fJ -lt-- $ .i. ~ '¥ ~{U..~· i~t
Transactions and Proceedingsof thePalaeontological Society of Japan
New Series

No. 38Palaeontological Society of japan] unc 1, 1960

CONTENTS
TRANSACTIONS
Page

380.

Permian Corals from the Taishaku District, Hiroshima Prefecture, Japan .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tsuruo YoKoYAMA 239
381. On the Miocene Pectinidae from the Environs of Sendai; Part 16. Pecle1z
kimurai YoKOYAMA and Pa/liolum cf. peckhami (GAim) ................ .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Koichiro MAsUDA

382. l\lolluscan Fossils from Tungyiiping in the Penghu Islands, Taiwan .....
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. Ichiro HAYASAKA and Shozo IIAYASAKA
383. A Note on Neoburmesia, a peculiar Jurassic Pelecypod, with Description

249
263

of Mytilids and Myacids from the Upper Jurassic Soma Group in
Japan ................................................... Minoru TAMURA 275
Short Note
6. Two jurassic Pelecypods from West Thailand ............ Itaru IL\YA\1128!

President: Teiichi KoBAYASHI
Councillors: Kiyoshi AsANo, Riuji ENoo (Publication), Seido EN no, Ilaruyoshi Fuw
MoTo (Treasurer), Shoshiro I-L"-~ZAWA, Kotara HATAI, Ichiro IIAYASAKA, Kazuo
IluzioKA, Nobuo lKEBE, Jiro .lVIAKIYAMA. Tatsuro MATSUMoTo, Masao MINATo
Tokio SmKAMA (General Affairs), Fuyuji TAKAI (Editor), Ryuzo ToRIYAMA
Secretary: Tetsuro HAN AI
Assistant Secretary: Takeo lcHIKAW AAll Communications relating to this Journal should be addressed to the
PALAEONTOLOGICAL SOCIETY OF JAPAN
Geological Institute, Faculty of Science, University of Tokyo, Japan

Trans. Proc. Palaeont. Soc. Japan. ~- S .. Xo. 38. pp. 239-2-18. pis. 27-28. June 1. 1960

~so.

PERi\IIA:\ CORALS FRO~I THE TAISHAKU DISTRICT.
HIROSHL\'IA PREFECTURE. JAPA:\*TSURVO YOKOYAMA
Institute of Geology and :\lineralogy, Hiroshima University!A,(!; !!J'it'fRl1l!1ii)(,:=.-lll:*lil1lf#l'll : &t*· .: Q)il!r1JQ)=.-!!I:*l!lllmlf!!lt. li cA. c Pseudoscluvagcrina 11\'fl·i?1.iJtyJI_ -n ·t..:;;:. lfrt.::.:.IHl'iif:t-:i .J: v>: LePido!ina ?tl'il.J~,. l!lll~'iJ(t.1J!1W~llf
1:."'?1.-"CQ)~I.l:i.~i!J.f.:. ·nii"~lt. Stylidopltyllttlli "C'~~·-:Htt?h. ~1111. Tl"aagenophyllum "C~*~,h;o, -t.tt~:.t c-?~. ;:Q)l1J!1JQ)=._II;l:*lllllmlltfi{\~=.:~}~Jil!:~L. Waagenoplly/lum
Ffi 4 flfl. Huangia ~ 3 f,f(. Styfidophyl/um ~ 2 f\1!. J; J: ~ LoPhopllyllidium ~ 1 fill~~~Lt.:,

llYl !11 •~Introduction and Acknowledgements

Previous works

This paper gives the results of inve3tigation on corals obtained from thePermian limestones of the Taishaku
district.
The occurrence of a number of spe·
cies of corals has hitherto been reported. from the Pseudosclncagerina zone
and other zones of the district (YosmNo.
1937: Hczi:--toTo, 19H: Mt:o.:,\TO. 195:1: andAKAGI, 19581: but none of the species
has been described. Among the Permian
corals. 10 species in 5 genera are distin·
guished by the present writer from thePseudoschwagerina and Lepido/ina zonesof the district.
The writer wishes to express hishearty thanks to Dr. lchiro HAYAs,\tn.
President of Shimane Cniversity. forhis kindness in reading the manuscript
and for his valuable guidance on the
study of corals. He also acknowledges
the helpful encouragements of Prefessor
Sotoji htA~tt.:RA of Hiroshima University.

l\Iany authors have noted the occurrence of fossil corals in the l\Iisaki
limestone and its equivalent. central
part of the Taishaku district. and insome limestones exposed at some other.parts of the district. but those fossils
have not been investigated paleontologically.
Y osH 1;.;o (1931) reported several coral
species from the district. of which
Waagenoplzy/!um sp .. Clisiopliy/!um sp. andTFentzele//rt sp. are of Permian age.
1-h:zntoTo (1944). in his Sakmarian
limestone, recorded the occurrence of
Akiyosiplzyllum cf. st,vlophorum Y,\BE et
St:GtYA~t,, and C!isiophy/lum sp. from his
Joe. no. 2. about 200m. south of thepresent writer's locality of I\·1isaka. inassociation with Pseudojusuli11a kra!fti,
P. llrotowi, P. tshenzysc/zetci, Schtcagerina
sp. and others. By MtXATO (1955, p.
108). ll"aagenoPhyllum akagoensis OzAwA
from Shiramizu. near the junction of
Taishaku-gawa and its tributary Zenbutsuji-dani. was presumed to be of the
Cppermost Pseudosclucagerina (?) or* RecciYed Feb. 28. 1959: read at the :\nnu·
al !\1eeting of the Society at Hiroshima.
Feb. 14. 1959.

2-!llTsuruo YOKOY.-1.\/A

Parafusuli11a zone.
Recently, AK.·\GI(1958) also re::orded the occurrence of
Stylidoplzyllum n. sp. and Huangia sp.
from his Pseudosclncagerina zone in
the Miharano area. some 2 km. ea.ot of
M~aka.
In this WaY. the coral species of thePseudosclnM~erilia zone have been madequite well known from the district.
:!\laterials dealt with in this paper

Through extensive reconnaissance ofthe district the present writer hashitherto obtained the following !;pecies:
1) from greyish limestone of the
Mi!'aka area, about ~00 m. north of the\Hsaka Primary School.
Styliclophyllum yolwyamai tertioseptatum,su bsp. nov.
S. eguchii. sp. nov.
Iluang:a misal?ensis, sp. nov.
H. spp. A and B
Lof>hop!tyllidi wn sp.
in association with abundant fusulinids,
including such genera as Pseudofusulina.
PseudosrhwagPrina and Sclucagerina. as
well as Palaeoap/,vsina /aminaeformis
KROTO\\"*.

:2) from the valley of " lppaimizu ", afamous .. geyser" of the district. about
1 km. sout);west of Toj6-town.
Waagenophy/lum ? sp. i nde!.
with such fusulinids as Yabeina spp.,
Sumatrina annar. Codonofusiella sp., etc ..
in a limestone-lens.
3) in a pebble in the limestone-conglomerate of the Neosduragerina zone exposed at about 100m. west of Nagano,
Conce11ia? sp.
4) from the massive grey or dark-grey* A reef-building Hydrozoa (?).

Sec H.
(1949): Two Permian Fossils from
China and Japan of uncertain Affinity. Proc.
japan Acad., Vol. 25, No. 6. pp. 215<~18, Figs.
1-6.
YABE

limestone of the Yasumoto Formation*.
which contains abundant fusulinids
characterizing the Lepidolina zone. suchas Lepidofiuti. Yabeina. Codl!ltofusiella,etc ..
JVaagenophyllumlonf.[iseptatum, sp. nov.
W. cfr. akasakensis IY:\IIE\
TF. sp.
l\lany calcareous algae also occur richly
in the formation.
Of these coral species. Stylidophyllum
eguchii, sp. nov. is a new form haYing
broader dissepimentarium and rather
regular direction of longer axis ofelliptical columella; and S. yokoyamai
tertioseptatum, subsp. nov., closely resembles, and may probably be conspecificwith Lmzsdaleia !? Waagenophyllum)
yolwyamai Oz.\ w A 1928 [ =Stylidop/zyllum
yokoyamai (0zAwA1. :'-.11:-;ATO 1955] fromthe .. Uralian "-Lower Permian** atKaerimizu in Akiyoshi district. Huangia
misalwnsis. sp. no..-. has a more densely
constructed corallite. though unfortunately it is preserved unsatisfactorily
in a fragmental material. and is a remarkable species in comparison withthe species in the coral faunas of other
districts.
Although no closer similarity is foundamong them. the Stylidophyl/um faunule
associated with the Pseudosclucagerinafaunule of the district apparently corresponds to that of the Pseudoschu:agerina zone of other districts, to theZo~e of Stylidophyllum volzi of Southern
China (IluA~G, 1932), to the Huangia
llasimotoi- Lop!wphyllidium suetomii zone.
according to Mn,:.\TO (1955. Table 1). andalso to that of the coral faunas which* The detail of the formation will be described by the writer in his future paper.
** It is now generally accepted OZAWA's
CPg should represent the Para[usuli11a zone.
as was pointed out by \'II:>~!\ TO (1955, p. 13-l).

380.
-,vererecognized by

Permian Corals from the Taishaku District
Hczt ~toTo* andAKAGI.

Species of lVaagenophyllum are foundabundantly in the upper half of the
Lepidolina-limestone of the Yasumoto
Formation, and they generally havemore irregular contlla than those known
previously : especially the former israther dendroid. in growth than phaceloid as in the latter, although corallites
are often found isolated in the rock.
Specimens allied in form to type-speciesof the genus, TVaagenopltyllum indicum,
have not been found in this formation.
In point of being in association with
Lepidolina faunule the occurrence in
the '{asumoto fauna much more closely
resembles the Kuma fauna (KAl':VIERA,
1953) as well as the Kitakami fauna(l\lt;-.;ATO and others. 1954) rather thanthe coral faunas in either the l'abei11a
zone (s. 1.) of Akiyoshi (OzAWA. 1925;
revised by l\1INATO, 1955) or of Akasaka
and neighbourhood (Y ABE and others,
cfr. ~iJ!'ATO, 1955, p. 32).
The Waagenoplzyl/um- and Stylidophyllum-faunas
occur
independently
from each other. Stratigraphical relations between them is tabulated asfollows in reference to the fusulinidzones. Taking into consideration thisstratigraphical relationship, the writeris led to distinguish two coral zones in
the Taishaku district: that is. theStylidophy/lum eguchii and the H'aagenop.'tyl/um longiseptatum zone, corresponding to the PseudosclmYtgeriiUl zone andthe Lepidolina zone, respectively.

Stratigraphic summary of the distribution of Permian wrals.
Coral zones

Coral species

H'aagenophyllum /ongisrptalum

IVaagenapJn·llum cfr. akasakensis.
lV. longiseptatum. sp. no\'., W. sp.

Fusulinid zones
LePidolina
Yabeiua

Waagenophyll:mz ? sp. inclet.

Neosclucagerina
Pamfusulhu

Pscudosclzzcagerina

Sly/idophyl/um eguchii

Description of species

Family Clisiophyllidae NtcHoi.so~
and Tuol\tso;-.;Genus Waageuophyllum HAYASAKA. 1924
!Vaagznop!Iyllum longisep!a/um. sp. nov ..
Plate ~8. Figures 3a-c

Description :-Corallum compound. fasciculate:! dendroidally and more loosely

Stylidophyllum eguc/zii, sp. nov .. S.
yokoyamai fer/ ioseptalum. su bsp.
nOY .. Hwmgia misakensis. sp. nov.,
If. spp .. /..oplwphyl/idium sp.

or irregularly. corallites being flexuous.
Corallites cylindrical with an average
diameter of 7 mm.: irregular but rather
circular in trans\·erse section. and moreregularly constructed internally. Wallrather thick. ~tajor and minor septa inalternation: all of them thin but usuallystrengthened with stereoplasmicdeposits* Of his species, .4kiyosiphy!lum sty!op/ll)rmn
is ascribed to the Yabeina zone by MI:-:ATO(op. cit .. p. 168).

242

Tsuruo YoKOYAMA

and slightly thickened toward the wall,and conspicuously sinuous in the peri'
pheral area where stereozone is widely
developed with a width of about half
the length of the major septa : theformer one slightly stronger than thelatter throughout the growth; 2(i innumber and about 2/3 of the diameterof corallite in length. while minor ones
are about 3/4 of the major ones: sometimes bending at the inner ends but
almost reach to the outer margin ofcolumella. but never connected withseptal lamellae. Tertiary septa quite
obscured. Dissepiments less numerous.
arranged concentrically. Columella elliptical. its structure being ··eccentric "in transverse section. constructed rather
thickly with axial tabellae. septal
lamellae and indistinct median plate.
occupying about 1/3 of diameter ofcorallite.
In the longitudinal sect ion. coarse
dissepiments are arranged irregularly,
and inclined steeply at the peripheryof columella facing their com·ex sides
toward inside. Stereoplasmic deposits
fibrous in appearance. Columella <.:omposed of gently arched axial-tabellae
and numerous, minute septal lamellae.
Comparison :-This species may be
more advanced form of the genus.
Comparing with Tlaagenophyllum akasakeusis (YABI·:). the species now inconcern is distinguishable in the following characters of corallites, from theoriginal material of Tr. akasakensis:
number of septa and their more regulardevelopment. stereozone and structureof columella; degree of attachment of
septa with columella. and of development of dissepiments in immaturecora II ites from that illustratecl by
MINATo (1955. PI. 37. Figs. 6a-e); andalso the corallum being more loosely
fasciculate and irregularly bent thanthe material described by OzA\\'A (1925'r
PL 14. Figs. 5 and 6).
Occurrence:- The IVaagenophyllu m·
lougiseptatum zone of the Yasumoto·
Formation. central part of the Taishaku
plateau. Tojo-ch6. Hiba-gun. Hiroshima
Prefecture. (liolotype :-lGSH Y. T. No. 3)

Waagenophy!lum cfr. alwsake11sis (YABE)
Platl: 28. Figures la-d and 2a-d
1909.

1915.

19:!5.

19:10.
1955.

Lonsdaleia akasakemis. YABE. foul". Geol:
Soc. Tokyo, Fol. 9 .•\io. 10·1. pp. 4-5 ..
fig. 3.
Lonsdaleia ( Waage11ella) akasakensis.
YABE and HAY.-\SAI\:\, four. Geo(. Soc.
Tok;o. Jlol. 22. pp. 100-104.
Waagellophyllum akasake11sis, 07.A w A.
four. Coil. Sci. Tokyo Imp. Cniz;.. Vol.
45 .•4rt. 6. p. 75. pl. 14. figs. 5, 6.
Waagt'nophyllum akasakemis, S:-IITH.
four. Pal .. Vol. 9. p. 36.
rvaagellopllyllum akasakensis. MI:--:ATO.
four. Fac. Sci. Hof.ofwido Unit•.. Ser. IV.
l'ol. IX. No.2. pp. 101-105. pl. 37. figs.
6a-e. 7.

Description :-Corallum
fasciculate.
with cylindrical corallites that are
irregular in transverse sections. 'Vallrather thick. strengthened with stereoplasmic deposits: the other structure
also arc thickened in the same \\'ay.
Septa in two orders. major and minor
in alternation : both somewhat flexuous
and thinning towards the center: theformer 22 in number in mature stageof corallites, and not wnnectcd withcolumella: about 1/3 of calicular diameter in length: minor ones about 1/2
or '2/3 of major ones : dissepimcnts
numerous: stcreozone distinct. Columella rather elliptical in outline andmore thickly constructed with septal
lamellae and axial tabellae. with an
indistinct median plate.
Comparison :-Compared with Waagenophyl!um akasakensis (Y ABE) in trans\"erse380.

Permian Corals from the Taislwku District

cSection. the present specimens coincidewith the former in major features. But
it has more irregular corallites that are
roughly fasciculate.
In comparison
with IV. aimgoensis Ou wA, the species
now in concern has relatively longer
minor septa.
Occurrence:- The !Vaagenopltyllum
longiseptatum zone of the Yasumoto
Formation.
IYaagenoPiiyllum sp.
Plate 28. Figures -!a-rl;
Plate 28, Figure 6

Description :-Corallum compound, irregularly and roughly fasciculate.
Corallites rather irregular in transverse
section, with the calicular diameterattaining about 4-5 mm.
Wall thin.
Septa in two orders, major and minor
in alternation: all being thin and flexuous. Major septa 21-22 in number withthe length l/3 of calicular diameter:minor ones about 2/3. sometimes 3/4 ofmajor ones. No major septa reach tocolumella. though the stereoplasms
grow irregularly and inwardly fromthe inner ends of some major ones connecting \Vith columella. Dissepiments
numerous: in immature stage of corallite. thicker stereozone develops. having
the thickness as wide as the minor
septa are long. where a few dissepiments occur. Columella rather thick,but irregularly constructed with axial
tabellae. septal lamellae and obscure
median-plate: it measures about 1/4 ofcalicular diameter. The ratios of columella to corallites are very variable.according to growth stages of coral lites.
C(nnparison :-Although the specimensshow the same features characteristicof the type species. W. iudicum. that is,in calicular diameter, septal nature, etc.,·this material is not identical with thelatter. The following are the differences
between them: .
1) :\lajor septa of the present species
do not reach to the columellum which
is more thickly constructed than in
the type species: 2) Corallum of theformer is formed of a less number ofcorallites that are more irregularly or
dendroidally fasciculated than those of
the latter. TVaagenop/iyllum tcengt'hengense lfu,\i-:G and ff'. akagoe11sis (0Z.·\W,\),obtained from the Permian of Southern
China (Hu.\:'\G, 1932) and from Akiyoshi(OzAwA. 1!:!25). respectively, are the otherallies. but the present species has
smaller corallites and thicker stereozone
which develop more thickly in earlystage of growth. The major septa of
the species no\v in concern. furthermore.
are inserted into the center. closely
approaching the columella. but in thelatter two species the septal ends andcolumella are a little more widely apart.
In comparison with H'aagenophyllum
akasalwnsis (YABE). the present form
has smaller dimensions and slim innerstructure.
Occurrence:- The IVaagenop/iyllum
longiseptat um zone of the Yasumoto
Formation of Taishaku district.
Waag.mophyllum ? sp. indet.

There is an imperfect, fragmentarymaterial from the dark limestone-lensof }'abeina zone. In an oblique section,
two kinds of septa with distinct stereozone are observable. Although it appears an oblique section of the preceding species, its exact nature is uncertain.
Occurrence:- Yabeina zone (s. 1.) of"Ippaimizu ··. near Tojo-town.
Genus Huangia Y ABE. 1950
Huangia misakeusis sp. nov.
Plate 21. Figures 5a-d

244

Tsuruo YOKOYILll.-1

Description:-The nature of corallum
unknown. Corallites irr~gular in shapeand size, 15-18 mm. in diameter. \Vallrather thick. Septa in two orders,major and minor in alternation; theformer about 30 in number (exact
number unknown), reaching almost to
the periphery of columella, andstrengthened with stereoplasm; minor
ones about 1/?.. to 1/3 of the former inlength and rather weak. but neverpenetrated into the tabularium which
is separated from dense dissepiment·
arium by the indistinct false inner \vallformed of the inner series of vesicles.
beyond which minor septa do not pro·trude. Dissepiments are arranged usually in herringbone pattern but irregular in parts. The width of dissepimentarium attains about 1/2 of radiusof corallites, and that of tabularium
which is modified by the irregular cut·edges of inclined tabulae, about 1/4.
but rather unequal in some parts.
Columella irregularly constructed withnumerous axial tabellae and septal
lamellae: median plate indistinct.
In the longitudinal section, triareal
arrangement is shown: dissepimentarium
is composed of numerous. fine vesicles
inclining gently but steeply inwards.
Tabulae rather horizontal but arranged
irregularly.
Columella made up of
numerous, steeply arched tacellae andseptal lamellae.
Comparison:-This species has more. thickly but irregularly constructedcorallites. The structure of columella.
irregular tabularium and clissepimentarium of this species differ conspicuous·
ly from those of lluangia ltasimotoi(NAGAo and :rvitNATO) from the Pseudo·sclnmgerinrt zone of Kitakami lVlassif.
Occurre111:e :-The Sty/idoplzyl/um eguclzii
zone of Misaka. about ?..00 m. north of
the Misaka Primary SchooL T6j6-ch6,

Hiba-gun. Hiroshima Prefecture. ~fiolo··
type: IGSH Y. T. No. 4).
Iluall[{ia sp. A
Plate '27, Figures '2a and b

Description :-A transverse section ofa coral. Corallum probably compound.
fasciculate. Corallite about 10 mm. indiameter. Wall is of medium thickness.
though strengthened with dark materials and almost destroyed. Major
septa preserved in about one half partof the corallite. in length being about
1/3 of diameter of corallite. reaching to
the the columella but not connectedwith septal lamellae. Minor ~epta observable scarcely in the outer r-arts wherecoarse dissepiments are found. Tabulae
rather numerous. Columella circular inoutline with diameter roughly eqlialing
the radius of corallite. composed of
distinct median plate, numerous radiatedseptal lamellae and axial tabellae.
In an offset. a small corallite whichappears rather trigonal in outline. a few
septa and indistinct axial-structure arerecognized.
Comparison :-This material is somewhat allied to the type species of thegenus. !Iuangia clzutsingensis (CHt) from
Weiningian (l\1iddle Carboniferous) ofSouthern China, but has a more closely
constructed. circular columellum.
Occurrence :-The Stylidophyllum eguchii
zone of Misaka .
llua11gia sp. B
Plate 27. Figure 3

DescriPtion :-A fragmentary material
showing only in a transverse section.
Corallite somewhat polygonal in outline,.
5 mm. in diameter. Septa in t\vo orders :major septa rather irregular but 2/3 ot

380. Permian Corals from the Taishalm Districtradius of corallite in length: minor
ones very short, alternating with theformer, about 1/3 to 1/4. In the preserved half of the corallite. major septa
are about 10 in number. Dissepirr.::ntal
zone narrow: and dissepiments lessnumerous and arranged irregularly withminor septa which neYer cro~s the innersurface of the zone. Columella constructed Yery loosely or irregularly
with septal lamellae and axial tabellae:
me~lian plate indistinct.
Comparison :-This species quite differsfrom the preceding one in the internal
structure, especially in construction ofcolumella and tabularium.
Occurrence:- The Stylidophyl/um egudnizone of 1\Iisaka.
Genus Sty!idopliyl/um FRoME:-:TEL. 1861

Stylidophyl/um eguchii, sp. nov.
Plate 27. Figures 4a and b

Description :-Corallum compound. cerioid: outer shape unknown. Corallites
more regular in shape and size: polygonal in trans,·erse section. \Vall thin
but strongly thickened. Dissepimentalzone broad. filled up with numerous,
fine but partly coarse vesicles withseptal ridges in part. Septa of twoorders. longer and shorter, in alternation; extend back into dis£epimental
area and connected with septal ridges
inside the wall especially where thedissepimentarium is narrower. Longer
septa 21 in number and usually notunited with columella: uniformly thin
but rather lophaloidal in the calicularpart. Shorter ones about 1/2 to '2./3 aslong as the former. Columella ellipticalin shape. composed of median plate.
septal lamellae and axial tabellae: thelonger axes or the median plates all
point to the oame direction. ~eptal

lamellae and axial tabellae are lessnumerous for a species of StylidoPh.vllum
in general.
In the longitudinal section preserved
unsatisfactorily, all the parts of corallite
structure are strongly destroyed by recrystallization of calcite fibers.
The
gently inclined coarse dissepiments, thehorizontal tabulae and the axial-tabellae
are in part free from the secondary
recrystallization, to preserve their original features.
Remarks :-Cnfortunately the material
is ill-preserved, especially in the longitudinal section. The bight of corallum
attains about 10 mm., being buried in alimestone block. The species has amore regular structure in cornpariwn
with the Chinese Stylidophyllids described by Ht·A;.;G (1932). In the features
mentioned al:oYe, the present species ismore approximate to the several Iranianspecies (Douc;L.\5, 1936), but it has thefiner dissepimentarium. larger tabularium and elliptical columella. not tospeak of the peculiar parallelism oforientation of the columellar medianplates.
Occun·ence :-The Stylidoplzyllum eguclzii
zone of Misaka. (Ho/otype: IGSH Y. T.
No.5).

Stylidophyllum yokoyamai
tertiosePiatum. su bsp. nov.
Plate 27. Figures la-cDescription :-Corallum compound. massive and cerioid, partly plocoidal. Corallites polygonal, irregular in size. Wallmoderate in thickness, strongly thickened by stereoplasmic deposits: so are thesepta, septal ridges and other structures.
Septa usually of two orders, major andminor in alternation: tertiary ones develop in some parts: all thickened

Tsuruo YoKo Y.-lMA
gradually toward the wall.
}Jajorsepta not united with columella. and li
in number. about 2/3 of the diameterof corallite in length. lVIinor ones more
irregu Jar in length and development.
Interseptal dissepiments arranged inconcentric or irregular pattern. Septal
ridges inside the wall correspond inposition to that of septa. Columellaalso irregular in shape and size, andcomposed of distinct a median plate.
septal lamellae and axial tabellae.
Median plates in some corallites connected with one of the major septa.
Septal lamellae and axial tabellae lessnumerous.
Peripheral dissepimentalzone rather broad.
In the longitudinal section. columellacomposed of median plate and conical.axial-tabellae. Tabulae horizontal, occupying a narrow zone, numbering
about 15 in a distance of 5 mm. Dissepiments rather coarse and less numerous.
Comparison :-The species is practically identical with Stylidophyl/um yokoJ•amai (OzAwA) in general aspects. only
apparently differing in the septal number in mature stage of corallitcs and in

the occasional development of tertiary
septa, and also in the simplicity ofcolumellar structure. In point of thegeological age, the former younger thanthe latter which belongs to the Parafusulina zone. according to OzAwA.
Occurrence:- The Stylidoplzyllum eguchii
zone of l\lisaka. (Ilo!otype: IGSII Y. T.
No. G).
Family Lophophyllidae GRABAu, 1928
Genus Loplwphyl/idium GRABAc, 1928
Lopliophyllidium sp.
Plate 27, Figure 7

Description :-Corallite solitary, small
with calicular diameter about 8-10 mm.
Well rather thick. Septa Yery thickand tough, counting ~0. almost reach tocolumella excepting minute. doubtfulcardinal-one. .Minor septa absent. Columella very large. roughly- circular or
almond-shaped with a cusp directing
the head to the presumable cardinal
septum ; about the same as the radiusof corallite in diameter; and made up

Explanation of Plate '.!.i
Figures la. b and c. Sty/idopliyflum yokoyamai ter/iosepta/um. subsp. nov.
la-b. serial transverse sections of the holotypc (X 2) .: lc, longitudinal section ( x2):
the arrows show the same corallite in both :>cctions.
Figures 2a and h. flua11gia sp. A.
2a, transverse section of a corallitc with a offset one (x3); 2b, longitudinal section(x3).
Figure 3, Huangia sp. B. transverse section (x7).
Figures 4a and b, Stylidophyllum eguchii, sp. nov.
4a, transverse section (X2): 4b, longitudinal section of the calicular part (X3),drawing through Camera Iucida apparatus.
Figures 5a-d, llua11gia misakensis. sp. nov.
5a-c, serial transverse sections (X2); 5d, longitudinal se..:tion (x2).
Figure 6. T·Vaagenophyllum sp.
Oblique longitudinal section (x5).
Figure 7, Lop!wpllytlidium sp.
Transverse section (x3.5).

YOKO YAMA:

Permian Corals from Taishaku

Plate 27

380.

Permian Corals ftom the Taislzaku District·of numerous. fine vesicular tissues. Byhigher magnification, the columellum isseen to be composed of axial tabellae,
septal lamellae and indistinct medianplate or striation connected with thecounter septum, as is found clisiophyllid
corals.
Comparison:- The species may be considered nearly to Lop/wplzyllum amygdalop!ty!loidea HuANG [ =Lophophyllidium
amygdalophyl!oidea (I-IuA:-:G)] from thePermian of Southern China, in general
aspects especially in the nature ofcolumella. but differs from it in septal
development; that is. in the Chinese
species the tertiary and also quarternary
septa develop in the peripheral stereozone, while in the present Japanese one
has fhe less-numerous, tough major
septa.
Occurrence:- The Stylidop!tyllum eguchii
zone of .Misaka.
References(1958): On some Permian l'or~(erafrom Japan. jubilee Pub!. in the Comme·
mora/ion of Prof H. Fl:JT.Itom, p. 66.
CHI, Y.S. (1931): Weiningian (Middle Carboniferous) Corals of China. Paleont.
Sinica, Ser. B, Vol. X!!, Ntsc. 5.
Dol'GLAS, J. A. (Hl36):
A Permo-Carboniferous fauna from Southwest Persia(Iran). Palaeont. Indica, N. S .. l'lfem. 1\lo. 6.
FLl'GEL, H. (1955): Zur Palaontologie desanatolischen Paliiozoikums IV. Permische Korallen aus dem sudanatolischen
Taurus. Neues ]b. Geo/. u. Paliiontol., .4bll.,
101. 8, pp. 293-318. Pls. 33-35
GEIHII. H. (1921): Die Anthozoen tier Dyas
von Timor. Paliionlologie L'01l Timor L\:,
Pls. CXL V -CL.
- - (1937): Pcrmkorallen aus dem ()stlichen
Karakorum und Triaskorallen aus dem
l\ordwestl ichcn Himalaya. Palaeontographica, 88A
GRABAL', A. W. (1928): Palaeozoic corals ofChina. Part. 1, Palaeonto/. Siuica, Ser. B,
AKAGI. S.

z;o/. 2, jasc. 2.
(1924) : On the fauna of the
Anthracolithic limestone of Omi-l'vlurain the Western part of E~,;higo. Sci. Rept.
Tol10k11 Imp. Uuiz·., 2nd ser .. <'ol. VIII, no.
1. Pis 1-7.
HERITSCH, F. (1936): Korallen der Moskauer-. Gshel- und Schwagerinen-Stufe
der Km·nischen Alpen. Palaeonlographica.
88.-!.
1-IcA:-:G. T K. (1932): Permian corals ofSouthern China. Palaeontof. Sinica, Ser.
B. l'ol. 8, fasc. 2. Pl. I-XVI.
Hczi~IOTO. II. (1!l<l4): Palaeontological study
on Titibu-System of the Taisyaku-kyo
Region. Hiroshima Preft!cture. Studies
from Geol. and Jlin. Ins/. Tokyo Buurika
Daigaku, No. 1.
]EFFOIWS. R. .M.
(19-H):
Penn:>yl\·anian
Lophophyllidid Coral:;. Unil'. Kansas
Pa/eoutol. Con/rib., Coeleutemta ..--lrl. 1. pp.
1-84, Pis. 1-28, figs. 1-9.
l\h:RRI.-UI, C.'\'. (19-1:?): Carbonift:rous andPermian corals from Central Oregon.
]our. J',t/eon/ol.. ml. 16. 11c>. 3. pp. 372-381.
Pis. 54-57.
l\11:--;ATO. M. (1955): Japanese Carboniferous
and Permian Corals. four. Fac. Sci. Ifokkaido Unit• .. Ser. IV. l'o/. !.\'. ;w. 2.
--and others (195-!): Zur Biostratigraphie
der perrnisd1en Formation des SetamaiGcliindes im Sud-Kitakami Gebirge(Stratigraphische und tektonische Untersuchungen des japanisd1en Palaozoikums, Tei I 9). ]our. Ceo/. Soc . .fapan, rot.
LX. no. 108. p. 378.
MooRE, R. C. (1956. edit.): Treatise on InYertcbrate Paleontology. Part F. Coelenterata. Geol. Soc. Amer. and Fniz,_Kansas Press.
- - and R. l\1. JEFFORDS (1945): Descriptionof Lower Pennsy!Yanian corals from
Texas and adjacent States. Fuiv. Texas
Pub!., no. 3301.
ScJIOCPPE, A. v. and P. ST.\Cl'L (1955): Die
Genera Verbeekiella PEKECKE. Timorphyllum GERTH, Loplwphyl/idium GRABAU aus
dem Perm von Timor. Palaeontographica
Supp/. lz•. V Art., Liefg. 3. pp. 95-196.
s~IITH, s. and T. A. RYDER (19:?()); The
I-lA Y.·\SAKA. I.

248

Tsuruo YOKOYAJ1A

genus Corwenia, gen. nov. .tlnn. ami_ J.Iag., Nat. liist., 91/z ser., vol. 18. p. 140.
T~-EKG. T. C. (1950): On the genera Stylidophyllum and Polythecalis. Bull. Geol. Soc.
China, z•ol. 30. nos. 1-4.
WAAGE:-<. \V. and l WE:"TZEL (1886): Salt
Range Fossils. Teil 6. Coelenterata.
Palaeontol. Indica. (13) l'ol. 1.
YAnE, II. (1909): l\laterials for a knowledgeof the Anthracolithic fauna of Japan.
four. Geol. Soc. Tokyo, z·ot. 9, p. 4.
- - (1950): Permian Corals resembling
lflaageJwphylhmz and Corwenia. Proc. japan

Acad., t•ol. 26. p. 76.
- - and I. HA YASAI<A (1916-17): Paleozoic
corals from Japan. Korea and China.
jour. Geol. Soc. Tokyo, z•ols. 22-23.
YoH, S. S. (1932): The coral fauna of thfr
Chisia limestone of the Lower Yangtze
Valley. Palaeontol. SiniL·a. Ser. B, vol. VIII,
fasc. 1. Pis. I-X.
YosJJJ:"O, M. (1937): Palaeozoic fossils foundin the limestone of Taishakudai, Bingo
Province (I-II). ]our. Geogr .. z•ol. XLIX,
110. 580, p. 269: no. 581, p. 307.

Explanation of Plate 28
Figures la-d and 2a-d. TVaagenophyllmn cfr. almsakensis (YARE).
Serial sections of accompanying corallitcs (xlO).
Figures 3a-e. Waagenophyllum longiseptatum, sp. no\'.
3a-d, serial transverse sections of ephebic stages of a corallite (x5): 3e. longitudinal section (X5). drawing through Camera Iucida apparatus.
Figures ·1a-d, IVaagenophylltmt sp.
4a-d. transverse sections. in which 4d is an ephebic part accompanying with anoth~rcorallite of ·mature· stage.

Y oKOYAMA :Permian Corals from Taishaku

Plate 28

Trans. Proc. Palaeont. Soc. japan. K S., No. 38, pp. 2·19-262, pis. 29-30, June 1. 1960~81.

ON THE l\UOCENE PECTINlDAE FROM THE ENVIRONSOF SEKDAI; PART Hi. PECTEN KIMURA! YOKOYAl\fA
AND PALLIOLUM CF. PECKHAM! (GABB)*
KOICHIRO IvlASUDA
Department of Geology, Facultv of Education, Tohoku University(~ti~f't.ia:•r':frrt;l(i.f.

Pectinidae; ~CI) 16, Pecten kimurai YoKOYA~IA &o: Palliolum

cf. jJeckhami (GABB) : l'eclell ldmurai l:t. B *-*!1J!Il)cp~k;/til•l? ~~ifftl:li" ~ t..:.~:..:.ill'1f:
l..:.m~t.d\!lt:·<b .Q, 9t L. kimurai Cl)!i;!J-~!l\'i:;f;:n::pJi:j£fJ: ~ Cl)'{;b--> t..:.t..:.~ c. .:..tt;.:.llJiN.>-c

1J!IJ.:t L.t..:.~~OYNDW.IIP.Nin:;tc~ ~ :it.t..:.t..:.~:.:. lVf'lE:{ill):{(.O!n: i '!? i '!;, t:·~ <Q)~~t;'.j:_ [.
-ct ·t..:.. 1n~,;, ..:..it.J?O)~'IiL~M~-r~ t..:.~. m:>\:it!!~fl;tr~ <O)iJE!1l!n·J?O)WJ!*~~J9t.it L.
kimurai rJ) !T 1L-- :1~. i1ff±ln:rpj(1frf!JJ\!ll..:.!lil?.tt ~ kimumi murayamai. kimurai ugoensis.
kimurai tigal/(mraensis, kimurai yudaeiiSis c. •~·inttt•~~ 77~ i&WJ;..:.ll.ll!.l?.h ~ kimurai
kimurai. kimurai nalwsoensrs 0) G !!lil\fH.::J.Htf..:.o~(;: Palliulum d. jJecklwmi (GALl B) ~¥K~i Lt..:.,
Jti m ~: - f!f-

Introduction and Acknowledgen:ents

Pecten kimurai. first described by(19:?51 from the l\'liocene ofthe ]6ban Coal Field. was subsequently
reported from numerous ~eogene local·
ities of Japan. and therefore it has been
considered to be important stratigraphically and chronologically. HoweYer.
because its true characters are not wellknown this species is confusing. that is
to say. the type consisted of rather im·
perfect specimens without designationof type locality or holotype. Ilis subsequently described Pecten munzyamai
closely resembles kimurai. but unfortunately it was not discriminated it fromkimurai at that time. lhTAI and NisiYA~IA (1939) designated the type ofkimurai to be YoKOYA~IA's Pl. 4, figs. 1.
2. 5. and identified Pl. 4, fig. 4 with
YoKOYA~IA* Read at the Annual :\lecting of theSociety at Tokyo, Dec. 7. 1958; received
April 3. 1959.

murayamai. but later they (1952) selected
the lectotype as Pl. 'l. fig. 4 which waspreviously identified \vith murayamai
and designated the type locality as
Tamaye. Kobisa, Obisa-mura. Futaba·gun, Fukushima Prefecture and theformation to be the Kamenoo. Howe\·er.
this locality is considered as belonging
to the Oligocene Shirasaka formation.
and since that species does not seem tooccur in that horizon, there may haYe
been a mistake in the labels. Consequently the type locality of kimurai isconsidered to be the l\lliocene Kokozura
formation at Izura. Otsu-machi. KitaIbaraki City, lbaraki Prefecture.
Numerous specimens of kimurai andits related species were studied and theresults lead to that the kimurai groupmay be classified into six subspecies,
namely. kimurai l?imurai. !?imurai murayamai, l?imurai ugoensis. llimurai tiga·
nouraensis. llimurai yudaensis. n. subsp.
and kimurai nakosoensis. n. subsp. respectively.

Koichiro MASUJJ.-1

250

Ackno\vledgements are due to Dr.
Kotora liATAr of the Department of
Geology, Faculty of Education. Tohoku
University. for his supervision. Thanks
are due to Dr. Jyuzo ARAr of the Chichibu Museum .\;atural History, Saitama
Prefecture and l\lr. Yasuhiko KA~L\DAof the Department of Geology. Facultyof Arts and Sciences. Nagasaki University, for their kind information of thestratigraphy. to Dr. Saburo KA:-.cNo of
the Institute of Geology and Mineralogy,
Faculty of Science. Tokyo Unh·ersity of
Education, for his kind offer of someplaster-casts of Patinopecten, and to
Messrs Shin-ichi Ho:-;~rA of the Kanazawa High School in Kanai-mura. Sado·
gun. "\'iigata Prefecture and Isamu
Chst;Kr of the Shiogarna Dai·ichi i\liddle
School. Shiogama City, i\Iiyagi Prefec·
ture and Dr. Tamio KoTAKA of theInstitute of Geology and Paleontology,
Faculty of Science. Tohoku University.
for their kind offer of specimens.
Description

Family Pectinidae
Subfamily Pectininae
Genus Patinopecten DALL, 1898
Patinopecten kimurai kimurai(YOKOYA~TA), 1925

Plate 29. Figure 1; Plate 30, Figure 6

1925. Pecten kimurai YoKoY;\MA, jour. Col/.
Sci .. Imp. Unit;. Tokyo. Vol. 45, Art. 5.
p. 2i. pl. 2. fig. 4; pl. 4, figs. ·1-6.

195/. Patinopecten kimurai. FUJIE and Uozu·:-11. Cenozoic Resl'arclt. No. 23. p. 34. pl.
24, tig. 10.

Description :-Shell moderate, rather
thin. suborbicular. compressed, equilaieral except for auricles: right valve

more convex than left: radiately ribbed
and forming an angle of about 100° at
apex. Right valve gently inflated. with
about 9, elevated. round-topped radialribs. fine concentric growth Jines andobtuse network: radial ribs a little
broader than their interspaces or sometimes nearly equal. diYided into twoor three. very fine radial threads byshallow longitudinal furrows near beak
but usually tend to become obsolete
do>vnwards, rarely dichotomous, andusually provided with a few or several.
faint. fine longitudinal striae or sometimes rather distinct longitudinal ribletson their backs and flanks: radial ribs
near submargins very low and slender.
much narrower than their interspaces.
sometimes dichotomous: longitudinal
striae on backs and flanks of radial ribs
usually appear at about half of discand rather more distinct near submar·
gins than those of central part of disc,but inaccessible in young shell: interspaces between radial ribs gently
rounded and smooth-bottomed. show no
sharp demarcation against radial ribs,
and rarely provided with a few, faint.
fine longitudinal striae near submargins:anterior auricle furnished with wideand shallow byssal notch. rather wide
byssal area. sculptured with several.
faint, fine radial threads and concentriclines: posterior one nearly equal to anterior and similar to anterior in sculpture: hinge with rather distinct cardinal
crura, wide and shallow resilial pit provided with rather distinct. short lateralridges. and ill-developed ctenolium inyoung shell. Left \·alve nearly flat ora little inl1ated, with distinctly elevated.
sharp radial ribs, fine concentric growthlines and rather distinct. fine network:radial ribs sharp. roof shaped but tend
to become more or less rounded t0wards
ventral margin in adult specimen: radial3 8 1. On the lvfiocene Pectinidae from the Environs of Sendai
Table I.

251

Measurements of the selected specimens of the kimurai group (in mm.)
lJ

~

'f)

::.>

r;
u

c.

<
(>3

I

63 I
60
60
36.5
36.5
65

HU

511.5
59.5

35
35
63

IS

/:.!

10
100'
28
6
100'
9
100'
26 '
26
4.
100'
.J. 5 100'I
.J I 100'
28.
10
100'

70

771-38

IR
I

63

'

59
28

30

15

....
..c

10.

~

100'
100'
95'

I

I,

R+il

F

L+ I
R+
L+ ·-

I

97

95
65. 5
I 37.4I

105

s

13 I 100'
8. 4 100'.J. 6, 100'64 i 35
37.2

123

I 55

I

12~4-1~RI .u
93. 5. 44

I 94

R+· :::. --1
L+li § G 123
R
1:>
109
I) I 100'
L II
6 I 100' L II ~38
11
13--1-roo:--R I
7. 3
7
3. 2

::;

; I~ ~ --~ ! I ~ i ~ ~~
(l)

I

I

L
L
L

- - - - 1- -

I

100'

15. 5
13. 3

R
R

100'
100'
100'

50
15. •IRR
37. 5! 20 I 6 I
10.81 7.3
1. 51 1oo'R
106
106 I 47
17
105'
L
·I I 100'
LL ~27. 51 2. 5. 5 15
4 I 100'
I.
24.5 2.J ' 1-! I
LL I
16
15 I 10
2. 2 100'
L___I _--.-------II
92
92. 5 41
11
105' IR
105' :R
10
10.3 100' IR
797735100' IL.!::70
69. 5 35 I
105'R
3 I 105'
::1
32
31
5
R
~
100
100
~ I 16.8 105'
L
~
82
79
37
L
11. 51 l05
107"). s 12
30
105'
L
1
73.5 30 I
9 I 105'75
L
7.6 100' ILIi
5
3.2 105' IL
IR
R --------L
11
100'
R
L
I
6
100' . R
I
100, ' R~
27. 5 I 27
13._1
22. 5, 22
12R
3. 5: 100' I RL
7 I 100'Rg
86. 5 ' 84
42
~
47
43
25
L
5
100'
LL
·.:::
28
28
15 I
100'
L
100

--

c
I

72
11
69
66

70

6i
65
68
61

62

36.5
85
37

35
82
c.8
6,1
::13

74

13

73
li!l

D

35

i

E I
1

106

1

I

I

100'

100'
100'

100'

55

80

44

16
11
10
8

55

1()5

75

95'
100'

1(15

44. 5
20 I

22

31
9 I
5.2
19 5
42 I 12.2
3s 1 8.5:
32
10.2
20.5
.t I

11 I 100•
12.
95'
100'
3
100'

I
I

4/.5

9
100'
11.5 100'
11 I 100'
8 8 100'

37 I
32 I
22.5
11 I

i1

F

28

u
::.>

I
I

38

75

1oo·
100'

100'
lUU'

I

~~

~i I ~~

116.

~-'I

1

I

-~ I

~~

~~-

i~

401 ~~

i~

I

II

I

1

104

I

47

15. 3

100'

R

--~---~-1

I

-----

+-Intact valn~s.
A-Izura. Otsu-machi. Kita-lbaraki City. Ibaraki Prefecture (Kokozura formation).
R-Kokozura. ;\akoso City, Fukushima Prefecture (Kokozura formation). C-Kagitori, Fukuoka-machi. Ninohc-gun. Iwate Prefecture (Kadonosawa formation). DAnaushi. Fukuoka-machi. Ninohc-gun. Iwatc Prefecture (Suenomatsuyama forma; ion). E-Yuda, Kintakhi -mu ra. Ninohe-gun, I wate Prcf ecture (Shi ratori formation). F-Totsugawa. Kanai-mura. Sado-gun, Niigata Prefecture (Orito formation).
G-Kitano. Yasawagi. Omori-machi. Hiraga-gun. Akita Prefecture (Sugota formation).
H-Ukibuta, Higashi-Yuri-mura. Yuri-gun, Akita Prefecture (Sugota formation).
1-Higashi-Shiogama. Shiogama City. 1\'firagi Prefecture (Ajiri formation).

252

Koiclziro M4SVDA

ribs near sutmargins low and slender,
their interspaces ~ometimes provided
with a few, very faint. fine longitudinal
str;ae; interspaces between radial ribs
usually smooth. rarely with rather fineintercalary threads which usually appear
near beak; anterior auricle somewhat
larger than posterior one, sculptured\Vith fine concentric lines and a few,
faint. fine radial threads, though sometimes inaccessible. posterior one similar
to anterior in sculpture. Interior surface of valves gently folded corresponding to external sculpture.
Dimensions :-Table I.
Comparison and Af(mily :-PatinoPecten
tokyoe11SiS (TOKL'!'AGA) (1906) originallyfrom the Pleistocene Tokyo formation
at Oji, Kita-ku, Tokyo-to, resembles
kimurai, but can be distinguished by its
less ele\·ated and prominent radial ribs,
rather more distinct division of theradial ribs, its larger TIL/II. shape ofauricles. rather distinct cardinal cruraof the right valve, small denticle at extremities of resilial pit and its obscuredemarcation against the internal surface
in the left Valve. 0TUKA (1934, 1!)36)
considered kimurai to be a subspecies of
tokyoensis, but here from a comparative
study it is thought to be of specificranking. PatinoPecten kagamianus molliwaensis Mi\si:DA (1958) from the l\'Ioniwa
formation at 1\Ioniwa. Sendai City, canbe distinguished from kimurai by having rather thick shell, less elevatedradial ribs. more distinct and numerous
longitudinal striae on the backs andflanks of the radial ribs in the rightvalve. by the somewhat more inflated left valve and by the shape ofradial ribs. At times it is difficult todistinguish between them in the caseof young shells. Kimurai resembles
Patinopectrtn kobiyamai KA~!ADA (1954)
from the Miocene Kabeya formation at

Nakayama, Ono-mura. Iwaki-gun. Fukushima Prefecture, but can be distinguished therefrom by the more elevated and fewer radial ribs of the rightvalve and by the left valve having
more numerous, more or less imbricated.
fine radial threads on the backs of radialribs and in their interspaces. Patinopectell c!ticllibttellsis KANNO (1957) fromthe lwadonosawa formation at Nenokami, Yoshida-machi. Chichibu-gun.
Saitama Prefecture. also resembles thepresent one, but it has a less numberof radial ribs.
Remarks :-Among the described features. the observable characters of theradial ribs depend upon the degree ofpreservation.
Their number varies
from 8 to 13. but in general the mostfrequent number is 9. In specimens
with a large number of radial ribs. they
are somewhat lower and a little morerounded than in examples with fewer
radial ribs. though otherwise they are
similar. In some specimens the longitudinal striae or riblets on the backs
and flanks of the radial ribs are rather
distinct but in others they are faint.
Type locality. Geological '[ormation and
Age :-Sea cliff at Izura. Otsu-machi.
Kita-lbaraki City, Ibaraki Prefecture(Lat. 36°40' 06" N .. long. 140°48' 02" E.).
Kokowra formal ion. Middle I\Iiocene.
Depository:-Topotype, DGS. Reg. :\os.
3701. 370~.
Distribution :-1\okozura formation in
Fukushima and lbaraki Prefectures andKadonosawa formation in Iwate Prefecture: both Middle lVIiocene in age.
!'atinopecten kinmrai mumyamai(YOIWYA~!A). 1926
Plate 29. Figures li, 7; Plate 30, Figures 3, 4
1926.

Pedell 111/IYI.I)'Umai YOKOYAMA, ]our.
Fac. !;ci .. Imp. Unir. Tokyo, Sec. 2. Vol.

381.

On the Miocene Pectinidae from the Environs of Sendai

teral except for auricles; right valve
somewhat more convex than left :radiately ribbed and forming an angleof about 100' at apex. Right valve
gently inflated. with about 9. elevated.
round-topped radial ribs, fine concentric
growth lines and obtuse network; radialribs broader than their intcrspaces.
divided into two or three, faint. fineradial threads by shallow longitudinal
furrO\YS near beak but tend to become{)bsolete downwards. and usually provided with several, faint. fine longitudinal striae or riblets on their hacks andflanks: radial ribs near submargins low
and slender. much narrower than theirinterspaces and sometime dichotomous:
longitudinal striae usually appear atlower half of disc. and rather more distinct near submargins than on central
part of disc. but not seen in youngshell: interspaces bet\\·een radial ribsgent],· rounded and smooth-bottomed,
but sometimes provided with a few.
very faint. fine longitudinal striae nearsuhmargins; anterior auricle furnishedwith wide and shallow byssal notch.
rather wide byssal area. with several.
faint. fine radial threads. concentriclines. and posterior one similar to anterior in sculpture: hinge with distinct
cardinal crura. wide and shallow resilial
pit ,,·ith wide-opening. rather low lateralridges. ancl ill-developed ctenolium inyoung shell. Left valve gently inflated.
with distinct. rather elevated radialribs. fine concentric growth lines andrather distinct. fine network; radialribs rather sharp near beak. usuallytend to become rather rounded. andwith a few. fine longitudinal riblets. orrarely they divided into t\vo or three,rather distinct, line radial threads byshallow longitudinal furrows on upper
half of disc: radial ribs near sub:nargins
low and slender. and sometimes their:2:>1

interspaces with a few. faint. fine longitudinal striae: interspaces between
radial ribs gently rounded and smoothbottomed, rarely withintercalarythreads which usually appear near beak:anterior auricle somewhat larger thanposterior. with several. fine radial
threads and concentric lines. and posterior one similar to anterior in sculpture. Interior surface of valves gently
folded corresponding to external sculpture.
Dimensions:-Table I.
Comparison and Affinity:-This new
subspecies differs from kimurai by theright valve having rather more elevatedradial ribs and by the left valve withradial ribs which are less elevated andsharp. and usually with a fe\v. finelongitudinal riblets on their backs andby the subequivalved shell. Also it isdistinguishable from murayamai by its
rather thin shell. rather less elevatedradial ribs of the right valve and by
the left valve having rather well de'' eloped longitudinal striae or riblets.
Type locality. Geological formation and.Age :-Road-side cliff at Kokozura. Nakoso City. Fukushima Prefecture (Lat.
36'51'18'' N .. long. 140°-:l'i'':w· E.). Kokozura formation. l'vlidclle 1\1iocene.
Depository :--Holotype. DGS. Reg. '\'o.
1!-'130, Paratype. DGS. Reg. Ko. 3713.
Occurreuce :-Kokozura formation at
the type locality. upper part of Kadonosawa formation and Suenomatsuyama
formation in lwate Prefecture and Takahoko formation in Aomori Prefecture:all Miclcllc to Late \Iio::.ene in age.
Subfamily Amusiinae
Genus Palliolum .1\lo;o.:TEROSATo, 188:1
Palliolum cf. peck/iami ,G .... aa:, 18G9
Plate 31, Figures 1-10

2!58

KOichiro Ji4SlJDA

Compare \vith:1906. Pecten (Pseudamusium) Peckhami. AR·:"OLD, U.S. Geol. Surz· .. Prof. PaPer. l\'o.
47. p. 56. pl. 3. figs. ti-S.
1934. Peden (l'seudamussium) Peckhami, OH·
SE, jour. Geol. Soc. ]apa11, Vol. 41. :\~J.
.J86, p. 126. pl. 4. rigs. 1-4.

Descriptions .·-Several cast or mould
specimens from the i\oso format ion:
their detail characters can not be
obserYed. However, these specimens
are characterized by the small. suborbinllar shell. a few, rather coarse concentric growth lines, faint. fine cross·hatches which are produced by faint.
fine radial threads and faint. fine concentric lines between the coarse concentric lines, small but distinct anteriorauricle with narrow and deep byssal
notch and rather wide byssal area,
sculptured with rather distinct. several,fine radial threads and concentric lines.
and the not defined posterior auricle.
This may be the first record of thisgenus from the environs of Sendai.
Described specimens :-About 1.5 km.
west of Ishikura, Taiwa-machi. Kurokawa-gun. 1\liyagi Prefecture (Lat. 38°~1'36"1\ .. long. 140'50'12"£.). Tuffaceous
sandy siltstone of the Aoso formation(late Early Miocene). DGS, Reg. No. :3'iO·t
1lssociated fauna :-Lima cf. goliath
S11.11TII. Gforipaflium crassi1•enium (YoKo·
YA:'-tAl. Lucinoma actilineatum (Cor-;rl:\D).
De11talium sp., Terebmtuli11a heleuae
HATAJ.
Dal/ina cf. raphaefis (DALL),
Laqueus sp., etc.
Remarks on the kimurai groupAs already pointed out. Patinopeden
tokyoensis is closely related to theldmurai group. HAT.\1 (]936) concluded
that kimurai is related to tokyoensis in
the sense of mutation and not Yariation.
and that kimurai is ancestral to tol~yo-

ensis. The geological range of the members of the kimurai group is restricted
to the 1\liocene and while that of tok.m·
ensis is from Early Pliocene to Late
Pleistocene. thus. the \\Titer also considers that the kimurai group may teancestral to tokyoensis.
Patinopecten kimurai kimurai is rather
abundant in the Kokozura formation at
the sea cliff of lzura. Kita-lbaraki Cit~'.
associated with such as Anadara zmta·
uabei KA:"EHAHA, G/oripallium izureusisl\L\SL'IH, !Uacoma oPfil•a (YoKoYA.\t.'l;·. etc.
A rather large number of 1hem consistof rather well·preserved isolated shell.
some of intact vah·es. and the minorityof water·worn or broken shells. Almost
all of them are arranged parallel withthe bedding plane. In the case of
intact Yalves, the right valve is alwa\·s
the lower and the left valve the upper.
therefore. it is probable that they wereburied in situ. and in the case of isolated ones, they are usually arranged
with the com·ex side upwards. Thus.
it is probable that the fauna at the
locality was not transported from aremote place.
Several specimens of nakosoensis werecollected from the Kokozura formation
at the type locality. about 3 km. ?\l\Wof lzura in association with numerous
molluscan shells. They occur usuallywith isolated valves. but sometimes asintact valves with natural orientation.
They are well preserYed. Since thegeological horizon at Izura is approximately the same that of Kokozura. it isconsidered that lzimurai and uakosoensis
are allopatric forms.
The relationship bet\\·een murayamai
and ugoensis of the Sugota (~TAst:r>A.
19!15) and Tanosawa formations is considered to be the same as the abo\"ementioned. In the case of the relationship between tiganouraensis and mura-381.

On the Miocene Pectinidae from the Environs of Sendai

yamai from the Ajiri formation in the·vicinity of Shiogama City. the same
phenomenon as that of the above
mentioned is observed. That is to say,though abundant specimens of tiganouraensis occur from the tuffaceous sandy
siltstone of the Ajiri formation at thesea cliff of Higashi-Shiogama. Shiogama
City in association with numerous molluscs. only a few specimens of murayamai occurred from the tuffaceouscoarse-grained sandstone with somerounded granules at Miyato-jima,l\arusemachi. !Vlonoo-gun, J\liyagi Prefecture,
about 10 km. east of the locality of
Shiogama, associated with a few other
molJuscs. In such a case the rock facies
differs at places in good accordance\Vith the change in the faunal facies.
The same relationship as alreadystated for other su bspecics is observedin the Higashi-Innai formation. Noto
Peninsula. Ishikawa Prefecture. that is
to say. murayamai is found in the fineto medium-grained sandstone at IligashiInnai. Wajima City. in association with
Operculina. Ostrea grrwitesta YOIWYA MA
and others. \Yhile tiganouraensis is foundfrom the concretions in the siltstone of
the same formation at Kuninagaide.
Suzu City, about 17 km. NE of HigashiInnai. in association with some molluscs
and crabs.
Yudaensis is common in the very finegrained sandstone of the Shiratori formation at Yuda, Kintaichi-mura. Ninohegun. Iwate Prefecture and sometimes
occurs from the fine-grained sandstoneof that formation at I\isatai. Fukuokamachi. Ninohe-gun. in association withnumerous molluscan shells such as
Ostrea granitesta, Siratoria siratoriensis(0TCKA), Clementia iizukai (YoKoYA:"-IA),
Soletellirta minoensis Y oKoY A:>.IA, Vicaryacallosa japonica YAm:: and HATAr, etc.
1t occurs usually with intact valves

2:)9

in natural orientation. Some specimensof kimurai o::cur from the siltstone of
the Kadonosa\Ya formation at Shikonai,
Kadonosa\va and other places. Fukuokamachi, in association with Solem)'a tokunagai YoKoY A:O..IA, Turri! ella kadouosmraensis On;r<A. etc. While nakosoensis isabundantly collected from the very finegrained sandstone or siltstone of theupper part of the Kadonosawa formation at Kagitori, Kamayashiki and otherplaces, in association with Jllacoma
optiva. Cultellus izumoensis YoKOYA.\JA,
Simull yabei On:" A. etc, the specimensfrom Kagitori usually occur as isolated
valves with the convex side upwards orsomestimes downwards, though they areusually well preserved. They arranged
parallel with the bedding plane andsome of them occur with intact valves
usually in natural orientation.
The specimens of 1zakosoeusis from theconglomeratic tuffaceous coarse-grainedsandstone intercalating granule conglomerate of the Suenomatsuyama formation at Anaushi. Fukuoka-machi and its
environs. consist of isolated valves andalmost all of them are more or less orseverely water-worn shells. It occurs
associated with rather water-worn shellsof Patinopecten yamasakii ninolzensis
MASUDA. CJ!lamys r.osibensis (Yor-:oYA:\IAl,
Lima goliath. Volsella di_ficilis KuRODA
and HABE. etc.. brachiopods. balanids
and echinoids. They are usually arranged nearly parallel with the bedding
plane or sometimes irregularly arranged.
A rather large number of them arearranged with the convex side upwards
or some of them with convex side downwards. Thus. it is probable that these
may have been transported from elsewhere. The occurrence of the specimens from the said formation at otherlocalities are nearly the same as thatof Anaushi, though the associated fauna

~!iO

Koichiro MASUDA

somewhat differs. It is noticed that the
specimens of ualwsoensis from theKadonosawa formation are usually rather
smaller in size than those from the
Suenomatsuyama formation. From theabove mentioned facts it is consideredthat yudaensis, kimurai and nakosoensis
are allochronic forms in this region andthe abo\'e mentioned data of the kimuraigroup may be an aid in the stratigraphyof that region.
As already pointed out, murayamai.
ugoensis. ti![mwuraensis and yudaensis
are probably allopatric forms, and therelationship between kimumi and nako·
socnsis may be allopatric. though sometimes they may be allochronic forms.
The geological range of the formergroup is restricted to the Early 1\liocenc
and that of the latter is probably restricted to I he l\liddle to Late Miocene
in age.
Thus. it is inferred that the different
localities of them were influenced bydifferent ecological conditions and thatthe variation of the external morphological features and the differences in_
ecological conditions may have had somerelation with the birth of the subspecies.
It is considered that the Early l\liocene
species of the llimurai group were originallv rather warm water inhabitants.
Heferences
AR:->OLD. R. (1906). Tertiary ;tnd <1uaternary
Pectens of California. U.S. Ceo!. Sun•.,Prof. Paper, No. 47, pp. 7-1·16, 53 pis.
FliJIE. T. and S. Uoznu (1957), Explanationof Cenozoic Fossils from :\orthcrn Japan. ~5. Cenozoic Research. :Vo. 23. pp. 3231, 1 pl.
IL'<="ZAWA, S. (1950), Tertiary l'aleogeography of North Japan. Short Papers. /nst.
Geol. Pa/eonl.. Toholw l/ni1•., No. 2. pp.
7~-98.

IL\TAT. K (1936), A :\otl' (Jfl the Distribution of cntain Species of l\larine Invertebrates. Bull. Biogeogr. .)'oc. fapmz.
Vol. tj, No. 12. pp. 12:l-l·ll.
--and S. NJSIYA:O.IA (1939). l'alacontologi·

Explanation of Plate 29
Palinop..·clen kimurai kimurai (YoKOYA~IA). Topotype. ({ight valve. xi. DGS, Rt:g.
1\o. 3701. Loc lzura. 6tsu-machi, Kita-lbaraki City. lbaraki Prefecture. Kokozura
formation.
Fig. '> Palillof!eden kimurai nakosoensis ~lASt:DA. n. subsp. Paratype, Right val\·e. X 1. DGS,
Reg. No. 19-tO. Loc. Kokozura, :\akoso City. Fukushima Prefecture. Kokozura formation.
Fig. 3. PatinojJeclen kimurai nakosoe11sis l\IAst·D.-\. n. subsp. Holotypc. Left valve. X 1. DGS,
Reg. 1\o. 19-tO. Loc Same as above.
Fig. 4. Palinopecll'/1 kimurai ugoensis (HAT.\ I and NJSIY A:O.IA). Topotype. Right vah·e, X 1.
DGS, l~eg. No. 1921. Loc. Ukibuta. Higashi-Yuri-mura. Yuri-gun. Akita Prefecture.
Sugota formation.
Fig. 5. Palillof>eclelz kimurai ligmumraensis (NAKAMUR.\). Left valve of a plaster-cast. X3/4.
DGS, J~q~. 1\o. 3703. Loc. About 500 m. east of the Tohoku Regional Fisheries Resear('h Laboratory, Higashi·Shiogama, Shiogama City. l\Iiyagi Prefecture. Ajiri
format ion.
Figs. 6-'i. /'atinopectcn kimurai 1/lltrayamai (YOI<OYA\1,\). 6. Right Yalve. X·l/5. 7. Right\':live, xI. De.;s. ({eg. No. 1904. Loc. Kitano, Yasawagi. 6rnori-machi, Hi raga-gun, .
. \!<ita Prefecture. Sugota formation.
Fig. 1.

38 1. On the Miocene Pectinidae from the Environs of Sendai
1. Pl. 9. p. 387. pl. 44, figs. 18-20.
Palhwpec/en kimurai, OTVKA.four. Geol.
Soc. japan, Vol. 50. No. 592. p. 223,
pl. 2. fig. 10.
1955. Palinnpeclen kimuroi. KA!"KO. Trans.
Proc. Pafoeont. Soc. japan. N. S .. 1\lo. 18.
p. 33, pl. li. figs. 4-8.

1934.

Description :-Shell large. thick. suborbicular. compressed, equilateral except
for auricles, nearly equivalve. thoughright valve somewhat more or very
rarely less com· ex than left valve:radiately ribbed and forming an angleof about 100° at apex. Right valve
gently inflated. with about 9. rather
distinctly elevated. stout. round-topped
radial ribs and fine concentric growthlines: radial ribs broader than theirinterspaces. usually divided into two·or three. faint. fine radial threads byshallow longitudinal furrows near l;eak
but tend to become obsolete downwards,
rarely dichotomous. and usually provided with several. faint. fine longitudinal striae on their backs and flanks
near dorso-vcnt ral margins; radial ribs
near submargins low and slender, narrower than their interspaces: longitudinal striae on backs and flanks of radialribs usually appear at about half ofdisc in full adult, but not in youngshell: interspaces bet ween radial ribs
smooth-tottomed, usually show rather
sharp demarcation against radial ribs:
anterior auricle with wide and shallow
byssal notch, rather wide byssal area,with several. fine radial threads andconcentric lines: posterior one nearly
equal to anterior, similar in sculpture:hinge with rather distinct cardinal
crura. wide and shallow resilial pit withrather distinct lateral ridges, and illdeveloped ctenolium in young shell. Leftvalve gently inflated. with distinct
radial ribs, fine concentric growth lines.
an~! rather distinct. fine network; radial25:~

ribs rather sharp near beak but usuaiiytend to become rounded towards ventral
margin. and sometimes with a few, very
faint. fine longitudinal striae on backs
and flanks near ventral margin in fuiiadult: interspaces between radial ribs
usually rmooth. sometime,; with one or
rarely two. very faint. fine radial
threads near beak but tend to become
obsolete downwards, and rarely withrather fine intercalary threads whichusually appear near beak: auricles
nearly equal to each other. with several.
rather faint. fine threads and fine concentric lines Interior surface of \·ah·es
gently folded corresponding to external
sculpture.
Dimensions :--Table I.
Comparison and Affinity :-The present
subspecies is distinguished from kimumi
by its large. subequivalv~d. rather thickshell, rather distinctly elevated radialribs which show rather sharp demarcation aginst their interspaces, ill-developed longitudinal striae and by theleft valve hadng rather rounded andsomewhat less elevated radial ribs thanthat of kimurai.
Remarks:-The number of radial ribs
varies from 8 to 12. but the most frequent numer is 9. The radial ribs ofmost specimens of the right valve areusually rather distinctly elevated andshow rather sharp demarcation against
their interspaces. but in some specimens
they are somewhat low and do not show
sharp demarcation against their interspaces.
Tl'Pe localitr. Geologiml formation and
A.g-~ :-Kinon~zaka. Yasawagi. Omorimachi. Iliraga-gun. Akita Prefecture.
Sugota formation. Early !'vliocence.
Described specimens :-Kitano, Yasawagi, Omori-machi, I-Iiraga-gun. Akita
Prefecture (Lat. 3H"27'{7" N., long. 1·10'':n '39" E.). Conglomeratic coarse-grained

Koiclziro MtisuDA
sandstone of the Sugota formation.
D<~S. Reg. Nos. 1904. 1~!05.
Depositoo• :-Holotype. Reg. I\o. ?, Institute of Geology. Faculty of Science.
Tokyo University.
Distrilmtion :-Sugota formation in
Akita Prefecture. Orito formation in!\'iigata Prefecture. Tano~·awa formationin Aomori Prefecture. ?-l'agura formationin Saitama Prefecture. Oisawa andShunezaka formations in Yamagata
Prefecture. Futatsugoya formation in
Fukushima Prefecture. Ajiri formation
in l\Iiyagi Prefecture. Higashi-Innai
formation in Ishikawa Prefecture, Taish u formation in '\'agasak i Prefectu rc
and Heiroku forn;ation in Korea :-all
Early :Miocene in age.

Patinopecten kimurai ugoensis(liATAI and ?\JSIYA:-.IA), 1939
Plate 29. Figure 4: Plate 30. Figure 5
1939.

Pectcmkimurai ugo(!lzsis liATAI and
Jour. Geol. Soc. JaPan, rot.

N!SIYAMA.

·16. No. 5-14. p. 39, ~ text ·figs.

Description :-Shell moderate in size
and thickness. compressed. equilateral
except for auricles. subequivalve, although left valve usually a little Jessconvex than right: radiately ribbed andforming an angle of about 105' at apex.
Right valve gently inflated, with about
9. low. smooth. flatly rounded radialribs. rather distinct. fine concentric
growth lines and obtuse net work: radialribs much broader than their interspaces. usually divided into two or
three. very faint. fine radial threads byshallow longitudinal furrows near beakbut tend to become obsolete downwards.
rarely dichotomous, and provided withnumerous, very faint, fine longitudinal
striae on their backs and 11anks near,·entral margin: radial ribs near sub-margins very low, tend to become obsolete towards dorsal margin: longitudinal striae very faint and onl~­
recognizable by reflected light. but alittle more distinct near submargins:interspaces between radial ribs gently
rounded and smooth, but rarely with afew. faint. fine longitudinal striae nearsubmargins: anterior auricle subequal
to posterior. furnished with shallow
and wide byssal notch. rather wide
bys~al area. with several. faint. fineradial threads and rather distinct concentric lines. and posterior auricle \\'ith
concentric lines and with or without faint. fine radial threads; hingewith distinct cardinal crura. wide andshallow resilial pit with distinct lateralridges and ctenolium in young shelL
Left val,·e gently int1ated. with distinct
but IO\\' radial ribs. concentric growthlines and rather distinct. fine network;radial ribs rather low. much narrower
than their interspaces. rather sharpnear beak but tend to become rounded
to\\·ards ventral margin: interspaces
between radial ribs smooth-bottomed.
rarely \\·ith an intercalary thread whichappears near beak: anterior auricle subequal to posterior one. with rather distinct, fine concentric lines and a fe\\·.
faint. fine radial threads ,,·hich tend
to become obsolete towards margins.
and posterior auricle nearly similar toanterior in sculpture, though radial
threads a little less distinct than thoseof anterior. Interior surface of ,·alves
gentl:-,r folded corresponding to external
sculpture.
Dimensions:- Table I.
Comparison and Affinity:- The present
subspecies is distinguished from theother subspecies by the lo\\·, flatJ\crounded radial ribs which are muchbroader than their interspaces in theright valve. and by the nearly equivalved

3 81. On the Miocene Pectinidae from the Environs of Sendai
shell. I lowever. in the case of theyoung u.c;oensis it is diftkult to distinguish it from the others.
rrpe locality. neological formation and
Age :-About 100m. west of the tunnel
at Ukibuta. Jligashi-Yuri-mura. Yurigun. Akita Prefecture (Lat. 39'18'45" K ..
long. 140°20'2S" E.t Sugota formation.
Early l'vliocene.
Depository :-Holotype. Sl\t Reg. .:\o.
1166.
Described specimens:- Topotype. DGS.
Reg. Nos. 1921 and 3672. Conglomeraticcoarse-grained sandstone of the Sugota
formation.
Distributio11 :-Sugota formation in
Akita Prefecture and Tanosawa formation in Aomori Prefecture: both
Early lVliocenc in age.
Patinopeclen ldmurai tiganouraensis(~AI\A!\JCfL\), }9clt)

Plate 2!-J, Figure 5
l!J40.

Pecten (/'alinopeclen) kimurai tiganoura·e11sis N,\1,.·\~ll:R,\, japan. four. Ceo/.
Geogr .. l'o/. 11. Nos. 1-2. pl. 13, fig. 5.

Descriptiou :-Shell rather large, suborbicular. compressed. equilateral except
for auricles: right valve more convex
than left: radiately ribbed and forming
an angle of about 100° at apex. Right
valve gently inflated. \Vith 6 to 7. elevated. round-topped radial ribs. fineconcentric growth lines and obtuse network: radial ribs broader or nearly
equal to their interspaces. sometimes\vith several. faint. fine longitudinal
striae on their backs and flanks: radialribs near submargins low and slender.
much narrower than their interspaces.
and sometimes dichotomous near beakby shallow interspaces; interspaces between radial ribs gently rounded andsmooth-bottomed: anterior auricle with255

wide and shallow byssal notch andrather narrow byssal area. with several.
faint. fine radial threads and concentriclines: posterior one nearly equal to anterior in sculpture. though less distinct
in posterior. Left valve nearly flat ora little inflated, with about 6, elevated.
sharp radial ribs. concentric growthlines and rather distinct. fine net work;radial ribs usually sharp but graduallytend to become more or less rounded
towards ventral margin. and rarely withvery faint longitudinal striae on theirflanks near ventral margin; interspaces
between radial ribs rounded and smoothbottomed; anterior auricle a little larger
than posterior one, sculptured with fineconcentric lines: posterior auricle similar to ·anterior in sculpture.
Dimensions:- Table I.
Comparison and Affinity :-This subspecies is distinguishable from ldmumi
by the less number of radial ribs andill-developed longitudinal striae on thebacks and flanks of radial ribs. It differs from the other subspecies by the
fe\\·er radial ribs and the nearly flat or
little inflated left valve. Patinopecten
cllichibuensis is distinguishable from thepresent one by the higher shell and thewell developed longitudinal striae on
the backs of radial ribs and in theirinterspaces.
Type locality, Geological formation and
Age :-Cliff of the hill immediately
northeast of the Shiogama Fisheries
I\Iarket. Shiogama City, :M.iyagi Prefecture (Lat. 38"18' N., long. 140°04' E.).
Ajiri formation. Early I\liocene.
Depository :-SM. Reg. No. 2555.
Described specimens :-Plaster casts
from the sea cliff about 500 m. east of
the Tohoku Regional Fisheries ResearchLaboratory, Higashi-Shiogama, Shiogama
City. :.Vliyagi Prefecture (Lat. 38"19'27"
N .. long.l-U ''02'52"E.). Massive tuffaceous

Koiclziro MASUD:l256

very fine-grained sandstone to tuffaceous
sandy siltstone of the Ajiri formation.
DGS. Reg. ~o. 3/03.
Distribution :-Ajiri formation in l\liyagi Prefecture and Higashi-Innai formation in Ishikawa Prefecture: both
Early ~liocene in age.

Patinopeclen ldmurai yudaensis
J\(ASL'DA. n. subsp.
Plate 30. Figures 1, 2

Description :-Shell rather large. moderately thick. suborbicular, compressed.
equilateral except for auricles: rightva!Ye a little more convex than left :radiately ribbed and forming an angleof about 100" at apex. Right valve
gently inflated. with about 9. rather
elevated. smooth. round-topped radialribs. fine concentric growth lines andobtus.:! network: radial ribs narrower
than their interspaces, divided into twoor three. faint. tine taclial threads byshallow longitudinal furrows near beak
but usually tend to become obsolete
downwards. and sometimes divided intorather distinct. t\YO or three or rare!~'a little more riblets with shallow inter·spaces. one being usually larger than.others: radial ribs near submargins low
and slender. much narrower than theirintcrspaces. sometimes dichotomous:interspaces bet ween radial ribs gently
rounded and smooth-bottomed. but rare·ly with a few. faint, fine longitutlinal
striae near submargins: anterior auricle
subequal to posterior. with \vide andshallow· byssal notch. rather "·ide bys~alarea, with fine concentric lines and afew, faint, fine radial threads. and pos·terior one similar to anterior in sculpture: hinge with rather distinct cardinal crura, wide and shallo\v resillial pit
provided with rather distinct. wide·
opening, short lateral ridges.
Left

Yalve gently inflated. with rather sharp.
moderately e\eyate::l radial ribs, fineconcentric growth lines and distinct.
fine network: radial ribs narrower thantheir interspaces. usuallv sharp near
beak but tend to become somewhat
rounded towards ventral margin. rarely
with a few, faint. tine longitudinal
threads on their backs and flanks, andrarely dichotomous: interspaces between
radial ribs gently rounded and smoothbottomed, rarely with a fine intercalarythread which usually appears near beak:auricles nearly equal. with fine concentric lines and a fe\\·, faint. fine radial
threads.
Interior surface of Yalves
gently folded corresponding to external
sculpture.
Dimensions:·- Table I.
Compariso11 and Affinity:- This subspecies differs from the other subspeciesof the kinmrai group bv the radial ribs
being narrower than their interspaces
and sometimes divided into two or threeor rarely a little more. rather distinct
riblets in the right valve.
Type locality. Geolo;..;iml formatioJl mul:t:;e :-Right riYer side of ~labechi-ga\vaat Yuda. Kintaichi-mura. i\inohe-gun,
Iwate Prefecture (Lat . .!1)"19' N., long.
lc!J·J!J'lO'' E.1. Shiratori formation. Early
lV!iocene.
Depository .·-Holotype, DGS. Reg. :\o.
1936. Paratype, DC~S. Reg. ~os. 1935.
~.!39 and IGPS. col\. cat. no. 176:21.
Ocmrrence :-Shiratori formation at
the type localitY and at :\isatai, Fukuuka-machi . .1\inohe-gun. lwate Prefecture.

PatinoPecten kimurai nakosoensis
l\fAsuoA, n. su bsp.
Plate ~9. Figures 2. 3

DcsaiPfion :-Shell moderate. rather
thin. suborbicular. compressed. equila-

MASUDA : Miocene Pectinidae

M A?UDA photQ.

Plate 29

381. On the Miocene Pectinidae from the Environs of Sendai
cal Notes on certain Japanese Scallops.
]our. Ceo/. Soc. japan. Fol. 4r;. 1\io. S-14.
pp. 36-47, 3 taxt-figs.
- - a n d - - (1952). Ched: List of JapaneseTertiary i\Jarine Mollusca. Sci. Rep .. Tolwku Unil'., Ser. 2, Special Vol. No. 3. pp.
1-46-1.
KA~IADA. Y. (195·1). Patinopeclell kobiyamai. a
New l\Iiocene Scallop from the Joban
Coal-Field. Japan. Trans. Proc. Palaeonf.
Soc. japan. N.S .. No.]!;, pp. 173-178, 1 pl.
1\.,.,:--;:-;o, S. (1955). Tertiary :\follusca fromTaishu :Vline. Tsushima. :\'agasaki Prt"
fecture. Japan. Ibid .. So. 18. pp. 31-35,
1 pl.
- - (1957). On Some l'\cw Species of Patilto·
Pecten from the Chichibu Basin. Sai·tama Prefecture. Bull. Chichibu ,1/us.
Nat. Hist .. So. 7. pp. 101-108, 3 pls.
MASL'DA. K. (1954). Fossil Pectinidac from
Fukuoka-machi. Ninohe-gun, Iwate Prefecture. Saito flo-on Kai ,\1w; .. Res. Ruli ..
No. 23. pp. ll-1-1. 3 tt·xt·figs.
- - (1955). Fossil Scallops from Yasawagimura. Akita Preiecture. :'\ortheast Hon·shu. Japan. Ibid .. ~vo. 24. pp. 18-2~.
- - (1958). On the .\Iiocene Pectinidac fromthe En\'irons of Sendai: Part 12. On
Pecten kagamianus YoKOYA~I,\. Trans.
Proc. Palaeont. Soc. Japan. N. S .. Ao. 32.
pp. 271-284. 2 pls.
N.-\I;A~!URA. :\1. (19,10), On Some Pcctinidae
Fossils from the 'Vliocene Deposits of
the Tomiya Block. i\hyagi-ken, '\orth·east Honsyu. Japan. Japan. jour. Geol.
Geogr .. Vol. 17. Nos. 1-2. pp. 1-15. 2 pls.
J\0\lt.:RA. S. (1935). Miocene ;\·lollusc:t from261

the Nisi-Tugaru District. Aomori-ken,'i'onheast Honsyu. japan. Saito flo-on
Kai Mus. Res. Bull.. 1\'o. 6. pp. 19-81. 7
pis.
01TKA. Y. (1934), Tertiary Structures ofthe ~~orthwestern End of the Ki takami~Iountainland. lwate Prefecture. Japan.
Bull. Earthq. Res !nsf .. Vol. 12. Pt. 3. pp.
566-639. 7 pis .. 1 map.
- - (1936). The Takasegawa Green Tuff
Beds of the Yuri District, Akita Pref.,Japan and Correlation of the Lower:\'eogcnc in Japan. Ibid., 'Vol. 14. Pt. 3.
pp. 438-452. I pl.
- - (1943), !VIiocene Mollusca from Iisaka
and 1\Ianseioozi. 1-lukusima Prefecture.
jour. Ceo/. Soc. japan. Vol. 50, No. 592.
pp. 221-227. 1 pl.
St:G,\1. K .. H . .iV1ATSL'I. s. S:\ITO. Y. KtTA·
1:AWA, !vi. SAsAKI. M. ~vi!YASIIITA andK. KA\\'ACI!I (1957), Explanatory Text of
the J6ban Coal Field. Geological Mapsof the Coal Field of Japan l. Geol. Sun·.
japan. pp. 1-143. 3 maps.
TOI<L':'\AG,·\, Y. (1906). Fossils from the En\'i rons of Tokyo. jour. Col/. Sci .. Imp.
Uni1·. Tokyo. Vol 21. Art. 2. pp. 1-96. 6
pls.
Yoi:OL\~!A. M. (1925). Molluscan Remains
from the Uppermost Part of the Joban
Co:tl-Field. Ibid.. Vol. 45. Art. fi. pp. 132. 6 pis.
- - (1927). Fossil Ivloltusca from the Oil·
Field of Akita. jour. Fac. Sci .. Imp. Uuiv,
Tokyo, Sec. 2. T-"o/. 1, PI. 9. pp. 317-387,
2 pis.

2G2

Koichiro MASUDA

Explanation of Plate 30
Fig. 1. Palilwpecten kimurai yudae11sis :\1..-..st.:DA. n. subsp. Holotypc. Right valve, X3/4. DGS.
Reg. No. 1936. Luc. Yuda, Kintaichi-mura, :\inohe-gun, lwatc Prefecture. Shiratori
formation.
Fig. 2. Pati11opecten kimurai yudaensis i\IAst.:o ..-.., n. subsp. Paratypc. Left Yah·c, x3j4. DGS.
Reg. No. 1935. Loc. Same as above.
Figs. 3-4. PatinojJecten kimurai murayamai (YOKOYA~I:\). Left valve. XL DGS. Reg. ~o. 1905.
Loc. Kitano, Yasawagi, 6mori·ma.:hi, Hiraga-gun, Akita Prefecture. Sugota forma·tion.
Fig. 5. Patinopecten kimurai ugoensis (IlAT.\1 and NISIYA:I.IA). Topotype, Left \'alve. x3j-l.
DGS. Reg. No. 1921. Loc. Ckibuta, Higashi-Yuri-mura. Yuri-gun, Akita Prefecture.
Sugota formation.
Fig. 6. Patinopecten kimurai kimurai (YOKOL\\IA). Topotype, Left vah·e. xl. DGS, Reg. No.
3702. Loc. Izura, Otsu-machi. 1\ita-lbaraki City. lbaraki Prefecture. Kokozura lor·
mat ion.
Figs. 7-10. Palliotum cf pecklwmi (GAnB). 7, 8. Right valve. xl. 9, 10. Left \·ah·e. XL DGS.
Reg. No. 3704. Loc. About L 5 km. west of lshikura. Taiwa-machi. Kurokawa-gun.
:\liyagi Prefecture. :\oso formation.

MASUDA : Miocene Pectinida~

MAsuoA photo.

Plate 30

Trans. Proc. Palacont. Soc. Japan. N. S .. No. 38. pp. ~li3-2'i4. pl. 31. June I. 19GO:;~~.

MOLLUSCAN FOSSILS FROl\1 TUNGYVPING IN THE
PENGHU ISLANDS. T AIW A~*
ICHIRO HAYASAKA and SHOZO HAY ASAKA
Shimane University and Tohoku University

ilii!'Ji~~m&~;Jti•:J;f~jt{t:fi: ~~C.l!iH!.ft:fi'Hb~ff~5}M~t\ Lt.:o 20 Ht'l• Meretrix
degucltii, .\/o11ilea ltmgyiipingensis. Aiurex pengluumsis. "llelongea cmt~formis tJ: ~if>k-c:. fll!
CO~< lihii'H: ~COi!I.i!.!CO{tLiY.Xl ·li!i!.':tfi\"(';b 7.> o .:..n.;, 4 ffrliilco#:fi::i. irfi'1*M1V)PJT~"m~l\1!! .. q)Jtif!:liiJ~llf c co£-a-7F L. -c"' ·7.> .t ? ;.:..~.:::-.n7.>,!f! iti. - fiJI • '!'· JJi. tf=-

YASAKA. 19-18) of the two volcanic stages
observed in the main island of Formosa.
The molluscan fossils here dealt withare rather small in number of species.
and the writers have not been able todetermine their geological age more indetail, but for some difference of theliving condition. especiall)' in temperature, between the fauna of the .. Byoritsu Beds '•I) in the main island of
Formosa and the present one. which
may probably be due to the slight difference in the geological age.
The fossils recognized in the material
from the present locality are as follows:

Tungyi.iping is an islet situated in
the southernmost part of the Penghu
Islands (or Pescadores Islands) in the
Formosa Strait about 50 km off the coastof western extremity of the main island·Of Formosa. The Islands have been
considered to be detached blocks of an
extended basalt mesa (DEct.:cHI, 1912;
HAYAs""''· 1948). In the Penghu Islands,
there are three basaltic flows alternatingwith the light brown. medium sandstone
beds about 15 meters thick. The uppermost one uf these sandstone beds contains, in places. some molluscan fossils,
which have long been left behind thepaleontological researches. The writers
had an opportunity to study some specimens from a reddish brown. more orless conglomeratic sandstone in Tungyi.iping island, which is considered tobe the same horizon as the fossiliferous{)ne stated above. The basaltic flows of
the present islands have been considered.
together with the intercalating sandstones, to be Pleistocene in age. fromthe petrographic and topographic points{)f view, and the age of their eruption
is considered to correspond to the younger one (Tatung volcanic activity, HA-

Anadara (ScaPharca) comea (REEYE)
A.
(S.
) sa/otci (DL 1 :"KE1~).'1.
(Diltwarca?) rlwmbea (BoR:")
Swwtta menstrua/is (:'vlE:--;KE),Heretrix deguchii H.\Y.'\S:\1\A and HAY:\·
SAK:\, n. Sp.
Dusinia gnmeri PHILIPPI
Caece/la chinensis DESHA YES
Anisocorbttla scaplwides (HINDS)
1) According to IL-\YA~AKA. Lii'i and YEN(1948). the richly fossilift.:rous sandstone
occupying the upper part of the so-called
Byoritsu Beds should be cliffcrcntiatccl as
the Tsusho {jlf!'j!f) formation from thesparsely mammifcrous conglomeratic part
below which is the~Bybritsu formation in
the revised sense.

* Received May 6, 1959; read at 59thlVIeeting of the Society. Oct. 9, 1954.
263

264

!chiro H4.YA.SAKA and Shozo HAYASAKA!vlonifea tungyiipingensis

HAY ASAKA

and

1-iAY.-\SAJ.;,\. n. sp.

Umboni11m (Umbouium) 1•estiarium (LI!'INE)
U.
(U.
) n.? sp.
ilrchileclonica jJerspeclim (Lr:-.::-.:r~)Cerithic/ea ci11gufata (G1-IELIN) \·ar.
Batilfaria murayamai YOKOY A~IA
Cerithium kochi PliiLIPPI
Simon neritoicleum (Lt ~-"E)
Phalium cancc•/liammz :\o:>.IURA
Bursa nobi/is (REEYE)
11lurex penglwensis 1-iAYASAKA and 1-IAYA·
SAK.-\, n. sp.
Jlelongena coniformis 1-iAYAS,\KA and HA·
YASAKA, n. sp.

Among the above-listed species. allof the I~ecent ones are living under
the condition of warm water widely
ranging from the Indian Ocean to thecoast of Japanese Islands. As a whole,
the present fauna most resembles thatof the Pliocene '' Byi1ritsu beds·· in themain island of Formosa (YoKoY,\~L\. 1923;
Ko:\tURA 1933, 1933'. ~inc species arefound to be common with the latter.
that is, Auadara comea. A. rlwmbea,
I Josonia gmueri, Umbouium vestiarium,
Arcllitectonica perspectim. FJati!laria nmrammai, Cerithium kochi, Si11um ueritoideum~nd Plw/ium crmcel/ianum. It is remarkable. however. that Anadara r/zombea
from the present locality has a type ofshell different from the specimens ofthe " Byoritsu beds." and that the othereleven species including four new species are hitherto unknown from thelatter fot·mation. Among the new species here described, .l1urex penglmensis
and ;l1elongeua con{formis are noticeable.
Kamely. the former species has a peculiar outline of shell. and its allied species
is known only from the Upper i\lioceneof Borneo (BEETs, 19-11). The latter
species has a close alliance toM. pugilina
living in the Indian Ocean and to 111.
madjalengkcnsis reported from the Pliocene of java (.\lAtnr:-:. Hl26\. Genus

il1elongena has not been reported to li\·ein the waters ranging from Formosa toJapan. and is known only as one of theindex fossils of warm water condition
from the l\1iocene and Pliocene rocks
exposed at several localities in Japan(YOKOLUIA, 1924. 1926: KANEIIARA, 1937).
From the above stated aspects, it seems
quite reasonable to say that the living
condition of the present fauna might
be more or less different from. and probably warmer than that of the ·· Byoritsu beds", though the general featuresof them closely resemble each other.
Several years ago, the senior author
reported an occurrence of echinoid
fossil A.stric/ypeus mmwi \'r:rlHILI •. whichis smaller in size than the typical
specimens. associated with the present
molluscan fauna (1. HAYASAt'''· 19-17).
:lstric/JPeus mmmi is quite frequently
found in the uppermost horizon of the" By6ritsu beds" and the remarks on
its systematic relations arc also givenin the above-cited literature. The Recent
species has a wide distribution in thecentral to southwestern part of theJapanese water both of the Pacific and
the Japan Sea sides. This species isalso recorded to occur in China Sea. but
has not been reported from the seasaround Formosa. The specimen collected from the present locality has an unusally small test. of which general outline is quite identical with the representative specimens of the normal size.
As the collection contains only a single
specimen, it is impossible. however, toknow whether the small size means ayoung form or a dwarf.
On the other hand. the relative sizesof the molluscan specimens here dealt
with are as follows:
1) species represented by rather small
shells than the normal sized specimens:
Anadara dwmbea. Caecella dzinensis,

382.

Molluscan fossils j1·om Tungyiiping in the Penghu Islauds

Architectonica perspertiva. Plwlium raucelliammz. Bursa tzobi/is.
:.!) species represented by rather young
specimens: Anadara cornea. Anadarasalotci. Sunetla menstrua/is.
3) species represented by shell slightly
larger than the Holotype specimen:
Ratillaria mumyamai.
4) new species are rather small insize compared with the average among
genera: Jlleretrix deguc/iii. Monilm lmtgyiipingensis: 5J the other nine speci~sare of the normal sizes.
From the abo\'e stated relations. it
can be readily recognized that thepresent fauna is. as a whole. eviclentlv
characterized by the predominant o~­currences of young or rather smallsized specimens. On the specimensof Batillaria murayamai having slightly
larger shell than the Holotype specimen.
we can not discuss about its relative
size but that it is. at least, an adultspecimen. because the present occurrence is the second record of this species.
and its aYerage size is far beyond ourknowledge. Such a characteristic feature of the molluscan fauna seems tocorrespond quite well to the associatedoccurrence of an unusually small echinoid. The present fauna including anechinoid fossil seems. insufficient in
number of indiYiduals for concludingthat it is a d\varfed fauna. Consequently. the writers wish to refrain fromthe final decision on this point until
further materials will be obtainedwith informations on their modes ofoccurrence.
In conclusion the writers wish toacknowledge their great indebtedness
to Prof. K. II.nAI of the Tohoku UniYersity for l1is suggestions and aid in
identifying 1he species of this faunule.

:!1>5-

Genus Anadara GRAY, 1841
A.1zadara (Scap/wrca) comea (Rr.EVE\ 1844
Plate 31. Figure 1
1844.

Area cornea REE\'E, Conch. leon., Vol.
2. Area. pl. 3. fig. 16.

1891.

Area (SeaPharca) cornea

KoBEI.T

MART!="!

Sysl. Conch.

1910.

u.

Ci!F:'\t:>;!TZ,

in

Cab .. Yo/. 8. Pt. 2. p. 167. pl. 42. fig. 5.
Area (Scaplwrca) cornea MART!~. Foss.
ron ]{wa. Samm/. geol. Reichs·!Hus.
Leiden. N. S. Vol. 1, Pt. 2. p. 379. pl.
5·L figs. 118-120.

19:!0.

.4rca (Scapharca) comea TESCH, Palaont.
I'Oil Timor,
Vol. B. p. 96. p!. 138 (20),1933.

:!rca (Area) comea No~n:RA. Sci Rep.
Tiihoku Imp. Univ .. Ser. 2 (Ceo/.) Vol.

fig. 256.

}ti.

p. 34. pl. 3. fig. l5.

Two young, well preserved left valvesof this species are in the collection.
Dimensions (in 111111) :-Height lfi.G,
length 18.5 and height 16.5. length 19.1
respectively.
Repository :-IGPS coli. cat. no. 71508.
Li11ing:-Southern Kyushu: Ryukyu
Islands; Formosa: the Philippines !Samar
Island is the type locality): Indian Ocean.
Geologic distribution :-Pleistocene of
the Ryukyu Islands: Pliocene of Formosa: Pliocene and post-Pliocene of java:
Pliocene of Formosa; Pliocene and postPliocene of Java; Pleistocene of Timor.
Auadara (Scap!wrca) satou•i (Dut-:KER)
Plate 31, Figure 2
1882.

Scaplzarea satowi Du="KER. Index Moll.
p. 233. pl. 9. figs. l, 2. 3.

Area (.41/0malocardia) satowi KOOEI.T in.
MART!;o.;l u. CtiE~IK!TZ. ~;·yst. Conclt.
Cab., Vol. 8. Pl. 2. p. 58. pl. 17. figs.
1. 2.
1911. .!lnadara (Scap/wrca) satowi YA:'-IAKAWA. ]our. Geol. Soc. Tokyo. Vol 18.
1891.

Jvo. 209, p. 12. pl. 4, figs. u. 15; pl. s,
Description of Species

figs. 5, 6: pl. 7. fig. 6

266

Ichiro H-n-..tsAKA and Shozo HALlSAJ.:~t

A single right valve. lacking a small
area of the posterior ventral corner, isin the collection. In general outline, thepresent specimen seems to be slightly
different from the full-grown ones ofthis species, but this difference is considered an individual variation. as isclear by comparing its younger part.
Dimensions Vn mm) :-Height ca. 53,
length 60.0, depth ca. 20.7.
Repository :-lGPS coli. cat. no. ii5U9.
Liviug :-Coast of Noto Peninsula,
Japan: Pacific coast of central to southwest Japan.
Geologic distribution :-Pleistocene ofcentral Japan.
A.1wdam (Dilurarca ?) rhombea
tBoR:-~). 1778
Plate 31, Figures 3a-b.-!rca rlmmbea REEVE, Conch. lco11., !'ol.
2. Area, pl. 2, fig. 12.
1891 Area (.-luomalocardia) rhombea KonELT
in l\1AilTI:XI u. CHE~INITZ, Syst. Conch.
Cab.. Vol. 8. Pt. 2. p. 39, pl. 3, figs.
2. 3: p. 57, pl. 16. figs. 5, 6.
1910. .-lrca (.-1J1adara) J'lwmbea MAin!;-.;, Foss.
!'. fcwa. Sam. g. Reichs-A1us. Leiden, N. S.
l'o/. 1, Pt. 2, 368. pl. 52, figs. 89--92.
1933. .-lrca (Area) rhombea NoMURA. Sci. Rep.
Tolwku Imp. Unir .. Ser. 2 (Geol.), Vol.
16. p. 37, pl. 4. fig. 13.

18-1-1.

Several well preserved specimens ofrather small size are in the collect ion.
Shell very thick. quadrate in outline.
equivalve. heart-shaped in lateral view,inequilateral. posterior side angularly
contracted at the upper part, androunded below. Umbones prominent,verv erect. rather remote from eachoth~r. beak more or less incurved anddirected anteriorly: ligamenta! area
broad. arcuately trigonal in profile,
sculptured with two or three cheveronshaped grooves.
Radial ribs 25-27.
rather narrow. rounded, anterior ribs

nodulous, ribs behind the contracted
angle are slightly broader than flattenedinterspaces.
Two spacimens are illustrated by
KoBJ-:J.T. One is large and very thick(KonEL T, op. cit. p. 39. pl. 3. figs. 2, 3),
the other one is small. probably rather
thin and with a more compressed shell(KonEJ.T. op. cit. p. 51. pl. 16. figs. 5, 6;.MARTIN, op. cit.). The present specimens
belong to the former type. This species
has been already reported from the" By6ritsu beds" by No:~,wllA, but his
specimen is represented by KoBF.J.-r's
second type.
Dimensiot/S :-Height Length Depth Valve38.9 mm 41.8
17.2
left
34.3
33.5
15.2
right
34.1
35 7
15.3
left
4.
31.8
3-1.9
14.7
right
5.
28.6
31.0
13.1
left
30,4
6. (illustrated) 28.5
13.6
left
1.
2.
3.

ReposifOI)' .·-IGPS coli. cat. no. 77510.
Liz1i11g :-Indian Ocean to China Sea.
Geologic distribution :-Pliocene of Java;
Pliocene of Formosa !represented byrather small and more compressed form).

Genus Sunetta LI;o.;K, 1807
Stmetta (Cyclosunetta) menstrua/is(MENJ<E). 18.!3
Plate 31. Figure ~
1855.
1855.

186·1.
1864.
1864.
1869.
1869.

!lleroe excm·ata SowERBY. Thes. Co11ch.,
Vol. 2. p. 610, pl. 126. figs. 13. 14.
.Heroe mens/ma/is SowERilY. Thes.
Conclt .. 'Vol. 2, p. 742. pl. 163. fig. 17.
1\/eroe excal'ala REEVE, Conch. Icon.,Vol. 14 ..lleroe. pl. 3. fig. 11.
;\leroe menstrua/is REEVE. Conch. /coil ..
Vol. 14. Meroe, pl. 3. fig. 9.
Sunetta menstrua/is RoMER. !t1onogr.
F'cmus. Vol. 2. p. 13. pl. 4. fig. 2.
Sunetla excm•ata PFEIFFER. Syst. Co11ch.
Cab., l'ol. 11. Pt. I. p. 83. pl. 29. fig.A.
Sunetta menstrua/is PfEIFFER. Syst.

382. Molluscan fossils from Tungyiiping in the Penghu Islands
Conch. Cub.. Vol. 11. Pt. 1. p. 85, pl.
29. figs. 10. 11. 12.
1922.

Sunetta excamta Yot.;OYA:'>lA, Jour. Col!.
Sci. Imp. Unil'. Tokyo. Vol. 44. Art. 1.
p. 147, pl. 11. figs. 6, 7. 8.

Two right valves of young individuals
are in the collection. Both of them areflat and exceedingly equilateral.
Dimensions lin mm) :-Height 18.7.
length 22.3, depth 4.4.
Repository :-IGPS coli. cat. no. 77511.
Lil'ing:-J>acific coast of central tosouthwest Japan: South Australia. New
Holland.
Geologic distribution:- Pleistocene ofcentral Japan.
Genus Jlleretrix LA~IARCK,
Jleretri.t deguclzii HAY ASAKA and
HAYAsAKA. n. sp.
Plate 31. Figures 8a-b

Descriptilm-Shell small. roundly rhombic. inequilateral. Anterior end rounded. posterior one roundly angulated.
Dorsal margin sloping with nearly straight curve, and about equal in length
both anteriorly and posteriorly. Ventral
margin arcuate but strongly biassed
anteriorly, nearly straight in the posterior half.. and arcuate in the anterior.
Beak small. pointed. Surface smooth.
with obsolete concentric colour markings and fine feeble growth lines. Hinge
narrowly arcuate. bearing three cardinal teeth and an anterior lateral. posterior cardinal being bifid, arrayed withnumerous filelike denticulations. Pallial
sinus inaccessible in both specimens.
Inner margin smooth.
Dimensions (in mm): - Height 13.5,
length 15.:), depth 4.0.
Repository :-IGPS coil. cat. no. 77512(Holotype) and no. 77513 (Paratype~.
Remarks:- The present species some-

2GT

what resembles Nleretrix meretrix (Lt:-;:-;t).
reported by YoKOYA~tA (1928) from the" Byoritsu beds" of Formosa. in having
a relatively short shell. However. it
differs from the latter species in having
rounded anterior and roundly angulate
posterior ends. and markedly biassed
ventral margin. Two small left Yalves
are in the collection.
Genus Dosinia ScoPou. 1777
Dosinia gruneri Pmt.JPPt, 1845
Plate 31. Figure 6

Cytherea (.·lrtemis) gnmeri PHII..IPPI.
Abbild. u. Beschr .. Vol. 3. p. 23. pl. 8. fig. 2.
1851. Artemis grmzeri REE\'E. Conch. lcou ..
Vol. 6. Artemis, pl. 5. lig. 31.
1928. Dosinia gruneri YoKOYA~IA. Imp. C.eol.
Sun,. Japan. RePort So. 101. p. 1-t. pl.

1845.

7, fig. 3.

Two specimens. one well preserved
and the other exceedingly water worn.
are examined. This species was alreadyreported by YoKOYA~tA and by :\o~rl'RA
from the Pliocene .. Byoritsu beds .. of
the main island of Formosa.
Dimensions (in mm): - Height 30.9.
length 31.1, depth 8.4.
Repository :-IGPS coiL cat. no. 7';'514.
Living: - West coast of Formosa:
China Sea.
Geologic distribution: - Pliocene of
Formosa.
Genus Caecella GR.\Y, 1853
Caecella chine11sis DEsHAYES. 1855
Plate 31. Figure I
1920.

f.rt'illia otsul'llsis YoKOYA~IA.four. Coil.
Sci. Tokyo Imp. Uniz•.. Vol. 39 (6). p.

109, pl. 7, figs. 21. 22.

Dimensions (in mm) :-Height 8.70 ..
length 11.00. depth 3.10.
Repositm·y :-IGPS coil. cat. no. 77515.

"2fi8Ichiro H4 YAS.4K.4 and Shozo H.-lYASAK.-1

Living :-Northern. central and west•ern Japan to Formosa.
Geologic distribution :-Pleistocene of·Central Japan.
Genus A11isocorbula IRimALE. 1930
Anisocorbula sraPizoides (HI:"os). 1843
Plate 31. Figure 5
1844. Corbnla scaplloides REEVE, Couch. Icmt ..
Fol. 3. Corbula. sp. 2·1.
19·19. Anisocorlmla scaplwides KURODA. !/lust.
Cat. japan. Shells. Vol. 1. p. 3. pl. l.
figs. 13, 14.

A single. rather well preserved rightvalve is in the collection. The Recent
distribution of this species 'videly
nlllges in the Indo-Pacific region. andthe specimens have been reported to beliving in the H6ko i.e., the Penghu
Islands. Formosa, by Kl'RODA (1941 ).
Repository :-IGPS coli. cat. no. 775Hi.
Lil'ing:-Centr. and west. japan: Pengnu Islands: the Philippines: Singapore.

Umbilicus narrow and deep, of which
the inner surface is spirally sculptured.
Aperture roundly square. rather small.
about one third of the entire spire inheight.
Dimensions (in mm) :-Height 10.05,
diameter 10.75.
Repository :-IGPS coli. cat. no. 77517.
Remarks :-As to the generic determination of this species. the writers
have a slight doubt. The present
specimen, in reality. has some characters identifiable with those of somesubgenera of the genus Gibbula, but thewriters are more strongly inclined toconsider it a new species of the genus.Honi/ea in the general aspects observedin the specimen. It is the only materialof this species at the authors' hand. andis easily distinguished from allied species bv its smooth base and rather
trochoid than turbinate shell form.
Genus Umbonium LtKK, 1807

Genus Monilea SwAJ:-<so:'-1, 1840

Umbonium ( [imboniuml oestiarium(Ln,l"E), 1158

:11onilea tungyiipingensis HAYASAKA
and J-L\\'ASAKA, n. Sp.

Plate 31. Figur.: 11
188\l.

Plate 31. Figures lla-c

Description :-Shell rather thick. high,spirally striated, trochoid with convex
base: whorls about 4, slightly convex,
separated by impressed suture. Protoconch consisting of about one and abalf smooth whorls. The sculpture of
the succeeding 3 whorls consisting of 3
strong spiral ridges separated by \\·iderinterspaces: on the body whorl. 3 feebleridges are added. one on the subsuturalzone and 2 on the rounded periphery.
Whole surface of the body ·whorl covered with fine oblique growth lines extending to the margin of umbilicus.
Base convex, smooth, \Vithout spirals.

Umbo11i11111 l'estiarium PI LSBL Y in TRY11fan. Conch.. 1 Ser.. Vol. 11. p.

o:-;,·150, pl. 58, figs. 1-8.

1935.

Umhonium (Umbonium) restiarium ?\o·Imp. UlliZJ., rot.

!\IL'RA. Sci. Rep. Tolzoku

18. p. 213. pl. 10. tlgs. 26a. 26b.

Two imperfect specimens of Umbmzium
having slightly depressed whorls ,...-ithsmooth surface are in the collection.
They are readily identified \vith U.
·l'estiarium (LI:"NE) in general respects.
Dimensions (in mm) of the larger specime1z :-Height 5.6, diameter 10.2 (long)and 8.6 (short).
Repositm:r :-IGPS coli. cat. no. 77515.
Lil'ing :-Formosa: the Philippines:
Singapore: Java: Indian Ocean !Type382. Molluscan fossils from Tzmgyiiping in the Penglzu Islands
locality).
Geologic distribution :-Pliocene of Formosa.
Umbonium ( Umbonium) n. sp. ?
Plate 31, Figures 18a-c

Desr:ription :-Two imperfect specimens
are in the collection. Regarding somecharacters, namely, the spinose subsutural band. convex base and highshell outline. among others, the present
species somewhat resembles Umbonium(Sucllium) suchiense obso!etum arenarium.MAKIY.UI."> (SCGIYA~IA. 1935) and living
Umbonium (Suclzium) monilifenem (LA~>t,\I<CK). But it apparently differs fromthe latter two speci~s in having no
spiral striae on its smooth shell surface
and a simple callus pad which is themost important characteristic of thesubgenus Umbo11ium s. str.. among
which the writers could find no identifiable species. The specimens are. however. too poor in preservation to bediscriminated as a ne\\' species. The
following are diagnoses shown of thepresent problematical specimens.
Shell moderate in size. conical withconvex base: whorls 't younger 3 convex, the last one slightly conca \'e under
the suture. Protoconch consisting ofabout one and a half whorls, depressed,
smooth. Surface smooth, with line oblique incremental Jines an:! subvertical
zigzag colour markings, closely set
side by side between the suture andthe margin of callus pad. Subsutural
band elevated and cord-like, conspicuously spinose. Spines high and pointed,
triangularly tapering in lateral view,
about 10 on the last whorL becoming
feeble towards the younger whorls.
Aperture roundly square. higher than
one half of the entire height of theshell. Body whorl rounded at the peri-

269

phery, base convex. smooth. \vith obsc·
Jete radiating incremental lines. Calh:s
pad smooth, simple. circular and remark·ably thick, about half of the base indiameter.
Dimensious (in mm) of !lie larger specimeu :-Height ca. 9.00, diameter ca. 11.15.
length of aperture ca. :1.35.
Repository :-IGPS coli. cat. no. 71519.
Genus Architectonica Riint:-.:G, 1798
Arclzileclonica paspectim , L~:-.::-.:EI. 1758
Plate 31. Figure 91835.
186-!.
1866.

1869.

1882.
HiS/.

1895.
1906.

1920.

1928.

1935.

Solarium Perspecfil'lllll KtE:-:ER. Spec. coq.
l'iL• .. Solarium, p. 3. pl. 1. fig. I.
Solarium perspectiL·um REE\'E, Concll.
/coli .. Vol. 15, Solarium. pl. 2. figs. lla. b.
Solarium Pen;pectirum SOI\'ERBY. Thes.
Couch.. Fol. 3. p. 223. pl. -!. figs. 36,
37. as.
Solarium persPectirum LtSCHKE, ]afJ.
J!eer.·Collch .. T'o/. 1. p. 19: T·'o/. 2. p. 73.
Solarium perspeclil'um Dt:;o;KER, /;:d.
Moll. Jlar ]ap .. p. 9L
Solarium perspec!il'um TRYO:-:. .llan.
Couch. 1 Ser.. Vol. 9. p. S. pl. 2. figs.
18-21.
Solarium Perspectimm PILSBRY. Cal.
Mar. Moll. Japan. p. 65.
Solarium persj>ectinmz MART!:-<, Foss.
l'rm Jaua. Samml. geol. Reichs·!1lus. L<'i·den, N. S. Vol. 1. p. ~46. pl. 37. figs.
59-!-597.
Solarium Perspectil'llm TESCH. Pa/iiout.
Timor. T·'ol. 8, p. 65. pl. 132. fig. 200.
Solarium perspectitwn YAKOYA:O.IA. Imp.
Geol. Sun·. Japan. R£'port :\'o. 101. p. 6:?.
pl. 5. 11g. 7.
Architecfouica perspectim ~O\IIJRA. Sci.
Rep. Tohoku Imp. Cuh: .. Ser. 2 (Ceo/.).
l'ol. 18, p. 19~. pl. 9. tig ..!l.

Two rather small gpecimens of thisspecies are in the collection. According
to REEVE, the characteristic features ofthis species are as follows:" Whorls smooth in the middle. spiral-Iclziro H.4Y.4SAKA atzd Shozo H.-!1-ASAKA

210

ly linearly grooved above and below.
obliquely rather distantly. impressly~triated throughout. base and marginof the umbilicus articulated with darkbrown."
Dimensions (iu mm) of the larger specimen :-Height 6.7. diameter 16.0.
Repositmy :-IGPS coli. cat. no. 77520.
Living:-Western Japan: Ryi!kyG islands: Penghu islands: China: Manila;
Molucca islands: Indian Ocean: Australia.
Geologic distribution :-Pleistocene of
the Ry1iky1i islands: Pliocene of Formosa: Post-Pliocene and Pliocene ofTimor: Pliocene and Miocene of ]a\a.
Genus Cerithidea SwAJKsox. 1840
Ceritlzidea cingulata (G~tELJ:'\). var.
Plate 31. Figure 16

A single. somewhat water worn. imperfect specimen is in the collection. Ribsof the present specimen are more orless oblique and fewer in number thanin G:-.tF.LIN's species. According to No1\tURA (1935). the named species "appears
in Japan dating from the l\iiddle Miocene epoch. As Recent it has a wide
geographical distribution ranging from
Northern to Southern japan: also IndoPacific and Australia."
Dimensions (in mm) :-Height ca. 28.0.
diameter 8.75.
Repository :-IGPS coil. cat. no. 77521.

closelv similar to the named species ingeneral outline. but the spiral cords
have a tendency to become more differentiated on the body-whorl. Xamel}'.
each spiral cord is accompanied by one
or two weaker spirals below. The
original description is as follows:"Shell moderate in size. many whorled. "\Vhorls somewhat convex withsutures distinct. Longitudinally plicate
and spirally corded. Plicae coarse.
rounded. mostly vanishing near the
lower suture, although occasionallyreaching it, strongest in the middle of
the whorls. about ten in number on thebody-\Yhorl. Spiral cords often tuberculous. Periphery rounded. Base com·ex
with several spiral cords like those of
the whorls. Aperture roundish. provided with a pozterior canar.··This species is closely allied to Batil/aria zonalis (BRccutEHE). which is acommon living species in Japan. but iseasily distinguishable therefrom by thestrongly acuminated spire and thinner
inner lip.
HeightDiameterDimensions:42.0 m m
12 7
1.
(illustrated)
415
36.3

~-

3.

1~.1

Repository :-IGPS coll. cat. no. 775~~­
Lil'ing :-Unknown.
Geologic distribution :-Pliocene of Formosa (Type locality).

Genus Batillaria BENso:-o;. 18-12

Genus Ceritlzium BtwcuitRE, 1/92

Batillaria murayamai Ym~OYA:\tA, 1928

Cerithium koc/zi PHtLIPPI. 1848
Plate 31. Figure 15

Plate 31. Figure 1~
19~8.

Potamides (Batillaria) murayan:ai YoKOYA!\IJ\, Imp. Geol. Surl'. japan. Report
No. 101, p. 53, pl. 4, figs. 5, 6.

Three specimens, slightly larger thanthe holotype, are examined. They are

koclzi PHtLII'PI. Abbild. 11.
Beschr.. Vol. 3. Ceritlzium, p. ~. pl. 1.

1951. Ceritlzium
fig. 3.
19~~-

Cerithium kochi YoKOYA!'.IA. four. Col/.
Sci. Tok_,·o imp. Unil•., Vol. 44. Art. 1,
p. 71. pl. 3. fig. 13.

382.

Molluscan fossils from Tungytping in the Pe11ghu Islands

Three specimens, all lacking theirbody whorls an1 apices. The whorls
are ornamented with five, close. tlat.
spiral ribs which are alternately large
and small and closely tuberculated.
The columella-fold is single, oblique,and strong.
Dimensions (in mm) of rather perfectspecimens :-Height 38.5. diameter 12.2.
Repository :-IGPS coil. cat. no. 77523.
Living :-Northern to western Japan:
the Ryi'ikyil islands: Fom1osa: thePhilippine~: Indian Ocean: east coastof Africa (Type locality).
Geologic distribution :-Post-Pleistocene
and Pleistocene of central japan: Pliocene of the RyGukyG islands: Pliocene
of Formosa.
Genus Simon Roor:-:c. 1798
Simon neritoideum (Lr:-::-:E). 1758
Plate 31. Figure 1-l

1833.

Sigaretus neritoideus

inSyst. Conch.
Cab .. Fa! 6. Pt. I. p. 18. pl. 3. figs.
7-11.
Sigaretus neritoideus REE\'E. Colich.
leon .. Vol. 15 . .. Sigm·etus ", pl. 1. fig. 5.
Sigaretus neritoideus TRYO:'\, :11an. C(m·ch .. I Ser .. Vol. 8. p. 55. pl. ~2. fig. 55.
Sigaretus neritnideus SowERHY. Thes.
Conch.. Vol. 5. p. 40. pl. 4-1. fig. l: pl.
2. figs. 16. 17.
Simon neritoideum No:-.n:RA. Sci. Rt·PTolwku Imp. Univ .. Ser. 2 (Geol.). Vol.
l\-lARTINI

1864.

1886.
1887.

lY35.

ll.

'YEJ:'\J(,\l'f"F

CHEMNJT7.,

I8, p. 205. pl. 9. figs. 26a. 26b.

A single specimen is referred to thenamed species. which is reported by S.
NmmRA fron1 the •· Byoritsu beds·· inthe above cited literature.
Dimensions (in mm) :-Diameter 36.8
(long) and 26.5 (short).
Repository :.:....IGPS coil. cat. no. 77524.
Li11ing :-The Philippines: East Indies.
Geologic distribution :-Pliocene of the211

RyGkyi'i islands: Pliocene of Formosa.
Genus Pha!ium LI:--;K, 1807
P/wlium cancellianum Nmit:RA, 1935
Plate 31. Figure 13
1935.

Plzalium cancelliaman NoMt:R.\, Sci. Rep.
Tohoku Imp. Unil• .. Ser. 2 (Geol.). Vol.
18. p. 169. pl. 8. figs. 25a. 25b.

A single. rather small specimen, v.:hichis slightly water worn. is referred to
the named species. Though the ribs
di~appear on the part of the bodywhorl. the peculiar cancellated sculpture of this species is distinctly observed on the portion behind aperture andthe younger whorls. The punctatecorrugations on the lower part of theinner lip are also distinct.
This species more or less resembles
Phulium strigatwn (GMEl.!!"). a living
species in the tropical to subtropicalregion of Asia.
Dimensions (in mm) :-Height ca. 30.0.
diameter 21.5. length of aperture 27.4.
Reposito1:v :-IGPS coiL cat. no. 77525.
Lil'ing :-L'nknown.
Geologic distribution :-Pliocene of Formosa (Type locality).
Genus Bursa Roo!:-;G, 1798
Bursa nobilis (REEVE). 184:)
Plate 31. Figure 10

Ranella nobilis REEVE. Conch. Icon.,Vol. 2. Ranella, pl. 4; fig. 16.
1899. Ranella nobilis MARTIN. Samml. Geol.
Reichs-Mus. Leiden. N. S. Vol. 1. pp.
146-1-17. pl. 23. figs. 340.,.3-12.
1920. Ranella (Bursa) nobilis TESCH, Paliiont.
1'011 Timor. Vol. 8. p. '11. pl. 79, Jig. 153.

1S-l3

A single, rather small specimen is referred to the named species. Although
the body whorl is preserved as a mould,
the acuminated spire. radiately starred

272

Ichira H·l }'.-IS'A/\.1 and Slzozo H·lY.-ISAKA

narrow varices and granulously ridged
whorls are the characteristics of thepresent specimen as well as of thespecies in general.
Dimeusio11s (in mm) :-Height 51.2.
diameter ca. ~5.9.
Repository :-IGPS coiL cat. no. 11526.
Living :-Pacific Coast of central Japan: Ryukyfi islands: the Philippines.
Geologic
distribution :-Pliocene
ofTimor: Plio:::ene and Mio:::ene of Java:
Pleistocene of the Ryukyu islands.
Genus Murex LJ:"NE. 11:18
Jlurf'.t peng/lUensis HAY:\SAI':\and liAY:'ISAKA, n. sp.
Plate 31. Fiv,ures 19a-c.

Descriptio":- Shell0\·ate-pyriform.
thick and stout. slightly higher thanwide. whorls provided with longitudinal
riblcts an'l spiral threads. the former
stronger than the latter. Whorls about
seven. rapidly increasing in size. spiralthreads increasing and axials be:::omingstronger with addition of whorls. Postnuclear whorls mostly lost. one volution
preserved. smooth and ro'Jnded. withincipient longitudinals at its lowermost
part. Second post-nuclear whorl withaxial riblets, narrmver than its interspaces which are \Vithout spiral threads,
or with incipient development at its
lower half. Third whorl with expanded
shoulders formed of strong axials
slightly narrower than their interspaces
which are provided with seYeral spiralthreads ; separated from second andfourth whorls by shallow sutures.
Fourth \vhorl with four spiral threads
on shoulder which is delimited by strong
axials, with three to four spiral threads
on its lower part. Fifth whorl withmany spiral threads on shoulder above.axial ribs forming short spine-likeshoulder~eight spiral threads on an1
below projecting shoulder. delimited byshallow suture. Sixth or body whorlwith eight strong. projecting. axial or
longitudinal riblets. be:oming spine-likeat shoulder; each axial about as wide
as its interspaces. Smaller and tuberclelike projections formed below projecting
spine-like shoulder. Body whorl covereel with spiral threads. which become
stronger on basal part. and appear
as ridges on last axial. Five axials of
last whorl com·erging into basalpart, fusing, then flaring outwards
posteriorly; last axial also converging
downwards, then continuing into curved
canal of which it forms a part. Aperture
ovate, inner lip rather thick, slightly~.:allous: outer lip weakly denticulate.
thick. Columella short. Canal partly
open. rccurved, oblique, rather long.
Dime11sions (ill mm) :-Height 5:2.4. diameter 111.5. height of aperature ~0.6,
length of canal 18.6.
RPposi!ory :-IGPS coli. cat. no. 77527
rHolotype).
Remarks:- This new species more orless resembles Jlurex ardjunoi BEETs(19-H ~ from the Cpper :\1 iocene of Borneo. but can be distinguished therefrom
by the more elevated spire which consists of more angulated step-like whorls.
and by the more strongly developedfasciole and canal. Also the axials of
the pre,;cnt species are stronger andmore outstanding.
Genus J1e/ongea ScHL'MACIIER, 1817
:lklongena coniformis I lAY ASAKA,
and HAYASAK.-\, n. sp.
Plate 31. Figures 20a-c

Description :-Shell of medium size.
thin. pyriform, rather low-spired. Spireconic. five preseved, body whorl separat-382. Molluscan fossils from Twzgyiiping in the Penglzu Islands·ed from preceding one with canalicularsuture. other whorls separated \Vithmore or less fused sutures. Nuculear
whorls lost. Postnuclear whorls four.
of which first is rather smooth. without
defined shoulders or spiral sculpture.
Second preserved whole with roundedshoulders, rather straight sides, and·incipient beads at its lower part justabove suture.
Third whorl withshoulders defined by small tubercles.
which grow into spine-like projections
on body whorl: area above shoulders
rather flat, rather abruptly ascending
into suture. Body whorl separated fromthird by canaliculate suture. which is
deep and rather narrow: its shoulders
characterized by spine-like projections:area above shoulders more or less concave. Spine-like projections of body\•;horl becoming higher and strongertO\vards aperture, where they areseparated by much narrower interspaces.
Body whorl covered with numerous,
close-set. spi rat threads, narrower thantheir interspaces. forming a net-workwith longitudinal threads. Outer lip
partly broken, not very thick. Inner
lip covered with rather thick callus.
Aperture elongately ovate. provided atits uppermost part ,...,·ith upturned posterior canal. Anterior canal rather\vide. Columella stout.
Dimensions (in mm) :-Height :i9.0. diameter -H.~ !maximum) and 30.8 !minimum\ length of aperture .t:n.
Repository :-IGHP coli. cat. no. 77599(Holotype).
Remark'> :-Among the known speciesof the genus, Melongena pugil!ina (Bon:'-1),
a Recent species from the Indian Ocean.
resembles the present new species.
which. however. can be distinguishedtherefrom by the higher spire. moreregularly dcvelo~e:l tubercules on theshoulders and by the more elongate

27:3

body whorl.
This species is also similar to 1Vfelongma madjalengkensis ?vhRT. reported by
MARTIN (1926) from the Pliocene of JaYa.
lH. mdjalengkensis, which is regarded asa direct ancester of M. pugil/ina by theoriginal author. differs from the present
species in having a canaliculate suture
not so strongly as of the latter. rather
flat or slightly concave shelf. and projections more regularly developed an:!
rather roundly topped.
References
C. (1941). Einc jungmiociinc \lolluskcn-Fauna von der Ilalbinscl Mangkalihat, Ost-Borneo. T'erlumdrl. t•an het Geolo!!i sell· .lfijnbouu·kundig Genool schaP voor
Sederlanden Kolonier. Geol. Ser., Dee/ 13.
DEGL'CHI. Y. (1912), Report on the Geologyof the Iloko (Penghu) Islands (in Japanese).
Published by the GorernmentGeneral of Formosa.
H.\YASAKA, I. (1947), Notes on some Fossil
Echi noids of Taiwan. II l. Acta Geologica
Taiwfmica, mi. 1, 110. 2. pp. 118-119.
- - (1948). An Outl!ne of the Geology andGeography of Taiwan. Hsuell i f$a chi/1.
Nanking (W}?:. 'i=1'H!Ut) 1'0/. 18, no. 6,
pp. 11-22.
- . LI:o.:. C. C. and YE:-o:. T.l'. (1948), An
Outline ancl some Problems of theStratigraphy of Taiwan. Acta Geologica
Taiwanica. 1'01. 2. 110. 1.
KA;o.:EitAilt\, K. (1937). On some Neogene
Shells from Japan. Part I. ]our. Geo!.
Eoc. Japan. mi. 44. no. j2/. pp. 781-785.
Kt:RODA. T. (1941). A Catalogae of Molluscan Shells from Taiwan (Formosa). with
Dcscri pt ions of New Species. :Hem. Fac.
Sci. & ilgri., Tail10k11 Imp. Uni11., t•ol. 22.
/10 . .J. pp. 65-216.
i\L\RTI:-<, K. (1926). Pliocene versteeningcn
van Cheribon in Java. IFetensclwPPelijke,Uedt>dt'elit~gen. no. 4, pp. 1-23.
'!\o:o.tt:RA, S. (1933). Catalogue of the Tertiary
and Quaternary :\Iollusca from theIsland of Taiwan (Formosa) in the Tnst it u tc of Geology and Palaeontology.
BEETS,

27·1

Ichiro HA.YASAKA and Shozo HH'ASAKA

T6hoku Imperial University, Sendai,Part l. Pelecypoda. Sci. Rep. Tolwku Imp.
Unit,., ser. 2. vo/. 16. pp. 1-108.
- '-- (1935a), dilto, Part 2. Scaphopoda and
Gastropoda. Sci. Rep. Tohoku Imp. Unit'.,Ser. 2. vol. 18. pp. 53-228.
- - (1935b), Miocene Mollusca from Siogama. :'\ortheast Honshu. Japan. Saito
Ho·on Kai Mus. Res. Bull.. no. 6. pp. 193234.
SUGIYA~IA, T. (1935). On the Variation of
the Shells of Living and Fossil Um·

bonium from Japan, and its Evolution,..
Part 2. four. Geo/. Soc. japan. 1'0/. 42.
110. 503, pp. 449-482.
YoKOYAMA, l\1. (192-1), Tertiary Fossils from
Kii. japan. four. Geol. & Geogr .. t•o/. 2. no.
3. pp. 47-58.
- - (1926). Tertiary rvlollusca from Southern Totomi. ]our. Foe. Sci., Imp. C:niv.
Tokyo. Sec. 2, t•ol. 1, pt. 9. pp. 313-364.
- - (1928), Mollu!>ca from the Oil-Field of
the Island of Taiwan. Imp. Ceo/. Surv.
japan. RePort 110. 101. pp. 1-112.

Explanation of Plate 31(All figures in natural size unless otherwise slated.)
Fig. 1. "lnadara (Scapharca) comea (Rr::r.vE), IGPS*' coli. cat. no. 77508.
Fig. 2. Anadam (Scaplwrca) salowi (Dc:'\KER), IGPS coil. cat. no. 77509.
Figs. 3a-b. Anadara (Dilm•arca?) rhombea (BORN), IGPS coli. cat. no. 77510. Left va!YC. a.
inner side, b. outer side.
Fig. 4. Stmelta me11strualis (Mr.;o.;KE), IGPS colt. cat. no. 77511.
Fig. 5. Anisocorbula scapltoides (1111'\DS), IGPS coli. cat. no. 77516. x3.
Fig. 6. /Josinia gnmeri Priii.IPPI. IGPS coli. cat. no. 77514.
Fig. 7. Caece!la chinensis Dr.snAYES. IGPS coli. cat. no. 77515.
Figs. Sa-b. Meretrix deguchii IIAYASAKA and HAYASAKA. n. sp. Holotype, IGPS cull. cat. no.
7i512. Left valve, a. outer side. b. inner side.
Fig. 9. Architectmzica perspectit•a (LI"'NE). IGPS coli. cat. no. 77520.
Fig. 10. Bursa nobilis (REEvE), IGPS coli. ca:. no. 77526.
Fig. 11. lJmbonium (Umboaium) z·estiarium (LI:"l'\E). IGPS coli. cat. no. 77518.
Fig. 12. Balil/aria murayamai YoKOYA~IA. IGPS colt. cat. no. 77522.
Fig. 13. Pha/ium cancel/ianum No:-.n;RA. IGPS coli. cat. no. 77525.
Fig. 14. Simmr 7/eriloideum (Lr:-<:-<E). IGPS coli. cat. no. 7752-1.
Fig. 15. Ceritlzium koclzi PHILIPPI. IGPS coli. cat. no. 77523.
Fig. 16. Ceritllidea cingula/a (G:-.IELI:'\), var .. IGPS coli. cat. no. 77521.
Figs. 17a-c. Monilea tungyiipingensis HAYAS:\KA and HAYASAKA. n. sp. Holotype, IGPS coli.
cat. no. 77517. a. lateral \·iew. b. basal Yiew. c. apical \'iew.
Figs. 18a-c. llmbonium (Umbonium) n." sp .. IGPS coli. cat. no. 77519, a. lateral view, b. apicalview, c. basal view.
Figs. 19a-c. Murex penglmensis H ..... YASAKA and HAYASAI\A, n. sp. Ilolotype, IGPS coli. cat.
no. 77527. a. lateral view. b. apical Yiew. c. apertural Yiew.
F'igs. 20a-c. Melo11gena coni[ormis HAYASAKA and HAYASAKA, n. sp. Holotypc. IGPS coli. cat.
no. 77599, a. lateral view. b. apical view, c. apertural view.
*)Abbreviation for Institute of Geology and Paleontology. Tohoku University, Sendai.

H AYASAKA and H AYASAKA:

K u M/\GAI

photo.

Mottuscan Fossil from Tungyuping

Plate 3 1

Trans. Proc. Palaeont. Soc. Japan, X. S .. No. 38. pp. 275-2~3. pl. 32. JunL' 1. 1!!60.

A NOTE ON NEOBURMESIA. A PECULIAR JURASSICPELECYPOD. WITH DESCRIPTION OF l\IITILIDS AND~TYACIDS FROM THE UPPER JURASSICSOMA GROUP IN JAPAN*:~8:1.

i\IINORU TAMURA
Faculty of Education, Kumamoto University·,

Seoburmesia YABE and SATO '&0: "'lytilids. :\lyacids: ttl.Mytilids 7Jf..V: Myacids 't.t'~c~ t... 1#-tt-c .Veoburmcsia
YAn~; and SATO Cl)f£~'t.t'~UM U.: o ::..hi?Oft1:il:tl§.~J;J.7'~Cl)Jt!!~'"C'I:t-t:'Cl)@.fiib'·9i; Cf.t:
Pteriacea Cl) ~i~'U: ;11<1:. ft!!Cl)[K~Cl).ll!;:m:::ttJl.IIJ~l!fl.:.lfR""- "Clllt$¥f.cfl:f{"Cj;, o o 3Z.:
.hi?Cl)•i•t.:.lt~tJllil~lk.V: 1:. '7 7""' . ;L-7-;;l- !:.' 7\KCl)J:ffll/ .=:.. 7 *j/f:Cl)fl(flf!b;f;; itt"(\,' 0.Vcoburmcsia Y ABE and S.-\TO lt.4·[il]Cl)~:tf.i.:. J: 'J chondrophore Cl)frf£b'·~.ZI>'.J l?.tt:f.
Pholadomya 1.:..i!:i:~t.c t Cl)"C;b o ::.C. n:btJ·-:d.:om N
1!
?MJi~Mill.IJ~Y=>-77f-i!f.Cl).~i&;Cl).-m:::txfH!b¥aflfCl)? 'I?

<.

0

Acoburmesia from the Nakanosawa formation of the Soma Group is an interesting genus having unusually wide
YABE
and SATo (1942) comoutline.
pared it with Burmesia HEALEY (1908)
from the Upper Triassic Napeng Beds of
Burma. chiefly from external ornaments.
Fortunately. the writer succeeded toTable 1.

collect many well-preserved topotypes
which admitted him additional observations with which on the taxonomic
position of the genus can be discussed.
Beside Neoburmesia are described here
Mytilids and Myacids from the Nakanosa\va formation in which are four distinct fossil zones. Geological notes andList of the fossils and their range chert.
· 1\akanosawa formation
5th zorie 6th zone 7th- zone 8th zone

Specific name.\Jodlo/us d. bipartitus 1:- SowER BY
X
1llodiolus (bwjJerna) plica/us ]. SowERBY
X.llodio/us (/llofJerna) sp.
Bracltidontes (Arcomytilus) /aitnuzirmsis (de LoRIOL)
Jlyoconcha ? s p.
X
Pinna cf. mitis PHILLIPS
Pleuromya? tnmctostriae TAML"RAX,1tyoplwlas ct. acuticostata (]. de C. SowERBY)
X
Pholadomya some11sis T A:\IURA, new species
X
Neoburmesia iu•akirmsis YABE and SATO
Homomya giilbosa (J. SOWERBY)
X_Goniomya 11mwscripta T~:\IL'I~,\. n('!\'<~~_ecie_!; _ _ _ _ -~-·

X
X

X
X
X

X

X
X

X
X

X

X
X

the fossil localities were listed elsewhere(TA:\HJRA, 1959-b). These fossils andtheir occurrences are shown in Table
1. Most of them are characteristic in* Receind Jan. 30, 1959; read at 72th
meeting of the Society at Hiroshima, Feb.
14, 1959.

275

!v1inoru TAMURA

27G

sandstone facies and widely distributed,
not only in South Asia but also in
Europe. Such Tethyan similarity. however, cannot be recognized in otherpelecypods of Soma. They are mostly
long-ranged and invaluable as time
indices.
The writer expresses his sincere thanks
to Prof. T. KouAYASIII of the Univ. ofTokyo for his kind guidance throughwhich this study was accomplished.

Bathonian form of Cutch than S~>II'ERrn-'s~
Occurrence :-5th zone at Locs. 2. 7.

Subgenus Inopema CmwAD, 1875
Modiolus (Inopema) plica/us ]. SowERBY
Plate 33, Fiuregs 5 8
1819.
183i.
1853.

Description of Fossils

Family l'vlytilidae
Genus Modiolus L.>.~o.IARCK, 1199
l't'lodiolus cf. biparfitus ]. SowERBY

1856.
1867.
1874.
1905.

Plate 32, Figures l!l, 20
1906.
d. 1818.

cf. 1837.
cf. 1906.
cf. 1928.

cf. 1929.

? 1931.
cf. 1940.

.l!otiiola /Jiparlila, Sm1 ERBY. p. 17.
pl. 210, fig. 4.
Mylilus biparlila, GOI.DFl'SS. p. 176.
pl. 131, fig. 3.
Jl/odio/a tu!ipaea, Boii!SSJAI\. p. 2.1.
pl. I, figs. 3-6.
Modio/a biparlila, DoliGL\S and
ARKEI.L, p. 17·1, pl. 12.
Jl/odio/a biParlila. ARKELL, p. 55.
pl. 2, figs. 1-.f and text.fig. 8.
Modio/a tuiipa, DIAZ·RO~IERO. p. 32 ..
pl. 2, figs. 14. 15.
Modiolus c.:f. bipartitus, Cox. p. 67.
pl. 5, figs. 11. 12.

Two internal moulds at hand arealmost identical with well-known Modiolus biParlitus. In the larger left mould(plate 32. fig. 20) a deep sulcus extends
from umbo to venter on which it gives
cnocavity. These features are. however,more or Jess exaggerated by deformation.
The surface is ornamented by very fineregular concent ric growth-lines. The
median part of shell is most inflated.
The specimens are closer to Cox's Upper

1910.
1931.

1936.
1940.

Modiola plica/a. SOII'EIWY. p. 87. pl.
248, fig. 1.
Jfytilus plica/us. GoLDFUss, p. 175. pl.
130. fig. 12 a.
,lfytibts Sowerbyana. Moiwis and L Y-CETT, pt. 2, p. 36, pl. •l. fig. I.
J!odiola Plicata. QuE>XSTEDT, p. 357. pl.
49, fig. 4.
111odio/a Sowerbyana, LAlciiE, p. 28.
1\!yti/us perplzmlus. de Loi~IOL and
PIETET, p. 156. pl. 13, ligs. 19. 20.
1\!odiola plical a, BENt;c Kl·:, pt. 4. p. 168.
pl. 4. fig. 6.
lvlodio/a perp/icala, Ro1w;sJ .u:, p. 30,
pl. 2, figs. 6 a. b.
Modiola Plica/a. DACQUU. p. :{0, pl. 5,
fig. 10.
1\!odio/a perp/icota, Dli\Z·Ro~IERO, p.
29. figs. 11-12.
1llodiolus (Pharomylilus) p/ica/w, Cox.
p. 13. pl. 1, lig. 21.
1llodiolus (lnopenza) plica/us, Cox, p.
71. pl. 5. figs. 13. 14.

Although the peculiar ornamentationon the dorsal side is variable among
illustrated specimens, they belong tothis Upper Bathonian-Kimmeridgian species. Whether it is conspicific with J\.'f.
(lnoj>emal perplicatus (ETAI.Lo:-o) is aquestion as noted by Cox (1940). The
distinction is in the ribs on dorsal sur·face .which are bifurcate in half-way
between dorsal margin and the carina
in Pe1Plicatus. In the Soma form, however. some (fig. 5 etc.) are bifurcatedas inPetp!icatus but others as in plica/us.
These specimens are found together andindistinguishable in most characters.
Therefore the writer deemed that per-·383.

A Note on Neoburmesia, a peculiar jurassic Pelecypod

p!icatus is synonymous with plicatus.
Occurrence :-5th zone at Loc. 7; I thzone at Loc. 3; 8th zone at Loc. 14.
,1/odiolus ilnoperna) gp.
Plate 3~. Figure ~Dr1scription :-Shell medium iabout 40
mm long •. moderatelv inflated, ensifom1
in shape; dorsal margin a little rounded:,·entral slightly conca,·e: both margins
nearly parallel in posterior: umbonalcarina indistinct: surface ornamented
only by growth-lines.
Obserl'ation :-A left Yalvc at hand may
be refered to Inopema by itg ensiform
shell. The surface is. however. ornamented only by growth-lines and thepeculiar ribs of Inopenza are absent on
the dorsal side.
Occurrei/C(' :-8th zone at Loc. 14.
Genus Brachidontes SwAJ:->so:-:, 1840
Subgenus Arcomyti/us Ac.·\Ss1z. 184~

Brachidontes \Arcomytilus ',laitmairensis Ide LoRio!.']'late 3~. Figures 3. ~1853.

Mytilus asper. :\!oRRIS, LYCETT, p. 39.

1867.

Mytilus (Septifer) asper. LAl'IIE. p. 30.

pl. 4. fig. 8.
pl. :?. fig. 5.

.l/ytilus taitmairensis. DIAZ·I~o\IERt•. p.
29, pl. :!. figs. 11 a. b and 12.
1935. Jlytilus(:lrcomytilus)
lailmairensis.
1931.

Cox. p. 1G•l. pl. 15. figs. 13. ll.
1936.

Mylifus (Arcomytilus) laitmairl'nsis, AR·

1940.

KELL. p. 359. pl. 53. fig. 2.
Brachidontes (Arcomytilus) laitmairensis.
Cox. p. 81. pl. 5, figs. 15-11.

Description :-Shell medium for genu5,
well inflated. cuneiform and widening
gradually towards its postero-Yentral

21T

extremity: umbo terminal: umbonal
region produced but not inflated. mostcom·ex at a little anterior to midheight:
hinge-margin about a half or a little
more of the shell lengh. slightly rounded
and passing into convex posteri- or andconcave ventral margin: umbonal carina
or ridg~ fairly distinct : posterocarinal
part depre,;se:l: ra:lial ribs numero:Js,
increase their number by divarication.
1Heasuremeul :Left \·alve (;\1M 3268)
L.
( .Ml\1 3369)

L
27.0 mm
28. (IH
19.0 mm17.0

Obsen•ation :-Three left valves and aright one are at hand. Among foreign
specimens. DIAz-Ro~JERo's from Central
Dancalia 1pl. 2. figs. 11. 12) are closely
allied to the Soma form. This species
is long-ranged from Bathonian to Argovio-1\immeridgian. Its dcscriminationfrom H 1 Arcomytilius) asprtr (J. So\\'ER9Y)
is a matter of discussion. The Soma
form is especially akin to the typicallaitmairensis.
Occurrence :-7th zone at Loc. 1!1 and8 th zone at Loc. 14.
Family ivlodiolopsidae
Genus l11yoconcha SowEIWY. 1824

11lyoconcha ? sp.
Plate 32. Figures l. 2

Description :-Shell medium for genus,
fairly convex. much inequilateral. oblong
and mytiliform: umbo small and indistinct. subterminal: dorsal margin slightly rounded and passing into rounded
posterior: ventral straight: anterior
short and rounded; shell body dilatedback\vard: umbonal angulation obscure;surface smooth: anterior adductor scar

218

JVlinoru TAMUR:lclose to umbo large, trigonal and bound€d by a pro:11inent cravicle: hinge unknown.
.lfeasurement :Right valve (l\11\1 3271)
R.
(MM 3272)

L

H

55 mm
26?

23 mm
11

Observation and Comparisol/ :-Threeinternal moulds of right valves and an
incomplete external mould of a rightvalve are refered to ,l1yoconcha by alarge anterior adductor scar bounded
by a prominent cravicle and by a terminal umbo. In outline they somewhat
resemble Mytilus but tne anterior adductor scar is too large for Jlfytilus. The
Soma from is a little different from
1lf_roconcha in general shape. though theform has a wide umbonal region and ismore or less similar to 111. crassa Sow.
which is the type-species of the genus.
Occwrence :-5th zone at Loc. 7.

Family Pinnidae
Genus Piuna LI:":-<I~. 1758
Pinna cf. mitis PHILLIPs
Plate 32, Figures 12-1-1

but obscure and become broad undulations near ventral margin.
Obsercation and Comparison :-Most bivalved specimens lack their umbonal
part and posterior. They closely resemble Pinna ct. mitis PHILLIPS by Cox(1940). Although the original description
is inaccessible to the writer. these specimens may be referable to this species.
Occurrence :-7 th zone at Loc. 15 and8th zone at Loc. 14.
Family Pleuromyidae
Genus P!euromya AGASsiz, 1845
P!euromya? puuctostriae T.un:R.-\
Plate 32. Figures ~7. ~8
1959-a.

p. 117. pl. 12. figs. 29-32.

One external mould of a left valve:tig. :27) and one internal mould of aright valve at hand are both deformed
and incomplete. Their regular undulation on surface. however. are characteristic in pwu:tostriae. Rows of punctae
are invisible in them probably due totheir poor preservation.
Ocwrrence :-5 th zone at Loc. 7 and8th zone at Loc. 14.

cf. 1!-!40. Pinna cf. mitis. Cox. p. 132, pl. 10.
fig. 11.

Description :-Shell medium for genus(90 mm long and 30 mm high). inflated.

wedge-shaped and tetragonal in section ;dorsal and ventral margins straight:
posterior gaping unknown: median carina distinct and dividing surface into twoparts of which ventral one is slightly
wider; dorsal half ornamented with
about 9 radial riblets and inserted by a
few riblets in posterior; ventral half
provided with radial riblets (about 4)
which are distinct near median carina

Pteuromya? punctoslriae. T.-\MUR.-\,

Family Pholadidae
Genus Jl;Jyop/w/as DouviLLE, 1907
Myop/w/as cf. acuticostata(J. de C. SowERDY'
Plate 32. Figures 25. 26
cf. 1827.

Plwladomya awticostata. ]. de C.
p. 88. pl. 146, figs. 1, 2?
Pholadomya acuthosta, .MOIHHS and

SOWERBY,

d. 1854.

LYCETT.

cf. l!-l23.

p. 121, pl. 13. fig. 13.

Jfyopho/as Doul'illei, LISS.-\JOURS, p.
199, pl. 32. figs. 8. 8 a.

Description :-Shelllarge forgenus,

383.

A Note on Neobzmnesia, a· peculiar Jurassic Pelecypod

well inflated. inequilateral. oblong or
subtrigonal and much longer than high:umbo indistinct. incurved and locatedanteriorly: anterior margin a little concave: posterior margin nearly straight;
ventral evenly rounded: anterior partwithout radials. more or less depressed;
no distinct sulcus seen between anterior
and middle part ; middle and slightly
depressed anterior parts radially ribbed:
radials coaser in anterior than middle
part, coarse but obscure in posterior;
growth-lines fairly distinct but weak inregion radially ribbed.
Observation and Comparison:- Three
specimens at hand are probably allied
to this species. The radial ribs areabout 40 in the left valve and a little
less in the right. They are irregularly
disposed.
Occurrence :-5th zone at Tochikubo:
7th zone at Loc. 13 and 15.
Family Pholadomyidae
Genus Pho/adomya SowERBY. 1825

Pholadomya some11sis TA~IUR:\,
new species
Plate 32. 1-'igures 10, 11
1939.

l'lwladomy.7 Protei. STEF A:"IXI, p. 263,
pis. 27, 28. figs. 6-8.

Description :-Shell small to medium,gibbose. a little higher than long. somewhat trigonal and expanding posteroventrally: umbo subtrigonal. inflated andslightly incurved; anterior margin very
short: lunule small. deep and distinct:
posterior margin slightly concave andlanceolate: escutcheon well defined:
ventral well rounded and demarcatedfrom anterior margin: posterior somewhat truncated and gaping: radial ribs
about 7 on middle part: concentric folds
or growth-lines fairly distinct.

279,lJeasuremmt :Bivalved shell (Ml\1 32i8)(l\ll\1 3279)( :-.1!\'1 3280)(MM 3281)

L

II

35mm
32
21
15

41mm
40

28
18

Observation and Comparison :-The radial ribs on surface are fairly distinct insome specimens but obscure in others.
Plzoladomya protei \BRO:'\G:\IART) by
STI,FA!':INI from Somaliland Jurassic has
five radial ribs but the shape of a shell(pl. ~8, fig. 7 al closely resembles theSoma form il\IM 3~79.. The original
figure of protei by BRo:o-:G:"IART 1)8~1)
is different in shape from that of theSomaliland form.
Occurrence :-5 th zone at Loc. 8: 7thzone at Loc. 15: 8th zone at Loc. J.l.
Genus Neoburmesia YABE and S:Ho, 1942
Type-species:- Neoburmesia iwakieusis
Y.-~.nr' and SATo.
Diagnosis :-Shell large. very inequilateral. equival\'e, inflated, somewhat
Parallelodon-like or elongate Plwladomyashaped: umbo much anterior: surface
divided into three parts by strong posterior carina and weak anterior carina:
anterior and posterior parts depressed.
covered with weak concentric ribs:
median part with distinct radial andconcentric ribs. tu berculate at theirjunction; escutcheon long. narrow andwell defined; posterior gaping distinct:
hinge edentulous.
Remarks:- YABE and S.Ho (1942) founded the genus on Neoburmesia iwakieusis
YAoE and SATo from the Koike limestone
near Koike, which is monotypic. The
presence of chondrophore was a question.
From the similarlity of external ornaments they compared the genus to Burmesia IIEAI..EY {19081 from the Triassic~apeng beds of Burma. It has a chondrophore. Together with Pro/aria IlEA-

280~1inoru T.-UJUR.4

LEY she placed it in the Burmesiidae
and considered Anatina and Plwladomya
as its close relatives.
Although it resembles Burmesia in
ornaments. it is evidently different from
Burmesia in the inilated and elongatedshell. very anterior umbo, distinct posterior gaping. It agrees with Plwladomya better than Bunnesia. The absenceof the chondrophore is. however, ascertained by cutting the umbo longitudinally as well as transversely. This
point is, further. confirmed by the elevated and strongly incurved umbo.
In the elongate forms. such as Plwladomya gigmztea ISo\1·.) '· Wooos, 1909),
P. arcuata AG.. P. nympheacea Ac., P.
pantica Ac., P. Bucardium J\c. (f\c;ASsJz,
1840) and P. e/eganla !vJe:-;sTEI~ (d'0RBIG:-.JY,
1843-47\. are they very similar to the type~pecies. This resemblance of shell form
is a proof for the close relation between
the two genera. But the distinct posterior carina. strongly inflated and incurved umbo and well developed posterior part are the distinction of thisgenus from these elongated Plwladomyas.
Its very low shape is also characteristic.
In the writer's opinion Pholadomya isprobably more numerous in Cretaceousthan Jurassic. Likewise. }ieoburmesia
is presumed to have derived from
Plzoladmnya by elongation of shell. Y ABEand SA-ro did not cite its taxonomic
position but the writer places it in the
Pholadomyidae.
Distribution :-Upper Jurassic in Japan.

Neobumzesia izmkiensis Y AilE and SA-ro
Plate 32. Figures 21-2-1; text-figure 1
1942.

N·eoburmesia iu·akiensis, Y.'\HE and SAp. 251. text-figs. 1-3.

TO.

Description :-Shell large, equivalve,strongly inequilateral. well inflated,much elongated and somewhat Parallelodon-like; umbo at about 1/5 or less of
the length from anterior, inflated. strongly incu rvecl and orthogyrous: anterodorsal margin short and inseparablefrom rounded anterior; posterior dorsal
nearly straight oi· a little concave andlong ; posterior rounded and produced :ventral nearly parallel to dorsal margin.
but slightly sinuate below umbo; posterior umbonal carina strong; anteriorumbonal carina obscure; anterior part
depressed. ornamented by only concent·ric growth-lines; median part \Videlydepressed and concave. ornamented byabout 20 or more radial ribs; posterior
part elongated. concaved and ornamented
only by concentric growth-lines. but
faint radial ribs visible near umbo, one
long ridge close and nearly parallel to.
hinge bounding lanceolate shallow escutcheon: upper half of posterior margin
widely gaping; hinge edentulous.
JUeasurement :-BivalYed shell (M!vl 3282)(MM 3283)(Ml\1 3284)

H
L
mm mm mm
79 24 22

98

4i

78

23

21
,,_
-=>

Ucwrrence :-7th zone at Locs. 13, J16
and 8th zone at Locs. 6 and H.

Genus Homomya AcAssiz, 1842
Homomya gibbosa (]. SowERHY)
Text-fig. 1. .\'eoburmesia iwalliensis YABE andS:\TO; xl/2 (internal mould ofa right valve)

Text-figure 2
1855.

Jlyacites gibbosa (Sow.), MORR 1s anrip. 138. pl. 12, fig. 14.

LYCETT.

383.

A Note on Nerbunnesia. a peculiar Jurassic Pelecypod281

18:55. Myacites Yezelayi (LAJOYE). MoRRIS
and LYCETT. p. 111. pl. 11. figs. 5, 5 a.
1863. Homomya gibbosa. LYCETT, p. 88. pl.
43. figs. 2. 2 a.
1~35. Homomya
rl'zdayi (d'ARCIIL\C). AR·
KELL. p. 338, pl. 49. fig. l.
1935. Homomya gibbosc:. ARK F. I.. p. 340. pl.
49. fig. 3.
UJ4S. Homomya gibbosa, (Cox and ARI(ELL.
p. 44.

genus, moderately convex, inequilateral,.
elongate trapeziform: umbo submedianor slightly anterior, indistinct and in-·curved: dorsal and ventral subparalleLand long: postero·dorsal concave nearumbo: ventral slightly rounded: anterior margin rounded. upper half mostproduced: posterior margin straight anddiagonal: posterior gaping distinct: ribs
about 30, not v-shaped and divided into
three sets: anterior and posterior setsfading away near dorsal margin and do
not meet directly at points but ah\·aysjoined by fairly long bars of horizontaL
set: about 6 ribs near venter inseparable into three sets and not angulate at.
their junctions: growth-lines concentricand very fine .

Text-fig. 2. Homomya gibbosa (]. SOII'ERBY):
x 1/2 (internal n;ould of a left valve).lleasurement :-A large internal mould of a bivalved
ahell (L: 115 mm. II: 15 nun, \V: 28 mm!
from Lima sandstone is in the collection.
Although its umbo and antero·ventral
parts are unpreserved. it is identified
with this well known species. In thewell inflated shell. strongly convex vent·ral margin. a fairly concave postero·dorsal margin. a obliquely truncatedposterior margin and a posterior gaping
it is similar to the type-specimen (].
SowERnY. 1823 and AREELL. 1935!. It islong-ranged in England from Inferior
Oolite to Corallian.
Occurrence :-5th zone at Kozawa (?l.
Genus Goniomya AGASSIZ, 1842
Goniomya nollrscriPta TA~n-RA.

new species
Plate ::12. Figures 15-18
1959-a. Gmziomya sp .. T~\~llJRA. p. 120 pl. 12.
fig. 28.

Description :-Shell medium-sized for.

Right valve (Ml\.1 3289)(l\1M 3290)
R(:VIl\1 3291)
R.
(\IM 3292)
L.
(M\-1 3293)
L.
(MM 3294)
L.

L

H

39mm

22mm

44

2-l

3:1

~2

42

2-1
21
20

43

35

Obseroation and Comparison :-Several
valves and moulds at hand bear characteristic ornaments of Goniomya. Theirribs are not strictly v-shaped and always
intervented by horizontal fairly longbars. Three sets of ribs are inseparable
on ventral side. No anterior and posterior sets intersect the ventral margin.
The mode of ornamentation is characteristic of this species. The ribs of
three sets are different in number andmost of them discontinuous. The posterior gaping is wide.
Gmziotnya !iterata from the Great Oolite
in England resembles this species but
its horizontal bars are very short. In
typical G. literata (]. SowERBY, 1864:
ARKELL, 1934), horizontal bars are restricted in the umbonal part. G. inflata

Minoru TAMURA:28~(1840) from the Oxfordian ofFrance is close to it in form and orna_ments, although the ventral side isprobably Jacking. The obliquity ofornaments which is here shown by theangle between ventral margin and theline running from the umbo to centersof horizontal bars is larger in injlata(SO') than in this species (65°).
AcAsslz

Whether the fragments of Goniomya
from the Sakamoto formation (T A'I.JUR_-\,
1959-a) belong to this species or not isa diflicult problem, though they show
a part of ornament. Here the writer,
however, refered them to G. ll01Wscripta.
Ocmrreuce :-5th zone at Loc. 8; 8thzone at Loc. J.l; 7 th zone at Loc. 15.

Explanation of Plate 32
Jl/yoconcha ? sp.
Figs. 1. 2. Internal moulds of left valves; x1; Loc. 7. (l\I:\1 3272, 3271).
Braclzidontes (.4rcomytilus) laitmairensis (de LORIO!.)
Fig. 3. Left valve; X 1; Loc. 1·!. (MM 3268).
Fig. -!. Internal mould of left valve; x1; Loc. 15. (;'viM 3269) .
. Jl!odiolus (!Jwpema) Plica/us .J. SoWERI3 Y
Fig. 5. Internal mould of a bivalved shell; xl; Loc. 3. (?\IM 3263).
Fig· 6. Internal mould of a right valve; Loc. 8. (M:\1 326-!).
Fig. 7. A broken left valve; x 1; Loc. 1-!. (l\IM 3265).
Fig. 8. Internal mould of a broken left valve; xl; Loc. 3. CviM 3266).
Jllodiolus (lnojJenza) sp.
Fig. 9. Left valve; xl; Loc. U. (MI\1 3267).
Plzoladomya somet1sis TA:>.tt.:RA, new species
Figs. 10. 11. Internal mould of a right valve of a bivahed shell; xl; Loc. 8. (~L\13278: holotype) .
.Pinna cf. mitis PHILLIPS
Fig. 12. Dorsal side of a bivalved shell; x1; Lac. 15. Cv1M 3273).
Figs. 13, 14. Ventral side and right valve of a bivalved shell; x1; Loc. 15. C"l~l 327-!).
Goniomya llalwscripta T,\:IIUHA, new species
Figs. 15, 17. Internal moulds of left valves; x1; Lac. S. (i'viM 3294. 3293).
Fig. 16. Holotype left valve; x 1; Lac. 15. (Mr..J 3292).
Fig. 18. Right valve; Xl; Loc. 15. (MM 3~91).
Jlodiolus cf. bijJartitus ]. SowERBY
Fig. 19. Internal mould of a right vah·e; xl; Loc. 8. (;\IM 3261).
Fig. 20. In~ernal mould of a right valve; xl; Loc. 2. (.tvE'vl 3262) .
.1.Veoburmesia iwakiensis Y,\nE and SATO
Figs. 21-24. llpper, side, under and anterior views of a bivalved shell; X 1; Loc. 15.
(MM 3282).

lv/yoplzolas cf. acuticostata (}. de C. SowERBY)
Fig. 25. Internal mold of a left valve of a bivalved shell; xl; Loc. Tochikubo. (11?\I3295).
Fig. 26. Internal mould of right valve; x1; Loc. 3. (l\II\1 3296) .
.P!euromya? prmctostriae TA~IL'RA
Fig. 27· Clay cast of an external mould of a left valve; x 1. Loc. I. (MM 3276).
Fig. 28. Internal mould of a right valve; xl; Loc. 1-t (MM 3277).
All specimens here illustrated arc kept ih Geological Institute, University of Tokyo.

T AMURA:

Upper Jurassic Pelecypods

Plate 32
. 9

4
'

"\

383. A Note on Neoburmesia. a peculiar jurassic Pelecypod
References cited
AGASSIZ, L. (1842-5). Etudes critiques surless mollusques fossils. Monographiledes l\lyes.
BEKECKE. E. W. (1905). Vcrsteinerungender EiEenerzformation von Deutsch·
Lothringen und Luxenburg. Abh. Geol.
Spezia/k. Elsaas-Lothringen. N. S .. Pt. 6.
BORISSJ.'\1.;. A. (1906). Die Pelccypoden derJura-Ablagerungen im europaeishen
Russland. 3 Mytilidae. Mem. Com. lfeol.
St. Petersbourg, .V. S. Lit>r. 11.
BRo:->GXIART. A. (1821). Rctigured, 1910.
Palaeot. llniversalis. No. 174.
Cox, L. R. (1935). Jurassic Gastropoda andLamellibranchia. In the Mesozit; Pala·
eontology of British Somali1and.
- - (1936). Fossil ivlollusca from Southern
Persia (Iran) and Bahren Island. Pal.
Judica. N. S. Vol. 22. 1lfezu. No. 2.
- - (1940). The Jurassic Lamcllibranch
Fauna of Kuchh (Cutch). No. 2. Pal.
Judica. Ser. 9. Vol. 3, Pt. 3.
DACQL'E. E. (1~10). Dogger und Malmaus
Ostafrika. Be it. Pal. u Geol. Osterr· U11·
gal'lls. Vol. 23.
DIAZ·RO\IERO. V. (1931).
Contributo allo
studio della fauna giurese della Dan·
calia. Pal. Ita!.. Vol. 31.
DOUGLAS, ]. A. and ARKELI .. W. J. (1928).
The Stratigraphical Distribution of the
Cornbrash. Pt. 1: The South.'Western
Area. Q.]. G. S., Vol. 84.
GoLoFt:ss. A. (1833-40).
Petrefacta Ger·
maniac.
HEALEY. M. (1908).
The Fauna of thel\apeng Beds of the Rhaetic Beds ofl}pper Burma. Pal. 111dica . •V. S. llol. 2.

283.

Jl[em. No. 4.
LAtsBF:. G. C. (1867). Die Bh·a!Yen des brau·
nen jura von Balin. De11kschr. A.kad.
lViss. Wie11. Vol. 27. Pt. 2.
LISSJ\JOUS. M. (1923). Etude sur Ia faunc
de Bathonicn des environs de :v!acon.
Trav. Lab. Gcol. F'ac. Sci. Lyon. !Uem. 3.
LORIOL. P. et PELLET. E. (187-1-75). l\lono·
graphic Palcontologiquc et Geologiquedes Etage Superieurs de Ia Formation
Jurassique des Environs de Boulogne·
sur-Mer. IIJem. Soc. Phys. d'Hist. Nat.
Gellet'e. Tm. 24. Premiere Partie.
LYCETT. J. (1863), Supplementary Mono·graph on the Mollusca from the Great
Oolite chictly Minchinhamptom and thecoast of Yorkshire. Pal. Soc. l..o~tdoll.
d'ORBIG:-IY, A. (1843-18·17). Description des~Iollusques et Rayonnes Fossiles. Pal.
France Terr. Cri:t .. Tm. 3.
Qt'ENSTEDT. F. A. (1856· 8). Der Jura.
Sow~:RBY. ]. and J. de C. (1812-·lli).
!\line·ral conchology of Great Britain. Vo/s.
1-7.
STEFAKINI, G. (1938). Palacontologia Della
Somalia. Fossil del Giurlias. Pal. Jfalica.
llol. 32, Sup. 3.
T AMlJR,\, M. (1959-a). Some Pelecypods
from the Upper Jurassic Sakamoto for·mation in Central Kyusyu, Japan. Tra11s.
Proc. Pal. Soc. japan, N. S .. Xo. 35.
See also ARKEI.L. W. J. (1929-37). Cox.
L. R. and ARKELL, W. J. (1948). MORRIS,
J. and LYCETT. ]. (1853-55). TAI\Il'R,\,(1959) and Y ABE, H. and SATO. S.
(1942) in Tra11s. Proc. Pal. Soc. ]apa11,
N. S .. No. 36, p. 179.

Trans. Proc. Palaeont. Soc. Japan, N. S .. No. 38. p. 284. June I. 1960

SHORT NOTESG.

TWO JURASSIC PELECYPODS FROM WEST THAILAND
ITARU HAYAl\II
Geological Institute. University of Tokyo

The specimens dealt here with were
·donated to Prof. KanA YAsm by l'vlr.
Saman BL'RAY;\S, chief of the Geological
Survey Division. Royal Department ofMines. Bangkok, Thailand. For the privilege of studying them, I thank themsincerely.

Eomiodon clmmp!wnensis H.w A :VII, n. sp.
Text.figur(.;s 1. 2

Description:- Shell small. trigonallyovate. not carinated. nearly as long as
high. moderately inflated (holotype, 1\IM3632. 1~.5 mm. long; 12.0 mm. high; 3.0mm. thick): antero-dorsal margin short:postero-dorsal long, slightly convex:
umbo prosogyrous. lying at about athird of length from front: escutcheon
narrow but distinct: posterior lateral
tooth PI stout. elongated along posterior
half of postero-dorsal margin : Pill apparently absent: surface marked withsomewhat rugose growth-lines: inner
ventral margin smooth.
Obseruation a11d comparison:- Tworight internal moulds are at hand. A
posterior lateral tooth is clearly impressed on the holotype. Surface concentrics

difference probably does not serve specific distinction. The elongated Pl. rugose
surface. smooth ventral margin, not excavated pre-umbonal margin and general outline suggest Eomiodon Cox, 1935,
instead of Astarte. It resembles Eomiodon fimbriatus (L YCETT, 1863: from theEuropean Bathonian and E. oulgaris
1-IAYAl\H. 1957, irom the Japanese LiasDogger. However. it differs from thetwo in the more trigonal outline. Eindicus Cox. 1935, from the Bathonian of
Attock and E. uamyauensis REED, 1936.
from the middle Jurassic of Burma havemore salient beaks and larger dimensions.
Occurrence:- Argillaceous sandstone
at the mouth of Chumphon River, Krah
Isthmus. Southwest Thailand. This may
be a Jurassic species.
Posidonia sp. ex gr. ornati Qt E:"!STEDT
Text-iigure 3

ll'lany specimens adhering to two slabs
are similar to Posidonia omati QL·E:-:srwr. 1851 though specifically indeterminable. Black impure limestone at Hin
Fon stream, l\lae Sot Basin, Tak, '\Vest

Text-ligures 1. 2. Eomiodon clmmplzonensi.~.
n. sp. L holot~•pe, x 1. 5. :.!. paratyp(.;, xl. 5.

Text-figure 3. Posido;ria sp. ex gr.
onwti QL'E:-.::STEDT. X 1. 5.

appear more sparce and stronger in theholotype than the paratype, but theThailand. Tmetoceras was found nearby,
and the age is probably Aalenian.

!Ill1960 4! 9 f.l 24 B

1960 !f- 9 ~ 5 ll

~ ll fl 19 II

I 1960 {f 10 J1 30 s

1960

~A~

8

iEB4Ht::t Sweden. Stockholm 7:.+. Gcologiska Instilutet ;N;Q)@;t'OY(E7~f.Jf3i:Z.~;t*1f·1 jj <Jcl ilJ #!}IE LL ,~~mw~X!!J) · immtre-fJ;j~ltil!!§i!trm~Q)t..:1riJ*;y. 4 f.l tf111l7 ~ ~ 77it*~-"lfHc u..:,News*1¥ 8 fl Copenhagen ~!mf!!!~i1.;,~ 21 @Jm~:!1l!rt¥~)t~~Q)~Wj<ftl~:iiXQ)~ftHQ)~f~A':E1tl~):!!{tQ)~·e<&V:iJ\Q)UiJ~:!1l!l'r"t~i~{1)Commissions {l)~{tn:·'f/E ~ .h -cv · 7.>,©> International Palaeontological Union
Palaeoecology: Calcareous Algae
2. Primitive Tetrapods and their passage to terrestrial life
3. Invertebrates: Passage forms and primitive phyla
4. Miscellaneous©> Commissions of the Congress
1. International Commission on Stratigraphya. Subcommission on the Stratigraphic Lexiconb. Subcommission on Stratigraphic Terminologyc. Subcommission on Carboniferous Stratigraphyd. Subcommission on Quaternary Stratigraphye. Committee on the terminology of the Silurian and Ordovician
f. Committee on the Mediterranean Neogene
2. Commission on the Geologic Map of Europe
3. Commission on the Geologic Map of the Worlda. Subcommission on the International Tectonic Map
b. Subcommission on the International Metalogenetic Map
4. Commission on Gondwana
5. Commission on Meteorites
6. Commission for the formation of an International Geological Abstracting Service
1.

1 9 6 0 1f- 5 fj 25 13
1960 ~6fj 1 13

.llill~**~JIJ!~ffi)tlJI,f{$~~F"Jri

EJ;,j;;~j:_~~~

13 ;;l>:i!i~¥.o+~¥1l1li ·~$
jj

fiji

~ 38 B'

250 Flfi !1f: :tt
9e 1T ;ft
r:p JPU~l*im<m ~ p ~** Ji':

Jll

~
~

It$

84i80 :tit).J:!Ui\ tll ~ tK ~ Jl P~ AU 2 / 13~'f:IW~i!ff.IJ.!llU.ttA;fHt

f.I

fil

:7G

13 *r--1 ~ ~~~ *l~*D ~ l±l~WmJ£( 1958 £F 12 fl 6 13 ;Jl(jf)1.

:N: ~ mli!
1.
2.

a
4.
5.

6.

•.
8.
9.

10.

Jjj\f?.HiB*ii!±tb.J~~0~~;t t.:lii§lJ~I:~l , ..Cf!IJW! (Rlti"C-a-~~ 7.>)/ij(l\l)ili~J'(IL~~.

!..d.: i. 011:~7.>,:lr1":f71"?-J'lU~ (22.5x27.5cm) lt:lfi}J~ILOOI"HC.71:f71" J.f...,,•s~1?9,~1Lfi~m••~~7.>.
••<•~·•~·M•-a-~~)tiS~~R(71"~71"?-m•~Isa)-a-R~t~7.>o~Jl& (14. 2 X 20. 0 em) li 1
;f l:'fl1\~~tfHIE7.>'a(6.f:i!10.r0i.02M; l.f:i!11;tl '!.iJl::f.f) liS~~~:~;tt.:!i\W!~}l]~-1" :.--:?~t-rWJI!({It!f~.
~FP0!J:Iit~ 7.>« Ols*XIi 71 :f71" :lr -*-a-1:!9 -?tt l!>o alfd~I<:.~L--rfii~~ 7.> <::. t:fJ>ib 7.>
iJ> t;, k/l!0;t ~. !J:07c ~ ~ t~ t:li <::. 01.~ -a-16:51-it~ ~.KA.fl. -r!f <llZ·~:fJ>ib 7.>,:ttk~li:lidl,f~R-a--?t:tl!>o fiiJ\!.fRJ5}0)1 C.f...,t.:t.,O)IiPI:tt~l'o
0.1:01l!i!/.l'£ -a-illrl::i J!>:ljjft!i~~iJ>'t"Wl!lifl H~l.ffi~ l!>oJjj{f{.,\!:.IU"BJt•m c ffii.!l!t~~J'(~~-a-Miie~ l!>oiJ IJf.lJ'(IIttli~«-r0J'(O):l!lH~I<:.Jtiftt0!JiH'l:t:t-r 't c.rr:-m~ l!>o Jtilil:li~~80)7 1117 7 «,t-Jlllllr.i!71JL-, IP.I-~~03ttJtliJfi.£FftM.Iic~7.>, fi~S • Jfii<4! • iifBJt~m • ~itt;S • ~ •J'i • ~!& • tili~ • it!!~ • H~~-a- .iE!/{I!ILildA ~ ~,Jmfi.iil: r:t~%'8 O)£XIc.m.t£0)m~~oos -a-{t;ra~ 7.>,
ti!i~

11.

laJljl~J{fJ.f'30%iW (Mi~·jjjji§•M£,(-a-~~)12.

EUI1ltl0~,~fi!Stt-a-mtwii<::Hna-9 7.>,!i*f-IJ.JIJ£Xtl't ~lli!13H0Nilr::l@~~7.>,

13.

Jlit.li~~0:lfHEI:::t-ot '-r7'~ .A.£ t.: li~~ C.~~ Gft ~ Al:.~ -rl\t? omr...-1m1<m 1oo tlll £ -z:l:t1mttt-z:. 'f":f1.0.l:li ~ ~:fJ:'f"O)~m-a-~m~~,

u. mi ~ m Jt
1.
2.

illi.m~~li!iRffi0~1!1! • I*~. iii#! -a-n? 0
t!iitR~~Ii/1ii:ffi ~S1l:.llll U.:J;~ft, 't0©ff~:b:fi!!WJ't' ~ ~ .13. -?;tl;0f&~~J:0;;F«<i0$ml' <::. c ??lift!
~r..., t.:J::'t'l~H> lt:~l!I! E1 M Hc.A.l..~o ~'Miltli!W:~ru£-a-~ ~ o

3.
4.
5.

}jj(fl~0:l*ffl~i*Jf.lli~~ c 'iiH%~~ 0~~1i::J: ~~it~ 7.> aii.i~!:~t\tli~i*ffllilHioii .a-~~ffl0l!I!El3 -a-t-rim -r~;g-,;::~t<{l~ 7.>"ili~~~~i~Jfl)ij(ffiHl:!llfi:lllKlt t-r. ~Jml3 M0NJiilc:ttllllll\~ ~o~~:fJ>fiiii~·~UF:~J'(f'3~-??NT.iEL-t.:~ftlt:li~l!I!B Hii>~:!!.!~ l!>o

6.
7.
8.

c

u

r:Jlli1tl0U:iiHi7cllllf Journal of Paleontologyt"2.iEii:±lll&~~0~HEic:}3t 'L <::. :f1.-??fi? oO)f,j.:~IC.Z\!if 7.>,