks:-In the shape and size ofshell, the number of volutions, the rateof expansion, the spirothecal structure,and the development of chomata, Pl"Ofusulinella daiyamensis HASEGAWA fromthe Omi Limestone is closely allied tothe type specimens described from the
Akiyoshi Limestone. Profusulinella li-

637.
Table 6.

383

Profusulinella of Omi Limestone

Measurements of Profusulinella daiyamensis in mm.

N

MEAN

SD

Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16

Length

11

1. 25

0.21

1. 32

1. 04

0.84

Width

15

0.75

0.06

O. 72

O. 76

0.58

Form Ratio

5

1. 72

1. 83

1. 37

1. 45

Proloculus

18

0.05

0.01

0.04

0.04

0.04

5

17
18
18
18
18

0.05
0.08
0.16
0.25
0.38

0.01
0.10
0.03
0.04
0.06

0.04
0.02
0.10
0.16
0.24

0.06
0.08
0.17
0.28
0.44

0.04
0.11
0.12:
o 18
0.28

1

4

2

9
14
13

0.03
0.14
0.25
0.45
0.59

0.06
0.09
0.11
0.12

8

0.49
1. 47
1. 75
1. 92
1. 78

0.60
O. 72
O. 76
0.52

6
6
6
6
6

.014
.020
.025
.023

1. 36

1. 60

O. 70

0.80

1. 94

2.00

0.04

0.07

0.04

0.06
0.07
O. 16
0.24
0.40

0.04
0.08
O. 12
0.20
0.36

0.04
0.06
O. 10
O. 18
0.30
0.02

O. 12
0.28
0.52

0.04
O. 10
0.28
0.48
0.64

1. 50
1. 17
2.17

1. 00
1. 25
2.33
2.40
1. 78

3.33
2.33

.010

.007
.012

.014

.024
.024
.024

.019
.029
.020

.029
.026

O. 76

Vol.

1
RadiusVectorHalf
Length

Form
Ratio

2

3
4

3
4
5

8

1

4

2
3
4
5

9

1

Thickness 2
of3
Spirotheca 4
5

14
13

.010

0.02
0.16
0.48
0.64

0.16
0.32
0.49

0.14
0.22
0.40

0.50
1. 60
3.00
2.67

0.94
1.14
1.11

1.17

.012
.012
.012
.019
.019

.012
.014
.024

.007
.019
.024
.024
.024

brovichi and its related species describedfrom the Kashir horizon are similar tothe present species in many respects.
The present species has also the similality to the genus Fusiella in manybiocharacters.
Occurrence: - Common in collections
ScI-18 and IT-I, 2, associated with
Pseudostaffella kanumai IGo, and Nankinella yokoyamai SADA.
Reg. Nos.:-TGU-72033-72038

.024

.024

1. 22

1. 43

.007

0.26
0.60
O. 70
0.50
2.60

.012
.019

Pl'ofusulinella probiconica
WATANABE,n. sp.

PI. 52, figs. 21-24

Description: - Shell medium in size,
ellipsoidal to short fusiform with convex lateral slopes and broadly roundedpoles. Mature individuals 5 to 6 volutions and 2.20-2.44 mm in length and1.48-2.00 mm in width. Form ratios from
1.22 to 1.49. Proloculus small, its outside
diameter 75-135 microns.

Kozo WATANABE

384

Spirotheca thin in inner volutions but
comparatively thick in outer volutions.
Spirotheca composed of three layers,
dense tectum, upper tectorium and thick
diaphanotheca. Thicknesses of spirotheca of the first to sixth volutions intypical specimens: 12, 21, 24, 26, 53 and48 microns, respectively. Chomata welldeveloped, symmetrical, high and massive with steep sides. Tunnel pathstraight and high. Tunnel angle of thefirst to fifthvolution in holotype 14, 22,
23, 33 and 42 degrees, respectively.
Remarks: - This species closely resembles Profusulinella sp. A describedby SADA (1965) from the Atetsu Limestone. However, the Atetsu specimens
have slightly larger form ratio andweaker chomata. The present specimens seem to represent the transitional
form between Profusulinella and Fusulinella.
Occurrence:- Rare in collections ScI-5
and ScI-7, associated with Akiyoshiellaozawai TORIY AMA.
Reg. Nos.:-TGU -72039 (Holotype),
72040-72042 (P aratypes)
Profusulinella pseudorhomboidea PUTRJA
PI. 52, figs. 19-20
1951. Profusulinella pseudorhomboidea PUTRJA in RAUSER-CHERNOUSSOVA et aI.,p. 171, pI. 17, fig. 2.

Description:-Shell small, rhombic inshape, having highly vaulted median
portion aud bluntly pointed poles. Lat.eral slopes almost straight to slightly·concave. Mature specimens 6 volutions
and 2.60 mm in length and 1.48 mm inwidth. Form ratio 1.53 in well-oriented
mature specimens. The first volution
almost spherical, beyond the second
volution shell becomes rhombic in shape.
Proloculus small, its outside diameter

120-150 microns.
Spirotheca thin in inner volutions but
comparatively thick in outer volutions.
Spirotheca composed of three layers,
dense tectum, upper tectorium and diaphanotheca. Thicknesses of spirothecarather variable, attaining 40 to 50 microns in outer volutions. Septa numerous, weakly fluted in polar regions,but almost flat in other parts of shell.
Tunnel path almost straight and rather
narrow. Tunnel angles of the first to
fifth volutions: 11, 13, 16, 19 and 26 degrees in typical specimen. Chomata
generally symmetrical, high and welldeveloped with steep sides.
Remarks:-The present material closely resembles Profusulinella pseudorhomboidea PUTRJ A described from the Russian Platform. This is also related toProfusulinella rhomboidea (LEE et CHEN)
reported from Japan in the shape ofshell and other biocharacters. Because
the specimens of the latter species were
not so well oriented, more sufficientmaterials are necessary for more exact
identification.
Occurrence:-Rare in coHec tions ScI-14
and ScI-21, associated with Akiyoshiellatoriyamai THOMPSON, PITRAT and SANDERSON.
Reg. Nos.:-TGU-72043-72044
Profusulinella sp. A
PI. 52, figs. 17-18

Description :-Shell small, short fusiform with pointed poles. Mature individuals 6 volutions and 2.16 to 2.51 mm
in length and 1.10 to 1.23 mm in width.
Form ratio from 1.91 to 2.05. Shell has
endothyroid juvenarium of one volution
followed by five to six planispiral ones.
Proloculus small, its outside diameter
about 50 microns.

Table 7.

Measurements of species of Profusulinella in mm.

-------------------._---- --- -- P. sp. A

Fig. 17
LengthP. pseudorhomboidea

Fig. 18
2. L601. 225

Width

Fig. 20r

Fig. 21

Fig. 22

Fig. 23I!-?

2. 600:1

2. 5602. 4402. 200II'?

1. 4801--------

I

1. 6752.000

1. 480

II

Fig.
p___
_

__ II

19

- - - - - - - - - - - - - - - - -- - - II
0.050

Pro loculus
Form Ratio

il

2.05

O. 125

O. 120

1. 67

1. 77

Vol.
1

RadiusVectorHalf Length

2
3
4
5
6

1
2
3
4
5
6

0.13
0.15
o 25
0.35
0.50

O. 71

0.08
0.12
O. 18
0.30
0.43

0.13
0.20
0.28
0.40

I
O. 13
0.28
O. 58
1. 05
1.25

Form Ratio

1
2
3
4
5
6

O. 83
1. 10
1. 64
2.10
1. 76

Thicknessof
Spirotheca

1
2
3
4
5
6

.012
. 024
. 028
. 024
. 036

O. 13
0.30
O. 55
O. 81
0.98

1. 08
1. 71
1. 83
1. 91
.007
.012
. 021
. 024
. 024
. 015

P. sp. B

P. probiconica

1

I
I

1

0.150

O. 130O. 135

Ii

II

1. 53

1. 22

1. 49

II

i

1. 3501. 1500.075

O. 100
2. 02

0.08
0.10
0.14
0.15
0.23
0.24
0.38
0.33
0.58
0.48
0.61
0.75
11----------- -----0_08 ----0.18
0.35
0.63
1. 05

0.13
0.27
0.38
0.54
0.75

-

:: ::
0.28
0.43
O. 60
1. 00
1.40

:: ::
0.28
0.55
0 73
O. 88
-

:: ::
0.28
0.53
0.73
1. 05
1.25

0.16
0.33
0.50
0.75
1. 03
-

1 25
1. 25
1. 64
1. 63
-

O. 94
2. 12
1. 89
1. 82
2.11
1 48

1. 20
1. 20
1. 69
1. 53
1. 35
-

1. 20
1. 38
1. 69
1. 61
1. 56
1. 43

1. 2 3 ,
1. 20
1. 32
1. 39
1. 37

0.25
0.45
O. 65
-

2. 320

1

~

.019
.012
.024.021
. 026
. 024
. 036
. 026
. 043
. 053
. 048

.019
.012
.024
.034
.048
.048

~

""~
[......
......
('>

I;l

~

o
~
.,..
t--

~.

_ _ _ _ _ _ __1012.012
.019
.019
. 024
. 024
. 024
. 041
. 050
. 048

~

:-<
~

O. 13
0.20
O. 31
0.45
O. 68

O. 15

Fig. 25--;1-----

O. 13
0.23
O. 33
0.48
O. 65

O. 08
0.13
O. 23
O. 33
O. 48

Fig. 24

('>

1. 20
1. 20
1. 69
1. 53
1. 35
.012
.012
.024
.034
.048
.048

"".,....
o
;;;l
(!)

.012
.012
.017
.019
.024
Ci:l
00

Ql

386

Kozo WATANABE

Spirotheca thin, composed of tectum,
upper tectorium and diaphanotheca.
Septa numerous, unfluted throughout.
Tunnel path straight, narrow and its
angle 10 to 19 degrees. Chomata rather
massive. Axial filling weakly developedin polar regions.
Remarks :-The present specimens issimilar to some specimens of Prolusulin ella daiyamensis HASEGAWA in generalshape of shell. The latter, however, ismore tightly coiled, and a larger shell.
Occurrence:-Rare in collections Scll-5,
IT-1 and IT-2 associated with Ozawainella sp. and Eostaffella sp.
Reg. Nos.:-TGU-72045-72046

Prolusulinella sp. B
PI. 52, figs. 25-26

Remarks :-Only one axial section andmany oblique sections were obtained,
being impossible for the specific identification.
Occurrence:-Rare in collection ScI-2,
associated with Staffella akagoensis
TORIYAMA.
Reg. Nos.:-TGU-72047-72048

Genus Pseudostaffella THOMPSON, 1942
Pseudostaffella kanumai IGO
PI. 51, figs. 1-5

Table 8. Measurements of Pseudostaffella kanumai IGO in mm.
N

MEAN

SD

Fig. 1

Fig. 2

Fig. 3

Length

11

0.56

0.13

O. 725

0.625

0.650

Width

13

0.58

0.12

0.674

0.675

0.625

Form Ratio

3

1. 02

1. 08

0.93

1. 04

Proloculus

13

0.03

0.01

0.025

0.038

0.030

0.040

0.05
0.10
0.16
0.26
0.33

0.01
0.03
0.04
0.04
0.05

0.05
0.09
0.16
0.28
0.38

0.04
0.07
0.10
O. 18
0.25
0.38

0.07
O. 14
0.23
0.30

0.07
0.11
0.20
0.33

5
6

13
13
13
13
5
2

1
2
3
4
5

6
6
10
11
3

O. 04
O. 10
O. 15
O. 24
O. 29

O. 01
O. 03

6
6

O. 76
0.89
0.92
0.90
0.92

0.21
0.17
0.13
0.12

Vol.
1
2

RadiusVector3
4

Fig. 4

O. 725-----------------------------------------------------------Half

Length

0.03
O. 05

O. 03
O. 05

O. 13
O. 24
O. 35

0.11
O. 16
O. 25

0.81
0.86
0.92

O. 75
O. 71
0.91
0.89
1. 00

0.13
0.23
0.34

6
1

2

Form
Ratio

3
4

5
6

10
11
3

0.93
1. 00
1.13

637.

Profusulinella of Omi Limestone

1957. Pseudostaffella kanumai IGo, p. 194-195,
pI. 4, figs. 26, pI. 5, figs. 1-5.
1964. Pseudostaffella cf. kanumai SADA, p.
234-235, pI. 22, figs. 4, 8-9.

Description :-Shell small, subquadangular or spherical with broadly rounded
periphery and slightly umblicated orconvex poles. Mature specimens 4 to 5
volutions measuring 0.63-0.73 mm inlength and 0.63-0.73 mm in width. Formratio 0.93 to 1.08. Proloculus minute, its
outside diameter averaging 30 microns
for 13 specimens. Inner first or second
volution with slightly different axis ofcoiling.
Spirotheca thin, composed of dense
tectum, upper tectorium and diaphanotheca. Septa numerous, closely attached,unfluted throughout. Tunnel path irregular, low and tunnel angles about 20
to 30 degrees. Chomata well developed,
massive, asymmetrical. Tunnel sides
steep and polewards slope gradually decrease towards poles.
Remarks :-The present specimens resemble the type specimens in the modeof coiling of inner volutions and in otherbiocharac ters.
Occurrence: - Common in collection
ScI -18, associated with Profusulinella
daiyamensis HASEGAWA and Nankinella
yokoyamai SADA.
Reg. Nos.:-TGU-72049-72053
Genus Akiyoshiella TORIY AMA, 1953

Akiyoshiella ozawai TORIY AMA

shape and tightly coiled. Outer volutions rather rapidly increased their axial
length. Axis of coiling straight to gently arched. Mature individuals have 5 to
6 volutions measuring 3.32-4.64 mm inlength and 1.40-2.18 mm in width. Formratio from 2.13 to 2.37. Proloculus small,its outside diameter 130-150 microns.
Spirotheca thin, composed of threelayers of almost same thickness. Septa
numerous, consisting of same elementof spirotheca. In axial sections, septal
fluting arranged in a series of invertedarch on the surface of outer tectorium,and club-shaped in saggital sections.
Chomata rather poorly developed in
the first volution and tunnel path almost
straight. Tunnel narrow, rather highand its angle gradually widened. Axial
filling developed in inner three volutions.
Measurement :-See Table 9.
Remarks:- Akiyoshiella ozawai TORIYAMA was originally described from theProfusulinella beppensis Zone of the Akiyoshi Limestone, Yamaguchi Prefecture(TORIY AMA, 1958). The present specimens is closely related to the type specimens, in the size and shape of shell,
septal fluting and other important biocharacters, although the present specimens lack uncoiled volution.
Occurrence: - Collections ScI - 5 andScI-7, associated with Profusulinella
probiconica n. sp., Fusulinella hayasakain. sp. and Staffella akagoensis TORIY AMA.
Reg. Nos.:-TGU-72054-72057

Akiyoshiella toriyamai THOMPSON ,PI. 53, figs. 1-4

PITRAT and SANDERSON

1953. Akiyoshiella ozawai TORIY AMA, p. 253255, pI. 35, figs. 1-9.

PI. 53, figs. 5-10

Description :-Shell medium, fusiform
to inflated fusiform with narrowly
rounded to pointed poles. Inner one or
two volutions elongated rhomboidal in387

1953. Akiyoshiella toriyamai THOMPSON, PITRAT & SANDERSON, p. 550-551, pI. 58,
figs. 1-14.

Description: - Shell medium in size,
elongated and slender fusiform with

388

Kozo WATANABE
Table 9.

Measurements of Akiyoshiella ozawai in mm.

N

MEAN

SD

Fig. 1

Fig. 3

Length

9

3.667

0.56

3.320

4.640

Width

9

1. 7030.33

1. 4002.175

Form Ratio

2

2.25

2.37

2.13

Proloculus

10

0.139

0.03

0.125

0.150

0.125

0.13
0.23
0.40
0.65
0.89

0.03
0.06
0.07
0.09
0.08

0.10

3
4
5

9
9
9
9
4

0.18
0.33
0.53
o. 78

0.18
0.20
0.40
0.63
0.10

0.15
0.25
0.43
O. 70
0.90

1
2
3
4
5

8
8
8
8
6

0.22
0.46
0.84
1. 35
1. 80

0.06
0.09
0.08
0.15
0.32

0.20
0.38
O. 75
1. 38
1. 75

0.23
0.48
0.93
1. 38
2.18

1
2
3
4
5

8
8
8
8
2

1. 68
2.04
2.12
2.12
2.22

0.48
0.21
0.29
0.26

2.00
2.14
2.31
2.26
2.26

1. 29
2.38
2.31
2.20
2.18

1

3
3
3
3
2

.026
.029
.041
.035

.017
.022
.024
.026
.026

.024
.031
.038
.048

Fig. 4

2.050

Vol.
1

RadiusVectorHalf
LengthForm
Ratio

Thicknessof
Spirotheca

2

2
3
4
5

.019

sharply pointed poles. Axis of coilingstraight to broadly curved in outer volutions. Mature specimens 4 to 5 volutions measuring 2.96-4.04 mm in lengthand 0.88-1.23 mm in width. Form ratio
from 3.04 to 3.66. Proloculus small, its
outside diameter 100 to 175 microns.
Spirotheca thin, composed of tectum,
upper tectorium and diaphanotheca ofalmost same thickness. Septa rather
strongly and more or less regularly
fluted, and septal loopes conspicuous inaxial sections. Tunnel rather wide and.017.. 024
.026
.048
.043

its angle commonly 20 degrees. Rudimentary chomata present on outer surface of proloculus and probably in thefirst but lacks in later volutions. Axial
filling developed in inner three volutions.
Remarks:-The present materials are
more closely related to the typical Akiyoshiella toriyamai THOMPSON, PITRAT
and SANDERSON, although the differenceis only in its form. ratio, suggesting a
gradational change with each other.
Occurrence::--:Found in collections
Scl-14, G-1 and IT-3, associated with

389

637. Profusulinella of Omi LimestoneFig. 10. Measurements of Akiyoshiella toriyamai in mm.
N

MEAN

SD

Fig. 6

Fig. 7

Fig. 8Fig. 9Fig. 10

Length

19

3.425

0.50

4.040

3. 760

2.960

3.200

3.258

Width

23

1. 1130.16

1. 225

1.160

0.975

0.875

1. 025Pro loculus

22

0.137

0.03

0.125

0.175

o. 1000.140

o. 125

Form Ratio

5

3.28

3.30

3.24

3.04

3.66

3.18

RadiusVector

Vol.
1
2
3
4
5

23
23
23
21

0.12
0.22
0.35
0.51

0.03
0.05
0.07
0.08

0.13
0.28
0.43
0.60

0.11
0.21
0.35
0.50

0.06
O. 12
0.20
0.33
0.55

0.13
0.23
0.35
0.45

0.11
0.21
0.35
0.50

1
2
3
4

23
23
23
20

0.27
0.61
1. 12
1. 51

0.11
0.21
0.34
0.29

0.35
1. 08
1. 70
2.03

O. 15

Half
Length

0.33
0.63
1. 00

0.35
0.75
1.15
1. 58

0.30
0.55
1. 00
1. 08

5

1

0.06
0.20
0.45
1.18
1. 53

1
2
3
4
5

23
23
23
18
1

2.18
2.79
3.13
2.67

0.70
0.69
·0.59
0.52

2.69
3.91
4.00
3.38

1. 20
1. 63
1. 89
2.20

1. 05
1. 67
2.25
3.67
2. 77

2.69
3.33
3.27
3.50

2. 73
2.62
3.07
2.15

1
2
3
4
5

5
5
5
5

.015
.024
.037
.040

.012
.024
.043
.048

.012
.024
.04&
.043

.012
.024
.028
.041
.040

.020
.024
.031
.024

.019
.024
.036
.045

Form
Ratio

Thicknessof
Spiro theca1

Profusulinella pseudorhomboidea PUTR]Aand Staffella akagoensis TORIY AMA.
Reg. Nos. :-TGU-72058-72063

Genus Fusulinella MOLLER, 1877
Fusulinella hayasakai WATANABE n. sp.
PI. 53, figs. 11-14

1958. Fusulinella sp. B. TORIY AM A, p. 56-57,
pI. 5, figs. 4-7.
1958. Fusulinella sp. C. TORIY AMA, p. 58-59,
pI. 5, figs. 8-10.

Description :-Shell medium, fusiformwith convex and bluntly pointed poles.
Mature individuals 6 to 7 volutions and3.28 to ·3.60 mm in length and 1.48 to
2.15 mm in width. Form ratio from 1.60
to 1.73~ Proloculus small, its outside
diameter 60 to 150 microns. The first
volution spherical, and beyond the sec~
ond volutions shell gradually becoming
ellipsoidal to fusiform.
Spirotheca thick for the genus, composed of tectum, diaphanotheca andupper and lower tectoria. Lower tec-

390

Kozo W AT ANABE

torium first appeared in the third volution and clearly discernible in mostpart of outer volutions. AVerage thicknesses 'of spirotheca in central part ofshell measured 15, 23, 37, 34, 40 and 60
microns, respectively. Septal counts un-certain because of lack of well oriented
saggital sections. Tunnel high, narrowand its path irregular. Tunnel angle
ranging commonly up to 15 degrees.and rarely up to 30 degrees or more.
Chomata well developed its sides very
steep, vertical and sometimes overhanging, but poleward slopes very gentle,-extending down lateral slopes.
Remarks :-The present species is conspecific with Fusulinella sp. Band F. sp.
C described by TORIY AMA (1958) from theProfusulinella beppensis to Fusulinellabiconica Zones of the Akiyoshi limestone.
Occurrence: - Common in collections
ScI-5, ScI-7 and UT-1, associated with
Akiyoshiella ozawai TORIY AMA and Fusulinella sp.
Reg. Nos.:-TGU -72064 (Holotype),
72065-72067 (Paratypes)

Fusulinella jamesensis THOMPSON,PITRAT and SANDERSON

PI. 53, figs. 15-16

1953. Fusulinella jamesensis THOMPSON, PITRAT & SANDERSON, p. 545-549, pI. 57,
figs. S-10 (partim).

Description :-Shell small, short and inflated fusiform with pointed polar ends
and convex lateral slopes. Mature specimens 1.68-2.44 mm in length and 0.901.25 mm in width. Form ratio 1.68-2.09.
Proloculus small, its outside diameter 50
to 100 microns.
Spirotheca composed of tectum, diaphanotheca and upper and lower tectoria. Lower tectorium first appearedin the third volution and clearly discernible in a part of median portion of shell.
Septa unfluted throughout, but slightly
complicated near poles. Chomata, its
sides very steep, and sometimes overhanging down lateral slopes. Tunnel
narrow and path regular. Tunnel angle
ranging from 11 to 29 degrees.
Measurement :-See Table 12 (p. 393).
Remarks:-The present specimens
closely resemble the holotype from the
Cache Creek Areas, British Columbia,
Canada.
Occurrence :-Found only in collection
UT -1, associated with Fusulinella hayasakai n. sp., and Akiyoshiella sp ..
Reg. Nos.:-TGU-72068-72070

Explanation of Plate 51
Figs. 1-5. Pseudostaffella kanumai IGO
1, 2. Axial sections; 3, 4. Oblique sections; 5. Saggital section: x 50, Loc. ScI-IS.
Figs. 6-S. Nankinella yokoyamai SADA
6-S. Axial sections: x 50, Loc. ScI-IS.
Figs. 9-14. Eostaffella postmosquensis KIREEVA
9-11. Axial sections; 12-14. Slightly tangential sections: x 70, Loc. ScI-lSu.
Figs. 15-20. Staffella akagoensis TORIY AMA
15-1S. Axial sections; 19. Oblique section; 20. Saggital section: x 20, Loc. IT -3, ScI-7.
Figs. 21-24. Ozawainella vozhgalica SAFONOV A
21-24. Axial sections: x 50, Loc. ScI-lSu.
Figs. 25-26. Ozawainella angulata (COLANI)
25, 26. Axial sections: x 50, Loc. ScI-lSu.

WATANABE:

Profusulinella of Omi Limestone

Plate 51

637.

391

Profusulinella of Omi Limestone

Table 11. Measurements of Fusulinella hayasakai n. sp. in mm.
Fig. 13

Fig. 14

N

MEAN

SD

Fig. 11

Fig. 12

Length

6

3.027

0.48

3.280

1. 960Width

7

1. 6320.32

1. 9001. 225

Form Ratio

3

1. 67

1. 73

1. 60

Proloculus

7

0.139

0.03

0.125

o. 100

Vol.
1
2
3
4
5
6
7

7
7
7
7
7
7
1

0.12
0.19
0.31
0.44
0.63
0.82

0.03
0.02
0.03
0.05
0.07
0.11

0.13
0.20
0.33
0.45
0.65
0.90

0.10
0.16
0.25
0.35
0.48
0.65

1
2
3
4
5
6
7

6
6
6
6
5
4
1

0.14
0.25
0.47
O. 73
1.10
1. 49

0.05
0.05
0.09
0.12
0.18

0.18
0.23
0.48
O. 70
0.93
1. 30

0.12
0.20
0.35
0.58
0.88

0.09
0.18
0.25
0.40
0.63
0.93
1. 28

0.18
0.25
0.58
0.88
1. 25
1. 70

1
2
3
4
5
6
7

6
6
6
6
5
4
1

1. 17
1. 33
1. 52
1. 66
1. 67
1. 76

0.14
0.27
0.21
O. 14
0.28

1. 40
1.13
1. 46
1. 56
1. 42
1. 44

1. 00
1. 25
1. 43
1. 64
1. 84

1.13
1. 40
1. 25
1. 45
1. 56
1. 61
1. 65

1. 40
1.11
1. 64
1. 75
1.72
1. 70

1
2
3
4
5
6
7

4
4
4
4
4
4
1

.015
.023
.037
.034
.040
.060

.012
.024
.048
.048
.026
.084

.017
.024
.026
.036
.048
.048

.010
.019
.024
.024
.031
.048
.031

.019
.026
.048
.029
.053
.060

RadiusVectorHalf
LengthForm
Ratio

Thicknessof
Spirotheca

References
BENSH, F. R.

(1969) : Carboniferous strati·
graphy and Foraminifera from the south·
western and southern slope of the Gissar

3.600
1. 475

2.150
1. 67

0.060

0.08
0.13
0.20
0.28
0.40
O. 78

0.150

0.13
0.23
0.35
0.50
O. 73
1. 00

Ridge. Tashikent Inst. Geol. Geophysics,
Acad. Nauk, USSR., p. 1-184, pIs. 1-22
(in Russian).
COLANI, M. (1924): Nouvelle contribution al'etude des fusulinides de l'Extreme·

392

Kozo W AT ANABE

Orient. Indochine Service Geol., Mem.,vol. XI, fasc. 1, p. 1-191, pIs. 1-29.
DUNBAR, C.O., Ross, C. et al. (1962):
Faunas and correlation of the Late
Paleozoic rocks of Northeast Greenland.
Meddel. om Grifmland. Bd. 167, Nr. 4,
p. 1-16; Nr. 5, p. 5-55, pIs. 1-7.
FUJITA, H. (1958): Geology of the Omi
Limestone (Permo-Carboniferous), Niigata Prefecture. Contr. Inst. Paleont.,
Tohoku Univ., vol. 48, p. 1-60 (in Japanese) .
HASEGAW A, Y. (1967): Profusulinella daiyamensis n. sp., from the Akiyoshi Limestone Group. Sci. Rep. Fac. Sci., NiigataUniv., Ser. E, no. 1, p. 9-15, pIs. 1-3.
- - (1969): Paleozoic formations of the Omi
districts, Niigata Prefecture. Guidebookof Geology in Niigata. Geol. Soc. Japan,
p. 1-25 (in Japanese).
HAYASAKA, I. (1924): On the fauna of theauthoracolithic limestone of the Omimura iii the western part of Echigo.
Sci. Rep. Tohoku Imp. Univ. Ser. 2, vol.
8, no. 1, p. 1-83, pIs. 1-7.
IGo, H. (1957): Fusulinids of Fukuji, southern part of the Hida Massif, central
Japan. Sci. Tokyo Kyoiku Daigaku, Sec.
C, vol. 5, no. 47,p. 153-246, pIs. 1-15.

(1960): Yabe.ina from the Omi Limestone, Niigata Prefecture, central Japan.
Sci. Rep. Tohoku Univ., vol. 2, Spec. vol.
4, p. 335-343, pI. 36.
- - and KOIKE, T. (1964): Carboniferous
conodonts from the Omi Limestone, Niigata Prefecture, central Japan. Trans.
Proc. Palaeont. Soc. Japan, N. S., no. 53.
p. 179-193, pIs. 27-28.
ISlm, K. (1934): Geological sheet map with
explanatory text, "Shirouma", 1: 75000.
Geol. Surv. Japan.
KATO, T. and IISAKA, G. (1934): The Omi
Limestone and Kurohime-Myojyo Tectonic Line. Jour. Geol. Soc. Japan., vol.
41, p. 417-420 (in Japanese).
KAWADA, S. (1954): Stratigraphical andpaleontological studies of the Omi Limestone in the Itagamine district, Niigata
Prefecture. Bull. Tokyo Univ., Education.
Geol. & Min. Inst., no. 31, p. 15-27 (inJapanese) .
OZAWA, Y. (1925): On the fusuline-limestone of Omi. Jour. Geol. Soc. Japan."
vol. 32, p. 27-35 (in Japanese).
RAUSER-CHERNOUSSOVA, et al. (1951): Middle Carboniferous fusulinids of the Russian Platform and adjoining regions.
Acad. Nauk. USSR., p. 1-380, pIs. 1-58-

Explanation of Plate 52
All x20
Figs. 1-10. ' Profusulinella omiensis WATANABE, n. sp.
1. Axial section' of the holotype; 2-8. Axial sections of para types; 9-10. Saggital sections of para types. Loc. ScI-G.
Figs. 11-16.' Profusulinella daiyamensis HASEGAWA
11, 13a, 15. Axial sections; 12, 14, 16. Slightly oblique sections; 13. Saggital section.
11a, 12a and 13, x 30. Loc. ScI-18u.
Figs. 17-18 .. Profusu(inella sp. A
17, 18. Axial sections. Loc. Scll-5.
Figs. 19-20. Profusulinella pseudorhomboidea PUTRJA
19, 20. Axial sections. Loc. ScI-14.
Figs. 21-24., Profusulinella' probiconica WATANABE n. sp.
21. Axial section of the holotype; 22. Axial section of paratype; 23. Slightly tangential section of para type; 24. Saggital section of paratype. Loc. ScI-5 and ScI-7.
Figs. 25-26. Profusulinella sp. B
25. Axial section; 26. Oblique section. Loc. ScI-2.

W AT ANABE: Profusulinella of Omi Limestone

Plate 52

393

637. Profusulinella of Omi Limestone
Table 12.. MeasureQlents of Fusulinella jamesensis in mm.
N

MEAN

SD

Fig. 15

Fig. 16

Fig. 17

Length

4

2.09

0.37

2.44

1. 68

1. 88

Width

4

1. 09

0.17

1. 25

1. 00

0.90

Form Ratio

3

1. 91

1. 95

1. 68

2.09

Proloculus

4

0.08

0.08

0.08

0.10

4
4

0.07
0.12
0.19
0.28
0.43
0.57

0.08
0.13
0.21
0.33
0.50
0.68

0.08
0.18
0.25
0.40
0.55

0.08
0.13
0.20
0.33
0.49

0.13
0.28
0.50
O. 78
1. 08

0.08
0.13
0.25
0.45
0.73
0.88

0.09
0.18
0.35
0.65
0.88

RadiusVector

Vol.
1
2
3
4
6

4
3

1
2
3
4
5

4
4
4
4

6

3

0.05
0.15
0.28
0.51
O. 74
0.98

5

Half
LengthForm
Ratio

Thicknessof
Spirotheca

4
4

3

0.02

0.12

1

3

1. 57

1. 00

1. 20

2

4

1. 30

1. 00

1. 09

3

4

1. 51

1. 31

1. 43

1. 35
1. 75

4

4

1. 84

1. 54

1. 80

2.00

5

4

1. 75

1. 55

1. 81

1.77

6

3

1. 58

1. 59

1. 59

1

3
3
3
3
3

.009
.019
.024
.029
.044

.010
.014
.024
.029
.041

2
3
4
5
6

(in Russian).
ROWETT, C. L. and MINATO, M. (1969):

Corals from the Omi Limestone, central
Honshu, Japan. Jour. Fac. Sci., Hokkaido
Univ., Ser. 4, vol. 14, no. 1, p. 7-35,
pis. 1-9.
.$ADA, K. (1964): Carboniferous and Lower
Permian fusulines of the Atetsu Limestone in West Japan. Jour. Sci. Hiro-

-

-

.010

.019
.024

.031
.048

.007
.024
.024
.026
.043

shima Univ., Sec. C, vol. 3, p. 225-269,
pis. 21-28.
(1965): Profusulinella of Atetsu Limestone. Ibid., vol. 4, no. 1, p. 95-116, pis.

9-10.
(1972):

Fusulinids of Profusulinella
Zone of the Taishaku Limestone. Trans.
Proc. Palaeont. Soc. Japan., N.S., No. 87,
p. 436-446, pis. 52-53.

394

Kozo WATANABESAKAGAMI, S. (1962-63): Lower Carboniferous Bryozoa from Omi Limestone,
Japan. Pts. 1 and 2, Ibid., no. 48, p.
321-330, pis. 49-50; no. 49, p. 25-34, pis.
3-4.
SHENG, J. C. (1958): Fusulinids from thePenchi Series of the Taitzeho Valley,
Liaoning. Paleont. Sinica. N. S. B., no.
7, p. 59-110, pis. 1-16.
THOMPSON, M. L. (1965):
Pennsylvanianand Early Permian fusulinids from Fort.
St. James area, British Columbia, Canada. Jour. Paleont., vol. 39, no. 2, p. 224-

Omi
Itagamine
Kurohime
AkiyoshiAtetsuTaishaku

""'-

~

i:k
1;!iJ

*

Ichinotani
Fukuji
Uta
Nishiyama
Gongen-yama

#ij

1'1

~Jj(

234, pis. 33-35.
- - , PITRAT C. W. and SANDERSON, G.A ..
(1953) : Primitive Cache Creek fusulinids·from central British Columbia. Ibid.,
vol. 27, no. 4, p. 545-552, pis. 57-58.
TORIYAMA, R. (1953): New peculier fusu-·
linids genus from the Akiyoshi Lime-·stone of southern Japan. Ibid., vol. 27,
no. 2, p. 251-256, pis. 35-36.
(1958): Geology of Akiyoshi. Pt. 3;.
Fusulinids. Mem. Fac. Sci. Kyushu Univ.,
Ser. D, vol. 7, p. 1-254, pis. 1-48.

'r

~
~I:!
±

<=l

m
fR

0)

~

til!

tM

ilfX
j§

!lJ

:m :m !lJ

Explanation of Plate 53
All x20
Figs. 1-4. Akiyoshiella ozawai TORIYAMA
1, 2. Axial sections; 3. Oblique section; 4. Saggital section. Loc. ScI-5 and ScI-7.
Figs. 5-10. Akiyoshiella toriyamai THOMPSON, PITRAT & SANDERSON
5-10. Axial sections. Loc. IT-3, ScI-14 and G-I.
Figs. 11-14. Fusulinella hayasakai WATANABE, n. sp.
11-13. Axial sections of para types ; 14. Axial section of the holotype. Loc. ScI-5, UT-l..
Figs. 15-17. Fusulinella jamesensis THOMPS01\, PITRAT & SANDERSON
15-17. Axial sections. Loc. UT-I.

Plate 53
W AT ANABE: Profusulinella of Omi LimestoneTrans. Proc. Palaeont. Soc. Japan, N. S., No. 95, pp. 395-408, pis. 54,55, September 20, 1974

638.

NOTE ON THE GENUS TRIGONIOIDES (BIVALVIA)*SEONG-YOUNG YANG
Department of Geology, Kyushu University, Fukuoka 812**

Trigonioides ~ie. "?v'-C:

Trigonioides kodairai O)~;tUt!re <b .Q~m1!£!I'ifJl¥iittiiJJIUifl~i¥llUi7./<mmJi.p I? f~~ L.. t-::t~*~ 1f~~~ L.. t::.o~ I? Ie. c 0)~;t\~1!!.~*0) i*J~rHj'lfii'i ~ ~*mIL1f~lItL.., Trigonioides (s. s.) IL"?v'-CO)wrr§;jjJi!.~1Jn;tt::.o ~t::., c:/1,c 13*-?:W:l¥i7~70)
tl*c.lt,!(:~tlL..t.:f.!i*, v'~~-C- Trigonioides c L..-Cil~lIllG~:/1,t:I3*o) T. matsumotoi,

T. suzukii, T. tetoriensis, T. mifunensis ~Wrr!ffi~ T. (Kumamotoa) c L.. -C~frt::.IL5E~

W!

T.Q o

f;;

%:

nately, internal structure of the typespecies of Trigonioides, T. kodairai, was
not sufficiently known and the typespecimens are noW missing.
I have recently collected a number ofgood specimens from the type-locality
and had opportunities to observe mostof the trigonioidid specimens describedby Japanese authors at the Universityof Tokyo, Kumamoto University, andFukuoka University of Education.
In this paper I primarily report a
result of my study on Trigonioides
kodaimi with special stress on the hinge
structure and discuss the classificationof the genus by comparison between
relevan t species.
This study has been undertaken withthe aid of grants from the Ministry of
Education, Japan. I express my sincere
gratitude to Professor Tatsuro MATSUMOTO of Kyushu University for his
pertinent guidance and arrangement andalso critical reading of the first draft ofthis paper. I am also indebted to Associate Professor Kametoshi KANMERA
for his kind advice and encouragement,
Dr. Tomowo OZAWA for his invaluable
help in field working, and Messrs.

Introduction
Trigonioides is one of the most interestingandimportantnon-marine
pelecypod genera distributed in Mesozoic
Asia. Since the genus was erected by
KOBAYASHI and SUZUKI (1936) based on
Trigonioides kodairai from Korea, it has
been reported to occur at many localities;
in southwestern and central Japan(MATSUMOTO, 1938, OTA, 1959 and 1963,
HASE, 1960, MAEDA, 1963, and TAMURA,
1970), in southeast Asia (HOFFET, 1937,
and KOBAYASHI, 1963 and 1969), in China(KOBAY ASH! and SUZUKI, 1942, and Ku,
1962), and in U.S.S.R. (MARTINSON, 1965).
A new family Trigonioididae wasproposed by Cox (1952) for this genus.
Although it was withdrawn by Cox (1955)
himself, it has been now considered asa valid family by most of authors. As
to the natural classification and thephylogeny of the trigonioidids there has
been dispute among authors. Unfortu* Received Jan. 21, 1974; read Jan. 12,
1974, at Fukuoka.
** On leave from Department of EarthScience, College of Education, Kyungpook
National University, Daegu, Korea.

395

396

Seong- Young YANG

Hiromichi
HIRANO and Kazushige
TANABE and Miss Mutsuko HAYASHIDA·of Kyushu University for their friendly
helps in various ways. My sincere
gratitude is extended to Professor
Yoshihisa OT A of Fukuoka University{)f Education who gave me instructive'suggestions, generously let me study his-specimens and, in addition, kindly guided
me to a fossil locality in Kyushu, toAssociate Professor Itaru HAY AMI and
Emeritus Professor Teiichi KOBAYASHI·of the University of Tokyo, and Professor Minoru TAMURA of Kumamoto
University, who kindly showed me their·collections with warmful encouragements. Dr. Itaru HAY AMI furthermore
read the typescript with kind sug;gestions.

Systematic Description
Superfamily Unionacea
Family Trigonioididae
Genus Trigonioides KOBAYASHI and'SUZUKI, 1936
Generic diagnosis: - Shell generally
medium in size, equivalve aud sub·eqilateral; outline variably suboval,
subtrapezoidal or sub trigonal ; umbo
'prominent, slightly prosogyrous or orthogyrous. Surface ornamented with·characteristic V-shape ribs in the medianpart and the reversed V-shape ribs on'both anterior and posterior sides; the:angles of the median V-sculptures very
.acute from about 10· to 20· and those·of the reversed V on both sides larger
than 30·. Hinge plate moderate or large
in breadth, provided with opisthocline
submedian teeth and posterior lateral
teeth; the number of submedian teeth
variable from two to five in right valve,three or four in left valve, and thenumber of posterior lateral teeth alsovariable, one or two in both valves.
All of the hinge teeth crenulated on one
or both sides; the submedian teeth
originated a short distance anterior to
the umbo. Two adductor scars situatedclose to the outer ventral ends of thesubmedian and posterior lateral teeth,
anterior one accompanied by a minutepedal scar. Shell margin crenulated
internally.
Remark :-1 divide the genus Trigonioides into subgenera Trigonioides andKumamotoa (n. subgen.) based On the
difference of hinge structures as described below.
Subgenus Trigonioides
Type-species :-Trigonioides kodairai
KOBAYASHI & SUZUKI, 1936.
Subgeneric diagnosis :-Shell medium
in size, suboval in outline with rounded
anterior and posterior margins andbroadly arcuate ventral margin, moderately inflated, equivalve and sUbequilateral, with more or less prosogyrous
or orthogyrous umbo, placed slightly
anterior from the middle point. Surface
ornaments generally the same as described in generic diagnosis. Hinge plate
moderate in breadth, provided with
opisthocline submedian teeth and posterior lateral teeth; three submedianand two posterior lateral teeth in rightvalve and two or three submedian and
one posterior lateral teeth in the left;
forming the following dental formula:

5

1

3
4

2

PI
(1')

PIlI
PII

Trigonioides (Trigonioides) kodairai
KOBAYASHI & SUZUKI, 1936
PI. 54, figs. 1-11, PI. 55, figs. 1-4,
Text-figs. 2, 4.

638.

397

Trigonioides (Bivalvia)
KOREA

36'~~--~--------~~--------~~

A;Namhae

B;Hadcng
128'

126'

GUMNAM-MYUN

N....2'

SEOlCHEON-MYUN

O~==..:..._ _~2===il3(km)For Nomhae

I

Text-fig. 1. Index and locality map of Trigonioides (s. s.) kodairai.

398

Seong- Young Y ANC

Text-fig. 2. Surface-ornamentationof the T. (s. s.) kodairai. A: side viewof the left valve, B: upper view of theleft valve.

1936. Trigonioides kodairai KOBAY ASH! &SUZUKI, Japan. Jour. Ceol. Ceogr., vol.
13, nos. 3-4, p. 248-250, pI. 27, figs. 1-4.

Material :-The holotype and paratypes
designated by the original authors are
now missing, and probably were lost
during the World War II. All of thepresent specimens were collected fromthe type-locality (see Text-figure 1).
The specimens numbered with prefix
KPE are preserved in the Departmentof Earth-Science, College of Education,
Kyungpook National University, Daegu,
Korea. Three plaster casts of the above
specimens (KPE 1001, 1002, 1003) are kept
in the Department of Geology, Facultyof Science, Kyushu University, Fukuoka,
Japan.
Description :-Shell medium in size,commonly about 30 mm in length, occasionally larger than 40 mm; anterior
and posterior margins well rounded,
ventral margin gently and broadly
arcuate, generally suboval or subellipti-

cal in outline; subequilateral and equivalve; ratio of length to height about
0.75; moderately inflated; test moderate
in thickness; umbo slightly prosogyrous.
placed at about 0.42-0.48 of the shelllength from the anterior extremity.
projected slightly above the hinge line;.
escutcheon and lunule both present.
Surface ornamented with characteristic
V-shape ribs in the median part and thereversed V-ornaments in both anterior
and posterior parts. The angles of themedian V-sculptures ontogeneticallydecreased, i. e. near the beak commonlylarger than 20·, becoming smaller toward
the ventral side down to about 10·, andthe angles of the reversed V-ornaments·
on both sides generally larger than 30·_
The radial ribs on the anterior side
finer and weaker but denser in contrast
with those on the posterior side. Ribs.
gradually effaced toward anterior andventral margin, especially so in adultspecimens. The median ribs number 1Q.
in the posterior half and 18 in theanterior half; the ribs sloping obliquely
toward outer dorsal sides, more than 11
on the posterior side and 15 on theanterior: the whole surface ornamented
also with numerous concentric growthlines of irregular interval and prominence.
Hinge plate and teeth generally thesame as described in subgeneric diagnosis; in more detail as follows:
5: narrow and elongated, with regulartransverse crenulations on posteriorside only, parallel to the anterodorsal margin
3: most prominent in the right valve.
elongated and crenulated on bothsides, subparallel to the anterodorsal margin
1: low and short, crenulated on anteriorside only
4: stout and highest in the left valVe,.

638.

399'

Trigonioides (Bivalvia)

crenulated on both sides, subparallelto antero-dorsal margin
2: moderate and elongated, sloping obliquely toward anteroventral side,
crenulated wholly on anterior side,
in upper part only on posterior side
1': not so distinct, immediately below
the umbo, a shallow elongated recess
the nature of which is doubtful
All of the submedian teeth are originated from a point a little anterior to
the umbo.
PI: quite narrow and not so prominent,
but elongated, with regular transverse
crenulations on dorsal side,subparallel
to postero-dorsal margin
PIlI: moderately prominent and elongated,withregular transverse

crenulations on ventral side, parallel
to postero-dorsal margin
PII: prominent and elongated, withregular transverse crenulations on
both sides, parallel to and extending
through whole length of the posterodorsal margin
Adductor scars subequal in size andform, situated close to the outer ventral
ends of the submedian and the posterior
lateral teeth; anterior one subcircular,
strongly impressed, accompanied with adistinct minute pedal scar which is
subtriangular in shape; posterior one
also subcircular but not so distinct;
shell margin crenulated internally,umbonal cavity moderately deep.

Measurements (in mm):Specimens
KPE 1001(RV)
KPE 1002(L V)
KPE 1003(BV)
KPE 1004(LV)
KPE 1005(RV)
KPE 1010(BV)
KPE 1011(BV)*
KPE 1012(BV)*
KPE 1013(BV)*
KPE 1014(RV)*KPE 1015(BV)*
KPE 1016(BV)*
KPE 1017(BV)*

---

I

i

Height

1-

34. 1
21. 3
31. 2
21. 7
20.9
25.1
26.0
20.1+
22.0
25.5
2? 1
23.6+
22.3

I
i

I
I

!

I
I

i

LengthD.

Infia.

43.0
28.6
42.2
29.3
29.2
33.3
30.5+
30. 1
30.8
31. 3+
31. 3
30.6
28.1+

20.6
12.9
17.5
13.8
12.9
16.0
14.3
16.4
11. 4
13.3
13. 7
16.5
?

7.0x2
5.5x2
?
5.3x2
6.4x2
?
?
?
?
6.8x2
?
?
?

--

!
I

I
I

!!

II

I

I

H/L

D/L

O. 7930.745
O. 739O. 7400.716
O. 754
0.852
0.668
0.714
0.814
O. 706
O. 771
O. 794

0.479
0.451
0.415
0.471
0.442
0.480
0.468
0.545
0.370
0.425
0.438
0.539
?

(RV) , (LV), and (BV) : right valve, left valve and bivalve respectively. (deformed specimens. D: distance between umbo and anterior extremity.

Observations :- The specimen (KPE
1001) is a well preserved right valve
and the largest among the present
material. It shows essentially the sameoutline and the same pattern of ornament as the original figure of the holotype (KOBAY ASH! & SUZUKI, 1936, pI. 27,)*: strongly

fig. 1). About half of the specimens arebivalved and all possess well preserved
test. The internal structures have been
observed on the four specimens (KPE
1006-1009) from which the tests weredissolved out by hydrochloric acid. Theinternal structures examined on the four400

Seong- Young YANG

show constant characters without noticeable variation.
Occurrence:- The specimens describedhere were collected from the light green
siltsfone and claystone of Hasandong
Formation at Sumoondong, Gumnammyun, Hadong-gun, Gyeongsang-nam-do,
Korea (see Text-figure 1).
It. is interesting to note that thesYmmetrical planes of the bivalved
fossils are posed vertically and theantero-posterior axes inclined to a
bedding plane, while the single valves
were commonly parallel to stratification.

I have not completed the stratigraphic
investigation of the present area. According to LEE (1972), who surveyed
the area in the vicinity of the fossil
locality, the subdivision of the Nagdong
Subgroup at Daegu-Waegwan Section
can be generally extended to the studied
area and it is undoubtedly assigned tothe middle part of the Hasandong Formation, Nagdong Subgroup.
The
Nagdong Subgroup at Daegu-Waegwan
Section was divided by TATEIWA (1929)
and CHANG (1966) into the following
formations in descending order:

Silla Subgroup. Disconformi ty··
Chilgok Formation
Dongmyeong Formation (jinju Formation)
Nagdong Subgroup Hasandong Formation
Yeonwhadong Formation (Nagdong Formation)............ Nonconformity···· ......... .
Pre-Gyeongsang Group (granite or granitic gneiss)

j

5cf1

Solid lines and cross mark; T.(s.st.) kodairci
Dotted lines; W. wakinoensis•.......•\•..

........:~....... .

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

o

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

10...... .....

.... ......

.... .....

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

20

Distance from beak - - - - - .

Text-fig. 3. Ontogenetic change of the angle of V-sculpturesdue to the distance from beak.

30 (mm)I

638.

Trigonioides (Bivalvia)

Discussion

On the surface ornamentation :-All of
the trigonioidid species have characteristic V-shape ornaments on the
median part and both of anterior andposterior sides are ornamented with thereversed V -shape ribs. The angles ofV-shape ribs on the median part deserve
consideration. The ontogenetic changeof them can certainly be observed asshown in Text-figure 3. There is adecreasing trend from beak toward theventral side. The Japanese specimens
are unfortunately so often deformedthat I cannot precisely compare thechange.
However, it can be one of the criteria
to distinguish Trigonioides from Wakinoa.
The angle in the early growth-stage iscommonly larger than 20· and it becomes
smaller with growth down to about 10·
in the case of the former, but in thelatter the angle near the beak is larger
than 40· and even in the ventral part
it is larger than 30·.
In view of the dissimilar pattern of
ornament, the specimen from Wakino
which was identified with T. kodairai by
KOBAY ASHI and SUZUKI (1936, pI. 29, fig.
13) is undoubtedly different from true
T. kodairai but probably referable to
Wakinoa wakinoensis. Even in the subsequent" collections from' the Wakino
Formation no specimen is referable to
T. kodairai.
OT A (1959) proposed the classification
based upon the reversed V-ornamentations, the so-called Kodairai type,
Suzukii type, and Matsumotoi type.
However, the ornamentation of T. kodairai as seen in the present topotypes
considerably differs from the figure of"Kodaiiai type" by OTA (1959, p. 100,
text-fig. 3). His figure of " Suzukii type"seems to have drawn on the basis of a401

deformed specimens, the ornamentationof which is essentially similar to thatof T. kodairai. "Matsumotoi type"
ornament is not also constantly maintained, but for a single specimen (OTA
1959; pI. 10, fig. 12). As OT A pointed
out, there is a considerable variation inornamentation, that is in the number ofthe radial ribs and the set of the Vsculptures, i.e., double, tripple or multiple
types as found by TAMURA (1970).

On the hinge teeth:1) T. matsumotoi and T. mifunensis:
According to TAMURA (1970), the dental
formula of these species is as follows:

5
(6)

3
4

1a

2

(PIlI)

1bl'al'b PHPIV

Although there is an intraspecificvariation in the hinge teeth 6 and l'b
as pointed out by previous authors (OT A,
1959; TAMURA, 1970), la, l' a and 1b are
constant and prominent in these species,
but they are not so distinct in T. kodairai.
The hinge plate of these Japanese
species is much wider than that of T.
kodairai, and 5, 4, 3, 2, and 1a are distinctly higher compared with those in
T. kodairai, respectively. Furthermore,
the relative ratio of the length between
them is quite different from each otheras seen in Text-figure 5. That is, thevalue of 1a/3 is much smaller in T.
kodairai (0.25) than in T. matsumotoi andT. mifunensis (larger than 0.6 in both).
The posterior lateral teeth of thesegroup cannot be certainly observed in
OT A and TAMURA's specimens.
2) T. suzukii: I observed all of thespecimens of T. suzukii stored in the
Fukuoka University of Education inwhich holotype is included, but I cannot
find 1b and l'b, and it is also very
difficult to ascertain posterior lateral
teeth. As shown in Text-figure ( thesubmedian teeth are similar to those of402

Seong- Young YANG

.~

...

4

5
Text-fig. 4. Hinge structure of T. (s. s.), T. (Kumamotoa), Wakinoa andHof/etrigonia. 1. T. (Kumamotoa) matsumotoi and mi/unensis, 2. T. (Kumamotoa) suzukii, 3. T. (s. s.) kodairai, 4. Wakinoa wakinoensis, 5. Hof/etrigonia
kobayashii.

T. kodairai, but not exactly the same.
'The hinge plate of T. suzukii is muchwider just like those of T. matsumotoi.and T. mifunensis the submedian teeth·of T. suzukii much stronger than those·of T. kodairai. In addition, the value ofla/3 is also nearer to those of T.
matsumotoi and T. mifunensis than to·that of T. kodairai.
In conclusion, it seems reasonable and.natural to exclude the above three
Japanese species from Trigonioides (s. s.)and place them under a new subgenus,
Kumamotoa.
3) Wakinoa: Wakinoa was established
by OT A (1963) as a subgenus of Trigonioides based on the type-species-', Nippononaia" wakinoensis OT A, 1959,
and its allied species. As illustrated in
Text-figure 4 and has been pointed out.already by previous authors, the hinge
structure of this group is distinctly

different from that of Trigonioides. The
hinge plate is narrow and the featuresof crenulations are irregular and dense
and the submedian teeth 1 and I' arevariable in contrast with any otherspecies of Trigonioides. Moreover, there
is some difference in surface ornamentation as mentioned above. Therefore it
seems also reasonable to exclude thisgroup from the genus Trigonioides andseparate it as an independent genus.
4) Hoffetrigonia: This genus was proposed by SUZUKI (1940) as a new genus
based on Trigonioides kobayashii (HOFFET, 1937) from Indochina (Viet Nam)by the reason that its outline and hinge
teeth differ from those of the Korean
and Japanese species.
After that,
KOBAY ASH! (1956) regarded Hoffetrigonia
as synonymous with Trigonioides because there is no remarkable difference
between them. And OT A (1959) agreed

638.

Trigonioides (Bivalvia)

403

RIGHT VALVE
SPECIES
T.kodoirai~3l'Ys J,~

r----- : :t--

K. matsumotoir--'--~

K. mifunensis

REMARKSJl.s

r--+r--"jf--....... ~ ........~ ........~w.

3/L

1bts'J

KPElOO?
KPE 100SKPE 1005

Hr-

KE 1963
GK 1500
KE 1950
KE 1948
KPE 1026
KPEI023t-'t-~

K.suzukii
H. kobayashiif---;- ,WuklOO

rt----"-.

t-:
W. wakinoensis
LEFT VALVE
SPECIES
T.kodairai

t-- :

,
6/4

os

.

:

~

2/4
0.5

laV4
05

4/L
os

Fig. 7

WIs5051
WIs 5050

WIs 5057

REMARKSKFE 1006
KPE 1004

K.matsumotoi

KE 1964

K.mifunensis

KE 1956
KE 1951
KPE 1021
KPE 1022

K.suzukii.

Hoffet(1937),PI.1, F;g.5........:........ ~ ... .

H.kobayashii

Wu'kIOO
Hcffet(1937hPI.I, F;g.4.. Fig.6

W.wakinoensis

WIs50SI

Text·fig. 5. Relative ratio of the length of submedian teeth in Trigonioididae.
6, 5, 4, 3, 2, la, l'a and lb: symbols of dentitions, L: length of the specimen, Prefix
KE: specimens of the Earth·Science Department, Kumamoto University, Prefix GK,
Wuk, and Wls: specimens of the Earth·Science Department, Fukuoka University of
Education.

with him. Subsequently, on account of
the presence of a small escutcheon dis·tinguishable from Trigonioides s. str.,
KOBAY ASHI (1968) placed the Hoffetri.
gonia as a subgenus of Trigonioides inwhich T. (H) kobayashii only was con·tained. As KOBAYASHI pointed out, theIndochinese trigonioidid species has sub·median teeth 5, 3, la, and 1b in rightvalve like T. matsumotoi and T. mifunensis
from Japan. Therefore, there is no dif·ference in dental formula between them,but the dentition of Indochinese species
shows unique features as illustrated in
the plates (HOFFET, 1937, pi. 1, fig. 4-7,
and KOBAYASHI, 1968, pi. 23, figs. 1a and1b) and the Text·figure 4 presented here.
In all of the Korean and Japanese
species of Trigonioides the submedianteeth are originated at a short distanceanterior to the umbo, while in the
Indochinese species they are originatedimmediately below the umbo. And thecrenulations in the latter are distinctly
denser than in the former, except for
Wakinoa. Moreover, the value of 1a/3
of Hoffetrigonia is also characteristicallyintermediate between the Korean andJapanese species as illustrated in Text·
figure 5. Hoffetrigonia is apparently
more similar to Trigoniidae in hinge
structures than any other Korean and404

Seong-Young YANG

Japanese trigonioidids, although there
may be no genetic connection.
To sum up, I agree with SUZUKI'S
opinion that the Hoffetrigonia is an independent genus.
5) Other species: I had no chance toobserve the specimens of T. tetoriensis
and T. kitadaniensis described by MAEDA(1963). However, according to his description and illustration, T. kitadaniensis
is hardly distinguished from T. tetoriensis
as TAMURA (1970) mentioned. MAEDA(1963, p. 82) described the dental formulaof T. tetoriensis as follows:
(5a)

3a

1a

4a

(5)

I'

2b

3

1a

4

1b

2

l'a

(PI)

PIlI

(l'b)

PH

PIV

In conclusion, T. tetoriensis (=T.
kitadaniensis) undoubtedly belongs to
the same group as T. matsumotoi, T.
suzukii and T. mifunensis.
I examined the specimens of T. kodairai
paucisulcatus SUZUKI kept at the
University of Tokyo, but the internal
structures could not be clearly seen.

3b

1b

2a

former are equivalent to the l'a, 1b andl'b in the latter, respectively. Nevertheless it is important to consider that
I' is crenulated on both sides. If so, 1b
may be assigned to 1b in TAMURA'S
formula. And 2b is also crenulated on
both sides, in which there must be
another tooth between I' and 2b in rightvalve in addition to lb. After all, thethe above formula may be presented asfollows:

4b

It is difficult to correlate the above
dental formula with TAMURA'S (1970),
because homology does not maintained.
Especially it is questionable whether or
not the teeth I', 1b, and 2b in the
RIGHT VALVE
SPECIES

a.l.

5

•

a. s.

1111

la
Q.

s.

I.

lb

a,s

PI

'"'

illil

"""

'lill11

"'"

1111'

1_ iw.
I-r-"u

UUill~ I J.J~ I

PV
a. S•

.' REMARKSKPE 1009

KPE10qS
KPE 1008

P i

11111111" ..• ,1

I~

K E 1963
G K1-fu.u.w.

''''" '''"

1111, 1111'_-t"'w.Uillw.

I '"'11'"'"

11111111'

6
:L.!.

a.

4
5• . •'-U.fL"'"LEFT VALVE
0.5:J.lJ1ll'
will'

KPE 10 2S

5.

.LU.J.lllJ.JilJ

a.

..

2
IP. 5
UJ.ll fi!.-

KPE I 026
Wu k[1111111"'''" 11111

'

la'
lb'
a. 5.~S. a.s.
J.'J-L .....

100~W"SOSII - .\ ' I........... ....... ..... ,.....
I ::.: i "[;;;,~;"I;;;,;;'''' :~...

W'.SOS?

J. . . :::: :::PII• a. s. l..I!.....!.

1lLlU.~1;.lJ r-

K. matsumotoi

K E I 948

I

I

Ut- i

sao

K E I 950::.·,d······""111111"

SPECIES5,___·~~~.~:I''''··

K.suzukii

T.kodairai

I p.

WW~

K.mifunensis

W.'tYQkinoensis

5,. UJ..IJ.J.JI-';;'::;';1--

1- r-'-'

1I1111'Lum

PII

a.

5 a,s

"'"'"" IIIIIIII:.u.r'"11'"' '1111'
WrII '"'" 1111"
Wr-

T. kodairai

K. matsumotoi

s.

::;;;

PlV
a. s. P. s.

':;; 'liH<----- ..

-.... .....
~.0 ___ ------.-REMARKS
KPE

1006

E

196" .

K

E , 'S.
"""i!
'"'
I=~ lUll '-E I 'S I----- .. ------ ----ww.J.w.w
E 1029, I .:.ililfw.L Iill! r- _.. _-_ .. ----. ------ -- _.. UJ.ll.IJ.llllllaE----W1fll----.!.ll f----- ----_ . ----- ----- W.
100
IJ.l1lllfllW,;;

I.lW.ll4lllW

K.mifunensis

K
K

K P

103

KP

\Ksuzukii.
k''''''"'

W.wakinoensis

Text·fig. 6.

.;.:..

t'-

Number of the crenulations of the hinge teeth.

a:. s.: anterior side, p. s.·: posterior side.

WI

S081

638.

However, as stated by SUZUKI (1940), it
seems quite similar to T. kodairai inoutline, size and the general dispositionof the hinge teeth.
Distribution and Phylogeny:- KOBAYASHI and SUZUKI (1936) originally described the fossils from Sumoondong and
Wakino under the name of Trigonioides
kodairai. Through this study I come tothe conclusion that the so-called T.
kodairai from Wakino is not true T.
kodairai, but referable to Wakinoa
wakinoensis. ,Therefore, the correlation
between Nagdong and Wakino Subgroupbased on the occurrence of T. kodairai
and others is left as a problem for
future study.
The problem on the phylogeny of the
Trigonioides has been frequently discussed, and the previous opinions may
be divided into two; one is that thecrenulations and the submedian teeth la,
1b, 11a and lIb became phylogeneticallyeffaced from the Trigoniacea throughTrigonioides to Nippononaia (KOBAYASHI,
1956) and the other that they became
contrarily prominent from Nippononaia
or Plicatounio through Wakinoa to Trigonioides (OTA, 1963, and HAY AMI in
HAY AMI and ICHIKAWA, 1965). In thepresent state of knowledge, I cannot
participate in the discussion, but my
opinion is inclined to the latter. Anyhow, the Trigonioides (s. s.) may apparently take the position. between
Wakinoa and T. (Kumamotoa) in evolutionary trend.
Proposal of subgenus

Kumamotoa
Genus Trigonioides KOBAYASHI &SUZUKI, 1936
Subgenus Kumamotoa
YANG, n. subgen.

405,

Trigonioides (Bivalvia)

Type-species :-Trigonioides mifunensis
TAMURA, 1970.
Included species:-Trigonioides matsumotoi KOBAYASHI & SUZUKI, 1940. Trigonioides suzukii OT A, 1959. Trigonioides
tetoriensis MAEDA, 1963. Trigonioides
mifunensis TAMURA, 1970.
Subgeneric diagnosis :-Shell relatively
large in the genus; subtrapezoidal, subelliptical, or subtrigonal in outline withrounded anterior margin and subelongated posterior margin; umbo prominent"slightly prosogyrous or orthogyrous;
equivalve and subequilateral. Surface
marked with the characteristic ornamentation of the genus. Hinge platelarge in breadth, provided with mostwell developed hinge teeth in the genus;
the dental formula as follows:

5
(6)

3
4

1a
2

1b
11a

PIII
(lIb) PH

PIV

where the teeth in parentheses' arevariable and sometimes absent. Mostof the hinge regularly crenulated on one
or both sides; the value of 1a/3 generally larger than 0.6.
References
CHANG, K. H. (1966): Stratigraphy and sedi-·
mentation of Nagdong Subgroup (Lower
Cretaceous), Gyeongsang Province, South
Korea. Jour. Geol. Soc. Korea, 2, (1),17-51, figs. 1-7, pIs. 1-3.
Cox, L. R. (1952): Notes on the Trigoniidae
with outline of a classification of thefamily. Proc. Malac. Soc. London, 29"(2-3), 45-70, pIs. 3-4.
-,- (1955): On the affinities of the Cretaceous lamellibranch genera Trigonioides
and Hoffetrigonia. Geol. Mag., 92, (4)"345-349.
HASE, A. (1960): The late Mesozoic formations and their molluscan fossils inwest Chugoku and north Kyushu. Jour.
Sci., Hiroshima Univ., (C), 3, (2), 281-

406

Seong-Young YANG

342, pis. 31-39.
HAYAMI, I. and icHIKAWA, T. (1965): Occurrence of Nippononaia ryosekiana fromthe Sanchu area, Japan. Trans. Proc.
Pal. Soc. Japan, N. S., (60), 145-155, pI.
17.
HOFFET, J. H. (1937): Les Lamellibranchissaumatres du Senonien de Muong Phalane(Bas-Laos). Bull. Servo geol. l'Indochine,24, (2), 4-25, pis. 1-5.
KOBAYASHI, T. (1956): On the dentition of
Trigonioides and its relation to similarpelecypod genera. Japan. Jour. Geol.
Geogr., 27, (1), 79-94, pI. 5.
- - (1963): On the Cretaceous Ban Na Yo
fauna of East Thailand with a note on
the distribution of Nippononaia, Trigonioides, and Plicatounio. Ibid., 34, (1),35-43, pI. 3.
- - (1968) : The Cretaceous non-marine
pelecypods from the Nam Phung Damsite in the northern part of the Khorat
Plateau, Thailand with a note on the
Trigonioididae. Geol. Palaeont. SE Asia,
4, 109-138, pis. 20-23.
- - and SUZUKI, K. (1936): Non-marine
shells of the Naktong-Wakino series.
Japan. Jour. Geol. Geogr., 13, (3-4), 243257, pis. 27-29.

- - and - - (1941): On the occurrence ofTrigonioides in south-eastern Manchuria.
Bull. Geol. Inst. Manch., (101), 77-81.
Ku, C. W. (1962): Note on the occurrenceof some late Cretaceous fresh-water
lamellibranches in the Chusing districtof Central Yunnan with a brief reviewof the continental Cretaceous of Yunnan.
Acta Pal. Sinica, 10, (3), 287-307, pIs. 1-2.
LEE, Y. K. (1970): Sedimentological petrology of Nagdong Group in Jinju-Namhae
area, South Gyeongsang Province, Korea.
(M. S.) Dept. Geol. Kyungpook Natl.
Univ.
MAEDA, S. (1963): Trigonioides from thelate Mesozoic Tetori group, Central
Japan. Trans. Proc. Pal. Soc. Japan, N.S.,(51), 79-85, pI. 12.
MARTINSON, W. B. (1965):
Cretaceous
Lamellibranches of the family Trigonioididae and their classification. Pal.
Jour., 1965, (4), Acad. Sci. U.S.S.R.
MATSUMOTO, T. (1938): Geology of the
Goshonoura Island, Amakusa, withspecial reference to the Cretaceous
stratigraphy. Jour., Geol. Soc. Japan,
45, (532) 1-46, pIs. 1-2 (in Japanese).
OTA, Y. (1959): Trigonioides and its classification. Trans. Proc. Pal. Soc. Japan,

Explanation of Plate 54
Figs. 1-11. Trigonioides (s. s.) kodairai KOBAYASHI & SUZUKI.
1. Right valve (KPE 1001) x 1.5, 1a; side view, 1b; upper view, 1c; anterior view, 1d;posterior view.
2. Bivalved (KPE 1003) x 1.5, Left valve side view.
3. Left valve (KPE 1014) x 1.5.
4. Left valve (KPE 1004) x 1.5, 1a; side view, 1b; upper view.
5. Bivalved (KPE 1013) x 1.5, Left valve side view.
6. Bivalved (KPE 1011) x 1.5, Right valve side view.
7. Bivalved. (KPE 1015) x 1.5, Left valve side view.
8. Bivalved (KPE 1010) x 1.5, 8a; Left valve side view, 8b; upper view.
9. Bivalved (KPE 1012) x 1.5, Left valve side view.
10. Left valve (KPE 1002) x 1.5.
11. Right valve (KPE 1005) x 1.5, lla; side view, llb; upper view.
Loc. ; Sumoondong, Gumnam-myun, Hadong-gun, Gyeongsang-nam-do, Korea.
All of the specimens illustrated are kept in the Department of Earth-Science, College of
Education, Kyungpook National University, Daegu, Korea. Three plaster casts (KPE 1001,
1002, 1003) of the above specimens are preserved in the Department of Geology, Faculty of.science, Kyushu University, Fukuoka, Japan.

YANG:

Trigonioides (Bivalvia)

Plate 54

407

638. Trigonioides (Bivalvia)
N. S., (34), 97-104, pI. 10.
- - (1959): On the "Nippononaia" fromthe lower Cretaceous Wakino subgroup,
north Kyushu, Japan. Ibid., (34), 105110, pI. II.
(1963): Notes on the relationship ofTrigonioides and Plicatounio, non-marine
Mesozoic Bivalvia from eastern Asia.
Geol. Rept. Hiroshima Univ., (12),503-512.
SUZUKI, K. (1940): Non-marine molluscan
faunule of the Siragi series in South
Tyosen. Japan. Jour. Geol. Geogr., 17,(3-4), pIs. 22-24.
- - (1943): Restudy on the non-marine

Busan
Chilgok
Daegu
Dongmyeong
Gyeongsang-nam-do
Gumnam-myun
Hadong-gun
Hasandong
Jinju
Kumamoto
Nagdong

~

ill

~

tt
W

=*

a~

*

~r,lfll$ii!i:

~mlRi

*ill

iiiJ
~.x

;jjjl
lr.TI

51
"'"

;H·I

Ji~

**

m

molluscan fauna of the Rakuto series in.
Keisyo-do, Tyosen. Jour. Sigenkagaku
Kenkyusho, 1, (2), 189-219 pIs. 14-19.
TAMURA, M. (1970): The hinge structure·of Trigonioides, with description of
Trigonioides mijunensis, sp. nov. fromupper Cretaceous Mifune group, Kuma-·
moto Pref., Japan. Mem. Fac. Educ.,.
Kumamoto Univ., (18), Sec. 1, 38-52, pIs ..
1-2.
TATEIWA, 1. (1929): Geological atlas of
Chosen, no. 10; Gyeongju, Yeongcheon,
Daegu and Waegwan sheets, Geol. Surv_
Korea.

NamhaeNamhae daegyo
Noryang
Silla
Seolcheon-myun
Sinnoryang
Sumoondong
WaegwanWakinoYeonwhadong

m ffl
mffl=*:tJ.

9t
ffr

ti(G

if.[

~ )1100

WrIWti(G* ~~ fiB
~

Mb

tIi!l
!Iff

~ 1E l~408

Seong-Young YANG

Explanation of Plate 55
Figs. 1-4. Trigonioides (s. s.) kodairai KOBAYASHI and SUZUKI.
1. Right valve. la; rubber cast of right internal mould (lb) x 2.5. Ib; internal mouldof right valve (KPE 1007) x 1.5. Loc. Sumoon-dong.
2. Internal mould of right valve (KPE 1008) x 2.5. Loc. ditto.
3. Right valve, internal view (KPE 1005) x 2.5. Loc. ditto.
4. Left valve, internal view (KPE 1006) x 1.5. Loc. ditto.
Figs. 5-6. Trigonioides (Kumamotoa) mifunensis TAMURA.
5. Internal view of right valve, rubber cast of (KPE 1026) xl. Loc. 500 m S. E. of
Tashiro (see TAMURA, 1970 for precise locality).
6. Ringe structure of right valve, rubber cast of (KPE 1023) xl. Loc. ditto.
Fig. 7. Trigonioides (Kumamotoa) matsumotoi KOBAYASHI and SUZUKI.
Showing the hinge structure of right valve, rubber cast of (GK 1500) xl. Loc. Gosyonoura Island (see OTA, 1959 for precise locality).
Fig. 8. Trigonioides (Kumamotoa) suzukii OTA.
Showing the hinge structure of the bivalved, rubber cast of (Wuk 100) xl. Loc. Rata(see OTA, 1959 for precise locality).
Figs. 9-14. Wakinoa wakinoensis (OTA).
9. Rubber cast of left internal mould (Wls 5081) x 2.5. Showing the hinge structure.
Loc. Rikimaru. (see OTA, 1959 for precise locality).
10. Rubber cast of right internal mould (Wls 5051) x 2.5. Showing the hinge structure.
Loc. ditto.
11. Rubber cast of right internal mould (KPE 1065) x 1.5. Showing the hinge structure.
Rikimaru, Miyata-machi, Kurate-gun, Fukuoka Pref.
12. Rubber cast of right internal mould (KPE 1063) x 1.5. Showing the hinge structure.
Loc. ditto.
13. Rubber cast of left internal mould (KPE 1072) x 1. Showing the hinge structure.
Loc. ditto.
14. Rubber cast of bivalved external mould (KPE 1067) x 1. Strongly deformed on
posterior part. Loc. ditto.
The specimens of T. (s. s.) kodairai (KPE 1005,1006,1007,1008), T. (K.) mifunensis (KPE
1026, 1023) and W. wakinoensis (KPE 1063, 1065, 1067, 1072) are kept in the Department ofEarth-Science, College of Education, Kyungpook National University, Daegu, Korea. The
specimens of T. (K.) matsumotoi (GK 1500), T. (K.) suzukii (WuK 100) and W. wakinoensis(Wls 5081, 5051) are kept in the Department of Earth-Science, Fukuoka University of Edu.cation, Fukuoka, Japan.

YANG:

Trigonioides (Bivalvia)

Plate 55

409*~~3'eD-O);fIlJt~ "1t.15" It,1960~0)3'eflJJ;JJ~ r'/-r7~71- t;::&lvt':i!1~¥J.J~J:O) I- ~',y? z-~'0 -C, JiUfiO)7iif~fflt*z-!l.lB ':'lvt':li'ilt:O)~H7<Jfi!¥H~Q C C {, t;::, ~fiO)IE~.::. "- -;;<. z-if:g1l'-t" Q,:1-.::. - ? ts:*ltt-el> Q 0 .:. O):ff:{Elt;fllJttt C 1" ? l1:1*t;:: {, iJ'iJ'n i?T, lE7!-t;:::t-01, '-C {, t± § ~ .nIt t:6I:l-C 1" Q
iJ~, iJ,;:t '0 -C IEI*J-cltf,iJfm ~ .nts: 1,' ? i?.;l,..b~l> ~ i -t" 0 -t':' -e, :m{E/~,y? T "./ /~ - C 1.. . -C{E~-t" Q {, 0) 0)'±~I*Jfi!¥z-if:g1l'I"t.: 1.....i-t"o/~ ,y ? T"./ /~ - 0) 1*Jfi!¥ «(illi1*ltj2St!-;6.;l,..)'/' "./,r-,; ry A "<=PlEilftnz-<=P'L'C L.t.:i!1~3'j!.0))(;jJtt;::~I-t"Qr,m~.!i ", '/' "./,r-,; ry A "i!1;fl!¥J.J~ ",-to)ft!! .......................................................................... (420 I'D(8%J ,/,"./,r-';ryA "rr;;.ffli!1~~", ,/,"./,r-.VryA "jjHt.cOOf*3'e~", -to)ft!! .............. (485f9)(10%) !M'~ "1t.15~~c~fJiffi", -to)ft!! ................................................ (470f9)(11%) '/' "./,r-,; ry A "1f;fUb~ ", -to)ft!! ................................................ (405 I'D(12%) !M'~ "~tJli!it!!7JO)ffIT~~i!1;fl!~~", -to)1i!! ........................................ (405f9)(13%) "<7"7 ~1"IE.i£:i!1;fl!~{t.15, i!1~~7H&O)l.!Iliffi1ic7J'$.. -to)ft!! ...................... (405F:l)(14%) i!1~~7H&O)l.!Ilil~c7J'$.. ffi)(;jRlt*. -to)ft!!········································(405F:l)(15%) '/' "./,r-,; ry A " B*t;:::t-ovt Q i!1~3'j!. <=P~3'j!.!ii:W{~.JlIO) 7 :t - nl3'~~" ................ (405 F:l)(16%) ~'.::. 7 "./ffSM. fLEfffITtiIf. ~-WiffITtiIf.~~. -to)ft!!.·· ... · ..... ·· .. ·.······················ (405 F:l)(17~) ,/,"./,r-,;ryA" B*ffIT~~J'aIHt.15~O)*~7j-;;(p (-to)-)". -to)ft!! ................ (470F:l)(18%) ,/,"./,r-,;ryA" B*ffIT~~JUiMt.15~O)*~7j-;;(p (-to)=)". -to)ft!! ................ (470F:l)(19 20'%) '/' "./,r-,; ry A ".jl~0)7j-;;(P C~{t. ", -to)1i!! .................................... (770 F:l)(21%) ,/,"./,r-,;ryA "{t.15@!&Il~I*JO)li'iJfSl:f*". -to)1i!! .................................... (770F:l)(22%) !M'~" <=P1Eit!!7JffIT~3'j!. C i!1~~" .................................... , ..... , ....... (770 F:l)
(23 24%) !M'~" {t.15!a!&Il~I*JO)Ii'iJ&f* (~3 @]'/'''./,r-';ryA) ". -to)ft!!·················· (1485 F:l)
(25 26%) ,/,"./,r-,;ryA "i!1;fl!¥J.JO)7j-;;(PC-tO)rJjMi!i.". -to)1i!! .......................... (1485F:l)(:I:~f1J%) :t p 9'- 7 A : {t.15!a!&Il~1*J 0) 1i'iJ&f* .............................................. (870 F:l)
(6~)

0

0

0

0

0

0

*~1.n~*, 'T*9rliJtf.I"O)~WEltuz-c '0-C{:t.:t.:6I:l. ~WE~t;:::;I'f9!z-:t-oiJ'vt1.....-C{:i L.t':oJ'PAllU!J!t~!l!0)t.:6I:l*~ L.t.:'T*9tt(illiz-if.t6l:li?.ni.l:I7Cimt;::l> ~ i-t" 0 -t':' -e,-to)J:, §r4"@] J: ~ ~fU;c-17f,g~$.l1z-f'F!!!

1....., ~~~.nt.:7J k ....... It, 3'eD-0)'M\1t:. *lttz-:t-oj2S ~ 1....., tt~z-~tf.I" 1.. . -C I, ,t.:t': <7J'$.z- C Q .:. c tUs: ~i L.t':o fAV~mO)7Jlt, It;O~{:t;::Jl;;~:t-oJ:lJj2S*Jtf:l:fflz-IJJ:I~O)J:, :t-o$;6.;l,..r~I,'o/~,y? T".//~-z-fAV~mO)7Jlt, ~~z-tf.1,';6.;l,..0)J:.

:t-o$;6.;l,..r~I,'o*~7iif~~~l~-e~Ao)~lt, J!'fI{ffi!i*.~&:'~.~z-:t-oj2S ~ 1.. . i-t"O)-elijm~*r~ 1,'0

*ttt;::)(;j-t" Q $;6.;z,.. Cj2S~Jt :"F 980ftmilf~~j2S~lt~~ 0 ~*~t*~l.!Il~ffflit!!'l!t~i!1~~J.)~f3e~1*J({111ft 17141) z-fAVfUffll!ifh, i -t" 0{t.15~~fffl

410
PROCEEDINGS OF THE PALAEONTOLOGICAL SOCIETY
OF JAPAN

13 *ti1:.~~~~ 113 @]{7IJ~vj: 1974 ~ 6 fl 15 .
16 131-=,*p'&11l:ft.~~'i!:if~tBl-=.:131t',,( fM-Jfl~;h,t:(~tm1!f 704;).
{~

A.

~14

7llt

WI:::! !\l;f.ks-El' J1fllgf3f. Deperetia!ff/f4I-=' '? v' "( ..
.................................. *l.i~ltz
WI:::! * ~iiIIII1l *jj~l*l5~i.P ~ (J) f;ltJtll]HJf 1itrftl
if!IJ~!lf~ .............. -N:~)lltUj:l . Illiljji1iJl!~

JJrt~1tW~J1f~~(J)11:;151-=''?1t',,( ............. .
. .•.. .. .. .. . J:!IlfltlliSfF . !Ilf)](ij1JJ~ . -N:~JII~fj:l
1Ij:rk:llB~4-1mi=~(J)=':l!Ha(J) ::t J

r:/ r ....... .

...................... ; .iNi!!Ijil(~ . 15m~~~*mWl5~*(J)::tJr:/r1:.~~c~~*(J)fFtEIC'?1,,',,( ................... .INi!!Ijil(~. I=' "'-1 Mil!: J:: fJ J1ff±\ L. t: I'j:tWll5m*C~
JE.~ .............................. :wpm~-~t.?r 1

1:/r*~7:13J::~~v-~7J1f='~~7:/~71 r ...................... , .... ·l5li~!lfJ1f11:;15Ic ,?1,,'''( ..................... .

. . W~9lE~ . BELLIDO, E. & RANGEL, B. C.
Two new genera of Mesozoic cyrtoid radiolarians ........ IcHiKAWA, K. & YAO, A.
IJ'~)](W~if./:~(J) Nummulites c Tethys tfi

i#lc!1!?IC:13I:J- 7.>1i-§!IJ1f Nummulites c (J).I:t.~
iJf3t" ............................. ~:;/:L§!IRlt
fi~!Ilf~!lf(J)Lepidocyclina c .:c(J)J1ff±\~f(§ . ...

=f!1!?n~ ·1i!!m~1:. . ~:;/:L§!I,q? . jiIjj~75'Jl!B .

il§fi nB' am 'i!:Jl!B • ='~:M~$ • ir:rta$1i4il .
wmii!fT
Microbiostra tigraphy of the Tomioka group
along the Kabura river, Gunma Prefecture, Japan ................ KONDA, 1.
Recent Foraminifera of the Hamana Lakeregion on the Pacific coast of Japan ..
................................ IKEYA, N.
m)II~!lf . ;f1'l~~!lf(J)1:i~~MH~11:;1:i,c <I-=.

~1:

lMl7Jci~~ IC'? 1t, "( .................. il§ m'i!:M

Jurassic Ammonite from near Inuyama,north of Nag:0ya (ttilit) ........ SATO, T.
Record of Pseudocalycoceras (Cretaceous
Ammonoidea) from Hokkaido ......... .
........ MATSUMOTO, T. & KAWANO, T.
On the genus Nakamuranaia (Bivalvia) ..
.............................. YANG, S. -Yo
A new proposal for the classification of" Propeamussium ", with description ofa new species .. OMORI, M. & INOUE, T.
A new species of Miocene Entemnotrochus
from the south of Nokogiri-yama, Boso
Peninsula, Japan .............. KANIE, Y.

KT -73 liit~41'j:t 0) microfossils- c I-=. dinoflagellates IC'?1,,',,( .... )](m.- • ~1llili#lc3't:
Early Cretaceous flora from Yuasa, Wakayama Prefecture, Japan ............... .
. ............. KANSI-IA, Y. & KIMURA, T_:tlUrW <~ fJ ~~;:"(J)r~*,lBt1i~ ..... ·lllilfi-N:zJI}]<:tiHI!!.(J) ~ fJ ~ ~ ;:" (J) lU~ . ·Illilfi-N:zJI}]
mJ.t!1!?*i¥i~~(J)~JtII ti 1:.~ J1flllllfNHl:;l5 (J)iJf3t (~;f1t~rW,

3 W,)~/I.--§!I••...••••.••.•..•.••••••••• ·W~9lE~
Ambo !1!?~lc~;{ffT7.> Copacabana<~:/;J-<:'/'7A

rti1:.~ c t~~tBJ(1itfilSA.: =f:f:i!!.:n~)..
. ................................. ~*i!Jl!J)*~M~Jf~4tB(J)<b fJ /] c r,,~m#., ...... ~7lc
ti1:.~?i}f3t1!f(J) 1 A. c L. "(if~tBR:::~tr t. c

!1!?~ilJliI~pff(J)tl*tB

c *~*~J1l! IR ~ A 7' A (J)~~***wtiOO-ti1:.~~IC~Ji L. "( ....... . f$FimW...... ;tcIE1E~

I='-;IJ II.- ~ "- -:'/7 A c~'WiiJf3t~~'i!:iJf3t~:/?r-cL."((J)§!I:ft.M~if~tB(J)*{5!:tU IC'? 1,,',,( .........•.. itra'-~ . Jf;~
13 *(J):l1!!/]f\1~tB(J):m:fXIC '?1t,,,( ...... =f!1!?:n~1974 ~ 6 foj 14 13 *~lfmlii3 ~~twq#,onrm:..tov'''(~tpnt.:~¥~~<:.''iXO) L. c tJ;tk:5EjMg~nt.:.
*~0)~lltI&'.:1Hr.tlglj~~ ·1ti:ff;n lEtt (11I:1Bt#jt) a-~/±\ L., 2 ~rdl,~:i!i:
H&~J{T Q L. c fr. tr. -:> t.:.

(0) ~J!um 23 ~H::' L.t..:tJ;v"o .waO).~~$#iXO)~5K5E~;n~rOOF>~a'9 fr.:ljii9i7.k$O)!!i ~~ta*=~I':J1i}fJlG a-rrts. v', ;C-O)~lJ1fillitJ;+)]" fr.5Em L. t.:A Ir. t~-9- T Q J(0) *~$~15-. flC$100 -%fjc~.~a-rrts. 5 L. c laS. IJ, ;c-O)t.:~O)IH~~~~ (~~:R. ~*~Jl!~)tJ;§£JE

L. t.:.
(0) **=~!JW5JIj~~.'='* ~tttJ;Hli*~nt.:. ~!i[t\,<:.":a1'4i0)~a-1$ljQ.

o iXO)~ttO))"~tJ!~~~nt.: (AB CIIWD.
~~lE~,
1ti:~mil!~,(0)

7tl!.1II lE, ra1~~$, IN::tti't-,
Reinhard SCHMIDT-EFFING.

ill!

tLl!.

~

11€

13

~14t1it$~~W=

45r!i'm**=1974 ~ 10 foj 19-20 131974 ~ 8 foj 20 131975 ~ t~~·~~

OOlif4~1W~flg

1975 ~ 1 foj 25-26 13

1974 ~ 11 foj 30 13

115 @] ~J

E =f- *

1975 ~ 6foj*

A

114 @] 19t1oHsin Yin LING, tt*:g?\i$. "*IIIIi!(P}j,f;:~. *~~-mttO)ifl:~tJ;li.~~ ;nt.:.

~(0)~lR;fUf¥j,~*=114@]19tl~<:."v'j:,

5E

20 131r.llfi!l~tLl!.:Jji§5~ (73"1 f· ~r JiJ) tJ!T5E~n"(v'Q.
1975~r,g~· ~~<:."v'j:~:,/~:/ryA rl!l~~~U§::i!i:~~TlIJijJ'&~J (t!t~iSA· E"'Uf~) tJ;T5E~n"(v,Q.

;I';)

m

b

"It

o l3*tLl!.1!i:*=!\!1JJIl*=U$~O)JJ.J~~~: JJGG v'j:* 49 ~J3f (Vol. 46) "t. /±\AA~nQ L. c laJ: IJ ~ L.t-:.
{It*1ID.IJO)t5tff~1il'W~Ir.L.t.:tJ;-:>''(, tJ:QA:.<!f-~Ir.~tltff,ljr~v'. (JJGG .ii~~~

1 9 7 4 ~ 9 foj 15 13

m

fIlU

1974~9foj2013§£

IT~fj:?fB*i51:.fJ~~
g ~ ~ 2-4-16
13 **=~.f~ -iz: :,/!J - P'l

)l:.

*

(~ ~ j:j ~
~

1iil

m95 %

1,200 f:q

EIJ .IilU :?f

~III)

**

84 7 8 0 1B')

JR*'i$f;lli.~OCS:~:lt2/ 13~*~.~n.!ilUl*~~li

~

III

~

Transactions and Proceedings of the PalaeontologicalSociety of Japan

September 20, 1974

New Series No. 95

CONTENTS
TRANSACTIONS
634. OKAMOTO, Kazuo and TERACHI, Masami : Miocene molluscs from the Bihoku Group at Miyauchi-cho, Shobara City, Southwest Japan ... . .. . . 341
635. Hu, Chung-Hung: Ontogenies of two Middle Ordovician trilobites fromthe Edinburg Formation, Virginia ......... .. .. . ...... . ... . .... . ... . . . 353
636. HATAI, Kotora, MASUD A, KOichiro and NODA, Hiroshi: Marine fossils from
the Moniw a Formation along the Natori River, Sendai, Northeast
Honshu, Japan. Part 2. Problematica from the Moniwa Formation .. 364
637. WATANABE, Kozo: Profu sulinella assemblage in the Omi Limestone, Niigata Prefecture, central Japan. (Studies of Carboniferous fusulinaceanof Omi, Part I) .. ...... . . . ... ... ...... . ..... . ...... . . .. .. . .. .... . . .. . 371
638. YANG, Seong-Young:

Note on the genus T rig onioides (Bivalvia) . ... ...... 395

PROCEEDINGS ..... .. ........ ..... . . .... . ...... . . .. ... . ..... .. . . .. . ....... . . . . 410