Transactions and Proceedingsof thePalaeontological Society of Japan
New SeriesNo. 102

Palaeontological Society of Japan
July 15, 1976

EditorTakashi HAMADA

Associate Editor Ik uwo OBA TA

Officers for 1975 - 1976
Honorary President:
Presiden t:

Teiichi KOB AYASHI

Tatsuro MATSUMOTO

Councillors (*Executive):*Kazuo ASAMA, Kiyoshi ASANo, *Kiyotaka CHINZEI,*Takashi HAMADA, *Tetsuro HAN AI, *Itaru HAY AMI, Tadao KAMEl,*Kametoshi KANMERA, *Tamio KOTAKA, *Tatsuro MATSUMOTO, Tokio
SHIKAMA, Tsugio SHU TO, *Yokichi TAKAYANAGI, Toshimasa T ANAl,*Hiroshi U]llt
Executive Committee:
General Affairs:

Tetsuro HAl AI, Itaru HAY AMI, Kiyotaka CHINZEI, Saburo

KANNO
Memb ersh ip:

Kazuo ASAMA, Kazuhiko UEMURA

Finance:

Hiroshi UJIlt

Planning:

Tamio KOTAKA, Jun'ichi T AZAWA

Publications
Transactions:Takashi HAMADA, Ikuwo OBATA

Special Papers:

Kametoshi KA NMERA, Ienori FUJIYAMA, Tomowo OZAWA,

Juichi Y ANAGIDA
II

Fossils" :Yokichi TAKAYANAGI, Toshiaki TAKAYAMA

Fossil on the cover is the six leaves in a whorl of Trizygia oblongifolia(GERM. & KAULF.) ASAMA from the Maiya Formation (Parafusulina zone),
Maiya, N. E. Japan.

All communications relating to this journal should be addressed to the
P ALAEONTOLOGICAL SOCIETY OF JAPANc/ 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. 102, pp. 317-333, pIs. 33,34, July 15, 1976

661. ON THE NON-MARINE MOLLUSCAN FAUNA FROM THE
UPPER MESOZOIC MYOGOG FORMATION KOREA *SEONG-YOUNG YANG
Department of Earth-Science, Kyungpook National University, Daegu, Korea~~J:fmq:,1:J!(7):!1n~J!p-[fJ:1*!llfJ¥gff t;:: "?\, 'L: :!1n~~g[fJ:1*!IJ.IJ¥g{I::.;o(7)q:" =:&ffi!.(7)Koreanaia cheongi, gen. et sp. nov. c. Nagdongia leei, sp. nov. ~~1tL,f.::o Koreanaia
cheongi 1:I:...'f:-(7)P3fm:fi'It~c.~rm~JWJ: Nippononaia-Wakinoa-Trigonioides (s.s.)-T. (Kumamotoa) (7) trigonioidid *1U (7)tJl:gem!.t.: c. Ji~l,;bn:Q ..'f:-(7)7't tJ. lliit;:: Plicatounio s p. c.
Unio sp. c. L L¥IH5~ntd) (7)1:1:. jI'fJ-;fi(7) unionid t.: c.~,hn:QiJ~..'f:-(7)~1tI:l:.~*iJ'&tJ:\,,(7)'"t:":Ft*t;::~;/'d.:Qo mft (1970) iJ'~cttLt.:: Wakinoa tetoriensis (MAEDA) I:l:.lliim (1963)(7) T. (s.s.) tetoriensis c. ~rm~JWt;:: !!J:li?iJ,tJ: ~13~,~ iJ';!;:Q(7)'"t:", mtd;:: Wakinoa tamurai (7)m;fi1H::1Jl!P~i'":Q
!4l;
~
0

*

0

Introduction

ting features on the molluscan fossils.
But the sample is so insufficient especially of the apparent trigonioidid features that I did not make clear the variation of its characters. Thus, since mycoming back home, I have added newcollection and found some new features.
This paper is to describe the Myogog
fauna in more detail and compare it with
the Nagdong fauna and Japanese Upper
Mesozoic non-marine molluscs.
This study was mostly carried out
under the guidance of Professor Tatsuro
MATSUMOTO at Kyushu University, Japan. I express my sincere gratitude toProfessor Tatsuro MATSUMOTO for his
pertinent guidance, arrangement and also
critical reading of the typescript of thispaper, to Professor Chang-Hi CHEONG of
the Seoul National University and Dr.
Ha-Young LEE of the Yonsei University
who gave me invaluable suggestion on
the Myogog Formation, and to Professor
Ki-Hong CHANG of the Kyungpook National University who gave me privilege

The Myogog Formation is quite important and interesting on the Korean
Late Mesozoic history, because it contains
a unique fauna and presents a characteristic geologic structure comparedwith the adjacent Cretaceous Gyeongsang
Group. CHEONG and LEE (1966) reported
the stratigraphy of this Formation witha list of fossils and assigned its age toUpper Jurassic. Since then, there has
been dispute on the fossil contents andcorrelation of the formation.
In 1970, CHANG and I investigated theformation, collected a number of wellpreserved molluscan fossils, and briefly
reported the result, regarding the formation as a part of the Lower Nagdong
Subgroup. However, at that time, we
did not precisely examine the fossils.
During my studying abroad at Kyushu
University, Japan, I found some in teres-* Received March 23, 1976; read October
19, 1974 at Nogoya.
317

318

Seong-Young YANG

Yeongyang--~r-----~--------------------~~======~~3~3rr

128°30'Text-figure 1. Index map.

to study our common collection withwarmful encouragement.
Stratigraphic note

The stratigraphy of the area aroundthe fossil locality is as follows in descending order (after CHEONG and LEE,

1966):
Gyeongsang Group
Silla Subgroup: Cheongyangsan Formation(mainly conglomerate, marls, sandstone,
mudstone, limestone and andesite lavas)
about 500 m- - - disconformity - - Nagdong Subgroup: Gasongdong Formation(mainly greenish grey marl, dark grey
shale and conglomerate) about 350-450 m
Donghwachi Formation (Red mudstone
Member, 100-450 m and Arkosic sandstone Member, 200-350 m)
Ullyeonsan Formation (mainly cobble orboulder bearing conglomerate associa ted
with light grey arkosic sandstone) about
500m---unconformity - - Upper Jurassic (?): Myogog Formation(mainly dark grey to black shale andsandstone) more than 150 m- - - fault contact - - Precambrian (?):
vVonnam Formation(mainly quartz-feldspar gneiss, quartz
schist and limestone)

661 .

JVIolh~scan fauna319

from JVIyogog F01"mation

N

7

:: ::
53

6

~g:

00
0000000
00000000000000
00000000000000
00
00000000000000
00000000000000000000
00000000000 ~ )000000000

00000000000~0000000000•~

0000000000000000000000
0000000000000000000000
0000000000000000000000
00000000000000000000000~~

000000000M~000000000000

3 0000000000000000000000
0 0000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

5

4

3

~ oooooooooooooooooooooo

00000000000000000000000~ oooooooooooooooooooooo

Mch - -- -- \o20000000000000000000000
000000000000000000000
000000000000000000000
000000000000000000000
00000000000000
000
000000000000
0000000000
00000 00000......~====~!......====~!
500

Text.fi g ure 2.

1000

2000 m129"O()

Geolo gica l map a r ound t he fossi l loca lity.

1: \Vonnam Fo rmation , 2: Myogog Fo rm ation, 3 : U llyeo nsan Formation, 4: A rkosic
sandstone Member of Dong hwachi Formation, 5: Red mudstone Member of Donghwac hi
Formatio n, 6: Gaso n gdong Formation, 7: Cheongyangsa n Fo rm ation, A: Localit y offossi l plants, B : Loca lity of molluscan fossi ls, C : Natio nal road .

320

Seong-Young YANG

The metamorphic Wonnam Formationis unconformably overlain by Ullyeonsan
and Donghwachi Formations. It has beenpresumed to be of Precambrian age without sufficient evidence.
The Myogog Formation crops out insomewhat triangular form, bounded by
the Galsan Thrust on the northwest sideand the Taegog Fault on the east sidein contact with the Wonnam Formationand is overlain unconformably by theyounger Ullyeonsan Formation on thesouthwest side. Thus, its lower limit isunknown. It displays an intense deformation in contrast with the gently inclined
Gyeongsang Group.
The Myogog fossils identified by
CHEONG and LEE (1966) are as follows:
Trigonioides sp., Plicatounio sp., Vnio sp.,
Corbicula aff. tetoriensis KOBAYASHI andSUZUKI, Corbicula sp., Viviparus sp.,
Cladophlebis denticulata (BRONG.), C.
browniana (DUNKER), C. geyleriana (NATHORST), Adiantites yuasaensis YOKOYAMA, Onychiopsis elongata (GEYLER), O.
mantelli (BRONG.), Equisetites sp., Ginkgodium gracile (?) T ATEIWA, Nilssoniasp., Podozamites sp.
They considered the above to be clearly
different from the Daedong biota andquite similar to but not identical with
the Nagdong. Therefore, as shown above,
CHEONG and LEE (1966) correlated the
Ullyeonsan, Donghwachi and Gasongdong
Formations to Nagdong Subgroup andthe Myogog Formation to pre-Gyeongsang and post-Daedong, Upper Jurassic.
However it seems necessary to restudy
the fossils in the light of up-to-date paleontology.
On the other hand, the problem on theage of Gyeongsang Group itself has notbeen clearly solved out yet. Before theWorld War II, many of the Japanesegeologists investigated thoroughly theage determination of the Group based on

the fossils contained and attempted theregional correlation of the East Asian
non-marine deposits. And since 1938
(KOBAYASHI), the Nagdong Subgroup, thelower part of the Gyeongsang Group,
has been approximately correlated withLower Cretaceous. However, a result of
my previous paper (YANG, 1974) has
shown that certain important species
from the Nagdong Subgroup is not identical with the species from Japan. Morestudies in paleontology as well as instratigraphy are necessary to draw acorrect conclusion of the geological age.

Systematic description
Superfamily Unionacea
Family Trigonioididae•

Genus Koreanaia, nov.

Type-species--Koreanaia cheongi sp.
nov., to be described below.
Generic diagnosis-Shell medium insize, equivalve and subequilateral ; outline
suboval or subquadrate ; umbo prominent,slightly prosogyrous.
Surface ornamented with characteristic trigonioidid
V-sculptures in the median part and thereversed V -ribs on the posterior ridge
which in turn run upward to form another set of V -shape riblets on the posterodorsal side. The angles of the medianV-ornaments from 35° to 45°. Hinge
plate moderate in breadth, provided with
opisthocline pseudocardinal teeth andposterior lateral teeth; the number ofpseudocardinal ones 3 in left valve, 2 inright valve and that of posterior lateral
teeth 2 in left valve, 1 in right valve.
All of the hinge teeth not crenulated,rather lamellar. Two adductor scars
situated close to the outer ventral endsof the pseudocardinal and posterior
lateral teeth; anterior one semicircular,

661.

Molluscan fauna from Myogog Formationand strongly impressed, accompaniedwith a minute pedal scar; posterior one
not so prominent. Pallial line simple anddistinctly impressed.
Remarks-On account of its V-shapeornamentation and the disposition of thehinge teeth, this genus is certainly allied
to Trigonioididae. But the present genus
Koreanaia is clearly different from thewell-known Trigonioides, Hoffetrigonia,
Nippononaia and Wakinoa on its lamellar
hinge teeth and the Obviously large angleof the V-sculptures. The latter genera
possess, that is, crenulated hinge teeth
and marked smaller angle of V-ornamentation. So far as the accessible monographs are concerned, there is no
genus, fossil and the Recent, with which
the present genus could be identified.
This genus is at present represented
only by a single species from the Upper
Mesozoic formation of Korea.

321

Koreanaia cheongi, sp. nov.
PI. 33, Figs. 1-18; Text-fig. 3.

1966. Trigonioides sp. CHEONG & LEE, Jour.
Ceol. Soc. Korea, vol. 2, pI. 1, figs. 1-4.

Etymology :-The specific name is dedicated to Professor Chang-Hi CHEONG
of the Seoul National University who haslargely contributed to the stratigraphyof Korea.
Material-Holotype (KPE 1031) andseventeen paratypes (KPE 1032, 1035,
1036,1281-1294) from Myogog Formation,
which are preserved in the Departmentof Earth-Science, College of Education,
Kyungpook National University, Daegu,
Korea (ColI. K. H. CHANG and S. Y. YANG,
and S. Y. YANG). Two plaster casts of
the above specimens (KPE 1031, 1035)
are kept in the Department of Geology,
Faculty of Science, Kyushu University,
Fukuoka, Japan.

Measurements (in mm).Specimen

L*

H*

D"

1*

H/L

D/L

Holotype (KPE 1031) (BV)"
Para type (KPE 1035) (BV)
Para type (KPE 1036) (LV)"
Paratype (KPE 1281) (BV)
Para type (KPE 1282) (BV)
Paratype (KPE 1284) CRV) *Para type (KPE 1285) (BV)
Para type (KPE 1286) (RV)
Para type (KPE 1287) (RV)
Para type (KPE 1288) (BV)

33.6
25.0
16.3
44.4
'12.0
48.7
47.7
24.3
22.5
17.0

24.1
18.6
11.1
34.0
33.9
37.6
37.9
14.9
16.0
10.9

13.1
9. 7
7.1
16.2
15.9
19.2
18.5
10.9
8.7
6.4

6.7x2

0.72
O. 74
0.68
0.77
0.81
0.77
0.79
0.61
0.71
0.64

0.39
0.39
0.44
0.36
0.38
0.39
0.39
0.45
0.39
0.38

5.1 x 2
?
?
?
?
?
?
?
?

Mean of H/L: 0.72; standard deviation of H/L: 0.06, mean of D/L: 0.40; standard
deviation of D/L: 0.03.
(Based on ten type-specimens, exclusive of the strongly deformed or broken specimens.)" L: length, H: height, D: distance between umbo and anterior extremity, I: inflation, BV: conjoined valve, LV: left valve, RV: right valve.

Description-Shell medium in size
(about 16-50 mm in length); anterior
margin well rounded, posterior one rather
straight or truncated, ventral margin

gently and broadly arcuate, generally
suboval or subquadrate in outline; subequilateral and equivalve; ratio of H/Labout 0.7; moderately inflated; test mo-322

Seong-Young YANG

derate in thickness; umbo slightly prosogyrous, placed about two-fifths of theshell length from the anterior extremity,
projected slightly above the hinge line;
escutcheon and lunule indistinct. Surface
ornamented with characteristic trigonioidid V -shape ribs in the median partand the reversed V-ribs on the posteriorridge, which, in turn, run upward to
make again V -shape ornaments on thepostero-dorsal side, while on .the anterior
dorsal side the reversed Vs or V-shaperiblets not clearly observed. However,on the anterior half the triple or multiple
V-shape riblets presented faintly and occasionally. The angles of the medianV-ribs about 35·-45· and those of thereversed V on the posterior ridge larger
than 45· and those of the V-shape ribletson the postero-dorsal side about 120·.
The line crossing the apices of the medianV -ribs slopes posteriorly, forming about
80· with the ventral line. The ribs andgrooves on the posterior half stronger andwider than those on the anterior half.
The V-shape ornaments on the anterior
part weakened with growth. and on theadult (large) specimens the anterior ventral part ornamented with growth-lines
only. The median ribs number morethan 17 in the anterior half, and 13 in
the posterior. The whole surface ornamented also with fine numerous concentric growth-lines of irregular interval
and prominence; strong posterior ridge
running from umbo down to posteroventral corner.
Hinge plate moderate in breadth, provided with opisthocline pseudocardinalteeth and posterior lateral teeth of unioidtype; two pseudo cardinal and one posterior lateral teeth in the right valve andthree pseudocardinal and two posterolateral teeth in the left valve, forming
the following dental formula:

5 3(6) 4 2PIlI
PH PlVAll of the hinge teeth smooth, without
crenulation or striation. Two adductor
scars subequal in size, placed close to
the outer ends of the pseudocardinal andthe posterior lateral teeth respectively;
anterior one semicircular, strongly impressed, accompanied by a minute pedal
scar, posterior one subcircular, indistinct.
Pallial line simple; umbonal cavity moderately deep.
The internal mould
marked with one postero-dorsal undulation running from the umbo down to thepostero-ventral corner, and in small specimens provided with impression of Vshaped ornament on the flank and weakcrenualtion around the ventral margin,
while in large specimens it is smooth
without V-shape impression or crenulation around the ventral margin.
Observations- The holotype (KPE 1031)

Koreanaia cheongi, gen. & sp. nov.

Text-figure 3. Surface ornamentationand internal structure of Koreanaia cheongi,
gen. et sp. nov.

661.

Molluscan fauna from Myogog Formation

is a specimen of well preserved conjoined
valves of which right valve is secondarily
depressed. Eight of 16 specimens areconjoined and one (KPE 1035) of theconjoined specimens slips each otheralong the postero-anterior axial plane.
All of the specimens possess well preserved test, then the internal structures
have been observed on the 6 specimens(KPE 1032, 1289-1293) from which thetest was dissolved out by dilute hydrochloric acid. So far as the examined
specimens are concerned, there is nomarked variation in the hinge structures.
However, in the internal structures, theV-shape impressions and crenulations
around the ventral margin are observedon the immature (small) specimens only.
This may be regarded as an ontogenetic
variation.
Occurrence-The described specimens
were collected from the black shale ofthe Myogog Formation at Myogog,
Jaesan-myeon, Bonghwa-gun, Gyeongsang-buk-do, Korea (see Text-figure 1).
The black shale contains plenty of themolluscan fossils of which the present
species is the least common. Half of thespecimens are found of conjoined state,
as pointed above, and all do not show
any severe defacement besides secondary
deformation, which are regarded as reflecting the fossil biocoenose or at least
fossilized not far from the living place.
The stratigraphic investigation of thepresent area was carried out mostly by
LEE (1965) and modified a little by CHANG
and YANG (1970).
Comparison-At first sight this species
looks like a certain species of Trigonioides
in surface ornamentation, but it is not
related with the latter, because the anglesof the V-shape ribs on the median partare larger than any species of Trigonioides. From this point of view thepresent species is closer to Wakinoa than

323

Trigonioides. The multiple V-shape ornaments are occasionally and irregularly
found on the anterior half of the present
species just like the T. (s. s.) tetoriensis(by TAMURA, 1970; and not by MAEDA,
1963) and T. (Kumamotoa) matsumotoi
KOBA YASH I and SUZUKI, 1941, as pointed
out by TAMURA (1970). However, theangles of them are also still larger in theformer than in the latter two.
What is more important is that theinternal structures of this genus arecertainly different from those of Wakinoa
OT A, 1963 and Trigonioides KOBAYASHI
and SUZUKI, 1936. The hinge teeth ofthe present species are rather smooth
without crenulation or striation. It isinteresting that the Nippononaia tetoriensis from the uppermost JUrassic (?)
Itoshiro Subgroup, Tetori Group, possesses
lamellar smooth hinge teeth as the present species. But the number of thehinge teeth is not identical and the surface ornamentation and the outline areclearly different from each other.
The material of Trigonioides yunnanensis Ku et MA, 1962 from China is
so fragmentary or ill-defined that sufficient comparison cannot be made. However, it is noted that the Chinese species
is similar to the present species in the
V-shape patterns and smoothness on theinternal surface and lamellar hinge teeth.
But the difference can be clearly foundby a careful comparison between the two.
The present species has smaller anglesof the median V-ribs than T. yunnanensis.
In the Chinese species the chevron-shaped
patterns are present on both sides andthe hinge teeth are not completelylamellar, but have crenulations at least partly.
Moreover, the outline and the ratio of
HIL are obviously different between thetwo species.
If the phylogenetic series of Nippononaia- W akinoa-Trigonioides (s. s.)- T. (Ku-324

Seong- Young YANG

mamotoa) is assumed (HAY AMI and ICHIKAWA, 1965; OTA, 1963; YANG, 1974),
the present genus Koreanaia can be regarded as representing an ancestralgroup of the series. In other words, thepresent genus may be considered as mostintimate to unionids among the trigonioidids from Far East Asia.
Revision on the Trigonioides tetoriensis-MAEDA (1963) reported the occurrenceof Trigonioides from Tetori Group andnamed it T. tetoriensis with a detailed
description on the hinge teeth. Subsequently, TAMURA (1970) observed MAEDA'S specimens, collected his own samples from the Tetori Group, and referred
it to Wakinoa.
YANG (1974) considered it as belonging
to T. (Kumamotoa) on the basis of theoriginal description of MAEDA (1963).
After that, I have had a chance to observe the type specimens by courtesy of
Dr. MAEDA. From my observation, I cancertify that the T. tetoriensis (MAEDA'S,
not TAMURA'S) is an only species to bereferred to Trigonioides (s. s.) among theJapanese trigonioidids so far. The difference between T. (s. s.) kodairai and T.
(s. s.) tetoriensis can be read only in inflation, that is, the T. (s. s.) tetoriensis is
more inflated than the type-species. In
other characters, there are no essential
difference between the two species. The
specific identity between TAMURA'S T.
tetoriensis and MAEDA'S T. tetoriensis isopen to question as the identity of thefossil localities and the stratigraphic
horizons is so. The internal structuresof the two are fairly similar, but thesurface ornaments are clearly different.
The so-called W. tetoriensis of TAMURA
shows distinctly the double or mUltiple
V-sculptures on the anterior surface, andthe V-angle is much larger than that ofT. (s. s.) tetoriensis. And the former possesses better developed pseudocardinal

1a than W. wakinoensis. It can be considered that W. tetoriensis of TAMURA isa transitional form placed between Wakinoa and Trigonioides (s. s.). And it isreasonable to separate TAMURA'S Wakinoa tetoriensis from T. (s. s.) tetoriensis
MAEDA. Hert( I propose Wakinoa tamurai, sp. nov. for TAMURA'S specimens.
And KE 1970 (fig. 1 of pI. II! TAMURA,
1970) is designated as its holotype.

Family Unionidae
Subfamily Unioninae
Genus Nagdongia YANG, 1975

Type-species-Nagdongia soni YANG,
1975
Generic diagnosis-See YANG, 1975, p.
178
Nagdongia leei, sp. nov.
PI. 34, Figs. 1-60; Text-fig. 4.

1966. Corbicula sp. CHEONG & LEE, Jour.
Geol. Soc. Korea, vol. 2, no. 2, pI. 1,
fig. 9.
1966. Corbicula aff. tetoriensis, CHEONG &LEE, ibid., pI. 1, fig. 10.

Etymolog)l- The specific name is dedicated to Dr. Ha-Young LEE of theYonsei University who has contributed
to the stratigraphy of Myogog Formationand the paleontology of Korea.
Material-Holotype (KPE 1219) and 376
paratypes (KPE 1201-1218, 1220-1277,
1301-1600) from the Myogog Formation,
which are preserved in the Departmentof Earth-Science, College of Education,
Kyungpook National University, Daegu,
Korea (Coli. K. H. CHANG and S. Y. YANG,
and S. Y. YANG).
Description-Shell small for the genus,
commonly about 20 mm in length, oc-

661.

Molluscan fauna from Myogog Formation

Nagdongia leei,sp. nov.
Text.figure 4. Basic morphology andinternal structure of Nagdongia led, sp.
nov.

casionally larger than 30mm; subequi.
lateral and equivalved; generally subel·
liptical or sub oval in outline; anterior
margin well rounded, postero.dorsal
margin rather straight or subtruncated,
forming obtuse angle with posterior
margin, ventral margin broadly arcuated.
Beak blunt below the umbonal line andturned forward, situated at about one
third (0.3-0.4) of shell length from anterior extremity. Hinge line gently arcuated. Surface sculptured with concentric growth-lines roughened at irregular intervals. Posterior ridge blunt andindistinct.
Pseudocardinal teeth 2 in right valve,
1 in left valve, posterior lateral teeth 1
in right, 2 in left valve. Posterior lateralones parallel to the hinge line, wellmarked, rather sharp, the upper one inleft valve thinner and not extending as
far back as the lower, pseudocardinal325

tooth in left rather stout and higher but
shorter than the posterior Ones. Posterior
tooth in right valve distinct and stronger
than those in left valve, lower one oftwo pseudocardinal teeth in right valve
blunt and high, while upper one thinnerand lower. All of the hinge teeth without
crenulation or striation, rather lamellar.
Two adductor scars placed close to theouter ends of the hinge teeth, sub equalin size, anterior one more strongly impressed, accompanied with a minute but
distinct pedal scar, posterior one not so
distinct; pallial line simple; internal
margin smooth; umbonal cavity moderate
deep; test fairly thick.
Observations-The holotype (KPE 1219)
is a well preserved right valve (L: 20.8mm, H: 15.7 mm, D: 8.2 mm, I: 5.6 mm)
and the paratypes are also well preserved,
in which 167 are right valves, 147 left
valves, and 63 conjoined valves. Besides
these, there are numerous fragmentary
or deformed specimens. All of the specimens have well preserved test. The internal structures have been observed on
the six specimens (KPE 1255-1260) fromwhich the tests were dissolved out by
dilute hydrochloric acid.
Occurrence-The specimens under consideration were collected from the same
locality as the above species (Koreanaia
cheongi). This species occurs innumerably, but the range in size is fairly small.
About 17% of the specimens are conjoined and the tests are conserved, notworn down.
Comparison-At a first glance thisspecies looks like a certain species ofCorbicula in outline and size, but it does
not show the characteristic cardinal teethof Corbicula. The present species is similar to but not identical with Sphaerium
anderssoni jeholense in outline. In thelatter species the postero-dorsal margin
is clearly truncated and rather straight,

326

Seong-Young YANG
Table 1. Measurements of L, H, D and I.
Specimen

L

H

D

I

L/H

I D/L

I/L

KPE 1201 (RV)KPE 1202(RV)
KPE 1203(RV)
KPE 1204(RV)
KPE 1205(RV)

12.9
13.7
15.5
16.2
16.0

8.6
10.8
11. 4
12.4
10.6

4.5
4.2
5.3
5.4
5.3

2.4
3.6
3.3
4.9
3.7

1. 50
1. 27
1. 36
1. 31
1. 51

0.35
0.31
0.34
0.33
0.33

0.19
0.29
0.21
0.30
0.23

KPE 1206(RV)
KPE 1207 (RV)KPE 1208(RV)
KPE 1209(RV)
KPE 1211(RV)

16.8
17.8
16.5
19.2
18.1

11. 7
12.1
12.3
13.3
13.4

5.3
6.6
6.8
6.7
6.5

?
3.5
3.7
5.4
4.8

1. 44
1. 47
1. 34
1. 44
1. 35

0.32
0.37
0.41
0.35
0.36

0.20
0.22
0.28
0.27

KPE 1212(RV)
KPE 1213(RV)
KPE 1215(RV)
KPE 1216(RV)
KPE 1217(RV)

22.6
19.7
21. 4
22.1
20.9

15.6
14.1
14.4
16.1
15.1

9.2
7.4
7.8
8.5
7.6

6.9
5.1
4.9
6.3
6.1

1. 45
1. 40
1. 49
1. 37
1. 38

0.41
0.38
0.36
0.38
0.36

0.31
0.26
0.23
0.29
0.29

KPE i218(RV)
KPE 1219(RV)*KPE 1220(RV)
KPE 1221 (RV)KPE 1222 (RV)

26.2
20.8
20.1
19. 7
24.5

17.2
15.7
14.8
14.8
18.0

9.4
8.2
7.3
7.2
8.7

6.1
5.6
5.5
5.2
6.8

.1. 52
1. 32
1. 36
1. 33
1. 36

0.36
0.39
0.36
0.37
0.36

0.24
0.27
0.27
0.26
2.28

KPE 1223 (RV)KPE 1224(RV)
KPE 1225 (RV)KPE 1227(RV)
KPE 1228(RV)

21. 8
22.0
27.6
27.3
28.5

15.3
16.6
19.4
20.7
20.5

6.8
7.2
11. 0
10.1
9.9

5.8
5.5
6.9
7.7
7.3

1. 42
1. 33
1. 42
1. 32
1. 39

0.31
0.33
0.40
0.37
0.35

0.27
0.25
0.25
0.28
0.26

KPE 1229(RV)
KPE 1230(LV)KPE 1231 (LV)KPE 1232 (LV)KPE 1233(LV)

27.0
14. 7
13.9
16.2
16.9

19.6
9.8
9.4
10.7
11. 3

9.7
5.4
5.0
5.7
6.3

7.5
3.3
?
5.2
3.3

1. 38
1. 50
1. 48
1. 51
1. 50

0.36
0.37
0.36
0.35
0.37

0.28
0.22
0.32
0.20

KPE 1234(LV)
KPE 1235 (L V)
KPE 1236 (L V)
KPE 1237 (L V)
KPE 1238(LV)

16.4
17.4
18.6
20.4
18.8

11. 4
11.6
14.1
14.4
14.4

5.9
5.8
6.2
7.3
5.3

3.7
5.3
5.4
5.7
5.1

1. 44
1. 50
1. 32
1. 42
1. 31

0.36
0.33
0.33
0.36
0.28

0.23
0.30
0.29
0.28
0.27

KPE 1219(RV)*: Holotype.

-

-

661.

Molluscan fauna from Myogog Formation

327

Specimen

L

H

D

I

L/H

D/L

IlL

KPE 1239 (LV)KPE 1240(LV)KPE 1241 (LV)KPE 1242 (LV)KPE 1243 (LV)

18.8
20.1
20.9
23.5
21.1

13.0
14.4
14.8
16.0
16.1

6.6
7.3
6.7
8.7
5.5

4.7
4.9
5.9
6.9
6.1

1. 45
1. 40
1. 41
1. 47
1. 31

0.35
0.36
0.32
0.37
0.26

0.25
0.24
0.28
0.29
0.28

KPE 1244(LV)
KPE 1245(LV)
KPE 1246 (LV)KPE 1247(LV)KPE 1248(LV)

25.4
21. 4
19.9
20.5
20.0

18.5
14.7
14.4
15.1
14.4

8.7
6.5
6.4
6.5
7.5

7.0
5.1
6.2
4.4
5.5

1. 37
1. 46
1. 38
1. 36
1. 39

0.34
0.30
0.32
0.32
0.38

0.28
0.24
0.31
0.21
0.28

KPE 1249(LV)KPE 1250(LV)KPE 1251 (LV)KPE 1252 (LV)KPE 1253(LV)

23. 7
22.8
21. 2
23.0
28.6

17.0
16.4
15.6
16.1
21. 2

8.8
8.0
7.1
9.2
9.4

5.4
6.3
5.6
6.4
7.2

1. 39
1. 39
1. 36
1. 43
1. 35

0.37
0.35
0.33
0.40
0.33

0.23
0.28
0.26
0.28
0.25

KPE 1254(BV)
KPE 1261 (LV)KPE 1262 (RV)KPE 1263(RV)
KPE 1264(RV)

20.4
23.5
16.4
21. 2
17.4

15.6
17.7
11. 2
15.0
12.3

8.1
7.1
5.8
6.6
5.9

5.1
7.3
4.1
5.0
4.4

1. 31
1. 33
1. 46
1. 41
1. 41

0.40
0.30
0.35
0.31
0.34

0.25
0.31
0.25
0.24
0.25

KPE 1265(RV)
KPE 1266 (RV)KPE 1267(RV)
KPE 1268(LV)KPE 1269 (LV)

13.8
20.3
13.4
18.6
22. 7

9.1
13.5
8.6
12.3
17.2

4.9
6.9
4.5

3.8
4.8
2.8

0.36

5.7

?

7.8

7.1

1. 52
1. 50
1. 56
1. 51
1. 32

0.34
0.31
0.34

0.28
0.24
0.21
0.31

KPE 1270(RV)
KPE 1271 (RV)KPE 1272(RV)
KPE 1273(LV)
KPE 1274(LV)

15.4
25. 7
22.2
16.5
23.7

10.3
19.8
14.9
11. 3
17.9

5.7
9.7
7.9
5.2
10.0

3.6
7.1
5.0
3.7
6.9

1. 50
1. 30
1. 49
1. 46
1. 32

0.37
0.38
0.36
0.31
0.42

0.23
0.28
0.26
0.22
0.29

0.3L1

Measurements based on 65 type specimens, exclusive of the strongly deformed or
broken specimens.

but in the former not so clearly. The
species is apparently intermediate between S. anderssoni anderssoni and S.
anderssoni jeholense in outline. However,with respect to the internal structures
the present species is not related toSphaerium but to Nagdongia. According

to SUZUKI (1943, p. 62), S. andel'ssoni has
two lateral teeth on each side of theright valve, one on each of the left, while
in present species pseudocardinal teeth
are two in right valve, one in left valve,posterior lateral teeth one in right valve,
two in left valve. Furthermore the twoSeong- Young YANG

328

adductor scars and minute pedal scaraccompanied with anterior adductor scarare fairly similar to those of the Nagdongia soni. From the viewpoint of theseinternal characters the present species iscertainly assigned to the genus Nag.
dongia, but its valve is distinctly more
inflated than the type.species of thegenus (N. soni). The details on the simple
ratios L/H, D/L and I/L and the com·
parison with the Nagdongia soni arepresented in the following.
Measurements- The basic morphology
and measurements are illustrated in Text.
Table 2.

figure 4 and recorded in Table 1, res·pectively.
The above fundamental data (L, H, D,
and 1) are taken as an arithmetic meanof three times measurements by 1/20 mm
scaled rule. The inflation, I, is measured
on the external mould made of 'modelling compound '. On each specimen threeexternal moulds were made and cut vertically from the umbo to the ventral
margin, on which the inflations are measured.
From the above data the simple ratios,
L/H, D/L and IlL, are calculated inArithmetic means of the simple ratios L/H, D/L and IlL.

N*

x±to.osax*

V*

s*

aX

0

R*

)(2*

Remarks

L/H 65
D/L 65
IlL 62

1. 41 ±O. 017
O. 35±0. 007
O. 26±0. 008

4.96
8.57
11. 54

0.07
0.03
0.03

0.00870.00370.0038

1. 27
0.26
0.19

1. 56
0.42
0.32

5.410
1. 231
0.638

N.S.*
N.S.
N.S.

N: sample size, x±to.osax: arithmetic mean with 95% confidence level, V: PEARSON'S
coefficient of variation, s: standard deviation, aX: standard error of the mean,0., R.: observed range, )(2: chi·square, N. S.: not significant at 95% confidence level.

1.25
,

1.45
!

1.35
!

1.75

1.65
!

1.55
!

1.85
!

!

-E=========-•._========:3----

M

N.soni

LlH

M

0.15
!

0.20

N./eei

0.25

!

0.30
!

!

0.45

0.40

0.25
!

!

0.50

!

-1=========-_.11:========3------!

tt

N. soni

M

•

0.13
!

0.16

0.19

•

•

M

OIL

N./eei

,

0.28

0.25

0.22
!

!

031

•

;

IlL

N.soniM

M_

Arithmetic mean range at 95°1. confidence level,--Observed range,

c=J Range of 2s.

Text.figure 5. Comparison of Nagdongia leei with N. soni.

661.

Molluscan fauna from Myogog Formation

relation to the univariate values. The
results are summarized in Table 2, in
which the values are represented as
range at 95% confidence level and thechi-square tests are shown in the rightside. The results of the chi-square test
indicate that the null hypothesis for anormal distribution is not rejected forthe considered characters.
The comparison of the univariate
values between molluscan samples canbe carried out only on the assumption
either of their isometric growth or exact
determination of their same stage. However, Nagdongia spp. show various allometric features with characters andsamples. In other words, the ratios varywith growth and samples. And it is also
impossible to determine the exact same
growth stage even among the different
specimens in a sample. Therefore, thestatistic routine works such as F-test andt-test on the present sample are not necessarily meaningful!. Thus, the comparison with Nagdongia soni is terminatedto illustrate simply in Text-figure 5.
Illustration of the characters on triangular graphs-For illustration of thetriple characters together, the triangulargraphs are used. The construction is asfollows: the values of three selectedcharacters (L-H-D, L-H-I) are added
H

L L-.lL..-~~~~'----:::.L--"-7----"-----"D. I
H

H

o 1
• 2

LL---~--~--~--~--~~D

Text-figure 6.

329

Triple characters (L-H-D, L-H-I) plotted on triangular graphs.

1: Nagdongia leei, 2: Nagdongia soni.

330

Seong- Young YANG

together for each specimen, and theirratios in percentage are calculated(BURMA, 1948). These percentages areplotted on the graph, which thus shows
proportions rather than absolute values.
Strictly speaking, as the ratios commonlyvary with growth, the specimens of thesame growth·stage should be selected as
far as possible. But as pointed out above,it is quite difficult to determine the ageof the shells, escpecially of different
samples. Then here all the samples aredealt with together ignoring the growthstage. Thus the illustration on Textfigure 6, where the present species isshown together with Nagdongia soni forcomparison, may reduce the essential
meaning, but the two samples represent
a particular pattern of dispersion respectively. The present species is fairly
distinct from N. soni in L-H-I graphwith a little overlapping. Even thoughin L-H-D graph the samples are somewhat partly overlapped between the two

Explanation of Plate 33
Figs. 1-18. Koreanaia cheongi YANG, gen. et sp. nov.
1. Conjoined valve (KPE 1281), 1a: right valve, 1b: left valve.
2. Conjoined valve (KPE 1282), 2a: right valve, 2b: left valve, 2c: dorsal view.
3. Conjoined valve (KPE 1283), posterior part broken out, 3a: right valve, 3b: left
valve.
4. Right valve (KPE 1284), posterior dorsal part broken.
5. Left valve (KPE 1288), immature specimen.
6. Right valve (KPE 1287), immature specimen.
7. Left valve (KPE 1036), immature specimen.
8. Conjoined valve (KPE 1285), left side view.
9. Right valve (KPE 1286), immature specimen.
10. Conjoined valve (KPE 1035), lOa: left side view, lOb: right side view.
11. Conjoined valve (KPE 1031, holotype), left side view.
12. External mould of right valve made of clay (KPE 1289).
13. Internal mould of immature right valve (KPE 1293) showing the internal impressionof crenulation on postero·ventral side.
1-1. Internal mould of immature right valve (KPE 1292) showing the internal impressionof crenulation on postero·ventral side.
15. Internal mould of left valve (KPE 1289) showing the pseudocardinal hinge teeth andinternal impression of crenulation running from near umbo toward postero.ventral
corner.
16. Internal mould of left valve (KPE 1032) showing hinge teeth, muscle scar (anterior
adductor scar and pedal scar) and weak impression of posterodorsal crenulation.
17. Internal mould of left valve (KPE 1291) showing hinge teeth and weak impressionof postero-dorsal crenulation.
18. Internal mould of left valve (KPE 1290) showing posterior lateral teeth and weak
impression of postero-dorsal crenula tion.
The multiple V-sculptures are occasionally shown on the anterior half (Figs. 1,2 and 12)
KPE 1281-1291 (Coil. S. Y. YANG), KPE 1031, 1032, 1035, and 1036 (Coil. K. H. CHANG and
S. Y. YANG).
All figures are about of natural size.
Loc. Myogog, laesan-myeon, Bonghwa-gun, Gyeongsang-buk-do, Korea.

YANG,'

Molluscan fa~~na from Myogog Formation

Plate 33

2c
3b

13

661.

Molluscan fauna from Myogog Formation

species, the dispersion patterns are also
fairly different from each other. The N.
soni shows wider domain than the present
species. And the former preponderates
toward H-L side, while the latter toward
H-D and H-I sides.
On some other species-CHEONG and
LEE (1966) reported Plicatounio sp. andUnio sp. But according to their illustrations, the two undetermined species seemto be fairly similar to each other. The
so-called Plicatounio sp. shows only thecompressed posterior ridge without plication of the genus. Thus, it seems reasonable to take them together as thesame species. Though the sample is too
small in number and fragmentary to describe and compare to another species, inthe outline of the shell it is fairly different from any other Nagdong union ids
so far.
Summary of results1) Two new species from the Myogog
Formation are described, Koreanaia cheongi, gen. et sp. nov., and Nagdongia
leei, sp. nov.
2) Morphologically Koreanaia can be
regarded as representing an ancestralgroup of the phylogenetic series Nippononaia- W akinoa-Trigonioides (s. s.)- Trigonioides (Kumamotoa).
3) The Myogog molluscan fauna isdistinguishable from any other known
Upper Mesozoic faunas from Far EastAsia.
4) Even though the age of the Myogog
Formation cannot be determined exactly
from the above paleontological evidence,
it can be said tentatively pre-Gyeongsang,maybe Upper Jurassic.
5) The undetermined species of the socalled Plicatounio and Unio and gastropods remain undescribed until more specimens are collected.
6) Trigonioides tetoriensis MAEDA, 1963
(non TAMURA, 1970) is revised to be as-

331

signed to Trigonioides (s. s.) instead ofT. (Kumamotoa) on the grounds of thesurface ornamentation and the internal
structures. For the so-called Wakinoa
tetoriensis of TAMURA, 1970, I propose
Wakinoa tamurai, sp. nov.
References cited
BURMA, B. H. (1948): Studies in quantitative
paleontology: 1. Some aspects of thetheory and practice of quantitative invertebrate paleontology. jour. Paleont.,
vol. 22, no. 6, 725-761, 23 text-figs.
CHANG, K. H. & YANG, S. Y. (1970): Stratigraphic position of Gyeongjeongdong
and Myogog Formations. jour. Ceol. Soc.
Korea, vol. 6, no. 2, 129-133.
CHEONG, C. H. & LEE, H. Y. (1966): The
Myogog Formation and its tectonic significance. jour. Ceol. Soc. Korea, vol. 2,
no. 2, 21-38, pis. 1, 2.
HAYAMI, 1. & IcHIKAWA, T. (1965): Occurrence of Nippononaia ryosekiana from the
Sanchu area, Japan. Trans. Pl'oc. Palaeont. Soc. japan, N. S., no. 60, 145-155,
pI. 17.
KOBAYASHI, T. (1938): The geological ageof the Mesozoic land floras in westernJapan discussed from the stratigraphic
standpoint. japan. jour. Ceol. Ceogr.
vol. 16, nos. 1-2, 75-103.
(1968): The Cretaceous non-marine
pelecypods from the Nam Phung Damsite in the northeastern part of the
Khorat Plateau, Thailand, with a noteon the Trigonioididae. Ceol. Palaeont.
S. E. Asia, vol. 4, 109-138, pis. 20-23.
- - & SCZUKI, K. (1936): Non-marine shellsof the Naktong-Wakino Series. japan.
jour. Ceol. Ceog!-., vol. 8, nos. 3-'1, 2'13257, pis. 27-29.
Ku, C. W. (1962): Note on the occurrenceof some late Cretaceous fresh-water
lamellibranches in the Chusing districtof Central Yunnan with a brief review
on the continental Cretaceous of Yunnan.
Acta Palaeont. Sillica, vol. 10, no. 3, 287307, pIs. 1, 2.

332

Seong-Young Y ANC

LEE, H. Y. (1965): Stratigraphy of the
Myogog Formation and the age of socalled Taebo movement. Seoul Natl.
Univ., (M. S.), 49 pp. pis. 1-9.
MAEDA, S. (1962): On the occurrence ofNippononaia in the late Mesozoic Tetori
Group. Trans. Proc. Palaeont. Soc. Japan,
N.S., no. 46, 243-248, pI. 38.
- - (1963):
Trigonioides from the late
Mesozoic Tetori Group, central Japan.
Ibid., no. 51, 79-85, pI. 12.
MOORE, R. C. (edit.) (1969): Treatise on
invertebrate paleontology. pt. N, nos. 1
and 2, Mollusca 6, Bivalvia, 951 pp. Ceo!.
Soc. America and Kansas Univ. Press.
OTA, Y. (1963): Notes on the relationshipof Trigonioides and Plicatounio, nonmarine Mesozoic Bivalvia from eastern
Asia. Ceol. Rept. Hiroshima Univ., no.
12, 503-512.
SUZUKI, K. (1943a): Mesozoic fresh-watershells from the Husin coal-field, southwestern Manchoukou. Jour. Sigenkagaku
Kenkyusyo, vol. 1, no. 1, 45-64, pis. 3,4.
- - (1943b): Restudy on the non-marine
molluscan fauna of the Rakuto Series in
Keisyo-do, Tyosen. Ibid., vol. 1, no. 2,
189-219, pis. 14-19.
TAMURA, M. (1970): The hinge structure of
Trigonioides, with description of Trigonioides mi/unensis, sp. nov. from upper
Cretaceous Mifune Group, Kumamoto
Pref., Japan. Mem. Fac. Educ., Kumamoto Univ., (18), sec. 1, 38-52, pis. 1, 2.
YANG, S. Y. (1974): Note on the genus
Trigonioides (Bivalvia).
Trans. Proc.
Palaeont. Soc. Japan, N. S., no. 95, 395408, pis. 54, 55.
- - (1975): On a new non-marine pelecypod
genus from the upper Mesozoic Gyeongsang group of Korea. Ibid., no. 100, 177187, pis. 16, 17.

Explanation of Plate 34
Figs. 1-60. Nagdongia leei YANG, sp. nov.
1-29. Right valves (KPE 1201-1229).
30-53. Left valves (KPE 1230-1253).
54. Conjoined valve (KPE 1254) dorsal view.
55. Internal mould of left valve (KPE 1255) showing adductor and pedal scars.
56. Internal mould of right valve (KPE 1256) showing adductor and pedal scars andsimple palial line.
57. Internal mould of right valve (KPE 1257) showing strong adductor and pedal scars.
58. Internal mould of right valve (KPE 1258) showing pseudocardinal teeth, anterior
adductor and pedal scars.
59. Internal mould of right valve (KPE 1259) dorsal view, showing hinge teeth and pedal
scar.
60. Internal mould of left valve (KPE 1260) dorsal view, showing hinge teeth and pedal
scar.
KPE 1203-6, 1211, 1223, 1226-7, 1232, 1236, 1243, 1249, 1260 (Coil. K. H. CHANG and S. Y.
YANG), KPE 1201-2, 1207-10, 1212-22, 1224-5, 1228-31, 1233-5, 1237-1242, 1244-48, 12509 (Coil. S. Y. YANG).
All figures are about of natural size.
Loc. Myogog, Jaesan-myeon, Bonghwa-gun, Gyeongsan-buk-do, Korea.

YANG:

Molluscan fauna from Myogog Formation

60

Plate 34

661.
A,ndong
Bonghwa.gun
Cheongyangsan
Euiseong
GalsanGasongdong
Gyeongsang
Gyeongsang·buk.do
laesan.myeon

Molluscan fauna from Myogog Formation~•

it tilliff W- III

*

•

1JJt

III
1£
tE r~ 1Il!I
j\lij
11f
11f j\lij:lt ~:::t III iID

Myogog
Nagdong
Silla
TaegogUllyeonsan
WonnamYeongju
Yeongyang
Daedong

333

gp

m

~

~

•

All
t:t
~
if 1I III
""-

;Ili!

*~
*-

m
;'1'1
~
~

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 102, pp. 334-342, pI. 35, July 15, 1976

662. COLOUR PATTERNS IN SOME CRETACEOUSAMMONITES EROM HOKKAIDO(STUDIES OF CRETACEOUS AMMONITES FROMHOKKAIDO AND SAGHALIEN-XXX)
T ATSURO MATSUMOTO and HIROMICHI HIRANO
Department of Geology, Kyushu University, Fukuoka 812~tWJHg€S!!l!~D7 :/.:£:-:t-1 r ~f3~~-~tWJH~S!!l!~g€7 :/.:£:-:t-1 r t;::I;J:.*1f~ .l:\"t~tMrt.r:. t.r:.\, ,~-r:, m!:~f3~~fqj;iJ~R"?
G t ~lit.r:.\"iJ' iJ,;tJ.-CiJ' i?Wll. L -c\"t.:iJ~,

<

on,

c

.:~:§! 6 $f*~f9l]iJ~~t±l ~tLt.:o -ttLl;J:.~~~:I1!!ml19'€lf1~ ;P]INf,tJ'i? 'J':>JLt;::Mt-c ~ -It:/ r .::.
7 :/~;WJ?i'YlJE:€i*~ t ~-r:, \"TtL t Texanitinae t;::~-t Go Protexanits (Protexanites)

bontanti shimizui MATSUMOTO 4 $, Protexanites (Anatexanites) fukazawai (YABEet SHIMIZU) 1 $, Paratexanites (Parabevahites) serratomarginatus (REDTENBACHER)

1 OO~~17IJt;::I;J:., c·tLt~~~:nrDJt;:::>JLrr-tG~JlfiJ~.;I;GiJ', f3*~~. fiLii, ~ili, rl3'~~m:Mi¥J~$ilit.r:.EiJ~fiHlIH;::.l: ~~t.r:.G': c, 1 fi~*-r:I;J:.~~I;J:.fiiJ,.;I;GiJ~, l'if:f-~L -C\"G':~ 1 • 2 fi~f3*iJ~~jrt-t G ~t;::M L, ~ 3 ~fi~-ttLl;J:.iJ't.r:. IJ ~t.r:. G': iJ't±ll. ~tLG 0
f3~I;J:.a1'l-~'€lfIt;::~*L-C\"G.l:? -r:.;I;G o t.r:.:to.~~~.x:t;::1J~.:t -C, 7 :/.:£:-:t-1 r 0)m!:~f3c,c~~-fdIH;::~ L -c;ti=f~~if1jilifi~~~Got~*~ft~· :>JL!Ilf'll-JH

Introduction

necessary information and Mr. Tatsuo
MURAMOTO who helped us much.

Traces of colour patterns are scarcely
preserved on fossil shells of the Ammonoidea. The hitherto reported ones arein some particulary well preserved specimens from the Jurassic of Europe. While
we are studying Cretaceous Ammonoidea
from Hokkaido and Saghalien, we haverecently noticed several specimens inwhich traces of colour patterns arepreserved. In this paper we report theobserved facts and extend some discussion for further study.
Before entering in the description wethank Messrs. Takemi TAKAHASHI and
Kikuwo MURAMOTO who provided
valuable specimens at our disposal with

Descriptions
The ammonites with traces of colour
patterns were contained in calcareous
nodules embedded in the Santonian finesandy siltstone in the western part of
the Teshio Mountains, Hokkaido (Fig. 1).
For the stratigraphy of this area readers
may refer to the explanatory text of thegeological maps of the scale 1: 50, 000,
" Sankei " (YAMAGUCHI and MA TSUNO,
1963) and "Tappu" (TSUSHIMA et al.,1958) as well as UEDA et al. (1962) and
OKADA and MATSUMOTO (1969).
The specimens are of six individuals
belonging to three species of the Texanitinae, a subfamily of the Collignonicera-* Received March 11, 1976; read Jan. 30,
1976 at Kawatabi.
334

662.

Colour patterns in Cretaceous ammonites

tidae. For the systematic descriptionsof the Texanitinae from Hokkaido andSaghalien readers may refer to MATSU·
MOTO (1970, '71). The observed facts
about the colour pattern are described
below according to the species.

1. Protexanites (Protexanites) bontanti
shimizui MATSUMOTO
PI. 35, Figs. 1-4

The following four specimens havetraces of colour ptterns:
A. T. TAKAHASHI'S specimen (PI. 35, Fig.
1) from a floated calcareous nodule inthe stream of the Detofutamata, a trio
butary of the River Haboro. This maylO}(mr::::::lCRETACEOUS~ OUTCROPS

Text·fig. 1. Index map showing ap·
proximate locations where ammonites withcolour patterns were found. 1: Detofu·
tamata, Haboro,
2: Kami.no.sawa, Ko·
tambetsu, 3: Aka.no.sawa, Obira. Chain:
Teshio Mountain watershed335

have been derived from the same stra·
tigraphic unit as B.
B. K. MURAMOTO'S specimen (PI. 35, Fig.
2) from the lower part of Unit U3 of
the Upper Yezo Group (YAMAGUCHI
and MA TSUNO, 1963) in the same
stream as A. (close to loco CK80 of
UEDA et aI., 1962).
C. GK. H5632 (PI. 35, Fig. 3; Text-fig. 2)
from loco R215 pI, Kami-no-sawa [=Haboro-goe-no-sawa], a tributary of
the River Kotambetsu, probably derived from Unit U3. It was collected
and described by MATSUMOTO (1970,
p. 327) but was not illustrated on thatoccasion.
D. GK. H5797 (PI. 35, Fig. 4), from loco
R207p, of the same stream as above,
collected by T. MATSUMOTO.
They came from the Santonian finesandy siltstone in the upper reaches ofthe Haboro and the Kotambetsu, within
the area of Geological Map "Sankei ",where fossils are generally in favourable
state of preservation.
The traces of colour patterns on these
specimens indicate that the shell of Protexanites (Protexanites) bontanti shimizui
MATSUMOTO has longitudinal (i. e. spiral)colour bands in three rows in lateralview, the first near the umbilical margin
along the row of umbilical bullae, thesecond at about the middle of the flankand the third outside the row of inner
ventrolateral tubercles. The last bandcovers the whole ventral area. For convenience' sake these three colour bands
may be called the inner, the median andthe outer ones. The overhanging umbilical wall is free from the inner colour
band.
Strictly speaking they are not equidistant. The interspace between the
inner and the median bands may besomewhat broader than the colour bands
themselves and that between the median336

Tatsuro MATSUMOTO and Hiromichi HIRANO

and the ventral bands is di3tinctly narrower than the median colour band. For
example, in Specimen A the following
approximate proportion is shown on theleft side of the shell (PI. 35, Fig. 1a):inner band: 7, inner interspace: 10,
median band: 6, outer interspace: 4,
outer band: 8 (ventrolateral)+6 (ventral half).
However the proportion is as follow3
on the right side of the same shell (PI.
35, Fig. 1b):
inner band: 7, inner interspace: 8,
median band: 8, outer interspace: 5,
outer band: 7 +6
Anyhow, the median colour band ismore or less deviated outside the midflank.
The above description about the detailsof the colour patterns depends on Specimen A, on which the traces of colour
bands are best preserved. The samefeatures seem to be maintained in Specimens C and D. In D (GK. H5797), which
is somewhat smaller than A, colour bands
are observable on its right side where
the same proportion as seen on the left
side of Specimen A is shown. Specimen
C (GK. H5632) is represented by a fragmentary body-chamber and its externalmould of a larger, probably adult shell.
So far as the preserved outer part isconcerned, the same feature as seen on
the right side of Specimen A is shown.
Specimen B is a small, probably immature shell, on which traces of colour
bands are very incompletely preserved.
In all the above specimens the tracesof colour markings are shown by darkbrown bands, with purplish tint in Specimen A and nearly brownish black in theexternal mould of Specimen C. The interspace or ground is beige or ochre,with or without pinkish tint. On thewell preserved colour bands it is noticed
that pigmental material is distributed

only in the outer layer of the shell structure. The distribution seems to bedenser in the outermost part. In our
specimens the growth-lines are better
marked on the dark coloured outer layer.
In other words the pigmental outer layer
seems to have been comparatively morestable, whereas the outer layer without
pigment was dissolved away from theinterspaces.

2. Protexanites(Anatexanites)

jukazawai (Y ABE et SHIMIZU)
PI. 35, Fig. 5

MA TSUMOTO (1970, p. 242) reported
that fossils of this species occurred fairly
commonly in the Himenoura Group ofwest central Kyushu about the middleof the Senonian (MATSUMOTO and UEDA,
1962) and that it was rare in Hokkaido,
describing only a single specimen fromthe upper reaches of the Haboro, as aprobable example (MATSUMOTO, 1970, p.
241, pI. 44, fig. 1).
Subsequently several better preserved
examples were obtained by K. MURAMOTO and T. TAKAHASHI from the Santonian of the Obira area, within thegeological map quadrangle of "Tappu".
They are all of moderate size, about or
somewhat less than 100 mm in diameter,
although they are provided with a living
chamber. This is much smaller than thelectotype from Kyushu (Y ABE and SHIMIZU, 1925, pI. 30, fig. 1; pI. 31, fig. 6,
designated by MATSUMOTO and UEDA,
1962, p. 173). However, the Hokkaido
specimens are indistinguishable from thesmaller specimens from the Himenoura
Group and regarded as being within thevariation of the same species.
One of the specimens from the Obiraarea, here called Specimen E for convenience' sake, in T. TAKAHASHI'S collec-

662.

Colour patterns in Cretaceous ammonites

tion from the Aka-no-sawa, fairly clearlyshows colour markings. Here again thepattern consists of three longitudinalhands in lateral view, the inner, themedian and the outer ones. Accordingly
it closely resembles the above described
pattern of Protexanites (Protexanites)
bontanti shimizui.
In this example the median band isslightly broader than the inner band andthe interspace between them is slightly
narrower or nearly as narrow as the innerband. The outer interspace is distinctly
narrower than the inner interspace, about
half as narrow as the median band.
Thus the median band covers the entire
breadth of the row of lateral tubercles
in its inner half. The outer band covers
the entire ventral part outside the row
of inner ventrolateral tubercles.
The following proportion illustrates theabove explanation: inner band: 7, innerinterspace: 6, median band: 8, outer interspace: 4, outer band: 8+6.
This difference of comparatively narrower lower interspace than in the preceding species may be correlated withthe relative shortness of the whorl heightin Protexanites (Anatexanites) Jukazawai
as compared with Protexanites (Protexanites) bontanti shimizui (about 38 percentof the diameter in the former as compared with 41 to 42 percent in the latter).
The colour bands are dark brownish
when the outer layer of the shell is better
preserved. The radial growth lines aremarked there. The interspace is ochreon the surface of the next inner shelllayer. Even if the dark colour is notwell preserved on some part, the shelllayer of the band is slightly but distinctly more elevated than the interspace.
Probably on account of this feature, theouter margin of the median band forms
a sinuous spiral line which is parallel toand at a regular distance from the row

337

of inner ventrolateral clavi. At the
middle growth-stage, with shell diametersof 40 to 50 mm, this spiral line is accompanied with slight elevation on crossing
the radial ribs. Therefore, the whorl at
this stage looks as if it had four rowsof tubercles on its outer half, but theseelevations do not persist and we do notregard them as true tubercles.

3. Paratexanites (Parabevahites)
serratomarginatus (REDTENBACHER)
Text-fig. 3

Incomplete traces of colour bands areobservable on the external mould (herecalled Specimen F) of the already described example, GK. H5629, of this species (MATSUMOTO, 1970, p. 260, pI. 36,
fig. 3), from loco R215 p, Kami-no-sawa[i. e. Haboro-goe-no-sawa], a tributary of
the Kotambetsu. This was contained in
the same calcareous fine-sandy siltstone
nodule as Sample C. The previously
illustrated internal mould (GK. H5629) isdevoid of the shell layers and no traceof colour pattern is observable on it.
The outer shell layer is attached to theexternal mould of Specimen F.
The colour pattern on this externalmould is represented again by longitudinal stripes, but in this case the innerdark band is broad, occupying the innerhalf of the flank. Being separated by anarrow interspace, comes the next colour
band wich runs on the row of double
ventrolateral tubercles. This seems toform a narrow band independent of thetrue ventral band, but the preservationof the ventral part is not good enoughfor a definite statement. It might forma part of the broad outer band which
covers the entire ventral part. Anyhow,
it is clear that Paratexanites (Parabeva-

Tats~~1'O NIATSUMOTO and Hi1"omichi HIR ANO

338

lOmm
L---l

3
Te x t-fi gs. 2- 3. Colour markings on f ragment a ry ammonites.
2. Specimen C [ =GK . H5632J, T. M AT SUMOT O'S ColI., from loc o R215 pI, Kami no-sa wa, Kotambetsu. Lateral (a) and ventral (b) v iews of fragmentarybody-chamber, of Protex anit es (Protexanit es) bontanti shimiz ui M A T SU M OT O .
3. Specimen F [ = GK. H5629J, T . M A T SUMOTO'S Co lI. , from the same calcareous
nodule as abo ve. Ex ternal mould of Paratexanites (Parab evahite s) serratom arginatus (R EDT EN BAC H E R) .
( H . HIR ANO photos .)hites) serratomarginatu s has colour bands
which are cons iderably different fromthose of the above described two spec iesof P1'otexanites.
Discussion

Reports of the colour pattern on fossil
shells of the Ammonoidea are quite few .
The hitherto described specimens aremostly those from the Jurassic of Europe(e. g. GREPPI N, 1898; SCHI NDEWOLF, 1928;
SPA TH, 1935; ARKELL , 1957). The present

paper may be the first report for Cretaceous examples.
As ARKELL (1957, p. L92) summarized,
the colour pattern in the Jurassic ammonites mostly take the longitudinal brown
stripes on a white grou nd (as in thecase of A maltheus, Androgynoceras andT ragophyLloceras) . The said one or morelateral white stripes on brown groundin Leiocera s and A steroceras may imply
that dark coloured stripes were so broadthat a narrow white interspace remained.
This is well suggested by the presence

662.

Colour, patterns, in Cretaceous ammonites

of a nar:row interspace in our case,although we cannot state conclusively
without inspecting the original specimensfrom Europe. Of course there can beradial and other colour patterns asreported by SCHINDEWOLF (1928) on
Pleuroceras ,and as suggested by certain
patterns in the Nautiloidea (RUDEMANN,
1921; FOERSTE, 1930; SEILACHER, 1971).
In the present case of six Cretaceous
specimens the colour patterns are all
represented by longitudinal stripes, which
are parallel to the orientation of thewhorl growth. In Cephalopoda the shelllayers are secreted through the epitherium at the frontal margin of the mantle(MUTVEI, 1964). Therefore the secretionof the pigmental material must hav:ebeen taken by definite parts of theepitherium within the entire margin.
This kind of physiological allotment may
be similar to that for the formation of
tubercles. Incidentally the colour bands
observed in our texanitine a,mmonites
always run on or parallel to the rowsof tubercles.
It is recalled here that in many spirally
coiled shells of gastropods colour patterns
are most commonly parallel to the spiralgrowth, although modifications to thisfundamental pattern occur frequ~ntly
and. other patterns are also mel1 with.
This is true for the fossil shells ofgastropods, as seen in a recent paperof KRIZ ,and LUKES (1974). In the)impetshaged shells of gastropods the colour
patterns which run radially toward theshell margin are common. In many shellsof bivalves and also brachiopods, including
fossil examples (e. g. CLOUD, 1941; KRIZ
and LUKES, 1974), the radially coloured
bands which run nearly perpendicular
to the shell-margin are common. They
all comform with the case of the
Cephalopoda in that the pigments are
secreted through certain alloted parta of339

the epitherium. This may suggest thatcolour patterns in mollusks and certain
other invertebrates ax:e not formed
volUntarily but probably controlled
genetically. Therefore they are fairly
constant like other shell characters. A
similar statement has already been
expressed by OZAWA (1975, oral communication) through his study of recent
populations of U mboniu m species.
Fortunately four specimens are available for the colour pattern of Protexanites(Protexanites) bontanti shimizui from theSantonian of Hokkaido. They constantly
show the same type of colour stripes,
although there may be slight variation
within the species.
Tl),e colour bands on the shell ofProtexanites (Anatexanites) Jukazawai isclosely similar to but not quite identicalwith that of P. (P.) bontanti shimizui.
This is interesting in view of the factthat in the morphological characters of
the shell, P. (A.) Jukazawai closely
resembles P. (P.) bourgeoisi (D'ORBIGNY),
which is alJied to P. (P.) bontanti (seeMATSUMOTO and UEDA, 1962, p. 174;
MA TSUMOTO, 1970, p. 24:0). Anatexanites
is distinguished from Protexanites (s. s.)by the development of a row of lateral
tubercles.
,It is also interesting to see that Paratexanites (Parabevahites) serratomarginatus, which has some affinity withProtexanites (Protexanites) bourgeoisi but
is sepflrated to another genus (see MATSUMOTO, 1970, p. 263), likewise has
longitudinal stripes but the mode of
banding is considerably different fromthat of the above two species.
, rh~se facts are favourable for theabove,; ,~entioned general stateme,nt.
Alt~o,t!gh SPATH (1935), was pessimisticabou( the, taxonomic distinction by ,colour
marking!), we consider that the colour
patter~s are important for the study

340

Tatsuro MATSUMOTO and Hiromichi HIRANO

n
Q

b

n

Text-fig. 4. Schematic illustration of
whorl-sections, showing the position ofcolour bands in three species.
a: Protexanites (Protexanites) bontanti shimizui MATSUMOTO
b: Protexanites (Anatexanites) /ukazawai(YABE et SHIMIZU)
c: Paratexanites (Parabevahites) serratomarginatus (REDTENBACHER)

of taxonomy, phylogeny, biochemical
physiology and other aspects of palaeontology.
Although many other ammonites occur
in the same formation of the westernpart of the Teshio Mountains, we havelittle noticed the colour patterns. Thismay be due in part to our carelessobservation and in part to the delicate
difference in the state of preservation.
At present we do not know what kindsof conditions are necessary for thepreservation of the colour patterns on
fossil shells of the Ammonoidea. We
notice, however, that well preserved
fossils of Gaudryceras sometimes havedark brownish "coating ", which isprobably a coloured outermost layer.
In this case the whole surface may havebeen coloured without figures, i. e. plain
dark brown.
We have not yet inspected the chemistry of the preserved pigment orsomewhat altered pig mental material.
The fact that the coloured outer shelllayer have been resistant against theprocesses of fossilization, diagenesis andweathering suggests a character of thepigment. Namely the pigmental materialmust have been insoluble or less soluble

in the sea water or interstitial waterand have attached itself firmly to theconchiolin. According to COMFORT (1951)
and Fox (1966), chromoproteins accompanied with melaninoid prosthetic groupand tetrapyrroles are the common
pigments in shells. The former is insoluble
in most liquid media, whereas the latteris soluble. The former is said to be
more common in advanced gastropods
and bivalves.
At present we cannot exactly tell thefunctional meaning of the colour patterns
in the natural history of the Ammonoidea.
There could be various cases. Somewhat
wavy pattern in Nautilus may serve forthe animal as a camouflage against
enemies. In other words the colour
pattern is protective. In the present
case of the Texanitinae the clearly marked
subconcentric colour bands around theumbilicus may be so distinct as to act
as a warning colouration. This possible
interpretation may be favourable for the
tuberculated ammonites belonging to the
Collignoniceratidae.
It may not be
accidental to have colour bands along
the row of tubercles, although we do
not exactly know the meaning of the
tubercles for the natural life of theAmmonoidea. It could also be consideredthat certain colour patterns might serve
as a sexual fascination. How to determine
one of these and other possible interpretations may be a future problem as is
the problem of adaptation for a certain
colouring in the Ammonoidea.

References Cited
ARKELL, W. J. (1957): Introduction to Mesozoic Ammonoidea.
In MOORE, R. C.
(ed.), Treatise on Invertebrate Paleontology. Part L, p. L71-LI28, Geol. Soc.
Amer. & Univ. Kansas Press.
CLOUD, P. E. (1941): Color-patterns in De-

662.

Colour patterns in Cretaceous ammonites

vonian terebratulids. Amer. Jour. Sci.,
vol. 239, p. 905-907.
COMFORT, A. (1951): The pigmentation ofmolluscan shells. Bioi. Revs., Cambridge
Phil os. Soc., vol. 26, p. 285-301.
FOERSTE, A. F. (1930): The color patternsof fossil cephalopods and brachiopods,with notes on gastropods and pelecypods.
Mus. Pal., Univ. Mich., Contr., vol. 3, no.
6, p. 109-150.
Fox, D. L. (1966): Pigmentation of molluscs.
In WILBUR, K. M. and YONGE, C. M.,
Physiology of Mollusca, vol. 2, p. 249-274,
New York, London.
GREPPIN, E. (1898): Description des fossiles
du Bajocien superieur des environs deBale. Mem. Soc. Pal. Suisse, vol. 25, p.
1-52, pis. 1-5.
KRIZ, J. and LUKES, P. (1974): Color pat.
terns on Silurian Platyceras and Devonian
Merista from the Barrandian area, Bo·
hernia, Czechoslovakia. Jour. Paleont.,
vol. 48, p. 41-48, pis. 1-2.
MATSUMOTO, T. (1970): A monograph of
the Collignoniceratidae from Hokkaido.
Part IV. Mem. Fac. Sci., Kyushu Univ.,
Ser. D, Geol., vol. 20, no. 2, p. 225-304,
pis. 30-47.
- - (1971): A monograph of the Collignoni.
ceratidae from Hokkaido. Part V. Ibid.,
vol. 21, no. 1, p. 129-162, pis. 21-24.
MATSUMOTO, T. and VEDA, Y. (1962): Palaeontological notes, In VEDA, Y., The
type Himenoura Group.
Ibid., vol. 12,
no. 2, p. 161-178, pis. 22 -27.
MUTVEI, H. (1964): On the shells of Nautilus
and Spirula with notes on the shell secretion in non-cephalopod molluscs. Arkiv
f. Zoologi, vol. 16, no. 14, p. 221-278,
pis. 1-22.

Aka-no-sawa
Detofutamata
HaboroHaboro-goe-no-sawa
Kami-no-sawa

(}j;

/
1R.
T t-=JIlt~

3fJ

3fJ~~/iR

1:

/

1R.

341

OKADA, H. and MATSUMOTO, T. (1969):
Cyclic sedimentation in a part of theCretaceous sequence of the Yezo geosyn:
cline, Hokkaido. Jour. Geol. Soc. Japan,
vol. 75, p. 311-328 (in Japanese withEnglish abstract).
OZAWA, T. (1975): Geographic variation of
Umbonium moniliferum (LAMARCK). Oral
Comm. Ann. Meet. Palaeont. Soc. Japan,
Tokyo, Jan. 26, 1975.
RUDEMANN, R. (1921): On color bands in
Orthoceras. Bull. N. Y. State Mus., no.
227-228, p. 315-320.
SCHINDEWOLF, O. H. (1928): Uber Farbenstreifen bei Amaltheus (Paltopleuroceras)
spinatum BRUG. Palaont. Zeitschr., vol.
10, p. 136-143.
SEILACHER, A. (1972): Divaricate patterns
in pelecypod shells. Lethaia, vol. 5, p.
325-343.
SPATH, L. F. (1935): On colour-markings inammonites. Ann. Mag. Nat. Hist., ser.
10, vol. 15, p. 395-398, pI. 8.
TSUSHIMA, K., TANAKA,' K., MATSUNO, K.
and YAMAGUCHI, S. (1958): Tappu. Expl.
Text Geol. Map Japan, scale 1: 50,000.
Geol. Surv. Japan, 66+8 p., 1 map (inJapanese with English abstract).
VEDA, Y., MATSUMOTO, T. and AKATSU, K.
(1962): The Cretaceous deposits in the
Chikubetsu area, Hokkaido. Sci. Rep.
Dept. Geol., Kyushu Univ., vol. 6, no. 1,
p. 15-32 (in Japanese with English abstract) .
YAMAGUCHI, S. and MATSUNO, K. (1963):
Sankei. Expl. Text Geol. Map Japan,
scale 1: 50,000. Geol. Surv. Japan, 50+9
p., 1 map (in Japanese with English
abstract) .

Kotambetsu
Obira
SankeiTappu
Teshioit :Pt lJlJ
3fl
'J'
~
j(

~
;ijJ

:J.il

342

Tatsuro MATSUMOTO and Hiromichi HIRANO

Explanation of Plate 35
Figs. 1--1. Protexanites (Protexanites) bontanti shimizui MATSUl\IOTO ................ Page 335
1. Specimen A, T. TAKAHASHI'S Call., from the Detofutamata, a tributary of the River
Haboro. Left (a) and right (b) sides and ventral view (c), xL
2. Specimen B, K. MURAMOTO'S Call., from the same stream. Left (a) and right (b)sides and ventral view (c), xL
3. Specimen C [=GK. H5632], T. MATSUl\IOTO'S Call., from Lac. R215 pI, Kami-no-sawa,a tributary of the River Kotambetsu. Outer shell layer on a part of the externalmould, with Inoceramus sp. at the lower right corner, x 1. (See also Text.fig. 2.)
4. Specimen D [=GK. H5797], T. MATSUMOTO'S Call, from lac. R207 pI, the same stream
as C. Lateral view, xL
Fig. 5. Protexanites (Anatexanites) /ukazawai (YABE et SI-II:-'IIZU) .................. Page 336
Specimen E, T. TAKAHASHI'S Call., from Aka-no-sawa, a tributary of the River Obira[=Obirashibetsu]. Right (a) and left (b) sides and ventral view (c), xL
Kyushll University (H. HIRANO) photos.

MATSUMOTO and HIRANO.-

Colour Patterns in Cretaceous ammonites Plate 35

Palaeontological Society of Japan, Special Papers No. 19 Bivalve
Faunas of the Cretaceous Himenoura Group in Kyushu

By Masayuki TASHIRO
Issued February 10, 1976; 102 pp., 12 pIs.
Price (postage and handling included) ...................... U. S. $. 15.00
The paper contains palaeontological descriptions of bivalve fossils from the Upper Cre·taceous Himenoura Group in western Kyushu, based on new collections containing 57 speciesof 40 genera, of which one genus (Mesochione) and 23 species are entirely new.

Notes aregiven on the stratigraphy of the Himenoura Group of local areas with geological maps andcolumnar sections that indicate collecting localities and stratigraphic positions of the des·cribed species, and the mode of occurrence of several kinds of assemblages and its relation
to the lithofacies. The range of the species and the comparison with faunas of extra-Japanese provinces are also concisely given.
The special papers are on sale at the Society.

Orders must be accompanied by remit-

tance, made payable to Dr. Kametoshi KAr;yIERA, Editor of the Special Papers, Palaeontological Society of Japan, Fukuoka Office, c/o Department of Geology, Faculty of Science, Kyushu University, Fukuoka 812, Japan.

The following backnumbers are also purchasable from the same office as mentioned above.
Number 11 (Issued Feb. 20, 1966): The Echinoid Fauna from Japan and AdjacentRegions. Part 1. By Syozo NISIYAMA .................................... U.S. $. 33.00
Number 12 (Issued Sept. 20, 1966): Postcranial Skeletons of Japanese Desmostylia.
By Tokio SHIKAMA ........................................................ U.S. $. 17.00
Number 13 (Issued March 16, 1968): The Echinoid Fauna from Japan and AdjacentRegions. Part II. By Syozo NISIY AMA .................................... U. S. $. 26.00
Number 14 (Issued Nov. 25, 1969): Litho- and Bio-facies of Carbonate Sedimentary
Rocks-A Symposium. Edited by Tatsuro MATSUMOTO .................... U. S. $. 12.00
Number 15 (Issued Feb. 25, 1971): Early Devonian Brachiopods from the Lesser
Khingan District of Northeast China. By Takashi HAMADA .............. U. S. $. 17.00
Number 16 (Issued Dec. 25, 1971): Tertiary Molluscan Fauna from the Yakataga
District and Adjacent Areas of Southern Alaska. By Saburo KANNO ...... U. S. $. 18.00
Number 17 (Issued Nov. 30, 1974): Revision of Matajiro YOKOYAMA'S Type Mollusca
from the Tertiary and Quaternary of the Kanto Area. By Katura OYAMA............................................................................ U.S. $. 20.00
Number 18 (Issued Nov. 30, 1974): Silurian Trilobites of Japan in Comparison
with Asian, Pacific and Other Faunas. By Teiichi KOBAY ASH! and Takashi
HAMADA .................................................................... U.S. $. 17.00(Numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 are out of stock.)

~ffi

~

118 @] 17IJ

1977 1'f- ;ff.!:~ ' 1'f-~

to

to

~t

*

Hit
ria

/'J',

:1m

1m

m *- ~
A!J:.
=[-

-H-

~

flli

1 9 7 6 1'p 10 .J'J*- -"'.
q-~il;: ~

13
4 13

1976 1'f-

1 Pl

1 9 7 7 1'f-

$ i.6 l\li W 13*
8)j

413

1976 1'f- ll )j 15 13

B* <!i' ~~m¥'~tMl IJ % No . 19, "Bival ve Faunas of th e Cretaceous I-limenoura Group in Kyushu" ([J1-1(;iEz.~ : 102 Jr, 1 2 IZJJ~ ; 1976 1'f- 2 )j 10 13 ¥HD tJ; , Jtl:iil~il'U fj-Jj;Ijrp(AitO)J21Jj;lj~ f-l'J 'c rU
qj-~;h.t.:o ~ {rrfi li 1 f:if1 3300 FJ (!Ej~RWI-' mJ§!Pi- 250 FJ1JQr,l:) , i±Jtli =r 812 ml1liJTlnl-mjTj ~flJ , :iL1+1*-+
Jm~l:iiIJtl!.~~~~ P'J, B*<!i' ':EJki~~*-t7JIJJ~-*iiiit1~~~~" ( J1N'M'r:J~, ml1liJ 19014; =5fWdHlml1liJ-:£I;5
J: ~~ ~~~o~iillT~~ r:J ~ 12172 Ci±Jtiillj;llIiJjlJic:iL:k") J, !IiIIRSic.):: I?tJ: H~ j1illjYj Ali, J: ~~o)IU> ,**:k+Jm~l:iilJtl!.~~~~ P'J, EI *1!l':t4~q~~*ffll1iZ.U'/Ej'IJ11-~jf!j.4tJfm*fm (JU§l.LJ *1f53f1,N) c- -q" I&=l&?o1976 1'f- ll )j ¥6fj--=y~0)~~::g;70J.{'Ff.&:O)t.: ot , fHJ1JO)~ '?t.:~~li , **jlfJlffjr1l§IKs A m} 3-23-1, /E}'[
H q~W~tn'~ ( =r 160) tltrI39- !J3~---c 9 )j)fd

c-iciill:9-lJ~nt.:~' oto N o. 101 +~~~ *lOOic , {iiiO)-'f7%'l::>iC.):: I) E':t~1jlf}ililj¢tJJO):k~~f:'lj;gO)t:;1i1JtJ;)z¥.{i: L i Lt.:o :f;>~?
If L ---c iill1J n~ ,t.: L i -j'" 0 W 10 JOJ I!l':t.¥.f} 1jlf :'iE}ili f,l1~ ~~ 4¢ 4JI,

:k~*~11Ij;g-0

to ~~fj-~H¢~T c L ---c , * ~t :kq~[J v~*ijj- ;gtJ;ge (:l ~ n i Lt.:o1 976 1'f- 7 )j 12 13

~n

AlW

1976 1'f- 7 )j 15 13

¥6

fj-

~

IT

*

*

a
~ ~ ~
Jt Jj( IK ij!j; ':t 2-4- 16~~

13 * ~ iHJ;i:j% --t ;/:!J - P3

(J1N ~ r:J ~
~

rnJ

*Fro

~

~p

MiU

102 %

1, 600 p:J

~

**
*

*

Jj( 84780 'Ii )

Iii

II I

±

Jj( jlfJl l;!/! .~ IK M: 3i: ~t 2 / 13

~ 1WlZJffi~n Jj) ij1*:tt~{±

~

[J

~

Transactions and Proceedings of the PalaeontologicalSociety of Japan

July, 15, 1976

New Series No. 102

CONTENTS
TRANSACTIONS
661.

YANG, Seong-Young: On the non-marine molluscan fauna from the Upper
Mesozoic Myogog Formation, Korea ........................... . . .. ... 317

662. MATSUMOTO, Tatsuro and HIRANO, Hiromichi :Colour patterns in some

Cretaceous ammonites .... . ........ . .... . ................ . .. . . . . . . . . . . 334