a -lt"~±~T~~~·!c.f
Transactions and Proceedingsof thePalaeontological Society of Japan
New Series

No. :~2

Palaeontological Society of japan
Novl:mber 10, 1958

CONTENTS
TRANSACTIONS
Page

348.

On the !VIiocene Pectinidae from the Environs of Sendai; Part 12. On Pecten

kagamianus Y oKoY Al\IA ..................... .
349.

. ................... 1\oichiro iVlASUDA 271

Molluscan Fauna from the Tertiary Formation of Chirai. 1\amisaroma.
Kitamino·kuni, 1-Iokkaido ......

.. Wataru ll."-SIMOTO and Saburo KANNo 285

350.

Late Triassic Palaeoplwms in Japan ... .. ...... .... .. .... .. . .... ... Akira ToKUYAMA 291

351.

An Interesting Crustacean Remain, Ctenocheles sujalmi n. sp. from the
Pakogene of Kyushu. Japan ........................................... Rikizo IMAIZUMI 299

PROCEEDINGS .............................................................................................. . 305
Systematic Index

307

Index of Fossils .................... .

309

President :Hisakatsu Y AnE

Councillors:

Kiyoshi AsANo. Riuji ENoo (Business and Accountant). Seido ENoo,

1-Iaruyoshi FuJII'.IOTo (Publication). Shoshiro HANzAwA. Kotara HATAI, Ichiro
HAYASAKA (General Affairs), Kazuo HuzioKA, Teiichi KonAYAsHI (Editor),
Jiro l\iAKIYAMA, Tatsuro MATSU~IoTo, Masao l\iiNATo, Tokio SHIKA:o.tA, Fuyuji
TAKAI (General Affairs). Ryuzo ToRrYAMA
Secretary:

Tetsuro I-IANAI

Assistant Secretary:

Takeo IcmKAwA

All Communications relating to this Journal should be addressed to the
PALAEONTOLOGICAL SOCIETY OF JAPAN
Geological Institute, Faculty of Science, University of Tokyo, Japan

Trans. Pror. Palaeont. Soc. japan, N. S .. No. 32. pp. 271- 21'\'l. pis. 40~1 I, J'\ov. 10, 1958

:348.

ON THE ;\fiOCENI:: PECTINlDAE FROl\1 'rHE ENVIRONS OFSENDAI : PART 12. ON PECTEN KAGAMIANUS YOKOYAMA*
KOICHIRO rviASUDA
Departnwnt of Geology, Faculty of Education.
'Tohoku University

ltittl'llf.t.i/i:rl~f!i*fedf,' Pcctinidac: -'CO) 1~. J>ec/elr kagamimms YoKOYAMA :c ..:n,-c:f.lOI!:
Pecten kagamianus YoKOYAMA t t. ft 'L$t.:: r. *?-r.!t!!:l.l· t:, CD~ t~O)~)j>::~ '?~ 'l'M'itH..t.:f.li\1!:.
Patinopecten kagamianus lmgamiamrs (YoKOYA:IlA), Pat. kagamiamrs monirmensis MASUDA. n.
subsp., Pat. kagamiamrs nimaensis !viASlJDA. n. subsp., Pat. kagamimms permirus (YOKOYAMA)
0trniffifili:-:.J}tt J? ttJ., c. c v:bl'J·? t.:., Ut ~:, v)~ -'< r:::-:>t-L'Jcl~~ rrP. t'rHWHO)OOf*'· it!!'t'l".f.f!'~'"'

Among the fossil Pectinidae knO\Ynfrom the l'vliocene formations of Japan.
Pee/en lwgmnianus is of particular interest because of its confusing characters.
limited geological range, more or lesssimilar lithology of the formations inwhich it occurs. and rather wide geographical distribution.
Numerous specimens from the Nanao
formation in Ishikawa Prefecture. andfrom the J\1oni\\'a and Oido formationsin Miyagi Prefecture. those preservedin the Institute of Gcologv and Palcon·
tology, Faculty of Science. Tohoku Uni·
versity, and in the Saito [-lo-on Kai ?vlu·
scum. both in Sendai City, and the mate·rials in the Institute of Geology, Facultyof Science. University of Tokyo in Tokyo,
were studied by the writer. The resultsof examination lead the writer to consider that !wgamianus may be classified
into four subspecies.
In this article the \\Titer describes themorphological characteristics of the
kagamianus group. and discusses theirrelationship with related forms.
The
geological significance, so far as can be
judged from the field data, is also given.

Introduction and Acknowledgements

PPc!en lwf.[amianus was first describedby YoiwYAMA from the Kimachi formation at 1\agami. Kimachi·mura. Yatsukagun, Shimanc Prefecture in 1923. Subsequently it was reported by him as
Pecten pennirus and Pecten PPrmims
var. paucicostata from ncar .1\anao, Noto
Peninsula, Ishikawa Prefecture (1926).
Later. the same author (1939) included
Pecten permirus and P. permirus var.
paucicostata in the synonym of Pectrn(Patiuopn·ten ?) lwgamianus YoKOY c\MA,with the statement that it sho\vs considerable variation in the number andsize of the radial ribs. l'viATsuMoTo (1930)
described Pecten p!icicostu!atus as new
to science from the l\ioniwa formationin the environs of Senclai City, but thisspecies was included into the synonymof Pecten !~agmnianus YoKoYAMA by NoMURA (l9AO). These different names sho\Ythat the present species exhibit variablecharacters.

* ReceiYed Feb. 5, 1958: read at 66th meeting of the Society at Akita. June, 15, 1957.
271

Koichiro MAsuoA

272

Acknowledgements are due to Dr. Kotora liATAr of the Department of Geology,
Faculty of Education, Tohoku University.
for his supervision. Thanks are due toProf. Sotoji IMAMURA of !he Geologicaland ivlineralogical Institute. Faculty of
Science, and l\lr. Kazuo 0~-:AllloTo of the
Department of Geology, Faculty of Education. both of the Hiroshima University.
for their kind offer of !he specimens
which they collected from the 1\'Iiocene
deposits in Shimane Prefecture, and also
to l\liss Yoko SuzuKI and Mr. K6ki NrHEI, students of the Faculty of Education, Tohoku University, for their assistance in the collection of some specimens.
Description

Family Pectinidae
Subfamily Pectininae
Genus Patinopec/en DALL. 1898

Patinopecten lwgamimms(YoKOY A~IA). 1923
1923.

Peel ell kagamiaiii/S YOKOYAMA, japan.
jour. Geol. Geogr .. Vol. 2, l'·io. 1. p. H.
pl. 1. figs. la-b.

YoKOYAMA's original description is asfollows: "Shell large. moderately thick.
much compressed (the right ,·alve a little more than the left), orbicular, subequivalve and equilateral. Both valvesradiately ribbed. The ribs on the rightvalve sixteen in number, broad and flatlyrounded, straight. broader than the interspaces and with a varying number of
longitudinal striae on them; the interspaces shallow, usually a little narrower
than the ribs and also longitudinallystriated. The ribs on the left valve
about equal in number to those of theright, straight, rounded. much narrower
than the interspaces and furnished witha fe\\· longitudinal striae which are present also on the latter. Shell margin
coarsely crenate. The ears seem to be
subequal. though the anteriqr is a little
broken.
Length and height 105 mm.
Thickness 25 mm.''
Remarks :-This species is characterized by the large. orbicular. compressed.
subequivalve. equilateral shell. flatlyrounded radial ribs which are broader
than their interspaces and divided intoa varying number of longitudinal ribletson their backs in the right val \'e. andby the left valve having the roundedradial ribs narrower than the interspaces
and diYicled into a few riblets by shallow longitudinal furrows.
The present species has been reported
as Pecten. Patinopecten, and Vola and
HATAI and NisiYAMA (1952) referred it
to Lyropecten. However. the genus Lyrapecten is characterized by having thevalyes with a hump or wave on theumbo and with distinct intercalarythreads in the interspaces, and by thehinge furnished with three distinct. oblique. divergent cardinal crura.
Although the generic position of thisspecies is doubtful. the writer refers it
to the genus Patinopecten with query.
The specimens of the present species
from the yarious mentioned localities
show variable characters, and based upon
several features they can be classified
into four subspecies. They are closely
related with one another. but may be
distinguished in their number and natureof radial ribs. the apical angle and thedepth of valves (Table 1, and figs. 1. 2,
3:'. The distinguished ones are Patinopecten kagamirmus kagamianus (YoKOYAMA).
Pat. lwgamianus moniwaensis !'vlAsuoA. n.
subsp .. Pat. lwgamianus nimaensis .\IAsuDA, n. subsp .. and Pat. lwgamianus permirus (YoKoYAMA). respectively. These
are considered to be geographical orOn the l'vliocenc Pectinidae from the Environs of Scndai

allopatric forms (lVlAYR, 1942).
1~vpe locality, Geological formation andAge:- Kagami. Kimachi-mura, Yatsukagun. Shimane Prefecture. (Lat. 35'25 N..
Long. 13~·58'1-:.) Kimachi formation. Ear-273

ly lVIiocene.
Depository :-1-Iolotype. Geological Institute. Faculty of Science. University ofTokyo.

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l\h:asuremcnts on the selected specimens of tlw kagamiamts group.

A-Kanagase, C)<{awara-machi, Shibata-gun. Miyagi Prefecture.
B-Moniwa, Scndai
City, Miyagi l'n:fccturc. C-Oido. Wakuya-machi. Toda-gun. l\-liyagi Prefecture. llKoganchasama. Wakuya-machi, T6da-gun, IVIiyagi Prefecturt•, E-lwafune. Wakuya·machi. TiHia-gun. Miyagi Prefecture. F-lwaya. Nanao City. Ishikawa PrefL"cture. G-1\okubu, Tokuda-mura. Kashima-gun. Ishikawa Prefecture. H-1-losoguchi. Tukuda·mura, Kashima-gun, Ishikawa Prefecture. 1-Hiuchidani, Higashi-Tsuchida-mura. Kashirna-gun, Ishikawa Prefecture, 1-Akazaki, .1\illla-machi. Nima-gun. Shimanc Prefecture.

274

Koichiro MAsuDA

ffl.fO.
100

,:

o

A
B

0

c

"

D

1950.

~0

Text-tlg. l.

Graph showing the frequencyof radial ribs.

A-PatinojJecten

kagamianus

moniu•aensis

MASUDA, n. subsp. from the l\loniwa formation at Moniwa. Scndai Citr. Miyagi
Prefecture.

B-Pat. kagamianus kagamirmus(YoKOYA·

from the Moniwa formation :ll Ka·
nagasc,Ogawara-m:~"hi, Shibata-gun.
Miyagi Prefecture.

MA)

C-Pat. kagamimms permims (YOKOYAMA)
from the Oiclo formal ion at Iwafune.
and Koganebasama, Wakuya-machi. Tfidagun, Miyagi Prcfcdurc.

D-Pat. kagamianus permirus(YoKOYAMA)

from the Nanao formation at Iwaya, Nanao City. Ishikawa Prefecture.

Patinopecten kagamianus kagamiamts(YOKOYAMA),

1923

Plate 40. figures 4, 5.
1923.

1930.

Pecten lwgamianus YoKOYAMA, japan.
jour. Geol. Geogr., Vol. 2. No. 1. p. 8,
pl. l. figs la-b.
Pecten p/icicostulatus MATSUMOTO. Sci.
Rep., 'Tolzoku Imp. Uniz• .. Ser. 2, Vol.
13, No. 3, p. 105. pl. 40, fig. 15.

1940.

Pee/ell (Pecten) kagamianus YoKoYAMA,NoMURA, Sci. Rep., Tolwku Imp. Univ.,
Ser. 2, Vol. 21, No. 1, p. 16, pl. 2. llg.
15.

Pecten kagamians YoKOYAMA, NoMURA
and ONJSJ, japan. jour. Geo/. Geogr.,Vol. 17, Nos. 3-4. p. 190, pl. 19, fig. 4.

Pecten (Lyropecten) kagamianus YoKO·
YAMA. KUBOTA. Shinseidai·IIO·I\enkyti,
No. 6. p. (.!, pl. 9. tlg. 6:!.

Shell large. moderately thick. compressed, orbicular. equilateral except forauricles: right valve slightly less convex
than the left or nearly equal; both valvesradiately ribbed and forming an angleof about 100, at apex.
Right vah·e with 15 to 18, stout, roundlopped radial ribs and fine concentric
growth lines; radial ribs broader thantheir interspaces, divided into a numberof fine riblets by shallow longitudinalfurrows and rarely dichotomous near
the beak with narrow interspaces: longi·
tudinal riblets on the backs of radialribs appear near upper half of disc andtend to become distinct towards theventral margin; radial ribs at extreme
lateral portions nearly flat, slender andweak: interspaces between the radialribs deep and smooth in the central partof disc. but shallow near the submargins
and with a single or a few weak intercalary threads: anterior auricle sculptured with several radial threads andconcentric lines. furnished with rather
wide and shallow byssal notch. and rath·er narro\v byssal area: posterior auricle
similar to the anterior in sculpture:hinge with wide and shallow resilial pit
provided with distinct lateral ridges,
rather simple cardinal crura, and ill·developed ctenolium in young shell.
Left valve with elevated, round-topped
radial ribs which are narrower thantheir interspaces in breadth and con·centric fine growth lines. ornamented byobtuse network: radial ribs rather sharpnear the beak but tend to become round·
ed towards the ventral margin. anddivided into several, fine riblets by shal·

275

On the l\Iiocene Pectinidae from the Environs of Sc!l!lai

llO

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Graph showing the relationship between the height and depth of shell.

low longitudinal furrows on lower halfof disc; radial ribs near the submargins
nearly flat, weak and slender. and witha single or a few. faint intercalarythreads; lon~itudinal riblets on the backsof radial ribs tend to become distinct
towards I he ventral margin; auricles
sculptured with sF-vera! radial threads
and concentric lines. the anterior one alittle larger than the posterior. Interior
surface of both valves gently folded corresponding to the external sculpture andcoarsely crenated at the ventral margin.
Dimensions :-Shown in Table 1.
Comparison and Affinity:- This species
resembles Patinopecten iwasakiensis (NoMURA) (EI35l which was described from
the Miocene Tanosawa formation at Hotatezawa. Jwasaki·mura, Nishi-Tsugarugun. Aomori l'refecture. but iwasakiensis
can be distinguished from the present
one by the left valve which has theradial ribs gradually increasing towards the ventral margin by divisionand intercalation. no longitudinal riblet
on the backs of radial ribs, and by theright valve which has low radial ribs
carrying two or three longitudinal shal·
low grooves on their tops. l'atinopecten
yamasakii (YoKoYAMA) (19:W) which was
described from the Miocene Shigarami
formation at Shimosoyama, Shigaramimura. Kami-Minochi·gun. Nagano Prefecture. also resembles the present one.
but it possesses a less number of low
and rather fiat radial ribs which show
tri- or bifurcation.
Pecten (C/zlamys) kagamianus miyagiensis described by NAKAMURA (l!J.lO) from
the Miocene Otsutsumi formation at 6tsutsumi. Taiwa-machi, Kurokawa-gun,l\liyagi Prefecture in the northern borderof Sendai is considered to be a synonymy
of Nanaochlamys notoensis (YoKoY A lilA)(HATAI and MAsuuA, 1953).
In "A Note on Pecten lwgamimws YoKoYAMA
IL"-TAI (1938) mentioned thatwhether Pecten sp. of the luzl[amimzus
type reported from the Miocene 1\unnui
formation developed in soutlnvestern
Hokkaido by NAGAo and SAsA (1934) is
identical with 0TuKA's (1936) questionable276

K6i<.:hiro MAsuDA

kagamiamts from the ivliocene Sugota formation at Ukibuta. Higashi-Yuri-mura.
Yuri-gun. Akita Prefecture. or with NoMURA'S (1935) s-hutaii from the Miocene
Tanosavva formation at 1-lotatezawa. Iwasaki-nmra, Nishi-Tsugaru-gun. Aomori
Prefecture. is a question. The writerconsiders that 0TuKA's P. aff. kaJ.;amimms
may be identical with NoMuRA's species.
Furthermore. 1-IATAI has discussed therelationship between lwgamianus and shataii, and has inferred that the rei a! ionexisting between them is an interestingcase of adaptation or lateral localization
produced as a result of migration.
Remarks :-This subspecies is characterized by its large. orbicular, compressed shell with 15 to 18. stout, round-topped
radial ribs bearing a number of close-set
longitudinal riblets on their backs. by
the hinge with rather sirnple cardinal
crura. by the ctenolium in young shells.
by the wide and shallow resilial pit
provided with distinct lateral ridges in
the right valve, and by the left valve
v.'hich is ornamented by elevated radialribs bearing several longitudinal riblelson their backs. and by the interspaces
being wider than the radial ribs andthe obtuse network. The right valve isusually a little less convex than the left
one or sometimes subequal to it, but it
seems that the right v:tl vc is sometimes
a little more convex than the left as
pointed by YoKoYAMA (19:23).
Described specimens :-1\.anagase. C>gawara-machi. Shibata-gun. l'vJiyagi Prefecture. Calcareous sandstone of the 1\loniwa formation. DGS. Reg. No. 3518.
Distrilmtion:-1\.imachi formation in
Shimane Prefecture, Moniwa formationin Miyagi Prefecture. and Nanao formation in Ishikawa Prefecture: all Early
Miocene in age.

PatinojJccleu kagamianus moniwaensis
1\'lASUDA, 11. SUbSp.
Plate H, figures 3, 4. 5, 6a-b.
1929.

1936.

Pecten (I'alinopecten ?) kagamianus Yo
KOYAliiA. Imp. Ceo!. Sun'. japan. Rep.
c\lo. 104. p. 2. pl. 1, tig. 1.
Pee/en (Vola) kagamianus YoKOYAMA,NoMURA and ZINBO. Saito Ifo·Oilf(ai,lfus., Res. Bull .. No. 10. pl. 20. fig. 3.

Shell large, moderately thick. compressed, orbicular. equilateral except forauricles: right Yalve nearly equal to ora little less convex than the left; both
valves radiately ribbed and forming anangle of about 1000 at apex.
Right valve with about 10. rather low.
round-topp<.'d radial ribs. a single or a
few intercalary threads between radialribs near the submargins. and line concentric growth lines: radial ribs muchbroader than their interspaces, and divided into numerous. fine riblets by shallow longitudinal furrows; longitudinal
riblets on the backs of radial ribs variable in strength and number, and first
appear at about half of disc length andtend to become dis! inct tmYards the ven·
I raJ margin: radial ribs at the lateralextremities very low and slender, andwith inlerspaccs variable in breadth:interspaces between the radial ribs shallow and smooth in the central part of
disc: anterior auricle furnished withwide and shallow byssal notch and rathc
er narrow byssal area: posterior auricle
sculptured with several. weak radial
threads and concentric lines: hinge withsimple cardinal crura. and wide andshallow resilial pit provided with lateralridges. and furnished with ill-developed
ctenolium in young shell. Left valve
with stout, elevated, round-topped radialribs and concentric growth lines, andOn the Miocene Pectinidac from the Environs of Scndai

ornamented by obtuse network: radialribs rather sharp near the beak, tend to
become rounded towards the ventral
margin, and divided into a few riblets
by shallow longitudinal furrows on lower
half of disc: interspaces much broader
than radial ribs, rather deep and smooth,and with a single or a few intercalarythreads in the lateral portions of disc:anterior auricle a little larger than theposterior. and sculptured with several
weak radial threads and concentric lim·s.
Interior surface of both valves gently
folded and coarsely crenated at the ventral margin.
Dimensions :-Shown in Table 1.
Comparison and :lfji.nity- Pal inopeclr'll
kagamimzus kagamimws can be distinguished from the present one by having
rather thick sl1ell. more numerous elevated radial ribs with more numerous
and more distinct radial threads on thesurface of auricles than that of IIIOilill'aensis.
This subspecies is related with PatiJzopecten kimurai (YoKoYAMA) (l9~!i) which
was described from the !'vliocene Kametwo formation <IiATAI and NtstYAMA.
1952) in Fukushima Prefecture. but !?imurai is distinguishable from the adultspecimens of the present one by having
more elevated radial ribs. less distinct
and less number of faint longitudinal
riblets on the backs of radial ribs in theright valve. and by the roof-shaped radial ribs which remain undivided in theleft valve. llowever, at times it is difticult to distinguish the young shells of
the present one from llimurai. because
in the young kagamianus monizcaensis
the radial ribs of the right valve lacklongitudinal riblets on the backs of ra·
dial ribs. and the radial ribs of the left
valve show roof-like shape with no riblet
on their backs. Thus the writer considers that the present one and kimurai

277

probably had a common ancester.
Remarks:- This new subspecies ischaracterized by its large, rather thin ,shell. 9 to 13. low. round-topped radial·ribs which are much broader than theirinterspaces and divided into numerous
fine riblets by shallow longitudinal furrows. very slender and low radial ribs atthe lateral portions of disc in the rightvalve, and by the left valve in haYing
elevated radial ribs which are much narrower than their interspaces and divided
into a few, fine riblets by shallow long-i
tudinal furrow~. and a few. fine radial
threads on the surface of auricles.
Type locality. Geological formation and.'lf.,'e :-~loniwa. Senclai City, 1\liyagi Prefl'cture. Lat. :38o13'N .. Long. l-t0',17'E.
l\loniwa formation. Early 1\liocene.
Depository:- Holot ype, DGS. Reg. No.
3!iOG, Paratypes. DGS, Reg. No. :{S07 and
No. 1.!76.
!Jistribution :-1\loniwa formation in l\li·yagi Prefecture, Nanao formation in
Ishikawa Prefecture. and Yanagawa andFutatsugoya formations in Fukushima
Prefecture: all Early Miocene in age.

Pat inopecten lwgamian us nimacnsis!'viAsUt>A, n. subsp.

Plate H, ligures 1. 2.

Shell moderate, moderately thick. higher than long. compressed. equilateral
except for auricles; right Yalve nearly
equal or a little more convex than theleft: both valves radiately ribbed andforming an angle of about 90" at apex.
Right valve with about 11, elevated.
round-topped. smooth radial ribs, andfine concentric growth lines. ornamented
by obtuse network: radial ribs muchbroader than their i nterspaces on upper
half of disc but tend to become subequal
towards the ventral margin, and divided

278

Koichiro 1\IAsunA

into several. fine riblets by shallow longitudinal furrows, and rardy clit:hotomous
near the beak with narrow intcrspaccs;
riblets on the backs of radial ribs on
central part of disc usually appear ncar
the ventral margin, but at the lateral
portions they appear on upper half ofelise: radial ribs at the lateral portionsof disc very low and weak : interspaccs
between the radial ribs rather smooth.
but sometimes with a single or a few.
faint intercalary threads; anterior auricle nearly equal to the posterior one.
sculptured with several radial threads
and concentric lines. and furnished withwide and shallow byssal notch and rat her wide byssal area: posterior one similar to anterior in sculpture. Ldt valve
with elevated radial ribs and weak con·centric growth lines, and ornamented byfine network: radial ribs narrower thantheir interspaces. rather sharp near the
beak. tend to become rounded and broad
towards the ventral margin. and divided
into a few, fine riblets by shallow longi·
tudinal furrows on lower half of elise:radial threads on the backs of radialribs fine and weak. but the middle one
extends to the beak; radial ribs at thelateral portions low and slender: auricles
sculptured with several, fine radial
threads and concentric lines: hinge withsimple cardinal crura. and wide andshallow resi lial pit provided with shal·
low lateral sockets.
Interior surface
gently folded.

Dimensions :-Shown in Table I.
Comparison and Affinity:-- This new
subspecies can be distinguished fro111
kagamianus moniu·acnsis by the sltell being higher than long, small apical angle,
elevated radial rills, ratltcr wide anddeep interspaces. and fine network in
the right valve. Also il can be distinguished from kagamimms kagamianus by
the higher shell. less number of radialribs, and smaller apical angle.
Remarks :-This new subspecies ischaracterized by its higher than long,compressed shell, fine n~twork on thesurface, 11 to 12, round-topped radialribs which are a little broader than ornearly equal to the interspaces inbreadth, and divided into several. fineri blets by shallo\\· lo;-~'5itudinal furrows
ncar the ventral margin on the cent rat
part of disc and on upper half of discat the lateral extremities. and by theleft valve having rather distinct networkon the surface. cle\·ated radial ribs which
arc divided into a few, fine riblets bysltallow longitudinal furrows.

Type fo,:ality. Geological formation and!l..t:c:-Railroad cutting on the San-inLine at i\kazaki. Nima-machi. Nima-gun,Shimane Prefecture. Lat. :15'00'43" N ..
Long. J:t~"24lW'' E.
Kawai formation.
Early l\liocene.
Depository: -llolot ypc, Reg. No. T.Nl\1.
~(i,Geological and 1\lineralogicallnstilute.
Faculty of Science, lliroshima University. Paratype, DGS, l~cg. No. 3580.
Occurrence:- Kawai formation at type
locality and Tachime, Nima-machi. Nimagun, and Tamatsukuri formation at
Ushirobane. l\litoya·machi, Hanseki-gun.
all in Shimane Prefecture.

Patinopecten kagmnimws permims(YOKOYAMA), 1926
Plate .JO, ligures 1a-b, 2, 3.
19~6.

19:.!6.

Pee/ell Pcrmirus YoKOYAMA, ]our. Geol.
Soc. 1'ollyO,. Vol. as, p. 10, pl. 2, fig. 1.
Peden Permirus var. paucicosla/a YoKO·

19:!9.

vAMA. Ibid., p. 10, pl. 2, fig. 2.
Pecten (l'aliuopec/e/1 ?) ka!famianus Yo-

Imp. (;eo!. Surv. ]apa11, Rep.
:Vo. 10-1. p. 2, pl. l, fig. :!, pl. :!, figs.

KoYAMA.

1. :!.

1!:135.

Patinopecten kagamiamts {YoKOYAMA).
0TllKA, Bull. Earthq. Res. bzst., VolOn the Miocene Pectinidae from the Environs of Sendai
13. Pt. -1, p. 8118, pl. !)5, tigs. 138, 14·1.

Shell large, thick, compressed, orbicu·
Jar. equilateral except im· auricles; rightvalve a little less con\'eX or subequal
to lhe left; both valves radiatelv ribbed
and forming an angle of about. lOW at
apex.
Right valve with 21 to 29. stout.
elevated. round-topped radial ribs andfine concentric growth lines: radial ribs
broader than their interspaces. and eli·\·ided into several. line riblets bv shal·
low longitudinal furrows; rib lets. on thebacks of radial ribs usually appear on
upper half of disc. and tend to become
distinct towards the ventral margin;
radial ribs at the lateral extremities verv
weak and slender: interspaces betwee;lthe radial ribs deep and smooth. butshallow near the submargins and some·times with a single or rarely a few,
very weak intercalary threads; anteriorauricle sculplUJed with several. line ra·dial threads and concentric I i nes. andfurnished with rather wide and shallow
byssal notch and rather wide byssal area:
posterior one similar to anterior in sculpture: hinge with conspicuous cardinal
crura, rarely with rather flat hinge plate\vith very faint striae parallel to thehinge line in full adult specimen, deep
and wide rcsilial pit provided with dis·tinct lateral ridges, and ill-developed
ctenolium in young shell. Left valve
with elevated, slender radial ribs andconcentric growth lines. and ornamented
by obtuse network; radial ribs muchnarrower than their interspaces. divided
into a iew, tine riblets by shallow longitudinal furrows on lower half of disc ;radial ribs at lateral extremities verv
weak and slender. and with a single o.ra few. line intercalary threads in theirinterspaces: auricles sculptured with
about ten radial threads and concentriclines, and anterior one somewhat larger

279

than the posterior. Interior surface ofboth \·alves gently folded and coarsely
crenated at the Yentral margin.
Dimen:;;ions :-Shown in Table 1.
Comparison and Affinity:- This sub·species can be distinguished from luz·
gamianus kagamiauus, kagamianus moni·
waensis ancllwgamianus nimaensis by the
thick shell, larger number of radial ribs,
characteristics of radial ribs and auri·cles. and the hinge area.
Remarks:- This subspecies is charac·terized by· its rather thick. compressedshell. 21 to 29, elevated. riJund·toppecl
radial ribs which are diYided into several. fine riblets, conspicuous cardinal
cura. deep and wide resilial pit provid·
ed with distinct lateral ridges, and rather wide byssal area.
l)pe locality. Geological formation and.-'l;,;e:-·fwaya, NanaoCity. Ishikawa Prefecture. Lat. 37'111'03'' N .. Long. 136"57'
0.1·' F. N;Jn:-to formation. Early l\Iiocene.
DepositOJy:- Lectotype. University ofTokyo (YoKoYAMA. 1926, pl. 2, fig. 1. here
designated).
Described specimens: -l waya, Nanao
City. Ishikawa Prefecture. Calcareous
sandstone of i'\anao formation. DGS, Reg.
No. 1888.
Distribution :-Nanao formation in Ishi·
kawa Prefecture and Oido formation inl'vfi yagi Prefecture: both Early Ivliocene
in age.
J\lode of Occurrence andGeological SignificanceThe l'vloniwa formation at Moniwa. Sendai City ..Miyagi Prefecture where abundant specimens of kagamia nus mouhwr'nsis occur. consists of granule conglo·
merate wit I! some rounded pebbles to l:On·
glomera! ic very coarse-grained sandstone
containing also Nanaoch/amys ltoloensis
l YoKoYAMA), Placopecten nomurai J'vlAsu·

280

K6ichir6 1\IASUDA

CryptopecfeH yallagmcaensis {No!\IURA
and ZtNBo). etc .. other pelecypods. gastropods. echinoids. balanids. brachiopods
and bryozoans. Among the pectinid fossi Is. a rather large number of kagamiamts
moniwaensis consist of somewhat waterworn and some \Vith more or less broken
shells, both of which arc arranged parallel with the bedding plane. Thoughsome specimens have their concave side
upwards. or irregular. the majority arearranged with their ronvcx side upwards. Among the pectinids from tl:e:\loniwa formation at l\loniwa. the thinand fragile Placopecten J/01/lll!'lli isabundant. rather well pi·eservcd andoccur as isolated or sometime as intact
valves.
Nanaochlamys notoensis andC1)'jJ!OjJecfen _\'illlagmcaf'l/sis both of which
occur in association with the mentioned
ones occur as isolated valves. but are
better preserved than lwgamianu.~ moniwaensis. From the lield data at 1\t.>n i wa,
it is considered that the shells of kagamianus monizcaensis were transported froma distance greater than the other mentioned species of Pectinidae.
Some specimens of lwJ.[amia11us IIJOitiz!'llensis were cullectecl from the ~ranuleconglomerate to very coarse-grainedsandstone of the l\-Ioniwa formation at
Kita-Akaishi. Sendai City, about 3 km.
west of lVIoniwa. in association withCo•PI oPel en )'111/flgmcaensis, 1'lanaoclzlam_l'S
no/oensis, etc.
They occur as isolated
valves. with the convex sides u pwarcls
or rarely downwards. and are arranged
parallel with the bedding plane. Thesemay have been transported from thesite of living to that of burial.
Several specimens of kagamianus kagamianus were collected from the granuleconglomerate of the 1\iloniwa formation
at 1\.umanodi>. Natori-machi. Nalori-gun.
about 4 km. SE of .Moniwa. in association
with pectinids as Nanaochlamys noloensis,
oA.

Chlamys kumanodoensis l\IAsuoA, Placopecten allilzoensis (MATSUMoTo). etc., otherpelecypods. gastropods,
brachiopods,
corals. echinoids and bryozoan-fragments.
These pectinids occur as isolated valves,
more or less water-worn, and arranged
parallel with the bedding plane with
1he convex sides upwards or very rarely
do\\'11\vards.
Abundant specimens of lwgamianus/?agamiml/ls from the calcareous sandstone of the l\loniwa formation at Kanagase. Ogawara-machi. Shibata-gun, about
18 km. south of lVIoniwa, were found associated with some J>lacoPecten akihoensis,
Nanaoclzlamys notoensis, a few Cryptopec/en yanagmcaensis. and gastropods. brachiopods, balanids. echinoids and bryozoan-fragments. These occur as rather
well preserved isolated or very rarely
intact \·alves. arranged parallel with thebedding plane and with the convex sides
upwards. In the case of specimens with
intact valves, it is considered that they
were probably buried i11 situ. becauseof their nat ural orientation.
From 1he field data. it is probable thatthe shells of kagamianus kagamiamts at
1\umanodo were transported from thesite of living to that of burial, while
those from 1\anagase lived in the environment in which they were buried. orat least they were not carried from aremote place.
From the available data concerning
the !\Ion iwa format ion, it is consideredthat the depositional conditions at :Moniwa and Kita-Akaishi were somewhat
different from those of Kumanod6 andKanagase. as can be judged from therock facies and the associated fauna.
Thus it is evident that Patinopecten ka~,;amianus muniwaensis and Pal. l<agamianus hagamianus are allopatric forms( ~VL-\. YR, 19·12).
The Nanao formation at lwaya. NanaoOn the !'vlioccnc Pf.:<.:tinidae from the Environs of Sendai

City, Ishikawa Prefecture from where
numerous specimens of lwgamianus permints occur. consists of richly calcareous
sandstone containing Nanaochlamys nutoensis. Placopecten akilwensis, Chlamys
ingeniasa (YoKoYAMA'. etc., foraminifers. brachiopods, echinoids. bryozoans,balanids and sponge spicule:>. All specimens of kagamianus pennines so far as
observed occur as isolated valves arranged parallel with the b2dding plane
and with the convex sides upwards.
Some water-worn shells or fragments arc
found in association.
The specimens from th<! calcareous
sandstone of the Nanao formation at
Hosoguchi and Kokubu. about 1.5 km.
south of Iwaya. Tokuda-mura. Kashimagun, include Pafillapecten /urgamianus
permirus and rarely Pat. lwgamianus
moniwaensis. Their mode of occurrence
are quite similar to that of Iwaya.
From the mode of occurrence it is considered that the specimens of the /wgamiamts group from the Nanao formation
were transported from the site of living
to that of burial.
The specimens from the mediumgrained sandstone of the Nanao formation at Hiuchidani, Higashi-Tsuchidamura, 1\.ashima-gun, about 13 km. westof lwava. comprise Patinopeclen lwgamiilllltS lwgamianus, Pat. lwgamianus moniwaensis and Pat. kagamimws permirus.
At that locality. lwr.:amianus moniwaensis
is the dominant species and occurs with
intact or isolated valves. while the others
occur as isolated more or less waterworn valves. These ev idcnccs suggestthat lmgamianus monil(·aensis at I-Iiuchidani lived in the environment in which
it was buried, at least it was not transported from a remote place. while theother species were brought from theirsite of living to that of burial. Lithology and fauna show that the deposition-281

at conditions at Iwaya, I-Iosoguchi andKokubu were different from that at
Hiuchidani.
Several authors (NEWELL. 1948, BuRMA,
l!l-18, SYlvEsTER-BRADLEY, 1951. et al.)maintain that closely related subspecies
arc not found together in the same bedat the same place, FLEMING (1957) statesthat different species of Pecten s. str.
are seldom sympat ric and there is nosuch record in Australasia. However,
SnuTo (1957) has discussed the occurrence of sympatric species of Paplzia
from the i\Iiyazaki group developed inl\liyazaki Prefecture. japan.
In the case of the Nanao formation thewriter considers that the three subspecies are allopatric but not sympatricforms. The reasons for such a view arethat a certain subspecies dominates a
population at a given locality, one subspecies occurs more frequently than theothers when coexisting with two or threesubspecies, and further. evidences oftransportation from the site of living tothat of burial also favors their allopatricnature.
Intact valves of Patinopecten kagamianus pennirus collected from the mediumgrained sandstone of the Oido format ion
at lwafunc. Wakuya-machi, T6da-gun.
l\li~~agi Prefecture. about ,17 km. NNE ofl\loniwa, arc arranged parallel with thebedding plane and with natural orientation, therefore. they were probably
buried in situ. The isolated valves oflwgamianus pennirus from the said locali·ty occur in association with P/acopecten
a/dlzoensis, P/acojJec/en 1mkuyaeusis MAsUDA. other pelecypods. gastropods, brachiopods, and bryozoan- fragments; allare rather well preserved. Thus, thefauna was not transported from a remoteplace. The specimens of kagamianus
pennirus collected from the tuffaceous
conglomeratic to very coarse-grained

282

Koichiro IVIAsunAsandstone of the Oido format ion at Oido
and Koganebasama. \Vakuya-machi. associated with abundant Placopecten allilw·
ensis. Placopecten zrakuyaensis, Clzlamys
kaneltarai (YoKoYAMA). Ch/amys cf. Ita·taii IVIAsllllA and AKuT.m, Nmwoclz/amys
notoensis, etc .. other pelecypods, gastro·
pods, brachiopods. echinoids, balanids
and bryozoan-fragments. occur as isolated valves. The majority of them arewater-worn shells. or sometimes fragments, but they are usually arranged
parallel with the bedding plane and withthe convex sides upwards. Therefore. it
is inferred I hat the Oido and Koganebasama specimens of lwganzianus permirus
may have been transported from else·
where.
Since the associated fauna of the Oido
formation suggests that they are appro·
ximately of the same age as I he l\loniwa
formation, it is considered these afford
further evidence that PatinojJct:/cn hagamianus pamirus of the Oidu formation,
and Pat. lwgamianus lwgamianus andPat. kagamimws moniwaensis arc allopatric forms.
Some intact valves of l'alinopecten
kagamianus nimaensis were collectedirom the very fine-grained sandstone of
the Kawai formation at Akazaki, Nima-machi. Nima-gun, Shimane Prefecture.
Since they do not occur from the sameformat ion as that of Pat. kagamianus
kagamimzus \Vhich is yielded from the
Kimachi formation. it is considered thatkagamimms nimaensis and lwgamiames/wgamirmus are probably allochronic
forms (l\1AYI~. 1D42) in this region. Since
the fossil fauna of the Kawai formation
indicates an Early !vliocene age and may
be correlated with the other mentioned
for mat ions carrying kagamiames kagami·
anus. kagamianus monitcaensis and kaga·
mianus jJcrmirus. it is considered thatthese subspecies are probably geographical or allopatric forms. However. conclusive remarks must be given after
the detailed stratigraphy of the Akazaki
region has been completed.
In general. the lwgamianus group col·lecled from sandstone or calcareous sandstone are usually rat her well preserved,
and some! imes occur with intact valves,
but those from granule conglomerate orconl-{lomeratic sandstone arc rather illpreserved and occur as isolated valves,
and the majority are water-worn or some·times fragmentary.
From the mentioned facts. it is inferreel that the lwgamianus group probably
prefercd a shallow clean sea bottom

Explanation of Plate 40
Figs. Ja-b. Patinopecten kagamiamts permirus (YoKOYAMA), a, Right valve, x3/5. b, Hinge areaof fig. Ia, x l. DGS, Reg. No. 1888. Loc. lwaya. Nanao City, Ishikawa Prefecture. Nan;to formation.
Fig. 2. Patinopecten kagamia11uspermirus (YoKOYAMA). l{ight valve. x2/3. DGS. Reg. No. 3253.
J.oc. Iwafune. Wakuya-machi, Tiida-gun. 1\Tiyagi f'refccture. Oido formal ion.
Fig. 3. Patinopeclen kagamianus permirus (YoKOYAMA). Right valve, xl. DGS, I~cg. No. 3333.
Loc. Oido, Wakuya-madti, Toda-gun, l\·Iiyagi Prefecture. Oido formation.
Fig. ·1. Palinopecten kagamianus kaKtiiiiianus (YoKOYAMA), Right vah·c, ·.: -l/5. DGS. Reg. No.
351S. Loo.:. Kanagase. Ogawara-machi. Shibata-gun, l\liyagi Prefecture. Moniwa forma·tion.
Fig. 5. Palinapecten kagamianus ka)(amianus (YoKOYAMA), Left valve, X4/5. DGS. Reg. No.
35Hl. Loo.:. Same as above.

MAs uDA:

M iocene Pectinidae

K. MAs uDA photo.

P late 40

On the Miocene Pectinidae from the Environs of Sendai

consisting of sand or shelly sand quite
free from muddy materials and inf'luenced by warm thermal conditions.
The geological range of the mentioned subspecies of kagamianus is rcstri·
ccd to Early l\liocene in a two-fold cliYision.
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- - (19·11), On Some Fossils from the Oido
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- - and K. MASUDA (1953). On the Miocene
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- - (1!J56). Some Fossil Pectinidae from the
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- - and N. ZINBO (1936). Additional Fossii
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1 pl.
- - (1!l·IO). Molluscan Fauna of the 1\Ioniwa
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Prefl·cturc. japan. Sci. Rep., Tolwku Imp.
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- - and II. ONISI (1940). Neogene Mollusca
from the Sennan District, Miyagi Pre-

Koichiro MAstJJJA
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Japan. and Correlation of the Lower
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SmJTo, T. (1957). Fossil Paphia from the J\fi.
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Vol. 28. Nos. 1-3, pp. 139-160, I pl. 9
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Sn.vF.STER·BRADLEY. P. C. (1951). The Sub.
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the United States. Jllim. 11!11s. Roy. Ilist.,
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YoKOYAMA, M. (1923). On Some Fossil l\lol·lusca from the Ncogene of Izumo. japan.
jour. Geol. Geogr .. Vol. 2, No. 1, pp. 1!1. 2 pis.
- - (1925). 1\Jolluscan I~emains from the Up·
permost Part of the Joban Coal-Field,
four. Col/. Sci., Imp. Uniz•. Tokyo. Vol.
45, Arl. 5, pp. 1-32. 6 pis.
(1925). Tertiary Mollusca from Shinanoand Echigo. fou·r. Fac. Sci .. Imp. Univ.
Tokyo, Sec. 2, Vol. 1. Pt. 1. pp. 1-23, 7
pis.
(1926). On Some Pliocene Shells from
Kaga and 1\;oto. four. Geo/. Soc. Tokyo,
Vol. 33, No. 3!J I. pp. 9-11, 1 pl.
(1929). Pliocene Shells from ncar Nanao.
Imp. Geol. Sun• .. japa11, Rep. No. JO.J, pp.
1-7, G pls.

Explanation of Plate 41
Fig. I.

Palinopecten kagamiamt!; 11imaeusis MASUDA, n. subsp. Holotypc. Reg. No. T. NM. 26.
Geological and Mineralogical Institute. faculty of Science. Hiroshima University.
Right valve, x7/8. Loc. Akazaki. Nima-machi, Nima-gun, Shim<tne Prefecture. Kawai
formation.
Fig. 2. Putinopecten kagamianus nim01ensis MASUDA, n. subsp.
Paratypc, DGS, Reg. No. 3580.
Left val vc. ;.-: 7jS. Loc. Same as above.
Fig. 3. P.ztinopecten kaJ<amiamts moniuuzensis 1IAstJnA, n. subsp. 1-lolotype, DGS, Reg. No. 3506.
Right Yalvc, X2/3. Loc. lVIoniwa, Sendai City. Miyagi Prefecture. l'vloniwa formation.
Fig. 4. Putiuopel'lcu /;agamianus mouiu•acnsis MASUDA, n. subsp. Paratype, DGS. Reg. No. 1476.
Left val\·..,, ><I. Loc. Same as abo\·c.
Fig. 5. P.ztinojJecteu kagamiauus mmziu·aensis MASUDA, n. subsp. Paratypc, DGS. Reg. No. J.176.
Right valve, , 1. Loc. Same as abo>e.
Figs. 6a-b. Patinofx'den kagamiamts mouiwaensis MASUI>A. n. subsp. Paratype, DGS. Reg. No.
3507. a, Left \'alve. x '2/3. b. Hinge area of Fig. Ga, xI. Loc. Same as above.

MAs uDA:

Miocene Pectinidae

K. MAsuDA photo.

P late 41

Trans Proc. Palaeont. Soc. Japan. N. S., No. 32, pp. ~85-290. pl. 42, No\'. 10, 1958

:3-Hl.

l\lOLLUSCAN FAUNA FROi\'f THE TERTIARY FORMATION OF
CHIRAI. KA.?IHSAROMA. KITA!vTINO-KUNI, HOKKAIDO*WATARU HASIMOTO and SABURO KANNO
Geological and !vlincralogical Institute, Tokyo University of Education:lt&if!:lt~FlHJt,'WU. J11Jl(H.i'io:>:';i'Lc-~;f:!'IEfUtbltf.r::-?t '1:'::1ftff·o:> I A t~*LUUfiJill:ltQ[]I

J:{lr.glll.J, nl*H.iii::J(!i)'i-tt "!> m.::::::>f.tJ. •:.rwt·Ji.l..l!t1 i '!'t..J:tiH., t.:c i:J·--; 1:' 4>:fl!lhH· G Pecten kanehami
t~:lifHt;-~:ttt.: c. cil;zn 'J. :ro)n/tiL:!M!u-+:'1:> t Ul-cl't~oJ-:<. HH'i·l, Ltoc0f;.tft6ltt'i'J;J{.Ht.... u11-", t.t lt'fillf0.lt!!Z'{Il!jf'U.: ~~ i:S :::}:'t1fi U.:fY:Icl ;,:, litlllii i' ~'1i t. .lliyagipedcll 0) 1 ~iHl. :1:5 J: C<Patinopecten 1 ~J!~~fcil\Xt...t.:"
m* TI • t.'!i!f~QB

deye]oped in an adjoining area, thesenior author visited the above mentioned locality**. and he made a collectionof the molluscan fossils including someinteresting scallops described in thisarticle, though he failed to discover"Pecte11 lw11eharai YoKoYA:..IA ".
The writers wish to thank Prof. Kotora IlATAJ of our Institute for his
valuable suggestions. Acknowledgements
arc clue to I'vlessrs. Akitoshi INoMA,
Hisashi Ivl!zuMoTo, and 1-likosuke WATA·
NAnE. students of our Institute. and l'vir.
Rikio YAMADA. a farmer residing in
1he area of the fossil locality. for theirkind assistance in collecting the fossils.

Introduction and Acknowledgements
In 1951. TAKEDA and KITAr.AwA briefly
wrote on the limestone resources in the
Chirai area. Saroma-machi. 1\itaminokuni. Hokkaido. and referred io amarine Tertiary formation yielding suchmolluscan fossils as Pecte11 fumelwmi
YoKoYAMA, Pecten spp., and Cardium sp.
According to this paleontological data.
the senior author correlated this formation with the Kawabata which is developed in Central IIokkaido when hecompiled the geological map of !Iokkaiclo in the scale of 1: 200.000: this was
published from the Geological Surveyof Hokkaido in 1957.
Since then. particularly from the interest of the first report of " Pecten
lwneharai '' from the Okhotsk side of
Hokkaido and also to its stratigraphic
significance in relation with the cold
water fauna of the Tokoro formal ion* Received Feb. ~6. 1958; read Feb. ~. 1958.

** Financed by the Science Research Expenditures Fund of the Ministry of Education

Text-fig. 1. l\laps showing the geographic
position of the fossil locality.
285

286

Wataru l-TAsJ!It<>To and Saburo KANr;oGeology and Fauna
The Tertiary formation in the Chiraiarea is very limited in its development
and unconformably overlies the Saroma
group of so-called Mesozoic age: it clips
very gently to the south.
The lithologic succession of the forrmtion is as foll.ow: the lo\\·est part consists of granule conglomeratic porous
sandstone of reddish brown tinge main!~·due to the cernentin:_~ material of ironoxide: this is superposed with an irregular alternation of brown sandstone andreddish brown conglomerate as a transitional part to the next younl!er massiw
brown sandstone which is in turn conformablv o\·erlain by a bed of yellowish
light grey tuff. The tirst and the last
mentioned beds yield molluscan fossils.
hut the former is superior to the latterin number oi individuals.
The lowesl. the reddish brown conglomeratic sandstone (Loc. I) yielded
abundant individuals of Glycymcris cf.
idensis KANNo, Chlamys tSn·iftopedeJI)
Slcijtii (BERNARDI). "PI'Cft'll'' sp., andil1iyagipecten saromensis I-IAst r.toTo and
KANNo, n. sp.. among which the last
mentioned is the most predominant. The
pelecypods are largely represented byisolated valves arranged horizontallywith the convex surface above. The
shell materials of them are hardly presen-eel. and almost :1!1 are represented
as mou Icis.
The uppermost. yellowish tuii iLoc. 2)
yielded Gfvcymeris d. idf'nsis KA:-<Nn.
Pat inof>eden a ff. lwhiymnai K.'l.!ltAnA.
Crenella tomiyae11sis HAT.-\! and \1.\KA.I\tuRA, Spisula sp .. and Turritel!a s-lutlaii
NoMuRA.
Among the mentioned molluscan fossils. Ch/amys iSw~(topecten) su·iftii (BERNARDI) range,; from Miocene to Recent.
ho,,·ever, the others are limited from mid-die to upper Miocene in japan. The faunataken as a whole apparently represents
a rather warm water assemblage likethat of the .Nanakita formation in illiyagi Prefecture. where G!ycymeris matsumoricnsis J-IAT.~.J and KAKAI\tURA, IHiyagipecten matsumoriensis 1\IAsuoA, Chlamys
kmtehami (YoKoYAMA). Crene!la I omiyaensis I-hTAr ancl NAKAMURA. and Dosinia
lumelwrai YoKOYAMA are characteristic.
lt may be added that PatinoPecten
t:higanouraensis NAKAMURA and Turritellas-lwtaii NoMURA. have been reported
from the Shiogama 1\Iiocene which isconsidered to be a correlative of the
Nanakita. Patinopecfen clziganouraensis
1\AEA!IIURA is allied to P. lwbiyamai KAMADA. though precise comparison of thetwo is difrlcult O\\·ing to the poor pre·senation of the former.
From the abm:e consideration. thewriters conclude that the Chirai fauna
is a correlative of the Nanakita and the
Shiogama.
Therefore, the geologicalage of the Chirai fauna may be considered as middle Miocene. at least, notyounger than the upper 1\Iiocene.
The Chirai formation is distributed in
an isolated srrwll area patched in the
Toyokoro-hitami tectonic zone in broad
sense (1-L~sJMOTo. 19S8J \\·here there isno development oi the typical green tuff
facies. regardless of that it is situatedbet\n.•en the ·· green tuff regions" of the
Okhotsk side of central Hokkaido andthe Inner zone of the Chishima (Kuricl)
geo-tectonic structure.
The yello\\'ish tuff bed of the Chirai
formation with above mentioned faunasuggests that it is a marginal facies of
the ··green tuff iormation" of the Kitami region. Among its fauna Turritella
cf. s-halaii is common to a coal-bearing
formation developed in the .. green tuffarea" in the west of Ikutawara-machi,
west of the Chirai area. (1-IAsrr.toTo andMolluscan Fauna from the Tertiary Formation of Chirai, Kamisaroma
NA,;Ao,1956).

In the east of the Chirai area, there
develops the oil-bearing Neogene Tertiary group which is superposed unconformably on the late r..Iesozoic deposits.
The following geological succession has
been reported: namely, the Tokoro
formation (or the Kurumatomanai) ofclastic sediments is oyerlain by the
Abashiri format ion of pyroclastic nature.
The former was once considered to beof the Oligocene Poronai stage owing
its faunal elements, but recently it iscorrelated with the cold water typedeposits of the Takinoue stage ISAsA and
INoUE, 1939; Sui MALl A and YAsAKI. l9fi7),
and is middle and lower l\Iiocene in age.
The latter is correlated with the Kawabata formation in central Hokkaido.
The cold water type of the Takinoue
stage is represented by the Chikubctsu
fauna which includes se,·eral Poronai
elements, while the soul hern one ischaracterized by the warm water Takinoue fauna which has been correlatedwith the lower Kadonosawa fauna of
Iwate and l'viiyagi Prefectures.
According to FuJIE and Uozu~>n (1957),
the Kawabata fauna (in their revised
meaning) is said to be distinguishable
from the Takinouc fauna in broad sensebeing the younger one, but no description of the faunal assemblage has been
published to date.
Since the Chirai fauna, as alreadystated, is compared with the Nanakita
fauna, it is younger than the Takinouefauna and older l han the Togeshita
fauna of the upper 1liocene Wakkanai
stage (llAsiMOTo, 1950). accordingly it
is considered to be of the Kawabata
stage.
If the foregoing remarks are accepted.
it is possible to consider that thewarmer Kawabata fauna overlaps thecold Chikubetsu fauna in the southern:!87

Kitami region. In this case, the problem
arises as to how was introduced such awarm fauna into 1he Okhotsk region.
Presently we have no information on a
fauna equivalt:'nt with the Chirai fromanywhere in the eastern part of Hokkaido.
Systematic Der.cription
Family Pectinidae
Subfamily Pectininac
Genus Miyagipeclf'll l\lAsunA. 1952
J\Jiyagipecfell saromensis HAs I :-.toTo

and KANNo. n. sp.
Plate 42, Figures 1-5.

Shell moderate in size. orbicular. subequivalve. equilateral. much compressed.
Right vah-e smooth, sculptured with
Yei~Y fine conct:'ntric Jines of growth andindistinct radial threads: auricles subequal in size, sculptured with concentric
growth lines and wide and shallow
byssal notch; interior surface inacccssable. Left valve ornamented with radialstriations and faint concentric growthlines; radial striations numbering about
20, tend to become obsolete on lower
half of disc, and associated with anintercalary between them: intercalaryradials disappear on lower half of discin adult shell, while the main radials
extend to its base, though they are
rather indistinct: radial striations separated bv intcrspaces much broader thantheir \\:idth: auricles subequal. though
the anterior one is slightly larger thanthe posterior, marked with about fiveradial ribs and closely arranged concent ric growl h lines: internal surface
slightly grooved in accordance with thesurface ornamentation. Height. 66mm.:
length. 67 mm.: hinge-length. 25 mm.:depth, ca. G mm.; apical angle. JU5°

288

\Vataru HASIMOTo and Saburo K.~NNO

measured on a plaster-cast of the halotype (right valve).
Comparisoll :-Jlliyagipecten matsumoriensis MAsunA, 1952 (~lAstmA, 1952. pp.
252-253, pl. 24. figs. 4-7), is allied thepresent new species. but the former
differs from the latter by having alarger apical angle. closely arranged
and larger number of radial ribs, andfainter radial threads on the lower halfof the shell of the leit valve. and fur·ther. the interspaces between the radial
threads in the former are narrower thanin the latter. The surface of the rightvalve of 1\IAsunA'S species is ornamented
with closely arranged concentric growthlines while in the present new species
they are hardly developed.
Remarl?s:-The distinction between
the genus Miyagipecfen and Placopecten
has been discussed by 1\IAsuoA (1952, pp.
251-252). The present new species some·what resembles Placopecfen allilwensis(IVL~T5UMOTO), (MASUDA, 1952. pp. 2:-i0-251,
pl. 24, fig. lll3l. in possession of radial
threads on the right valve. though they
are hardly developed, and the radial
threads on the left which are weakly
developed marginally.
However, thepresent specimens are referred to thegenus Miyagipecteu because the surface
sculpture of the right a!ld left valves
are clifferent.
Locality and Geological Formal ion:~
Loc. 1, a road side cutting at the entrance of the Jyltroku-go valley, Chirai.
Saroma-machi, Tokoro-gun. Hok ka iclo.
The Chirai formation, Upper i'vlioccnc
in a two hold division.
Repository :-Geological and lVIineralogical Institute. Tokyo UniYersity of
Education, Reg. Nos. 6195 (holotYpe).
6196 (paratype).

Patinopecten aff. kobiyamai
KA MADA. 195"1
Plate -1~. Figures 8-9.

Remarks :-An incomplete right andleft \'alves were examined. Though thepresent specimens resemble 1\AMAD.••.'s
type species in the general features.
some differences exist bet ween them.
Namely. the shapes of the ribs areclosely similar. especially in that minor
striations are developed in the interspaces of the .radial ribs in the marginal
part of the left vah·e, however. thenumber of radial ribs of the writers'
specimens exceed those of the type:-;pecies: there are more than nine radials
in the left and right vaJyes whereas
there are only five or six radials on thetype specimen. Considering the numberof radial ribs, the present specimens
seem to be a species different from
KAMADA's. and from general morphology,
a descendant of that species. The present specimens resemble Patiuopecten
kimurai (YOI<OYAMA), (YoKOYAMA, 1925, p.
27. pl. 4. figs. 1-6), but the former differs from the latter by having narrow
radial ribs and more flattened shell of
the left valve. Therefore, the present
specimens may represent a new form.
but the state of preservation does ~Cotpermit establishing a new name.
Repository :-Geological and .to.·lineralogical Institute. Tokyo University of
Education. Reg. No. 6~00.

References
FUJIIc, T. and S. CoZUl\11 (1951). Remarks of
the Cenozoic Fossils (in Japanese). Shillsddai uo Kenkyu (Cenozoic Research). no.
23. pp. 3~-37.
Geoiogical Sunl'Y of Ilokkaido. (1957). Geo-

Molluscan Fauna from the Tertiary Formation of Chirai. Kamisarorna
logical !\lap (Jf llokkaido in the scale of
1 : 200. OOIJ (part 5).
fL'I.NZAWA. S .. K. IL>\TAI et al. (1953). Geo·logy of Sendai and its Ell\·irons. Sci. Rep ..
Tohoku Unir .. ser. 2, rol. 25. pp. 1-50,
with 2 maps.
HASIMOTO, \V. (1%0). The Geolog~· of the:\l:trginal Part of the Kabato J\lassif (inJapanese). Bull. Geol. Comm. Flokkairlo,
110. 13. pp. 1-7.
- - (1958). Considt-ration on the GeologicalHistory of the Yczo·Saghalien Geosyndi·
nal :\rca (in Japanese). ]ub. Pub!. Cm11111 ..

l'rnf. H. fvJr~roTo's Sixtieth Birthrl. pp.
101-112.
--and S. NA.cAo (1956). The Oil-Indication
and !\at ural Gass from l\lonlwtsu·gu n,
Kitamino-lwni. Hokkaitlo (in japanese).
]our. japan. Assoc. Pelr. Tech.. rol. 21. no.
3. pp. 102-\0:i.
KA~IADA. Y. (19:i·l). Patinopecten kobiyamai, a~ew i\Iioccnc Scalop from the Johan
CoaJ.Field, japan. Trans. Prnc. l'alaMnl.
Soc. japan. N.S., 110. 15. pp. 173-l'i.S. pl.
23.
KuBOTA.. K. (\!150). A New Species of !'l·clen(P/acopecten)
fromthe :\eogc·nc: ofSouthwesh:rn llokkaido. japan. ;1/in. andGeol.. ro/. 3, no. 5. pp. 183-185. pl. 7. figs.
1-1.
11ANSFIELD. W. C. (1936). Stratigraphic ~igni·.
ti<ance nf 1\liocenc Pliocene and l'lcisto·
n:nc Pectinidac in the Southeastern
United Stall·~. jour. Pal., l!o!. 10 .. pp. 186-187. pl. ~~. ligs. l ~3.
1\L\.SUDA. K. (1!152). On Some Miocene Pee·tinidae from the Em·irons of Sendai.
Trans. Proc. Ptrlaeont. Soc. japan. N. S ..
no. 8. pp. ~·19-25~. pl. 24.
- - (1957). A Note on Miyagipr.ctrn ma/sumoriellsis MASL' PA. Saito Ho·on 1\ai ·Mus.,

289

Res. /Jull., no. 26. pp. 31-39. pl. -1.
MATSUMOTO, II. (19:{0), On the Marine
Faunae of Three Fossil Zones of theUpper 1\liocene of Xatori District. Pro·
vincc of l~ikuzcn. Sci. Rep .. Tohoku Imp.
Unit• .. st·r. 2. l'ol. 13. no. 3. p. 106, pl. 40,
figs. 'i-S.
NAKAMURA. 1\1. (1940). On Some l'cdinidac
Fossils from the l\lioccne Deposits of
the Tomip Block. l\liyagi·kcn. North·e:~st Honshu. japan. fapall. ]our. Geof.
Geogr .. ro/. 17. 11os. 1-2. pp. 1-15. pis. 1-2.
KoMURA. S. (1935). Miocene :\lolluscs from
Siogama. 1\ortheast Honshu. Japan. Saito
Ho·on 1\ai Mus .. Res. Bull .. no. (j, pp. \93-231. pis. IG-17.
- - (1940). l\Iolluscan Fauna of the 1\loniwa
Shell 1\cds Exposed along till' Natori·
gawa in the Vicinity of Scndai. Miyagi
Prefecture. Japan. Sci. Rep .. Tolwku Imp.
l.,'llil' .. SCI'. 2, 1'0/. 21. 110. J. pl. 1, figs. 2, 3:
pl. 2. tig . .J.
SAsA., Y. and T. INOUE (1939). The Strati·
graphy of the Tertiary Formations on
the Environs of i\bashiri. llokkaidn (inJaparwsc). jour. ]aj>rm. :lssoc. 1'1'/r. Tech ..
rol. 7. no. 6, pp. 1-11.
SmMADA. T. and K. YAZAKI (I 956). The
Report of the Geological Sur\'cY on theEnvirons of Abashiri·city. Holtkaido (in..JapancSL'). ]our. japan ..-lssoc. Pl'lr. Tech.,
1'01. 22. 1/tl. ], pp. 26-3:!.
TAimDA. '\'. :ntd Y. KITAKA\I'A (l!l51), On. the. Liml'slone Developed in the Envi•rons of Chirai. Sai·oma·mttra. Kitamino·kuni. Ilnkkaido (in japanese). Rep. Geo/.
Sun•. f/okkaido, no. 6. pp. 1~-lli.
YoKOYAMA. l\1. (1925). ?vlolluscan Remains
from I he Uppermost Part of the jo-Ban
Coai-Fi~ld.
]our.· Coli. Sci .. Imp. Unit•.
Tol..')lo. vo/. ·16, art. 5. pp. 1-31.

2!:10

Wataru HASIMOTo and Saburo KANNO

Explanation of Plate 42
Figs. 1-5: Miyagipecten saromensis HASIMOTO and KANNO, n. sp.
1. Right valve of a plaster·cast of the holotype. Reg. No. 6195.
2-5. Left valves of a plaster·cast of the paratype. Reg. No. 6196.
Fig. 6: Crenella tomiyaensis IIATAt and NAKAMURA. Reg. No. 6199.
Figs. 7a-b: Spisula sp. indet. Reg. No. 6201.
Figs. 8-9: Pati11oj>eclen aff. kobiyamai KAMAPA
8. Right valve. Reg. No. 6200.
9. Plaster·cast of a left valve, showing the external sculpture.
Figs. 10-11: Glycymeris cf. idensis KANNo
10. Plaster·cast of a right valve.
11. Inner mould of a right valve. showing the taxodont teeth, Reg, No. 6l!l8.
All figures in natural size

liA si Mo To & KANNo :S. .t\oKI photo.

Mol luscan Fauna from liokkaido

Plate 4~

Trans. Proc. Palaeont. Soc. Japan, N. S .. No. 32, pp. 291-298, pl. 43, Nov. 10, 1958

350.

LATE TRIASSIC PALAEOPHARUS IN JAPAN*
AKIRA TOKUY AMA
Geological Institute, University of Tokyo*1llr$.=:!ll;'f-O) Palaeopharus: til!¥ • P:l$h~iil~IC:.J: f), i::. O)~:IJ: Cardiniidae 11:.1/.ill,.,,preheterodont (:heterodont >ei.'lll'f;tt:t;..~fifllJ~L'<b.O*:bi'f!i)I~JL-t.:O)"l.\ L.O)fl.ll;t'IC:.ffriillW .Minepharus (: jtK~j!J;t/tfl7iO)C:f.l\ >elli..!lt~ f...,, i'o'U3t.i¥1f~tj-:(l'~~.lll!:b•.; ffr,~'l pseudocardinal teeth >e~M t.,t.:" ~i!lii;1Hilf-¥1C~'M:fr~I<:.JiH fJ.JJll]O) Carcliniidae 0--~L'ib .0" JUPJ(l-J'r .fr¥1CJ: ~~On 0 tt 'Ll't.: "Pleuroplwrus" oblongatus !i;kj~;@O)f!~:;$:1C:.J: f) Palaeopharus 11:.1/.i!T .0 '}I:IJ:!f.lj-:> t.:o
~

Ill

00

ported from Maritime Province ofSiberia. may be a subspecies of oblongatus.
3. ,lfineplwrus triadicus ToKUY AMA represents a new subgenus. linking the soca lied Triassic Pleurophorus (\'l AAGEN'S
sense. 1907) with Palileopharus.

Palaeoplrarus KITTL is an importantmember of the Upper Triassic faunas ofJapan, e. g. the Kochigatani fauna at
Sakawa and Sakuradani, the Nabae atHeki. Nabae and Kyowa and the l'vline
at Mine. It is often accompanied by
JV!inetrigortia and "Bakevellia," and indicates the shallow water facies of an embayment, inland or open-sea. KoBAYASHI
and IcHIKAWA (1951) were the first tofind this genus in japan at Nabae andHeki. Subsequently another 2 species
and 2 varieties were added from Heki
by KoBAYASHI and·fcmKAwA (1952), from
Nabae by NAKAzAwA (1955) and from
Kyowa by NAKA!'lo (19571.
Here thewriter describes the following tllree
forms from the l'vline series:
1. obfongatus (KOBAYASHI and IcJIIKAWA)
which is widely known from Sakawa(KoBAYASHI and ICHIKAWA, 1950), Sakuradani (ICHIKAWA, 1954) and Mine
(KATAYAMA, 1939),- and was referredto Pleurophoms, but the Mine form
proves its being a Palaeopharus.
2. buriji KIPARISOVA (1954) which was re-

Table 1.

Palaeopltarus in Japan.
Area

Palaeoplwrus
oblrmgatus (KOBAYASHI &*••lclliKAWA)
oblongatus buriji KIPARISOVA * - - - - maizuruensis KonA v ASH! &- ***ICHIKAWAmaizuruensis n. subsp. by-*
NAKAZAWAmaizuruensis var. inwmurai- -*NAKANO
11wizuruensis var. flexicoslalus- - *NAKANO
paucicostatus NAKAZAWA-*(Mi11epharus) triadicus ToK~- '*YAMA, n. sp.

* Received March 22, 1958; read at the67th Meeting of Palaeontogical Society ofjapan, April 26, 1958 at Niigata.

See the Table for Palaeophams inJapan. On this occasion the develop291

292

Akira ToKUYAMA

ment of the "pseudocardinal" teeth in
the Triassic "schizodont" pelecypods isalso discussed.
The writer is greatly indebted lo Professor T. KoBAYAsm for his kind. guidance and encouragement.
Hinge De,·elopment in the Triassic"Schizodonts ''The hinge apparati of the Triassic
Schizodonts can be· classified into thefollowing groups:.1. True $chiwdonts or :llyop/wria group
including Trigo11odus. Pachycardia. lfeminajas, Myop!wria and illilwlri),;ollia.
2. Prc-llcterodonts
2A. "Pleuroplwrus "*group
including"1'/eump!wrus" and Cardinioides.
2n. Cardinia group including Pa/aeopha·rus. Jsoprisles and Cardinia.

R

3o 3b

••

Myophoria

4~ 2'

L

1•41
3

P.!.J..!!I)"Pteurophorus "

l~>

Alii

All
A!.J.!!_I)

i

)~~t

-•
All

3

\ z;;;>
2

Pll.!t!!.llp

Palaeopharus
Pll
P.!J.!!.I)

Cardinia
Pll

Text-figure 1. Hinge arrangement of prehdcrodonts and schizodonts.

* As Cox pointed out (MARWICiz, 1953).
the generic name. Pleurophorus K!NG (184-1).
is preoccupied by 1'/europ/wrus. MuLsANT(18-12). a scarab _Coreoptera (S<;HUI{T7.E,
KOCKENTHAL und IlEIDER, 1935).
CHAVA."i195,1) proposed Permophorus for its substitu·
te, but it is open to question whether Pe/'1110·
p/torus is valid or not, because Pleurop!wrella
GmTY (190-1) or Pleurop!wrina I.rcnAREW(1925) may be its synonym (NEWELL. 19-10.
1957). For the time being the writer uses
" Pleurophorus" for the pelecypod genus inquestion.

The tirst group is the true schizodont
in which Oil(! triangular media•1 tooth~ exists ·on · lhe · left vaiYe. andthedental arr:1ngement is as shown in fig.
1. In -the second group. the triangular
median tooth is seen on each ntlve (3and ~; awl tooth :~a becomes obsolete.
According to CHAVAN !1954. in NEwELL,
1957) the hinge formula of "Permopi/Oms" is :2, (•Jb:. PIJ-(:)a;, 3b. PUl. but
NEwELL CO\lld not confirm the existenceof the tooth 3a in the Ame1:ican "Permop/wrus ". As shown in the above formula. posterior lateral teeth are de\·elopAnother Permian
ed in this group.
genus Ce!toiclcs KEWELL (19:17) has 2. (Jb).
Pll in the left and 3b. (['II. PIII in theright yalve. Triassic .Cardinioides KonA.YASHL and lclllKAWA ~}95:2; has the samekind of hinge, although jts cardinal ih a
pseudocardinal. In the third group the
tooth ~a become.s obsolete and"' is separated from the nymph in some forms;
laterals arc developed in the anterior -as
well as in the posterior -J~art. althoughanterior laterals are insignificant insome pri rn iti ve forms. The so-called
pseudocarclinals are often seen in thethree groups. In the first group the
tooth ~ (or ~b) is crenulate as in
Trigonodus and Pac/Jycardia .. The Unionidae belong to this group in vvhich theposition of pseudocardinals is variable.
In the 2A group the left cardinal tooth
takes the aspect of the pseudocardinal
as in Cardinioides. In the 2B group it
is not a cardinal but a lateral tooth.
KonAYASIII and lciiiKAWA (1951) emphasized the resembl:cutce·of the pseudocardinal tooth between Unio and Ptilaeopharus. but the resemblance may be superficial. because the pseudorardinal inunionicls is really a kind of cardinal
tooth. while in Pa/aeoplwrus it is generated from an anterior lateral tooth. The
writer thinks that the presence orLate Triassic Pah'!'•.•Pharus in Japanabsence of a " pscudocardinal tooth " isnot so essential for the pelecypod classification as I hey arc evaluated. Palaeo·plzams should be separated from Uuiogroup which is perhaps a descendant of
the Myoplwria group. The three groups
are all closely allied in the muscle scars
and ligament characters. although theirhinge apparati are different genetically.
The oldest is the Myoplzoria group fromwhich the "Pleuroplwrus" group waspresumably derived in the Carboniferous; subsequently the Cardinia groupfrom the second group in the late
Triassic period and attained its acme in
the Jurassic. This is the link between
the " pre-heterodunts " and I he true
heterodonts which the latter t1ourishedin the late l\1esozoic and Cenozoic. lt isinteresting to see a transitional form
between the "1'/europlwrus" and Cardinia
groups in the !\line collection'>; 1llincplw·
rus. new su bgcnus. may be the mostprimitive and earliest member of the
Cardinia group.
ne~criptionof Species

Su perfami I y Cardiniacea
Family Cardiniidae ZrTTEL
Genus Palacup/wrus Kr-rTL. emend.
KonAYASllt and lcmKAWA
l!!Oi:

Pal<u•opharus KrTTL, Rep/. Nonceigian
Arctic H.rp..•dilion, 1898-1902, no. 7.
p. 3-1.

P/eurofJ/wrus, BonM ]b. K. K. Preuss.
G. L-.rl.. 1/d. 35, S. 556.
1931 : l'.Jiaeop!rams KollAY AS Ill and lcmKAWA. Tr. l'roc. Pal. Soc. Japan, N. S., 110.
], p. 7.

191-1:

Diagnosis: ·Shell elongated to subelliptical; umbo prosogyrous, located atanterior a fourth or so: lunule distinct,
striated by growth lines; ligament

293

opisthodetic. external and supported bywell defined nymphs in anterior half ofshell: area fairly large, elongated andstria ted transversely by growth lines.
Anterior addctor scar stout. sl rongly
impressed; posterior one lar~er and lessdistinct; pedal retractor scar very deep,
just behind anterior adductor scar. One
cardinal tooth t:~b) on right valve andtwo 1~b and -lbl on the left: one posterior lateral tooth on each valve strong
and massive.
Anterior lateral toothwide and its groove finely crenulate andpseudocardinal-like. Ornanwnt variable:
test smooth or concentrically striatedand often radially costate.
Remarks:- Bt)HM (1914. S. !i!ili) consider·
ed andersoni to be a Pleuroplwms but
andersoni as well as japanese species ofPa!aeop/zarus are separable from "Pie·urophorus" KrNG in the generic rank
as KoBAYAsHI and IcumAwApointed out.
They laid stress on the pscudocarclinal
tooth in this genus. In the typicalmaizuruensis from Nabac and lleki. it
looks like a cardinal tooth and similar
to a pseudocardinal in Unio. NAKAZAWA(1955) noticed extensive variation in its
shape and called it a "pscudocardinal
area " which does not mean a tooth.
because the area in each valve does notinterlock each other. In the Kyowa
specimen. tNAKANo. 1957. pl. !1. fig. Ill.
the .. pseudocardinal " tooth is elongatedand parallel to the inner margin of alunule and crenulation seen on groove
which separated the tooth or a "lateral"from the margin. In Mineplwrus, newsubgenus. the lateral tooth is primitiveand separated from the margin by ashallow groove which is non-crenulate.
The Mine and K.yowa specimens suggestthat the so-called pseudocardinal toothin Palaeopharus is merely a variant
from the primitive lateral tooth. On
the other hand U11iu bears the hinge

294

Akira ToKUYAMA

apparati of Myophoria-type. Its pseudocardinal is a kind of cardinal tooth andthe crcnulatc tooth on the right valve
interlocks with the crenulate socket on
the left valve. Therefore. so far as the"pseudocardinal " is concerned, Palaeopharus is essentially different from Unioand the resemblances are superficial.
According to NEwi·:LL (1957) Permian'' Pleuroplwrus"
has thefollowing
characters*:
Lunule and escutcheon well develnped.
ligament opisthodetic and parivincu lar,supported by well defined nymphs which
are limited lo the anterior one-fourthof the dorsal margin: dentiton consisting usually of one postero-lateral tooth(Pili) in the right valve along the shell
margin which passes over a single
lateral (PII) of the left valve: one
cardinal tooth in each valve. that of theright (3b} passing abO\'e that of the left(2): rarely. there is an addilinnal poorly
developed. inner postero-lateral tooth(PI) and an outer cardinal (4b) in left
valve of a few individuals.
This agrees with Permian ·· Pleurophorus" in the characters of lunule,escutcheon, ligament, nymph and hinge
arrangement. but the teeth 2 and ·Ia
and nymph are more developed in thisthan in that genus. The tooth 2 isvery small and elongated in this, while
it is a triangular boss of moderate sizein "1'/europ/wrus ". Furthermore, um-.
bones are pointed a little more posteriorly in it than in "Pl!'uroplwrus ". Triaplzorus l'vL~RWICK (Hl5:~) from the Upper
Triassic of New Zealand agrees withthis in cardinal teeth. nymph and posterior lateral tooth, but an invaluabledistinction is the absence of the "Pseudocardinal" in MARw 1cK'S. The hinge
apparat i of the Upper Triassic "Pleurop/wrus" curionii BITTNER disagree withthose of Palaeozoic "Pleurop/wrus" s.
str. (BiiHM, 1914). BtTTNr:R's may becongeneric wit l1 MARW tcK's. Jurassic
1\alentera !\IARwtcK (1953) is also a
relative of Triaphoms. 1\.a/en/em appears to be related to Myoconcha rather
than Palaeoplwrus. After all. Cardinia
AGAssiz may be the closest ally to
Pa!aeoplzarus, although AGAssiz's isdistinguishable from this by its surface
ornament and anterior lateral tooth.
The two genera are so closely related
in interior and ligament characters thatthey belong to the same family. l'vlore
precisely. they have similar arrangement and shapes of cardinal. posterior
lateral Ieeth and equally large andelongated ligament area. Moreover. in
Minepharus, a new subgenus of Palaeop!wms, the anterior lateral groove is not
crenulate and the lateral is thoughsmalL similar to the one in Cardinia.
The strong muscular impressions andentire pallial line are the features common between the two genera. Therefore.
l'alaenpltarus 111 ust be referred to the
Cardiniidae.

* KING (1850) illustrated two prominent
cardinal teeth in each valve and a marginal
lateral tooth in the left valve. but BoHM
(1914) and NEWELL (19·10) pointed out hiserroneous observation. Its dental formuln is2, (4b), PII- (3a), 3b, Pill according to
CHAVAN (1954).

1!l39:

PalaeojJharus oblongat us (KonAY ASHI
and lcHIKAW A)
Plate ·13, figures 8-11.
Pleurophorus cfr. Perlo11gatus BoHM II}'KATAYAMA. f. Geo/. Soc. Japan, t•o/.
-J{j, p. 381 (listed).

Ple!lroplwrus oblongatus KoBAYASHI
and lcHJF;AWA, ]. Fac. Sci. Unit•. Tokyo,
set. 2, mi. 7, p. 212, pl. 1, fig. 10.
1954: Plettroplwrus cfr. oblongatu;; ICIIIKAWA•
19511:

Late Triassic Palaeopharus in Japan]. lnst. Polytech. Osaka City Unit•.. t•ol.
], 110.

1. p. '10.

DescrijJtion :-Shell three to four times
as long as high: umbo subterminal.
anterodorsal margin almost straight:
anterior part roundly trigonal : dorsal
and ventral margin~ almo~t straight andparallel in median part: posterior
margin more gradually rounded thananterior. Lunule small and triangular:
ligament opisthodetic, external: lig<..ment area elongated. and striated transversely by growth lines. Anterior
adductor scar ovate, strongly impressed:
posterior one subrounded. large and lessdistinct than anterior one: p~dal retractor scar small and pitted. just behindanterior adductor. Pallial I inc entire.
Left hinge consists of a cardinal (3b).
"pseudocardinal" and posterior lateral
tooth: 3b \\·elded to an elongated nymph.
Right hinge consists of a triangularcardinal tooth (2) and a socket just posterior to 2. "Pseudocardinal" wide. andcorresponding to one on the left valve,
but they are not interlocked with eachother: they are so to speak "cardinalareas". Surface ornamented with conC<!ntric lines of growth: radial markings
weak and found on posterior area. if
present.
11feasurement in 111111.

LengthHeightLeft valve
Right internal mould
Immature shell

70. 5
4-1. 5

20. ,j

34. 5

10. 8

HJ. ;{

Obsen•ation:- Due to the secondary
erosion no pseudocardinal is preservedin the Kochigatani specimens. /\.." pseudocardinal" tooth is, however. well developed and resembles Unio's superficially. but they are genetically quite different.
In some specimens no radial
marking is present. but others have 34 very weak angular and widely spaced295

ribs. The latter may be no more thanvarietal forms. The anterior portion isa little acuter in the !\line form thanin the typical Kochigatani form.
Comparison:- The !\line form is indistinguishable from the typical form if
the pseudocardinal is not preserved.
because the two forms are similar in
the outline. muscular scars. pallial line,
ligament features and in the hinge
apparati. especially in the anterior hingearea. They arc almost identical in thegeneral outline and surface ornaments.
The preservation of the typical form incoarse sandstone suggests that the"pseudocardinal" is eroded out in theholotype. Therefore the writer thinksthat "Plem·op!wrus '' oblongatus should
be referred to Palaeop/rarus. Carnic
Pa/aeopharus buriji KJPARJsovA from
:Maritime province of Far East may bewnspecific with this. According to her(1954, p. H) the surface is feebly marked
by radial striae. Faint radial striae andpseuclocardinals are sometimes recognizable also in this species. That form
differs from this in the more anteriorly
pointed umbo and more inflated posterior
outline. but the difference may be within
the limits of a species. The range ofvariation is often very large in suchshallow water or brackish water molluscs. From maizuruensis and andersoni
it is easily distinguishable by the absenceof distinct costae.
Occurrence:- 1\..bundant in the whole
1-Iirabara stage of the Mine series atlvlugikawa. Shiraiwa.
Hirabarazaka.
Hirabara, Okubata. Sugiwara and northof Shirogawara. Rare in the Aso stage
at Sonose. Ecologically the shell ismost common in the transitional zone
from bituminous embayment to the opensea facies. Sometimes it forms shellhanks with "Bakevellia" and .l\1inetrigonia.
This species inclusive of the Kochiga-

Akira ToKUYAMA

296

tani and Siberian forms is \'cry widelydistributed in northeastern Asia in the
Carnic age.
Pa!aeop!wrus ob!ougatns buriji
K!l'ARISOYA

Plate 43. figure 1::!.
1951:

Palaeopflarus buriji

KlPARISOVA,

Field

illustrated hand booh etc .. p. -!4, pl. 34,
figs. 5. 6.

Characterized by very weak pseudoradial striae in postero-dorsal area. The
striae are widel~· spaced. angulated on
the top and crossed by concentriclines of growth. The posterior outline isslightly more inflated in Siberian (KIPARI·
sov A. tlg. 5) than the common 1\Jineform. Hinge norm:d for Palaeop/unus.
Occurrence :-Common in sandstone of
the upper I-lirabara formation and middle !\so formation (mid.- up. Carnic)
and upper Carnic of Maritime Provinceof Siberia (T; of KIPARrsovA).
Subgenus J11im•pharus ToKt:YAr.-tA.
new subgenus
T_lj'Je species:- Palaeopltams (:11inrplw·
nts) triadicus ToKUYA:l.IA. ne,,· subgenus
and species.
Diagnosis:-Shell elongated. elliptical.
a little compressed. :1t1d slightly tapering anteriorly; umbo prosogyrous. at afourth from anterior extremitv; ligament opisthodetic. subinternal: ligamentarea triangular and depressed; I unule
small but distinct. Internally. anterior
adductor scar very strong; posterior one
subcircular. larger and less distinct thananterior; pedal retractor scar small.
prominent. Pallial line entire. Hinge
consists of a right and two left cardi·
nals, and a lateral tooth in anterior andposterior. Tooth 2b not clearly separa·ted from margin of lunule; 4b elongated.
slender and welded to a depressed triangular nymph; a socket 3b' deep. fairly
short. Socket PI' profound and remarkable. Pill less distinct than PI. A narrowfurrow divides anterior lateral (Alii).
Ornament consists of stout pseudo-radial
costae and concentric lines of growth.
Remar!?s :-In this subgenus the anterior cardinal 2b. is not so remarkable
as ·· Pfeurop!toms" in which. according
to Bt>HM and NEWELL 2b is stout andtriangular: posterior cardinal 4b slenderhut distinct in this subgenus. while in
Permian .. Pleuroplzoms" it is not separated from the nymph. WAAGEN (1907),
however. described 2b. 4b and 3a of"P." wrionii from Seiser Alm. Thereiore. except for its rudimentary anterior
lateral. it agrees with Triassic ·· P!euro·
plwrus ··. This rudimentary lateral iscleYeloped into a pseudocardinal of
Palacoj>lwrus. Therefore the presenceof the anterior lateral groove is an
important distinction of Palaeoplzants
from "P/europhorus ": the groove iscrenulatc in Pa/aeoplzarus (s. str.). but
non-crenulate in lllilleplzants. If it iscrcnulale. there is no distinction of thissubgenus from the typical Palaeopllarus.
The writer opines that "pseudocardinal"of Pa!acoplwrus is derived from thelateral tooth ontogenetically. This subgenus is closely related to Cardinia inthe musculature and hinge, although
the anterior lateral is a little weakerin the former than the latter. They
agree with each other in the arrangementof cardinal teeth, elongate-trigonal nymph
and massive lateral teeth. general feature of hinge area, prominentopisthodetic
and external ligament. stout muscular
impression and pallial line. Thus .. Pleurophoridae" are linked with the Cardiniidac by this subgenus.
Cardinia is said to be related toLate Triassic Palaeopharus in Japan

Trigonodus (W AAGEN, 19117). but its hinge
is ncit her of Trigonodus- nor Jl!yoplioriatvpc. and agrees with that of l'alal'op/zarus. especially this subgenus. Therefore Minep/zarus is a primitive form of
the Carcliniiclae.
."ipecies:-P. (Minepharus) triadicus.
monotypic.
Distribution :-Carnic: Japan.

Palaeophams i MincP/wrus: triadic us
ToKUYAMA. new subgenus andnew species
Plate 43. ligures 1-'i': rcxt-ligure ~-Description:-- Shell moderate in size.
but small for Palaeop!tams. elongated.
elliptical. a little compressed and slightly taperin.~ anteriorly: umbo prosogyrous. at a fourth from ant:.>rior extremity:
hinge lirie a little longer than a half ofshell: ligament opisthodetic. external:
ligament area wide. distinct. locatedrJear middle and transversely striatedText-figure ::!.

Palaeoplmrus (.lfinepllarus)
I riadicus.

by growth lines. Lunule small· but
distinct.
Hinge and other interior
characters of Mineplwrus. Surface covered \vith several stout and rounded pset d)radial costae on dorsal side. They begin
in the earliest stage and becon1e stout
and widely spac~d. GrO\Yth striae fairly
strong, concentric and somewhat irregularly.

297

111easurcmeut iu 111111.

LengthHeight1-lolotypc (Left)
Paratype (Right)\·:~rietal form (Left)\·ariatal form (Right)

50. 5

21.4

"15. 3<15. 515. ()
21. :!

~4.G

17.0

Obsen~tllirm :- !\ small and rounded
proclissoconch is preserved in an immature shell tlig. 5). In the subsequent
stage the radial rib starts on the postcrovent raJ side \Yhere it is originated fromthe concentric rib or striation. Thiscon(entric line curves down to theposterior corner and develops into aradial rib. The same process of costalion was found by B,~mM (l!l03) in andersnni. The umbo lies at or ncar the
middle in the juvenalium. but is slightly:mteriorly in later stages of growth. A
varietal form (fig. c!) is very short. Itsinternal mould closely resembles thatin Cardiuia.
Comparison:- This species is shorter
than Palaeoplwrus and resembles Cardillia in outline. Except for radial costae
this is close! y related to Cardinia. bothinternally and externally. The surface
ornamentation of this species is similar
to those of Palaeopharus andersoni, !'.
verlongus. " Pleuroplwrus ., curionii and
Palaeozoic"PleurojJ/mrus ·•radial us.
From all or them. however. this iseasily distinguishable by its hinge apparati. It is a linking form between
the so-called Triassic ·· Pleuroplwrus"
and Palaeoplwrus and also between
Palaeop/wms and Cardinia; the earliest
member of Cardiuia is coexh;tent withthis.
Ocwrrence:-Common in 1he transiticnal zone from the inland to open-sea
facies of the middle llirabara stage (low.
Carnici at Ilirabarazaka. west of Omine.
l\Iine in Kagato.

Akira ToKUYAMA

298

References cited
BtinM, j. (1903), Ubcr die obcrtriadische
Fauna der Bareninsel. K. S1•e11slw VeteiiSk.
Akad. !/mull .. Bd. 37, Nr. 3, 76 S., 7 Taf.
- - (191·1), Zur Gattung Pleuroplwrus KINGund !Uyoconclla SowERBY. ]b. k. k. Preuss.
geo/. L-:1., Bd. 35. S. 5·19-561, Taf. 21.
IcnmAwA, I<. (1954), Late Triassic Pelecy·
pods from the Kochigatani (;roup in the
Sakuradani and Kito Area, Tukushima
Prefecture. Shikoku. Japan. Part. 1. f.
Ins/. Poly/ec/1. Osaka City Univ .. ser. C, L'Ol.
1. no. 1, pp. 35-37, pis. 1, 2.
KATAYAMA, M. (1939), Stratigraphical Studyon the l\Iine Series in Prov. Nagata. f.
Geol. Soc. japan. mi. -16. pp. 217-234, pl. 8.
KING. vV. (ISH), On a New Genus of Palaeo·
zoic Shells. Ann. Mag. Nat. !list., l'Of. 14.
pp. 313-317.
- - (1850), A Monograph of the Permian
Fossils of England. vol. I. pp. 1-253, pis.
1-23. Palaeon/ogr. Soc. London.
KoBAYAsHI, T. and K. IcHIKAWA (1950). Late
Triassic J\lytilus, Volsella. /'lt:urophorus
and !1/yoconcluz from the Sakawa Basinin Shikoku. Japan. f. Fac. Sd. Univ.
Tokyo, sec. 2, 1'01. 7. pt. 3, pp. 208-215,
pl. 1.
- - & - - (1951). Palaeopharus, a Late
Triassic Pelecypod Genus. Tr. Proc. Pal.
Soc. ]ajxl11, N.S., 110. 1. pp. 7-12. pl. 1.
- - & - - (1952). The Triassic Fauna of

the lleki Formation in the Province ofTamba (Kyoto Prefecture), Japan. ]apa11.
f. Geol. Geogr., l'Ol. 22. pp. 55-81, pis. 1-3.
MARWICK, J. (1953), Divisions and Faunasof the llokonui System. Geol. Sun•. N. Z.,
Pal. Bull., no. 21. 141 pp., 12 pis.
NAKANO, M. (1957), Carnian Fossils from
Kyowa, Okayama Prefecture, japan. ].
Sci. lliroshima Unit•., scr. C, m/. 2, no. 1,
pp. 63-67, pl. 9.
NAKAZAWA, K. (1955), A Study on the Pelecypod-Fauna of the Upper Triassic
Nahal' Group in the Northern Part of
Kyoto Prefecture, japan. Pt. 3. f. Col.
Sci. U11il•. Kyoto., ser. B. MI. 22, 110. 2,
pp. :!·13-260, pis. 13-Hi.
NEWI,LI,, N.D. (19·10), Invertebrate Fauna of
the late Permian Whitehorse Sandstone.
Bull. Geol. Soc. rlm.. t•ol. 51, pp. 261-325,
pis. 1-10.
- - (1957), Notes on Certain Primitive He·
terodont Pelecypods . •-!m. ,\Ius., Nol'itates,
1/0. /857. pp. 1-14.
NicoL. D. and W. T. ALLEN (1953), A new
pelecypod genus from Upper Triassic
strata in Peru. f. Wasltin~:ton Acad. Sci.,r•o/. 13. no. 11, pp. 34·1-46.
ScHUR<m, KOKENTHAL und HEWER (1926-40),
Nomenclator Animal ia Genera et Subgenera (A-T). Ber/i11.
WAAGEN, L. (1907). Die Lamellibranchiatcn
der Pachycardientuffe tier Seiser Aim.
AM. geol. R-A., Bd. 18/2. 180 S., 3•1 Taf.

Explanation of Plate :13
Pa/aeopharus (Mineplwrus) triadiws ToKUYAMA, new subgenus and new
species ........................................................................ 297
1: llolotype, left valve: 2-7: paratypes: 2.4: short varieties: 5: immature left valve
showing prodissoconch. x 3: 6, 7: internal moulds of both valves showing hinge andinterior. Loc. Hirabarazaka, west of Omine, Mine city, Prov. Nagato.
Figs. 8-11: Pa/acop!wrus oblmrga/us (KoHAYASIII and ICIIIKAWA) .......................... 294
8: Internal mould of immature left valve, showing hinge apparatus. Loc. West ofllirabara, Mine city.
!l: Elongated form. Loc. Hirabarazaka: 10: surface of left valve, loc. ditto.
11: ;t: right internal mould showing hinge apparatus and interior: h: clay cast of
the same specimen. Loc. ditto.
Fig. 12:
Palaeopllarus ob/onga/us buriji KIPARISOVA ..................................... 296
External clay cast showing weak ribs in the posterior area. Loc. North of Ominein Mine.

Figs. 1- 7:

All figures except fig. 5 are in natural size. All specimens illustrated here are depositedin the Geological Institute, University of Tokyo.

ToKuYAMA:P lat e 43

Late Triassic J>alaeopharus

1

5

3

6

7

8
9

12
10

Trans. J>roc. Palaeont. Soc. Japan, N. S., No. 32, pp. 299-30-1, pl. 4-1, Nov. 1o. I !l:i7

351.

AN INTERESTING CRUSTACEAN REMAIN. CTENOC!JELESSUJAKUI N. SP. FRO.M THE PALEOGENE OF
KYUSHU, JAPAN*

RIKIZO HviAIZUMIInstitute of Earth Science, College of Arts and Sciences,
Tohoku UniYersity:hmr~im.=:*C'/EJJIJ:

vi" e:.H Ctenocheles sujakui n. sp.: {f{:~~rNJ~/J1jffi~!AtH.!~~ljr,fiJ=:~~ftil.tal:~ifr 11 lj-Jl',f,/!1.\t 249.68 m :toJ: U 309m O)}llili!fffiliff"f~~-/)·1; **11111i'li:.J: ~ t~H~"' H
t:. Ctenocheles sujakui n. sp. ~ifG""L.,t.:, 'CO)*iVCrt:JrPf.::.r;r:.~mtf.fifliir:f:lt1i:E,'{I<:J: 1Jft'lf.11~1
O)j.;:llfftJ•I;tlU.f!cHt, W.l:jfni<:J: ~lfHJ-~ttThiJ, relict -c'JJ~,
1.!.lt>t1 0 0;..t.:rn!li .:e- O)*!!Rir.t!;?f<:6:J:> IJ • {t1iO)W:!U1-c' t t>tJ. ~ ~"9 (, :ltl!f!"f::: ~ t.: ~ t
GLAESSNER -/): Victoria O)lttlffrtttJ: ~ Ctenocheles t•ictor ~ 1947 q::::mfl;·l,"[~ 'i5a"f~:tJ~<0).:

the Crustacea at his disposal. l-Ie isalso grateful to Emeritus Professor
Hisakatsu YABE, Professors Sh6shiro
I-IANZAWA and Kiyoshi 1\sANo of theInstitute of Geology and Paleontology of
Tohoku University, Professor KotoraliATAI of the Department of c;eology.
College of Education, Tohoku University
and Professor Kenzo YAGt of the Insti·
tute of Earth Sciences. College of 1\rts
and Sciences, Tohoku University for
their continuous encouragt'mcnt s.

The crustacean remains here descri·bed, were collected from the Kishima
formation in the boring cores of theWell. No. 11 of the Kogayama Coal
Mines, Nagao, Minami·Taku-mura, Ogi·gun, Saga Prefecture by Mr. Tomosuke
SuJAKu of the Mitsubishi i'·.'Iining Com·pany and were submitted to the writerwith other remains of a new genus of
the Goncplacids. They proved to be avery rare genus of the Family Callianas·sidae, of which descendant is a relict in
the Japan Sea, Ctenoclzeles balssi Krsm·
NOUYE, 1926.
Although the C/enocheles remains are
fragmentary, they have some importancefrom the stratigraphic view point by
their well-defined characters.
The writer is indebted to l'vlessrs To·
mosuke SuJAKu and Y 6ichiro MoRINAGA,
Yasuhiro KAMADA and Toshio KrHARA for
kindly placing the fo:osil specimens of

Description
Tribe Thalassinidea
Family Callianassidae
Genus Ctenocheles KtsHtNouvE, 1926
Two Rare and Remarkable Forms of Macrurous Crustacea fromJapan, A1mot. Zoo/. japon., Vol. 11, pp.
63-66. Fig. 1.
GLAESSNER, M. F., l!H7, Dcl'apod Crustacea(Callianassidae) from the Eun:nc of Vic·
toria. Proc. Roy. Soc. Victoria, Vol. LI X.
KISHINOUYE, K., 1926,* Received April (j, 1!!58: read at the 55th
Meeting of the Palaeontological Society ofJapan, Oct. 10, 1955, at Scndai.
299

300

Hikizo IMAIZUMI(Yew Series). Par. 1. pp. ·l-7. Pl. l. Figs.
8 and 9, Text-fig. 1.
Genotype: Clenocheles halssi KISHt:-;ouYE.

In his description of Ctenoclteles z•ictor
from the Eocene Rivernook House, on
the coast about one and a quarter miles
southeast of the mouth of the GellibrandRiver. Victoria. i\1. F. GLAESSNER has
already stated that Cteuoclte!es wasestablished for a living Thalassinidcorresponding in essential features with
Callianassa. but distinguished by theexcessive deYelopment oi the right chclliped. which resembles that of thelobster-like deep-sea Decapod Tlummastorfw!es. Specimens of Tliaumastoc/ie!es
japonicus Cu.MAN arc collectccl from
depth of about -100m. of the Sagami
Bay. Shizuoka Prefecture and I\umanonada. by dragnets.
Only a right cheliped of this species
was collected by DoFLEtN from Japanesewaters and was described by BALss as? Pentacheles nov. sp.
Therefore. thespecific name of the genotype was denominated as ba!ssi by KisHINOUYE.
The genotype. Ctenoche!cs balssi K1sm·
Noun: was collected at Osu. ncar Kashiwasaki, Niigata Prefecture. This specimen. measuring 10 em in length. is
fcmaL::, and is more or less mutilated.
This deep water dweller is blind. Anyother specimen of Recent species has
never been known to be collected thereafter.
1\I. F. GLe\EssNER included Jschnodactylus (lsclmodactylus coolwi RATIIntrN. lll35:
Jsc/modactylus Cltlfellus I~ATHBUN. 193:-i:[srfmodrtctylus? dentatus RATII11UN, l!l35)
from the Paleocene and Eocene of
Alab:una anci l\lississippi and Thaumastodw!es rupeliensis lh:uRLEN. 1939 from thelVIiddlc Oligocene of Hungary. in thegenus Ctenod1eles. The incomplete chclipeds of Tlwumastodwles
rupeliensis
BEURJ.EN.
1939 possess distinctive fea-lures of Ctenocheles. K. BEURLE!'; drewattention to their striking resemblance
to the cheliped described hy BALSS as
Pentachles sp. ?
The fragmentary han1s and fingers of
Jsdmodactylus also correspond with
Ctcnocheles in their shape and weakornamental ion. though the dent iculat ionof most of these fingers is incompletely
preserved. It should be noted that theiridentification with Ctenoche!es does notaffect other species of lsclmodactylus,
Isdmodactys macrodaclylus (ScHLl'TER)
and lsclmodacty!us esocinus (FRITSCH}, inwhich long spiny claws are associatedwith lobstcrlike remains of the carapace
or abdomen.
Long fingers with longpointed teeth arc obsened in more than
one family of Decapod Crustacea.· but
the shapes of ornamentation oi the handand fingers make it possible to distinguish them.
Ctenoclieles has an asymmetrical anrl
unequal first pair of the pereiopocl andvery specialized large cheliped. The
only specimen of the genotype. Ctcnoche!cs balssi has first pereiopocL of which
the right one is larger than the left
and is specialized in the shape of thefinger like a comb.
Syntype No. 1. the manus with thelixed finger of the present species of the
Ctenocheles is determined as the rightone. by the swelling of both surfaces ofthe manus and the vertical furrow
behind the articulation with the dactylusof one surface. The surface with avertical furrow behind the articulation
with the dactylus. is inner one andtherefore the manus is determined as
the right one by the orientation of theinner surface of the manus. This rightmanus of the present species of the
Ctenocheles (syntype Ko. 1), belongs to
the smaller cheliped of the first pair of
the perciopoda. The other four syntypes

An Inter..;st ing Crustacean f<emain, Ctenof'heles sujakui n. sp.

of the present ~pecies of the Ctenoclzelcs,(syntypes. ?\o. II- V). are isolated. long.
thin and denticulated fingers. They are
no doubt bel on.~ to the larger one of till'
fin;t pair of the pereiopocla. The left
manus (syntype No. VIII) of the present
species is larger type.
It is not always the case that in tlw
same taxonomic unit of Crustacean De·
capuda, the one cheliped. whether it isright or left. is longer than the other.
Though it has never been a~sured in theliving or fossil species as the Ctenoche!cs.
have commonly asymmetrical chelipeds
especially in the male. The present
species of the C/enoche/cs has the leftlarger cheliped. while the known specimens of Ctenm:lteks vir:tor and Ctenod~t·­
les ba!ssi. have the right larger chelipeds.

Ctenochl'll!s sujalmi n. sp.
Plall' ·1-1. figures 2-5.

Based on the right manus with thefixed finger (syntype Xo. I), four fragmental fingers (Syntypes No. II-V.i ofthe larger chela (perhaps. left one). !heright immovable finger of the second
pereiopod (syntype No. VJ,, the fragmental posterior part of the chela (syntype
No. V!I). and the anterior part of tlw
left manus with the stump of the fixed
finger (syntypc No. VIII).
Palm of the right manus elongate
about one and a fifth times as long as
hi.~h: swollen. thickness half of thewidth: superior border blunt, almost
straight but gently swelled in the middle
part: inferior border also blunt, but thinncr than the superior: raised and swollen
in the middle and the posterior part.
with 7-8 pits along the inferior margin.
A vertical furrow behind the articulation with the dactylus on the inners.1r.' 1: e is broad and shallow. Nunw-

301

rous irn:gularly polygonal pavements
apparently belonging to the lower layer
cover the whole surface except the
distal port ion. Manus of the left chela.
decorticatecl, outer surface covered withpolygonal pavements: palm much swollen: proximal end lacking: articulatingcond~·Ie with the movable finger is large:
the immovable finger is strongly dc!lcxed.
fixed finger imperfect! y preserved.
perhaps shoncr than the palm. and ovalin cross section at the base. with blunt
and imperiectly prescrvC'cl teeth along
the prehensile edge. fingers of thelarge chela very thin. platy and longattenuate abruptly in the distal part.
with regularly altcrnating longer andshorter pointer! teeth: longer teeth oft'1e fln!-(cr are regularly spaced andgradually shorten their length to theanterior part of the finger. the posterior
part a~1d the base of the finger unknom1:
bet\n•en the longer teeth about threeor four shorter teeth ~rranged, in theseshorter teeth there are differences inlength. and the one near the longer
teeth shorter than the others: the curvature' of the teeth slightly directed backwards in most cases: the distal ends ofthe teeth curved. The base of the rightimmovable fingers, (syntype No. VI\
showing the inner superior surface with
the ill-preserved small teeth along theprehensile edge. perhaps smaller chelaof the second pereiopod. The fragmentof the posterior part of the manus(synt ype No. VII), perhaps belongs to
the left larger chela of the first pcreiopocl. co\·ered with irregular pavements.
Dimcnsio11s :-:1\'lanus 1syntype No. I):
length of palm: 16.:! mm: width of palm
at distal part: llnm1. maximum width
in the middle part of palm: lcl mm.
width of proxim::d part of palm: 12.5
mm: thickness of palm: 6.8 n1111; lengthof fixed finger: 10 mm: basal section ofRikizo IMATZUMI

302
fixed finger: 2.5mmX1.8mm.

Fingers (syntypc No. II): length. 29
mm+. width, 2.5 mm±: (syntype No.
Ill); length, 26 m m +. width. 2.fi mm ± :syntype No. IV. length. 20mm+. width.
:~ mm±; syntype No. V. length. ll mm-1-.
Distances between the longer teeth. 5mm and 5.8 mm in syntype No. ll at
the anterior part; 4.2 mm and 5 mm insyntype No. III at the anterior part, thedistances between the longer teeth become longer forward. (syntype No. VII):fragment of thC' posterior part of themanus of the left larger chela. width,
8.5 mm+. length. 14mm+. (syntype No.
VIII); the left manus, the width of theanterior part. 12-13 mm: sect ion of thestump of the immovable finger. height.
2.7 mm. width, 0.7 mm.
Geological J/orizon. Locality and Re·
positm:v:-Kishima formation, Ashiya
group: from the boring core of thewell, No, 11 of the Kogayama Coal
mines, 1\litsubishi !\lining Company, at
the western extremity of Nagao. ivlinamiTaku·mura. Ogi-gun. Saga Prefecture*;
IGPS Joe. no. Sa-002; lat. 33°17'18'' N.,
long. 130°7' E., T. SuJAKU coli.. 1953,
syntype No. I. sample number of theboring core No. 59, 2·19.6 m in depth.
dark siltstone, IGPS coli. cat. no. 79567:
syntypes No. II-VII. sample number ofthe boring core no. 68. 309m in depth.
dark siltstone. IGPS col!. cat. no. 7!:1568.
Syntypc No. VIII. without sample num·
ber of the boring core. but seems to benear to No. 68, syntypes No. II-VIII. 309
111 in depth. dark siltstone, IGPS coil.
cat. no. /9:168. with a molluscan frag·mcnt (Crassatcl/iles? sp.).
Remarks :-Cienoche!es victor is larger
in size comparing with Ctenodwles sujakui, the length of the finger of Cteno-* Jtd"llliVJ ':VJ£ 1n11tH~ ~ wftt~Srri.v:IJ.
~mwr. f!i.l111i!lllftr-l:.~li!i_,~.~rill~ ll1

c/wles victor is more than 14 111111 andthe length of its long teeth are over 2
111m and the length of its short teeth
are less than l/2mm. while the lengthof the anterior part of the finger ofCtenocheles sujalwi is more than 29 mm
and the length of its long teeth arc over
2mm and the length of its short teeth
are less than 1 mm. Morphologicallythey resemble very much, but the specimen of the finger tlgured by M. F.
Gt.AESSNER in his figure 9. Plate I. (M.
\V. G. K. No. 1925) shows the long teeth
bending slightly forward and the longteeth of the fingers of the large chelipcds of Cteuoche/es sujalwi leaningslightly backward. except the anterior
long teeth of the syntype No. II.
C/Pilocheles sujakui resembles closely
to the living Ctenocheles ba!ssi. but diffen; from the latter by the robust shapeof its finger, and hy the shorter palmof the smaller cheliped of the firstpcreiopod.
lsclmodactylus culte!lus RATHBUN, 1935
is described by the two specimens asfollows, the one is the dactylus of theleft cheliped, hololype (this specimen is
mistaken for the right one by 1\l. j.
RATHBUN, in the description, p. 14, but
stated as the left one in his explanationof the figure. p. 139), preserved in the
Alabama Museum of Natural History,
from the Eocene Sucarnoochee formation
at Estelle, Wilcox County, Alabama andthe other is the right propodal finger.
paratype, preserved in the John I Iopkins
University from the lower Eocene at
Dry Creek, Jackson, Hinds County.
Mississippi. These two specimens arealso smaller type. Among these two
specimens. paratype. the right propodal
finger is 8.6mm in length (end lacking).
1.·1 mm in height at articulation, 0.5 mm
in width of the teeth. The propodal
finger of the left smaller chela, (syntype,An lnkrcsting Crustacean J<cmain, C/enacheles sujalmi n. sp.

No. h of Ctenocheles sujalmi is morerobust than the propodal finger of theright smaller chela of Jsclmodactylus

culte!lus. lschnodactylus cooltei RATHBuN.
1935 is collected from the Eocene
Sucarnoochee formation. Midway in
Prairie Creek region. Wilcox County,
Alabama (holotype and paratype) andfrom the Sucarnoochee formation. Estel·le. Wilcox County, Alabama (other spe·cimens). the type locality of lsc/modacly·
Ius cultellus. The specimens of !sc/mo·
dactylus cookei are the right manus only.
which belongs probably to larger cheli·peel. It is more smooth in its su rfacc
and smaller than Ctenoche/es sujalwi.
The larger cheliped of Ctenocheles suja·
kui is easily distinguished from Ctcno·
cheles w/tel!us by its larger articulating
condyle with the movable finger.

lsclmodactylus (? \ de,rtalus

RATHBUN.

1935 are composed only of the rightpropodal fingers and collected from thesame locality as the other specimens oflsclmodactylus cultellus RATtHiul'l, Dry
Creek. Hinds Country.
These three
species of Isclmodadylus. Isdmodacly/us

cultel!us. I sclmodartylus cool~ei. I sclmo·
dactylus ( ? ) dentatus may actually
represent the different part of the same
species. respectively, the dactylus andthe propdal fingers of its left smaller
cheliped. the manus of its right larger
cheliped and the right proporlal finger
of its larger cheliped.
The incomplete chelipeds from thel\liddle Oligocene ( Kisceller Tegel) of
Obunda near Budapest. Hungary which
K. BEuRLEl'l 09:l~l) clescribcd as Tlw·
wnastocludes mpe!iensis possess the303

distinctive features of Ctenoche!es. but
Ctenocheles sujakui is easily distinguish·
eel from the preceding species by thelarge number of the short teeth of thefinger. The living Australian Ctenoclzeles
collini i\·1. \YARn seems to be Yery robust.

References cited
V. K. (HJ:N). ~eue lkcapoden-Krc·
h!ic a us dem ungariscllt'n Tert iii r, 5
1\bbil.. Taf. ;-. Pa/aeo11/. Zeilsdt .. Fo/. 21,
pp. 135-160.
GLAESSNJo:R, M. F. (1929), Fossi lium Cat:1logus.
I : Animalicr. Pars 4 1. Crustacra Decapoda.
- - (19·11). Decapod Crustacea (Callianassidae) from the Eocene of Victoria. Proc.
Roy. Soc. Victoria. l'o/. LIX. New f"a ..
i'ar. 1. pp. '1-7. Pl. 1. Figs. il and 9. TextJig. I.
KISHINOUYr:. K. (1926). Two Rare and Rc·
nurkable Forms of J\lacrurous Crustacea
from Japan . .'\mwt. Zoo/. japon., Vol. 11.
pp. 63-6ti. fil~· 1.
~AGAO. T. (HI:!S). A Summary of the !'a leo·gene Stratigraphy of Kyushu. Japan.
with some Accounts of tht: Fossilifl'rous
Zones. Sci. Rep. Tolwlw Imp. Unit• .. Seco.
Ser. (Geology). Vol. X II, No. 1. pp. 1-10.
1'1. I. Table I.
- - (19·11). On Some Fossil Crustacea fromjapan.]our. Ntc. Sci .. 1/oldwido lmj>. Unil• ..
~er. IV. Vol. VI. No.2. pp. 85-100, 1'1. :?6.
RATIInUN, M. J. (1935). Fossil Crustacea of theAtlantic and Gulf Coa:;tal Plain, Geol.
Soc. America. Sp. P .. 1\'o. 2. pp. G3-66,
1'1. 14. Figs. 1-12. 19-22 and 2-1.
YAMASAKI, T. and
MORINAGA, Y. (19 50),
Stratigraphical Relation bctewecn the
Sasebu and Karatsu Coal-fidds. Kyushu.
jour. Geol .."'oc. ]apall. Vol. LX. 1Vo. 710.
pp. 473-486. 5 Text-figs.
BEURLEN.

304

J~ikizo IMAIZUMIExplanation of Plate 4-l
Fig. I.

Ctenoc/ieles balssi 1\tsHtNOUYE, collcctccl :11 cJsu, ncar, Kashiwasaki. Niigata Prefecture,rc1>roduced from Fig. 1 of KtsmNoUYE's paper, nat. size.
Figs. 2-1. Cte11ocheles sujakrmi n. sp., Kishim:~ formation and Ashiya group, from the boringcore of the \V ell, No. ll of the Kogayama Coal mines, Mitsubishi !\lining Company,at the western extremity of Nagao, ivlinami-Taku-mura, Ogi·J.(Un, Saga Prefecture,
T. SuJAKtr, coli., 1953, syntypc No. I. sample number of the boring core No. 59, 249.
6m in depth; syntypes .:-\o. II-VII. sample number of the boring core No. 68, 309m
in depth; syntypc No. VIII. without sample number of the boring core, but seems
to be ncar to No. 68. with a molluscan fragment (Crassatellilcs? sp.).
Fig. 2.
Syntypc No. I, right manus with the fixed finger, external vil'W, '<. 8/3.
Manus of the same specimen as fig. ~. external view, x 7/3.
Fig. 2a.
Manus of the same specimen as ftg. 2, internal view, x 7/3.
Fig. 2b.
Manus of the same specimen as fig. 2, internal view, x 5/2.
Fig. 2c.
Manus of the same spedmcn as fig. 2, internal view, x 1~/G.
Fig. 2d.
Fixed finger of the same specimen as fig. 2, uppcr view, X 12/5.
Fig. 2c.
Fixed finger of the same specimen as fig. 2, lower ,·iew, x 2.
Fig. 2f.
Fixed finger of the same specimen as fig. 2, antt'l'ior Yiew, x 3.
Fig. 2g.
Synlypcs No. !1-V. four llngcrs of the: larger chela (perhaps, left onl') and theFig. 3.
right immoYable fingl!l' of the second pereiopod. syntype No. VI, x 2.
Syntype No. ~VIII, anterior part of the left manus with the stump of the fixed fin.
Fig. ·1.
ger, >< 23/12.
Same specimen as fig. '1. X 13/6.
Fig. ·Ia.

I MAIZUMl:

Ct enocheles su}·akuz. n. sp.

Plate 44

305

PROCEEDING OF THE PALAEONTOLOGICAL SOCIETY
OF JAPAN

r13 4:?11:111''(0 m'iO [OJ ~~J 1958$ 6 ,E! 6 II
Jtifijif!);:~ Jli!•'f.ffl; Jibfi•'jl; li:~'T=f.i~IC.t5 1• •""'C!#Hill

U:o

(~0

r.· 13 il) o ~~I::H ~t ~ ~iiii1H!i0'

K.lMif~MEIIltA:O.>ii!i ~ -c,n ~ o

1. Pamfusulhw and Pseudodolio/ina foundin the Base of the Kamiyoshida Group.
the Uppermost Strata of the Chichibu
System, Kanto l\·lassif ........... .
................. Rokuro MoRIKAWA
2. On somt.: Fusulinids from the Higashizawa Valil'y. l\1amiyoshida-mura, Chichibu-gun, Northern Part of Kantol\!assif ................ J~okuro l\IQRIKAWA
3. Fusulinids from Shiroishi-yama, Northern part of Kanto Massif ........... .

r114~~i~l'.¥-1··r:i-~m n rnJl~lJi'<J 1958If. 9 f1 '21 11Jiillf;;J;:c'f: l!I!"N$ Jibt1·Y. ~1~~_nft~;::t;t 'L'~~m t.-

L (~f<tJ· 1'2 ?Do W!J~n::t-Jtt ~;WM15·llf:uq::,~l¢iiilfffiiJ ll{Xv).itli I) -r;,n 1.>o
1. (JJL!llOXt/,f.:IC!YJ"t ~ 2, 3 0.>11!\~!; 1Jfl;,·<T-«o .............. ~~m"~* =rifllJjill
2. On Sum<.: Carboniferous Corals fromthe Kitakami l\lountains ((t,bi;).......................... Makoto KATO
3. The Upper Palaeozoic Corals from theSouthern Part of the Tanba District.
Japan .......................... Shigeo
SAKAGUCIII and Noboru YAMAGIWA-1. Two Cephalopod-Species from the Norian Nariwa Group "\'estern Japan.
. . . . . Keiji N,\KAZAWA
5. Pelecypods of the Mizunuma Jurassic
in Miyagi Prefecture with some Stratigraphica!H cmarks ((~;!TC) .. ltaru HAYAMI
li. Taxonomic Notes on Genus Cardiniawith Description of a l\ew Species fromthe Low~r Lias of Western japan((t;t,'D. .. .. .. ..
. ............ ltaru HAYAMI
7. Bajocian l'clccypocl Fauna of the Aratozaki Formation in Northern Japan............... Rokuro MoRIKAWA-1. Foraminifera from the Akahira Groupin the Northeastern Corner of the Chichibu Basin. Central Japan ........ .
....................... Hiroshi UJIIE
5. bllliF.!t:IKTi~i'!liJ>till'!O)!~!lll'Jilr. "?l ''L .

. ............................... .ftiti.Hn.::.-.
6. Plica/ounio of the Wakino Formation ..
. .................. Yoshihisa OHTA'i. 1'\liocene Pero/rochus and its AssociatedFauna from Tochigi Prefecture. Japan...........
. .. ~~roK~~
8. On Some l\lorinc 1'\lioccnc Mollusca
from Mic Prefecture, japan ......... .
Yoshio ARAI<!

..... ltaru [lAYAllfl
S. On 1\umatrigonia, a New Subgenus ofFrengw:lliel/a, and a Tosaper'icll from theCarnic Tanoura Formation, in Kyus~·u,Japan (tt,r:.;) ............ l\linoru TAMUIM9. Carnic Pelecypmh; of Matsukuma inCentral 1\.yushu, Japan ((\:,fl.;) ...
........................ Minoru TAMUIM10. Trigoniidae. Ostreidae, Jlakevelliidae,
Pteriidac. Cardiidae and i\startidae fromthe Upper Jurassic Sakamoto Formationin Central Kyusyu, Japan (lt.bG) ..... .
....................... Minoru TAMURA
11. Taxodonla and lsodonta from the Upper Jurassic Sakamoto Format ion inCentral Kyushu, Japan (f\':,flC:) ........ .
........................ l\linoru TAMURA
12. Trigonioides and its classification ((~it~:)................. Yoshihisa OuTA
13. On the "Nippononaia" from the Lower
Cretaceous \Vakino Subgroup, North
Kyusyu, Japan ((~.r!.:) .... Yoshihisa OuT A
1-1. (lliilr{.il£r~lfti~@: Pectinidae ( ;e 0) J.l).
Pecten swiftii BERNARDI K"?l 'L ((~~;~).............................. l\'lW ~:-R&306
15. ftlrE!t-f.i!iJIJ.\'li*lfilf Pectinidae ( ;,:- OJ 15),
Pecten cosibeusis YoKOYAMA &V: ;_:-v)W.:J
iillf<!H<:-:>L '"l (f~ih'D .......... lt'JW :1f:·-f!~
16. On some l\Iiocene P•.IIloPe in japan (('\.
M;) .................... Kiyotaka CH!~ZE!
:..-- ::1 ;t 7f =Carci1lop/ax (('\.;\%) ................ -0-J.jUJit

17. **'41'il- t!JQl~fl fflj!!l;~(l) r11 ffr IJJ: i

18. Studies on the Ostracoda from japan
IV. Family Cytheridcidae SARS 1925 ((\:
.lie)................. Tetsuro HANAr

19. Elcctron·l\Iicroscopic Fine Structure of
Fossil Diatoms. VI. Observation onSome Diatoms Found in Dicalitc ·• DL72~3 .... '........... Haruo OK UNO
20. Palynological Notes on the Cenozoic
Rocks from Japan I ................. .
. . . . . . . . . . . . . . . . . . 1\-lisaburo SH!MAKURA
21. m=~·lfa~ rtE ~:c O).i!illl!ll!tm! t mt'l!'.<-

t <KiThrf'FI¥b/lli0 t 01:::-:>L •"C.. 1:jffl~W:I

SYSTEMATIC INDEX(Note:

Every reference is to the number of artil:il')

PALAEOZOOLOGY
Protozoa
KANllMA. M. and SAKAGA~Il. S.: J/esoschub(•rlella. a new Permian Fusulinid Genus fromJapan ................................................................................ 31~
YosHIDA. S.: Palaeogene Foraminifera from Kombumori. Eastern Hokkaido. J;:tpan ...... 315

Cue len terata
MtNATO, M. and KATO. l\1.: N.:!w Spe«.:it:s of Sipho11ode11dro11 frl)m Japan .................. 313- - - andTwo Carboniferous Corals from the Kitakami Mountains, North·. .. .. . . . . .. . . .. . . .. . . .. . . . . .. . . .. . . .. . . . . . . . . . . .. .. .. . . .. .. .. . .
3~8east Honshu
A short Note on /.mJ.wialeoidr:s loriyamai l'vhNATO .................. 333---and- - - a n d NAKAZAWA, K.: Two Carboniferous Corals from Okayama Prefecture...
308
YosHIDA.. T. and KATO. i\1.: .. Onimaru type" Coralg newly found in the Northern Kita·
3 _;:)
kami Mountain Region. japan?~

1\Julluscoidea
KATAOKA, j.: llryozoa from the Daishaka Formation (Pliocene). 1\·linami·Tsugaru.gun.
329
Aomori Prefecture
KoTOH. ]. : Brachiopoda from the Daishaka and Tsurugasaka Fossil Zones. l\Iinami Tsu·
garu·gun. Aomori Prefecture ........................................................ 306
ToKUYAMA, A.: On some Upper Triassic Spiriferinoids from the Sal\:twa Basin in Prov.
Tosa. Japan .......................................................................... 3~~- - - : On some Jurassic Hhynchonellids from Shikoku. Japan ........................ 327

l\Jollusca
1\J<JYAMA, l\1.: :lmussiopectcn iilomiensis (OTUKA) and its Allies from Japan .............. 311- - - : .New Fossil Chlamys from the Environs of Nagano City. japan . . . . . . . . . . . . . . . 344
HAsHIMOTO. W. and KANNO, S.: l\lolluscan Fauna from the Teritary Formation of Chirai.
Kamisaruma, Kitamino.Jwni. l!okkaido . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
349
IIAYAMI. I.: On the Occurrence of Cardinioides in the Liassic Kuruma Group in Central
Japan ................................................................................ 311:.
-~~-. Raduloneclites, a new Pectinid Genus. from tht· Liassic Kuruma Group in Cent·ral Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................................ 320- - - - : Liassic Chlamys . .. Camptonecles" and other Peel in ids from 1 he Kuruma c;roupin Central Japan . . . . . . . . . . .
.. . . .. . . .. .. . . .. .. .. .. .
.. .. .. .. ..
326- - - . Liassit' Volsella, Mylilus and sonw other Dysodont Species in Japan.......
:~30~~-: Supplementary Deso:riptions of the Liassic Pelecypods from the Kuruma and
Shizukawa Groups in Japan .......................................................... 337
I-ltRAYAMA, K.: On Lucinoma aokii. a new Pleistocene Lamcllibranch from Chiba Prefecture. japan. ?\otes on Japanese Lucinid :vlolluscus, Part 2....................... 3·12

307

...1

308

Systematic Index

lTOIGAWA, ]. : On the Miocene Lucinidac irom the l\Iizunami Group, japan .............. 305- - - - : On some Cephalaspid Opisthobranchia from the japanese lVIioccne ............ 334
KANNo. S.: Fossil and l~cccnl. Species of the Genes Panomya from japan . .
. .......... 307
KoBAYASHI. T.: Nipponiirigonia and Rutitrigonia in japan ............................... .
On an /lturia from the Poronai Shale in 1-Iokkaido- - - - : An Aturia from (?) Kusu Count~·. Oita Prefecture. Kyushu. . . . . . . . . . . ....... .
- - - - : A Gotlandian Nautiloid from the 1-lida Plateau in japan
MASUDA. K.: On the l\Iioccne Pectinidae from the Environs of Sendai: Part 10, On Pee·
. ........................ 336
ten (:-lequipeden) yauagau·acnsis No~rURA and ZINBO...
Ibid.: Part 11. On Pecten (CI!lamys) crassi11enius YoKOYAMA and its related
Species . . . . .
. . .. . . .. . .
. . .. . . .. . . .. . .
. . .. .. .. .. .... .. .. ..
341
ll>itl. ; Part 12, On Pee/ell ka;;amianus YoKOYAMA .............................. 3-18
l\IATsur. 1\I.: Species of the Genus Nej>funea from the Palaeogene Formations in the Kushiro Coal Field, llol:kaido, japan .................................................. 338
illATSUMoTo. T.: A Turonian Danwsifes from Ilokkaido, Japan. (Studies of the Cretaceous
Ammonites from I-lokl;aido and Saghalien) ......................................... . 319
NAKAZAWA, K.: "Monophyllites ·· aralwrensis sp. nov. from the i\laizuru Zone ........... . 340
SHIBATA. 1\-1.: Some Molluscan Fossils from the Eastern Part of the Tanzawa l\lountainland. .. . . . . . . . .
.. .. .. .. ..
.. .. .. .. .. ..
. ....... . 309
SHUTO, T.: Gra11uli.titsus from the l\liyazaki Group (Palaeontological Study of the l\liya.
zal<i Group, V) . . .
.. .. .... ..
. .................... . 3-16
TOKUYAMA. A.: Late Triassic l'alaeopharus in Japan
350

Arthropoda
IMAIZUM!. ]{.: A Miocene Fossil Crab, Faratymolusyabei. n. sp. from Nagano Prefecture .. 310- - - : Three new l\Iiucene Species of Callianassa from Nagano Prefecture ............ 318
An interesting Crustacean 1\emain, Ctenocl;e/es sujakui n. sp ................... 351
KoBAYASHI. T.: Some Cambro-Ordovician Fossil~ from the Tan'gyang or Tan yo District,
South Korea. . . . . . . . . . . . . . . . . . . . .. . . .. . . .. . . . . . . . . . . . . . . . . . . . .. . . . . . .
339

PALAEOBOTANY
ENuo, R.: Stratigraphical and Palaeontological Studies of the Later Palaeozoic Calcareous Algae in Japan. X Ill. A Restudy ot the Genus Physoporella... . . . .
3-17
IcmKAWA. \V.: Some Notes on a rare Species Triceratium simp/ex j. BRUN .............. 323- - - : Once again on a rare Species Triceratium simp/ex]. BRuN ............ Short notes 2
Kir.IURA. T.: i\ksozoic Plants from the Tctori Series, Central Honshu. Japan ............ 331
OKuNu. 1-1.: Electron-Microscopic fine Structure of Fossil Diatoms, V; Observation onsome Diatoms found in Celatoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-13
SuzuKI. K.: On the Occurrence of Cercis in japan ..................................... 332
TAKAHASHI, K.: Sabalites aus den \·\Takata Schichten von Tsushima, Nordkyushu ........ 335

l\Iiscellanea
I-lATA!. K.: Interesting Sand-pipes from the Miocene Toyoda Formation, Yamagata Prefecture, Japan . . . . . . . . . . . . . . . . . . . . . . . . .
.. .. .. .. .. .. .. .. .. .. .. ..
321

INDEX OF FOSSILS
Notes: Every reference is to the number of article: words in it:1lics arc names ofgenera and species: words in hea\·y type, names of new families, genera and species.

Cncis Endoi . ................... .
. ... 332
- - sp ..... .
.332
Cltlwnys in).;eniosa tanakai ................ 33·1
kolakiensis . . .
. ................ 326
kurumensi.Y . ......................... 326
cf. kurmJu'usis............... 326

A··Ad eon" sp. . ............... .
.334
Alderiua lum::awai... . . . . . . . . .
. ...... 329
Amussiopec/en iifomiensis . ................. 311- - p!anicoslulatum . . . . . . . . . . . . .
. .. 311- - praesignis.....................
.311- - yabei .
.. .. .. . . .. ..
311
Am.lf[da/ophyllum giganteum .............. 308
A11tropora daishakaenRis
.329
.329
- - elongata ......... .
- - lwlaii.3~9Arcomytilus sp.
. ................ 33(1Arcomytilus dairensis. 33(1
As! rea (Pachypoma) omorii ............... . 309
Aturia minoensis var. . ................... 32·1
. ................ 317
yokoyamai.

obe.~aB

Berkeia shantungensis
Boliz·ina k/einpelli ..
Burmirhynchia ...... .
·• - - " eapillala . . .
- - japoni('(l ..
- - (oriiiOSI/l'IZSis ..

......... 3-14

sp ..... .
............. 326
Cladophlebis sllins!mensis .
.:n1c:ampltysoporel/a conforma. . . . . . . . . . .
. 347- - facet a.. .. .. .. .. ..
. 3Hllurltwsn . . . . . . . . . . .
. ............ 34i
C/isaxopltyllum mm atetsuene . ............. 30/l
C/isiopltyllum :1ff. nl'coyanum ............. 328
Coleopora tsu{lnruensis. . . . . . .
. .... 329
tsugarueusis mn.•udai . .
. .... 329
Co plot ltyris adamsi . . . . . . . . . . . . .
. 306
Crassima rgi nate//a parvinl'ieular ia ........ 329
Cryptopecten yana;:awaensis ..... . ........ 336. ...... :~!)1
C; euocheles . ....
- - sujakui.
.351
Ctspidaria (?) a sp.
.337(?) b sp ................. .
. ... 337
Cydammina paci,lica ....... .
. ...... 315
pacifica var. kushimensis ...
.315....... 339. ... 315.. ... 327. .................. 327' ... ' ........... . :~27
. .................. :l27(~l'liclmacCallianassa Shikamai . . . . . . . . . . .
.318- - Tanakai . . . . .
. ......... 318. .. 311!
- - l'agii.
.. Camptonectes •· oishii . . . . . . . . . . . . .
. .. 326" subflabelfiform is . ................. 326" asp.
................. 326" b sp.
. . . 3~6........... 316.350
Cardiniidae............... 316
Cardinioides................. 316- - ot•atus. ....... 31G- - variclus . ............... .
..... 316
- - sp. ···············
Cassidulina margareta ...... .
.. .. 315
. .. 305
Cavi/ucina (Monitilora) kitamurai .

sp. . .......... .

.334

Cyliclmatys sp ................... .
Cymbella cistula ................ .

.334
.3·13

Damesites ainuamts ..................... 319
Decorifer ena .............. .
.334
Dipltyphyllum delicatum... 3~8£,/folium sp ....
.. ........... 326
E•1tosolenia aff. t•asiformis............. 315.. ........... 334
cocy/china aJfabilis.
habei.......
. ............ 334-- tokiensill . . . . .
.344
Eopecten (?) sp. . . . . . . . . ................ 326
Eoscap!umdcr corpu/enta .................. 334
309

Index of Fossils

310

Exodrdla sp ............. .

........... 3~9Gforipalfiroll aassit•e11inm . ................. 341- - iZIII't'IIHiH . . . . . . . . . . . . .
. .... 341
Grammalodmr (?) sp. . ................... 337
Gramtli[usus .............................. 3-16
- - dna/is.....................
. ...... 3-16
- - koiJIUITI/IH . . . . . . . . . . .
. .......... 3.(6- - mntsrwwtoi. . . . . . . . . . .
. .... 3·16
Gullulina cf. adhaerens. . . . .............. 315- - cf. problema ........................ 3!5- - d. r·arians .......................... 315
J[/la/iotis (Hulwfiolis) koikei ............... . 309
J/,wzaslumia . . . . . . . . . . . . . . . . . . .
. .. :l39( ?) sp. . ............................ 339/Jemithyris psi/lacca ...................... 306
f!exaphyllia sp. . . . . . . . .
. ............ 325............. 337!fomomytl saloi . ....... .
... 3:llsp ....

I
lddingsiu orit•nlalis. . .. . 339;Uineplwrus .............................. 350
Miyagipecten sarc11nen.~is .................. :l49.. Jfmrop!zylfites " amlmrensis . ............. 310
l\lytil idae ................................ 330
Jlyt ifus (Fafcimyl ilus) lzl•rcmirus .......... 330(-) subsp ................... 330(--) stricapi/lalus ................ 330( - ) - subsp ................... 330( - ) sp ........................... 330

Nep/zmea dispar .......................... 338- - ezoana .............................. 338- - lwruhalai .......................... 338- - modesloidea : ........................ 338- - onohelsuensiR ....................... . 338- - slzoroensis .......................... 338- - sitakarensis . ......................... 338- - sub1•m·inalu ......................... . 3:ls
- - sp.
. ............................ 338
t\'ipponitrigonia . ........................... 31·1
1'111/l'l'X(I.................
. . . . . . . . . . . 314- - kikudziana......... 314. .... 3l-1
- - t/171/IIUII/1/i .................. .
....................... 311- - sagall'ai.
.. ....... 314- - sakamofoensis .......... .
]limzimr /mslzinJensl' ...................... 315- - soradriensc \'ar. lmulmmorit•nse ...... :l15)(

Kallirhyndzia sp.
. ................ 327
1\.inf!s/onia . . . . . . . . . . . . . . .
. ... 339
- - pm·a/ll•fa..................... 339

L. .... 3<)6
Laqueus rull(•l/us ............ .
. ...... 333
Lmzsdalenidt•s /oriyamai . ....... .
.305
Lucinoma acutilinea/a................. 34~- - rwkii ........ .

. ........ 312
Mesoselwberl ella . ..
. .... 312- - slzimtuluniensis ...
.... 312- - /lzlllllfJHIIIIi;l-/e/osira distans \'ar. lira/a ...
.... 3-13
grmmlata .................... .
... :~13- - - - forma cun,ala .................. 343;l/ichelimweras lzidense ................... . 345

0.. Oslrea" a sp. . ......................... 330" - .. b sp ............................. 330
Oxy/oma (?) sp ........................... 330pPa/aeopharus . ............................. 350- - oblongatus .......................... 350- - oblongalus lmriji .................... 350- - (Miuep/zarus) lri(l(/icus ............. . 350
Panomya . . . . . . . . .
. ................ 307--amp/a.........
. ................ 307- - beringiana .......................... 307
gigcml ea ............................ 307. ............ 307
i Z/111/0 . . . . . . . . . • .
simo/omensis . . . . . . . . . . . . . . . . . . .
. :{07
Paralldodon sp ........................... 337
Parasmittina I rispinosa cwmtll'ii'IIHis . ....... 329

311

Index of Fossils

Paralymolus yabei ........................ 310
Pan·irh\'1/chia bella.327
Patinopecten kagamimzus ................. 3·1!\- - - - kagamianus . . . . .
. .......... 34S- - - - molliwae11sis ................... . 348- - 11imae11sis.............
. .. 3•18- - permirus . ....................... 348-- aff. kobiyamai. . .
. ...... 349
Pil!ucina (Sydlorina) yoko_ramai . ........... 305
P/1'/hometopus lo11gispinus ................ 33~
Pleuromya lmshidoll'lzsis .............. ... 337
Pro/acardia kurumensi,q ...
. . 337
Pseudog!am/u!iiiii obtusissima.315
Pteria (s. 1.) kilalmm iensis . ............... 330
Punctospir~(er.322- - triadil'IIS .
.. .322- - triadiws kasfri1miensi11 .............. 322
Pupa hiyoslziensis................. 33-1

Saxoluci11a (J!egaxinus) k·hataii .......... 305
Sip!wnodendron japonicum ................ 313....... 313- - nakazau•ai............. 322
Spiriferinuidf'8....... 322
IICIII(Ii . .......... .
. ...... 322- - sakmt'clli/IH ...... .
......... 322- - yeharui .... .

'I'
Tegu/a (Chlorostoma) nm·usei... 309
Tcre/lratuliua coreauim. . . . . . . . . . . . .
. 306- - gouldi....... . ...................... 306- - japouiur...............
. ...... 306
Te/mcydus ('f'ialom................... 343
Tlzracia suhrlwmbica ..... ................. 337- - sp.. .. ..

. .................... 337

Triccratium simplex ...
. ......... ' .. 323........... Short note 2

R
Uadulonec/ites .....
. ...... 32ll
- - japonicus ........................... . 3:!ll- - - - var. com·exus . . . . .
. ........ 320
Ret usa (Coe/opltysis) s/wkuborensis.
33·1( - ) sp ........................... 33·1
" Rhynchollella" aff. bouchardii...... 327" - - " d. haradai .......... .
.327
Ringicula ( Ringiculina) minomzsis . ......... 33•1( - ) sp.
.. .. .. .. .. .. .. .. . 33·1
Rutitrigonia... 31·1- - yeharai ..... ....... .
'3J.l

Va1'iam11ssium (?) sp ..
........... 326.315
l'irl{ulina lwshiroenHiH.
Volsella baket'elloideH .................... 330...................... 330- - sp. ·····
Volmtlella m inoensi11 ...................... 334
yamcw!'h i i .......................... 334
sp ......... .
................... 334'"

sSabalites taislwensis ...

v. ...... 335

TValluci na lwbei .......................... 305- - okumumi . ........................... 305

a -lt"~f.~~~-~·i~fTransactions and Proceedingsof thePalaeontological Society of Japan.!\ cw Series

No. ~!i ,..._No. :;~1957- 1958

Palaeontological Society of Japan
November lU, 195H

The heading in Japanese commemorates the handwriting of Prof. lVI. YoKoYAMA,
father of japanese palaeontology, who was Professor of stratigraphy and palaeontology at the Geological Institute, Imperial University of Tokyo.
The fossil on the front page is Argonauta tolmnagai YoKoYAMA. I!H3.

CONTENTS
Number 25 (Published April 30, 1957)
Transactions
Article

30:>.

306.
307.
308.
309.
310.

311.

Page

Junji lTOIGAWA: On the l\Iiocene Lucinidae from the rvrizunami
Group, Japan....... . .. . .. . . .. . . .. .. ... . . . ... . .. ...... . . . ... ... ...... .... .. . . . ... ... . . .... 1-6
Jiro KoToH: Brachiopoda from the Daishaka and Tsurugasaka
Fossil Zones, Minami Tsugaru-Gun. Aomori Prefecture ... . . ...... . .. 7- 10
Saburo KANNo: Fossil and Recent Species of the Genus Panomya
from Japan ................................................................................. 11- 16
l'vlasao lVIJNATo and Kciji NAKAZAWA: Two Carboniferous Corals
from Okayama Prefecture .. .. .. .. .. .. .. .. .. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .. .. .. . .. 17- 20
Matsutaro SmnATA: Some l\Iolluscan Fossils from the EasternPart of the Tan;..mwa Mountainland ............................................. 21-25
I<ikizo 11\IAIZUMI: A Miocene Fossil Crab, Paratymolus yabei, n.
sp. from Nagano Prefecture ..................................................... 26-30
Masahiko AKIYAMA: "lmussioPecten iitomiensis \OTuKA) and its
Allies from Japan .................................................................... 31-39
Proceedings ................................... 40

Plate

1

2
3
4
5
6-7

Number 26 !.Published June 15, 1957)
Transactions
312.

313.
314.
315.
316.

Mosaburo KANUMA and Sumio SAKAGAMI: J11esosclmbertella, a new
Permian Fusulinid Genus from Japan .......................................... 41- 46
8?vlasao l\hNATo and Makoto KATo: New Species of Siplwnodendron
from Japan ................................................................................ 47- 50
9Teiichi KonAYASHI: Nipponitrigonia and Rutitrigonia in japan ... 51-61 10-11
Saburo YosmnA:
Palaeogene Foraminifera from Konbumori,
Eastern Ilokkaido. Japan ............................................................ G3- 68
ltaru I-L"-YAMI: On the Occurrence of Cardinioides in the Liassic
Kuruma Group in Central japan ............................................... 69-73
12Publications received .................. 62
Proceedings ................................. t'l
Number 27 (Published September 30, 1957)
Transactions~H7.

Teiichi KoBAYASHI: On an .-ltnria frum the Poronai Shale in
Hokkaido .............................................................................. 75-80
318. Rikizo h1AIZUMI: Three new Iviiocene Species of Callianassa

13

ii

319.

320.
321.
322.
323.

from Nagano Prefecture ......................................................... 81-85
Tatsuro l'viATsuMoTo: A Turonian Damesites from Hokkaido,.Japan. !Studies of the Cretaceous Ammonites from I-Iokkaido andSaghalicn) ................................................................................. 8G- 88
ltaru I-IAYAJ\11: Radu/onecliles. a new Pectinid Genus. from the
Liassic Kuruma Group in Central Japan ..................................... 89-93
Kotora HATAI: Interesting Sand-pipes from the l\liocene Toyoda
Formation. Yamagata Prefecture. Japan ....................................... 95-98
Akira ToKU\'AMA: On some Upper Triassic Spiriferinoids fromthe Sakawa Basin in Prov. Tosa. Japan ....................................... 99-106
Wataru lcmK"nvA: Some Notes on a rare Species Triceratium
simplex ]. BRuN .......................................................................... 107-109
Publication received ..................... 94
Proceedings ................................ 110

H

15
16

17
18

Number 28 (Published December 15, 1957)
Transactions

326.
327.

328.
329.

Teiichi KonAYAsm: An _-{furia from (?) Kusu County. Oilal'reft•cture. Kyushu................................................ 111-114
Takashi YosHIDA and Makoto K."-To: "Onimaru type" Corals
newly found in the Northern Kitakarni Mountain Region. Japan.................................. " ..................... " ................... " .... " ... """ 115-117
Itaru 1-lAv AMI : Liassic C/llamys . .. CmnjJ!onectes " and other Peel inids from the Kuruma Group in Central Japan ........................... ! 1!)-127
Akira Toi<tJYAMA: On some Jurassic l~hynchonellicls from Shikoku. japan .............................................................................. 128-13G
Masao MINATo and Makoto KATo: Two Carboniferous Corals
from the Kitakami 1\Iountains. Northeast Honshu. Japan ............ 137-142
jun KATAOKA: Bryozoa from the Daishaka Formation (Pliocene),l\linami-Tsugaru-gun. Aomori Prefecture ................................... 143-153
Publications received ................. 118
Proceedings ................................. 15·l

19

20

21

22

Number 29 (Published April 10. 1958)
Transactions
Itaru HAYAMI: Liassic Vo/se//a, .Mytilus and some other Dysodont
Species in japan ........................................................................ 155-165 23-24
331. Tatsuaki KIMURA: 1\lcsozoic Plants from the Tetori Series,
25a
Central Honshu. Japan .............................................................. 166-168:{32. K(·iji SuzuKI: On the Occurrence of Cercis in Japan ................. Hi!)-.17125b333. l\lasao l\IINATo and l\lakoto KATo: A short Note on Lonsda/eoides
toriyamai l'vliNATo .................................................................... 172-174
334. junji hoiGAWA: On some Cephalaspid Opisthobranchia from the
330.

iii

japanese Miocene ..................................................................... 175-183
Proceedings ................................. 184

26

Number 30 (Published june 20, 1958)
Transactions
335.

Kiyoshi TAKAHASHI: Sabalilcs am; den Wakata Schichten vonTsushima, Nordkyushu ............................................................... 185-188
27a336. Koichiro MAsunA: On the Miocene Pectinidae from the Environs
of Sendai; Part 10, On Pecten (Aequipecteu) ymwgawaensis NoMU·RA and ZINBo ........................................................................... 189-192
27b
337. ltaru HAYAMI: Supplementary Descriptions of the Liassic Pelecypods from the Kuruma and Shizukawa Groups in japan ............ 193-200
28338. Masaru MATsUI: Species of the Genus NePtunea from the Palaeo·gene Formations in the Kushiro Coal Field, Ilokkaido, japan ...... 201-210 29-30
339. Teiichi KoBAYASHI: Some Cambro-Ordovician Fossils from the
Tan'gyang or Tan yo District. South Korea ................................. 211-21<1340. Keiji NAKAZAwA: ·· ll1onojJ/iyl/iles" arakurPnsi~ sp. nov. from the
Maizuru Zone ........................................................................... 217-219
31
Proceedings ................................. 220
Number 31 (Published August 1:1, 1958)
Transactions
341.

342.

343.
344.
345.
346.
347.

Koichiro I\fAsUilA: On the .Miocene Pectinidae irom the Environs
of Sendai: Part 11. On PerfPII ICh/amys) rmssiveuius YoKoYAMA
and its related Species ............................................................... 223-229:~2Katsumi H1RAY AMA: On Luri!loma ao/{ii, a new Pleistucl'nc
Lamellibranch from Chiba Prefecture. Japan. Notes on JapaneseLucinid l'vlolluscus. Part 2.......................................................... 231-236:~3Haruo 0KuNo: Electron-Microscopic fine Structure of Fossil
Diatoms, V: Observation on some Diatoms found in Celatoms ... 237-242 34-35
Masahiko AKIYAMA: New Fossi I Ch/amys from the Environs ofNagano City. Japan ..................................................................... 243-247
36
Tciichi KoBAYASill: A Gotland ian Nautiloid from the Hida Plateau
in japan..................................................................................... 248-252
37
Tsugio SnuTo: Granulifusus from the Miyazaki Group (Palaeontological Study of the Miyazaki Group. V J ................................. 253-264
38
Riuji EN Do: Stratigraphical and Palaeontological Studies of theLater Palaeozoic Calcareous Algae in Japan, XIII. A Restudy of
the Genus PllysojJOrel/a . ............................................................... 265-269
3!l
Short Notes

2.

Wataru lcmKAwA: Once again on a rare Species Triceratium
simPlex ]. BRuN ........................................................................... 230

iv

Proceedings ................................. :ao:\umber 32 1 Published November 10, 1958)
Transactions
K6ichir6 rvL~sUDA: On the ~iliocene Pectinidae from the Environsof Scndai; Part 12, On J>ecten kagamianus YoKoYAMA .................. 271-284 40-41
349. Wataru HAsiMOTo and Saburo KANNo: Molluscan Fauna fromthe Tertiary Formation of Chirai. Kamisaroma. Kitamino-kuni,
llokkaido. . ................................................................................ 285-29042350. Akira ToKUYAMA: Late Triassic Palaeopharus in japan ............ 291-298
43351. Rikizo hrArzu:o.n: An interesting Crustacean I~emain. Ctenocheles
sujakui n. sp .............................................................................. 299-304
4,1
Proceedings ................................. 305-306
Systematic Index ...................... 307-308
Index of Fossils ........................... 309-311

348.

NEWS
International Oceanographic Congress Lt. New York 0 United Nations Building "(' 1959 ~:8 f] 30 Fl ;/Jd:, \I } J 12 1:J 1 "t'001J•H 7.> ., C. C. L'li (I) The History. (2) The Boundaries. (3) The
Deep Sea. ('I) Dynamics of Organic and Inorganic Substances &V' (5) The Marine Lift
Regime U> 5 symposia :~;:,Hiifli~tn::t>.Oil:f!i1 5 (i) symposium L'l.l~0 5 P.~mil:Mil&~tl.Oo(a) The palaeogeography of marine floras and faunas,(b) Biogeographical regions in the sea.
(c) Evolution and adaptation in the sea.
(d) The behavior of marine organisms as influenced by environmental factors,(e) Physiology of marine plants,(f) The culture of marine organisms as a means of understanding cvironmental
inllucncc on populations.
~'f.l4~'irlltJ!C.IIIJ{t'ltH!i.t t •,. Dr Mary SEARS, Chairman, Woods Hole Oceanographic Institution. Woods llole, Mass .. U.S. A.

·lth Panafrican Congress on Prehistory (;t«Jv.;t:-f,U=":.--="·0 Lcopoldville "(' 1959:1f:8H 2-1-.....29 ~w:.nHmt il .o c..t !U.J: "? t.:o ~~LHf. t ~$jllJ~·f.OO{~. ~ 2 $tli~I.:~·Y.~II,t;.
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Secretariat du IVme Congres Panafricain de Prchistoirc
Laboratoirc de Geologic
Universite Libre de Bruxellcs
50. avenue F.-D. Roosevelt
Bruxcllcs (Belgique)

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