a -lt"'~±.MJ~~~.:!-· i~t
Transactions and Proceedingsof thePalaeontological Society of Japan
New SeriesNo. 25

Palaeontological Society of Japan
April 30, 1957'

CONTENTS
TRANSACTIONS
Page305. On the Miocene Lucinidae from the Mizunami Group, Japan ........... .
... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Junji hoJGAWA 1
306. Brachiopoda from the Daishaka and Tsurugasaka Fossil Zones.
Minami Tsugaru-Gun, Aomori Prefecture ........................... ]iro K<nou 7
307. Fossil and Recent Species of the Genus PatZomya from Japan .......... ..
.. . ... .. . ... .. . .. . ... .. . ... .. . .. . .. . ... .. . ... . .. .. . .. . .. . ... ... .. . .. . ... .. . .. . ... .. . Saburo KAN~o 11308. Two Carboniferous Corals from Okayama Prefecture .......................... .
... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... Masao MJNATO and Keiji NAKAZAWA
309. Some Molluscan Fossils from the Eastern Part of the Tanzawa
Mountainland ......................................................... Matsutaro SIIIIIATA
310. A Miocene Fossil Crab, Paratymolus yabei, n. sp. from Nagano Prefecture ........................................................................ Rikizo IMAJZUMI
311. Amussiopecfen iitomietzsis (OnJJ,A) and its Allies from Japan ........... .
.. ...... Masahiko AI<JYAMA. ... ... ... ... ... .. ... ... ... .

31.. .............................................................

40

PROCEEDINGS .................. .

President:

17
21
26

Hisakatsu YABE

Councillors: Kiyoshi AsANO, Riuji ENDo (Business and Accountant), Seido ENoo,
Haruyoshi FuJJl\IOTo (Publication), Shoshiro HANZAWA, I\otora I·IATAI,
Ichiro HAYASAKA, (General Affairs), Kazuo HuzJOI\A, Teiichi KonAYASIII(Editor), Jiro MAKIYAMA, Tatsuro MATSUMoTo, Masao MINATo, TokioSIIIKAMA, Fuyuji T AKAI (General Affairs), Ryuzo ToRIYAMA.

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

Trans. Proc. Palae:>nt. So:. Japan. N. S., Ko. 25, pp. 1-6, Pl. 1. April 30, 1957

305. ON THE MIOCENE LUCI:KlbAE FROM THE MlZUNAMIGROUP, JAPAN*]UNJI ITOIGAWA
Kyoto Ur.iversity

fliJ~~l!fi!F.~~mttt l.ucinidae: i\\\1~ • !fft-J'j\ljjWlh">f/iJIJ'~fe'ili:J: I) il€ Lt.:. 6 flljQ) Lucinidae t:.llr,-t ~;,ft1.i J;l~t:. --:>~ • -c k'lt& r.HillH\1tfi L. ~t.:.-.k~Jilfn:. --:>i., -c ~~ L t~o '*. t.:... lVallucina .{!j(,Q).:....VJ(m ·~lii!.tH.t.:.o-!M~.Jllw=

Wallucina habti ITOIGAWA
Wallucina okunptrai ·n. sp ..
Pillucina (Sydlorina) yokoyam~i (OUTKA)
Saxoltlcina (Megaxinus) k-hataii (OTUKA)
Luci~ooma acutili11:ata (CoNRAD)
Caviluchza (Monitilora)· kitamurai (HATAIIntroduction and Acknowledgements

In the inside zone of southwesternJapan, there are found scatterings ofthe Miocene strata that are assumptively
representing the First Paleo-Setouchi
supergroup (IKEBE, 1951) i. e. Mizunami,
Isshi, Ayukawa, Tsuzuki and Tsuyama
groups etc. Yielding rich faunas andfloras, these strata are interesting sub·jects for the members of the PaleoSetouchi research group. The Mizunami
group. the type of the supergroup, wasdeveloped in three mutually connectedbasins, Kani, Mizunami and Iwamura in
Gifu Prefecture. The present writer isstudying the stratigraphy and paleon·
tology of this group and he has partly
reported the results.
This paper is the third result andprepared in view of taxonomic and paleoecological accounts of the Lucinid
pelecypods from the Mizunami group.
These are the interesting forms inasmuch
as they are the indicators of various
environments.
The following species are. collectedfrom the Mizunami group in the Iwamura and Mizunami basins.

e~

NISIYAMA)

The writer is indebted to Prof. J.
MAKIYAII.IA for his suggestions and revision of English. Thanks are also due
to Dr. T. KuRODA and Dr. T. HABE for
informations about the taxonomic mala·cology.
Paleoecological t-.otes

Some paleoecologi~al aspects of these
species were observed in field and laboratory considering the data of stratigraphy
and fossil fauna. Although these data
are not complete at present presumably
overlooking minute species, the conclusion might not be very different fromthat based upon the more accumulatedmaterial.
Cavilucina ( Monitilora) kitamurai<lhTAI et NrsrYAMA) and .Wallticina
okumurai n. sp. are found only in ·theShukunohora sandstone associating Miogypsina kotoi HANZA w A, Operculina com·
plmzata japonica l-l... NzAwA, Aloidis* Read June 28, 1956; received Apr. 28, 1956 ·1

2Junji lTOIGAWA

m'sataictzsis 0TUKA and Turbo ozawai
0TUKA etc. Both valves of every individual of these two species are attachedsnowing autochthonous origin in the
sandy environment. The fauna of Shukunohora sandstone represents the warm
sea waters and peculiar to this group.
It seems that this two species inhabitedin the warm and shallow waters withsandy bottom.
JVallucina hahei hoiGAWA is found in
the sandstones as a member of DosiniaNt'PP01zomarcia fauna. It is indicating
a sandy neritic environment, and theattached valves show also the autochthonous origin.
Pillucitw (Sydlorina) yokoyami (0TuKA) is found in the marginal facies
developed near the basement with thefollowing species:
Nippmwmarcia
nakamurai
lKEBE,
Vcnerupis siratm·iensis (OTUKA ). Nassarius simizrei 0Tuic-\. Turritella s·hataii
NoMURA.
Most probably this species sho\vs thesimilar environment to that of Wallucitza lzabei hmGAWA.
Saxolucitza(Afega:r:itzus)
ll-hataii(OTuKA) accompanies with Vicarya yokoyamai TAJ<EYAMA. Vicaryella ishiiana(Y oKoY A 1\J A), Sanguinolan·a minoensis(YoKOYAI\1,\), Cyclina japotzica KA:o.JADA
and Ceritltium kanelzarai FuJITA and
0GosE etc. and indicates the sandy
brackish environments.
Lucinoma acutilineata (Co:-~uAu) is thecommon and important species in this
district. Two different occurrences are
known ; the one being autochthonousshowed by the attached valves is in the
muddy and silty sediment and tt:e otherca!'e being allochthonous is in the sandstone. In the former case, this species
is a good indicator of an environment
under a mttddy inland sea.

Description of species

Family Lucinidae
Genus TVallucitza lREOAJ.E 1930
Wallucina habei hoiGAWA 1955
Pl. 1. figs. 3a -b.
1955: Wallucin:J habei lTOJGA w A, Mem. Col!.

Sci., Kyoto U11iv. Ser. B. Vol. 22, No.2.
Art. 1, p. 139, pl. 6, figs. 1, 2.

Geologicaloccurrence:-

1. Kubohara sandstone, Iwamura basin.

2. Togari formation, Mizunami basin.
3. Tsukiyoshi formation, Mizunami basin.
Localities :1. J 3011I, Kamigiri, Iwamura-cho, Enagun, Gifu Prefecture.
2. ] 40026, Nenga-hora, Togari, Mizunami
City.
3-a. ] 40041, Matsubara, Toki-cho, Mizunami City.
3-b. J 40049, Kujiri, Toki City.

Associated fonns :1. Dosiuia nomurai 0TUKA, NipP01zomarcia nakamurai IKEBE, Clitzocardium
slzinjiense(YoKOYAMA),
Glycymeris minoensis hoiGAw.~.
Euspir:J meisensis MAKIYAMA, Turrilella s-Jzataii NoMURA, Nassarius
simizui 0TuKA etc.
2. Doshzia nomurai OnrJ\A, Nipponomarcia uakamurai I 1< •mE, Gibbula
lukiyosicnsis (On.:o.JA et SAKA) etc.
3-a. Vicmyella ~~~lziiaua (YoKoYAMA),
Ccrithium kaneharai FuJITA et
0GosE, Sanguinolaria minoensis(YoKOYA~lA) etc.
3-b. Turritella s-lzataii NoMURA, Euspi1·a
mcismzsis MAKIY Al\IA, Protorotella
togaricnse MAKIYAl\IA etc.
JVallucina okumurai hoiGAWA n. sp.
Pl. 1, figs. 1, 2.

Shell small, suborbicular, as long as
high, thin, moderately inflated, roundlyOn the 1\Iiocen~ Lucinidae from the Mizunami Group. Japan.

produced anteriorly : antero-dorsal margin short, concave : p<>Stero-dorsal sideslightly convex, graduall}· descending toposterior margin : anterior margin rounded : ventral side arched : beak small,prominent; sculpture consisting of fineregular concentric lamellae and obscureradiating striae ; dorsal area more orless marked: lunule small, cordate,dissymetric: hinge plate narrowly long,delicate: cardinal and lateral teeth frail,
well developed: inner margin denticulate;inner side with fine radiating striae.
Dimensions:- Height. 5 mm., length,
4.5mm.

Holotype :- ]C 1500001, Paratype :- JC
1500002.
Remarlls :- This species is closely
resembling TVallucina habei hoiGAWA,
1955, but it is distinguished in having
the thin and inflated shell with the fineconcentric lamellae, and the narrowly
delicate hinge plate. Wallucina lamyi
CHAVAN, 1938 is another allied species
but the present species has the thinnerand more orbicular shell, and its hinge
plate is more delicate v.ith the fine andfrail teeth.
This species is named in honor oflate Mr. Kikuo 0Kl'MURA who helped
the writer in the field.
Type Locality:- River-side cliff ofShukubora valley about 100 m. SW of
the bridge at S of Shukubora, Hiyoshicho, Mizunami City, Gifu Prefecture.
(J 40020) (lwamura, 35° 24' 06" N, 137°
16' E)

Geological occurrence :- Shukunohora
sandstone, Mizunami basin.
Associated forms :- Miogypsina kotoi
HA:KZA w A, Operculina complattata japonica HANZAWA, Aloidis nisataiensis
0TuKA, Cavt"lucina kitamurai (HATAI etNISIYA,\IA), Turbo ozawai 0TUKA, Acteon
ozawai 0TUKA etc.

3

Genus Pillucina PILSBRY 1921
Pillucina (Sydlorina) yokoyamai (0TUKA)
Pl. 1, figs. 4, 5.
1934: Lucina yokoyamai Ona;:A, Bull. Earthq.
Res. ltzst. Tokyo Imp. Univ. Vol. 12. p.
615. pl. 47. figs. 29-32.
1935: Luci11a (Lucinisca) yokoyamai OTUKA,
four. Fac. Sci. Imp Univ. Tokyo, Vol.
5, p. 27. pl. •1. fig. 38.

Shell small in size, suborbicular. as
long as high, moderately convex: beaksmalL pointed, turned inwards, touching,placed slightly back of dorsal margin:
antero·dorsal margin short, concave,
bluntly angled to subrounded anterior
margin: postero-dorsal margin also
short. nearly straight descending tosubtruncated J:OSterior margin ; ventral
margin regular:y rounded. connecting
both to posterior and anterior ends
gradually ; sculpture consisting of many
radiating striae · crossed by concentric
incremental lines: radiating striae notdi\'aricate. weak at middle part; concentrics fine, ocassionally strong; lunuleovate. deep, well marked; teeth of rightvalve consisting of a cardinal and 2
laterals : teeth of left valve consistingof 2 divaricating cardinals: inner sidewith fine radiating lin'3s; muscularscar well-marked; inner margin fine:ycrenulate.
Dimensions:- Height, 6 mm., length,
6mm,
Remarks:- This species was described
originally by 0TuKA from the lower
Kadonosawa series (Miocene) as a species of the Genus Lucina. 0TUKA states thealliance with DALI.'s Lucinisca. Examined in detail, it is clarified that it has
the characters of the Genus Pillucina
and the Subgenus Sydlorina i. e .. theteeth and its not divaricated sculpture.
The murricate sculpture of the Genus
Luc:'nisca is not at all seen in thisJunji !TorGAwA:

species.

Geological occurretZce :1. Kubohara sandstone, Iwamua basin.
2. Togari formation, Mizunami basin.
3. Tsukiyoshi formation, Mizw1ami basin.
Localities :1-a. J 30246, Nakanislli, Yamaoka-cho,
Ena.gun, Gifu Prefecture.
1-b. J 3011L Kamigiri, Iwamura-cho,
Ena·gun, Gifu Prefecture.
2. J 40026, Nenga-hora, Togari, Mizu·
nami City.
3-a. J 40041, Matsubora, Toki-cho, Mizunami City.
3-b. J 40049, Kujiri, Toki City.
A~sociatcd forms:- 1-a. Barbatia ktt·
bam hme>AWA, NiPPorzomm·cia nakamzwai lKEBE, Venerupis siraton·cnsis(0TVKA),
Nassarius simizui 0TUKA,
Proto1·otella dep1·essa MAKIYAMA, 1-b.
same to the associated fauna-(1) of
J-Vallucina habei hmGAWA, 2. same tothe associated fauna-(2) of Wallucina
habei lTmc;AwA, 3-a. same to .the associate:! fauna-(3-a) of Wallucitta lzabei
hoiGAWA, 3-b. same to the associatedfauna-{3-b) of Wallucitta habci hmGAWA.

Genus Saxolucina STEWART 1930
Saxol:rcina (Megaximts) ll·hataii (OnJKA)
Pl. 1. fig. 8.

1934: Luci11a k-lzataii OTUK A, Bull. Earthq.
Res. bzst. Tokyo Imp. U11iv .. Vol. 12, p.
614. pl. 47, figs. 5, 6.
1938: Luci11a (Mi/tha) k-hataii OTUKA, four.
Fac. Sci. Imp. Un!v. Tokyo, Vol. 5. p.
27. pl. 4. fig. 38.

Original description:- Shell r.ather
small, more or less thin, with the stir·face more or less irregularly and concentrically lamellated ; anterior end
longer, attenuated ; posterior end moreplump, obscurely vertically truncated;beak low pointed : lunule small, crescent-ric in form. deeply impressed, with fine,close. more or less irregularly crenatedstriae parallel to the hinge margin ;postero-dorsal area more or less distinct
extending to the postero-ventral margin:
Ligament impressed, broadly curved.
Remarks:- The remarkable featuresof this species are as follows ;1) very weak or obsolete teeth, 2)well marked, dissymetric and deep
lunule, 3) well marked posterior area,
4) anteriorly 2 radiating lines, 5) smooth inner margin.
This species belongs to the section
Megaxinus under the Genus Saxolucitza
on account of the above noted features.
It is distinguished from the Gen).ls
Miltha by the weak or obsolete teeth.
Geological occurrence:- Tsukiyoshi
formation, Mizunami basin.
Localities:1. J 40008, Shobasama·hora, Tsukiyoshi,
Mizunami City.
2. J 40041, Matsubora, Toki cho, Mizunami City.
Associated fonns :- Vicarya yolwyamai
TAKEYAr-.tA, Vicaryella ishiiana (YoKoYAMA), Ceritltimn ka11eharai Ft:JITA etOc.osE, Cyclitta japonica KAMADA, San·
guinaloria mitzoe1zsis (YOKOYAMA) etc.
Genus Lucitwma DALL 1901
Lucinoma acutilineata (CoNRAD)
Pl. 1. figs. 9-12.
1849: Lttcina acutil;n:ala CoNRAD, U. S. Exp/.
Exped. Vol. 10. Geol. p. 725.
1909: Phacoides acutililleata. DAJ.L, U. S. G. S.
Prof. P{lper. No. 59, p. 116. pl. 12. fig.
6.
1931: Phacoides (Lucinom:~) awtilineata, EnmR!NGTON. U11.'v. Calif. Pub/. Geol. Vol.
20. p. 76. pl. 4. fig. 5.

Remarks :- This is one of the common
species in the First Paleo-Setouchi super·group. The limits of this specie's haveOn the Miocene Lu;:inida~ from the Mizunami Group, Japan

been discussed by American and Japanese authors.
The specimens at hand from the Mizunami group are 111-preserved so that
determination is difficult, but it seems
to fall within the limit of Lucinoma
acutiliueata (CoNRAD) seeing generalfeatures. Further investigation will bemade when sufficient material is supplied.
It is distinguished from the Recent
Lucimmza amwlata (REEvE) from Kagoshima by having the compressed shell,
short lunule and the sculpture which
consists of regularly spaced, periodic,
concentrically lamellar threads and fineintercalary striae.
The similar examples are collectedfrom the First Paleo-Setouchi supergroup as follows :Isshi group (Kaisekizan formation),Awa formation (lkegata member, Hiramatsu member, Makino member), Fujiwara group (Toyoda formation), Yamabegroup, Tsuzuki group (Kaya mudstone,
Shiodani sandstone), Tomikusa group.
Geological occurrence :1. Yamanouchi formation,
Mizunamibasin.
2. Maki siltstone. I wamura basin.
3. Kubohara sandstone,. Iwamura basin.
Localities:l. J 40028, Togari, Miztmami City.
2. J 30168, Hachiyato, Agi-mura, Ena-gun,
Gifu Prefecture.
3. J 30111, Kamigiri, Iwamura-cho, Enagun, Gifu Prefecture.

Associated forms :- 1. Acila submirabilis I\11."'-KIYA'-IA, Cteltellus izumoensis
YoKoYAMA, Macoma sp., Pati1zopect(!tt
sp. etc. 2. Nuculana pe1mula (Y oKoYAMA), Venericordia siogamensis No:-.mRA
etc. 3. same to the associated fauna-(1)of Wallucina habei hoiGAWA.

Genus Cavilucina P. FisHER 1887
Cavilucina ( Monitilora) kitamurai<HATAI et NisiYAMA)
Pl. 1. figs. 6, 7.

1949: Codakw kitamurai HAT AI et 1\ISIYAMA,
four. Paleont. Vol. 23, p. 91. pl. 24. fig;;.
5. 6.

Remarks:- This species is de~cribedby HAT AI and NisJYAMA. as a species of
the Genus Codallia. Examining many
examples from the type locality, it isconcluded that this species does notbelong to the Genus Codakia, but to theGenus Cavilucina. The reason is asfollows;
1) The shell is moderately inflated.
2) The sculpture of this species consists of fine, regular and concentriclamellae, and the fine radiating threads
in the interspaces.
3) The teeth are feeble a11d ocassionally obsolete.
The Genus Cavilucina is divided into
three Subgenera: Cavilucina s. s., Monitilom and Barbierella.
This species falls to the Subgenus!IJmzitilora with the features of sculpture,
teeth and lunule.
HATAI and NisJYAMA noted the calcareous and granular material depositedon the inner surface. This appears to
be a specific character, inasmuch as
shown by the majority.
This record of the occurrence ofMonitilora is most probably the first inJapan.
Geological occzeneuce :- Shukunohora
sandstone, Mizunami basin.
Locality :- J 40020, Shulrubora, Hiyoshicho, Mizunami City.
Associated forms:- Same to the oneof Waltucina okumurai n. sp.
References
CH A\' AN,

A. (1~38), Es~ai critique de classifica-

junji !TOIGAWA

6tion des Lucine3. jour. de Conchy. Vol.
81. pp. 133-153~ 198-216. 237-282. Vol. 82,
pp. 59-97. 105-130, 215-243.
DALL. W. H. (1901), Synopsis of the Lucinacea
and of the American Species. Proc. Cl. S.
Nat. Mu$. Vol. 23. pp. 779-833.
- - (1909). Contributions to the Tertiary
Paleontology of the Pacific Coast, 1. The~lio<:ene of Astoria and Coos Bay, Oregon.
U. S. Geol. Sun• .. Prof Paper, Ko. 59.
ETHERINGTON, T. ]. (1931). Stratigraphy andFauna of the Astoria Miocene of Southwest Washington. U11iv. Calif. Pub/.
Geol.. Vol. 20, pp. 31-114.
FUJITA, K. and OcosE, S. (1950, 1951), Libo·
logic Classification of the Cenozoic Strata
in the Northern Area of Mizunami-machi.
Toki·gun, Gifu Prefecture. Japan. jour.
Ceo/, Soc. japan, Vol. 56, pp. 481-492.
Vol. 57, pp. 99- l 10.
GHANT. U.S. and GALE. H. R. (1931). Catalogueof the marine Pliocene and Pleistocene
l\·lollusca of California. Mcm. Sat! Diego

Soc. JI.~·J/. Jlist. Vol. 1.
HATAr. K. and NrsJ.YAMA, S. (1949), New
Tertiary Mollusca from Japan. jour.

Paleont .. Vol. 23. No. 1, pp. 87-94.
HrRAYA,.,IA, K. (1954), On som~ Miocene
Species of the Lucinoma from Japan, with
Description of Two New Species. ]apa11.
four. Geol. Geogr. Vol. 25, Nos. 1-2, pp.
101-115.
ITOIGAWA. J. (1955). The Cenozoic Strata in
the Iwamura Basin, Gifu Prefecture. Japan. jour. Ceo/. Soc. japatl, Vol. 61, pp.
511-517.
- - (1955). Molluscan Fauna of the Mizunami
Group in the Iwamura Basin. Mcm. Coli.
Sci. Kyoto Univ. Ser. B. Vol. 22. No. 2.
pp. 127-143.
LAMY, E. (1920). Revision de:~ Lucinacea vivants du Museum d'histoire naturelle deParis. ]our. de Conchy.. Vol. 65, pp. 71122, 169-222. 233-318. 335-388.
0TL'KA. Y. (1934). Tertiary Structure:; of theNorthwe;tern End of the Kitakami 1\lountainland. Iwate Prefecture. Japan. Bull.
Earthq. Res. !nsf. Tokyo Imp. Uuiv.. Vol.
12. Pt. 3, pp. 566-638.
- - (1938). Mollusca from the Miocene of
Tyugoku. Japan. jour. Fac. Sci. Imp. U11iv.
Tokyo. Sec. 2, Vol. 5. pp. 21-45.

-----------------------------------------------------·-----------------------Explanation of Plate 1
Walluci11a okumurai !TorGAWA n. sp. Holotype. Reg. No. JC1500001. Left valve, x3. Loc.
Shukubora, Hiyo:;hi-cho, l\olizunami City. Gifu Prefecture.
Fig. 2. Walluci11a okumurai ITorGAWA n. sp. Paratype, Reg. No. JC1500002. Right valve, x 3.
Loc. Same as above.
Figs. 3a-b. Wtzll11cilla habei lTOJGAWA, a. Left valve. x 3. b. Internal view of 3a, x 3. Loc.
Kamigiri, Iwamura-cho, Ena-gun. Gifu Prefecture.
Fig. -1. Pilluci11a (Sydlorill!l) yokoyam:Ji (OTUKA). Right valve, x 3. Loc. Nakanishi. Yamaoka·
cho, Ena·gun. Gifu Prefecture.
Fig. 5. Pilluciwz (Sydlori~~rz) yokoyam1i (OTUK.-\.), Right valve. x 3. Loc. Same as a~?ove.
Fig. 6. Caviluci11a (Mo11ililora) kitamr4rai (HATAI et N!SIYAMA). Right valve, x 1. Loc. Shukubora,
Hiyoshi-cho, Mizunami City, Gifu Prefe..:ture.
Fig. 7. Caviluciua (Mollifilor.J) kitamurai (HATAI et NISIYAMA), Left valve. x 1. Loc. Same asabove.
Fig. 8. Saxolucitw (Megaxinus) k·halaii (OTUKA). Right valve, x 1. Lo::. Matsubora, Toki-cho.
Mizunami City. Gifu Prefecture.
Fig. 9. Lucilwma aclliilimata (CoNRAD). Mold of Left valve. x 1. Loc. Hachiyato, Agi-mura.
Ena-gun, Gifu Prefecture.
Fig. 10. LuciiiOIIIO ac11filimata (CoNRAn). Right valve. x l. Loc. Same as above.
Fig. 11. Luciuoma acutili11eata (CoNRAn). Left valve. x l. Lo~. Ebisuba, Haibara·cho. Yamabegun. Nara Prefecture.
Fig. 12. Luci11011W acutilineata (CONRAD), Mold of Right valve. x 1. Lo:. Hachiyato, Agi-mura,Ena·gun, Gifu Prefecture.
Fi:;r.

1.

Plate 1

J. hmGAWA: Miocene Lucinidae

2

1

3a

.,
,;···
5

.

4

3b

.,
·. ,· , . ··..· .

6

8

7

'.
t.,
.

.

.. "·~
:"9o

~-

12

.

·.

.

.

10

Trans. Proc. Palaeont. So:. Japan, N. S.. 1\o. 25, pp. 7-10, April 3'). 1957

.306. BRACHIOPODA FROM THE DAISHAKA AND TSURUGASAKA
FOSSIL ZONES, MINAMI-TSUGARU-GUN, AOMORIPREFECTURE.*.TIRO KOTOH
Ishihara Sangyo Kaisha, Ltd., Tokyo Bran::!l.·Office
W~**~illlll!llEf:l. :k~iml:&V:~71!0Cft.:Ei#l::iiNt7.>~JJi~li'H::zt\,-c: l!im~ft.i;:.. 3(. fl'R.:Il~:&:V:ili.X~~J: IJ, Pliocene c;i5;t t?:fL:<;,~i!JH:&U~71!t(ft1:imd~lil-ttJ.,}jjij)Em 6 fill Hemithyris
psittacea (GIIIELI:o~). Coptothyris adamsi (DAvmso:-~), Terebratalia coreanica (ADAMS andREEVE), T. gou!di (DALL), Terebratulitta jopo11ica (SOWERBY), Laqueus rub?llus (SoWERBY):.:gr\.,-c~~L. . .:.;tL~~~*.i-tt-?1Ui1\1.1J!ilifJ!~l3H~L.t.:.l{,v:>·CJ&7.>oii ~ ~ rm

Here the coarse sediments occur in thelower part and the fine grained ones in
the upper.
The two fossil zones, from their stratigraphic position, faunal content andlithological characters, are regarded ascorresponding to the Shibikawa formation of Akita Prefecture, and to be of
Pliocene age.
Here I wish to r~cord my thanks toProfessors K. HuzwKA, T. INouE and T.
T.-\KAYAsu of the Akita University for
their encouragement, and to Mr. T.
rvliYAJI:\1.\ of the Nippon Mining Com·pany for his interest taken in the work.
Thanks are also due to Dr. K. HATAI of
the College of Education, Tohoku University, for kindly looking over the
manuscript.
Leaving the micro-fauna for anotheroppotunity, the brachiopods discriminated are:

The Brachiopoda dealt with in thisarticle are from two localities, one (DS·149) belonging to the Daishaka fossil
zone, and the other CDS-140) to tbe
Tsurugasaka fossil zone. The fossils
were collected by the writer during thesummer of 1951 on the occasion ofgeological field work for the Nippon
Mining Company.
The Daishaka and Tsurugasaka fossil
zones are exposed in the vicinities of
the two mentioned lccalities as shownin the text- figure. At Daishaka, thefossil zone consists of pebbly or cobbly.
coarse to medium grained sandstone
with mudstone breccia and intercalates
thin mudstone layers. This zone is infault contact with the adjacent formations. At Tsurugasaka, the fossil zone
consists of granule conglomerate, coarse
to medium gra·ined sandstone and intercalates several thin mudstone layers.

----

Tsurugasaka
Daishaka........ +- ...
Hemithyris psittacea (G:-.tELIN)+
Coptothyris adamsi (DA v 1DSON)++..................... +Terebratuli11a jopo11ica ( 3owERBY) · · · · · · · ·
.. +
... +
Terebratalia corea11ica (ADAMS & REEVE)
Terebratalia gouldi (DALL) ···+Laqueus rub~llus (SOWERBY) .............. ······ ····· ...... ··· ·+* Read s~pt. 27, 1952-;- raceived May 7, 1956.

~

I

8

]iro KOTOH

Text·fi~ure.

Showing the precise localities:
2 ...... Tsurugasaka fossil zone.

Of the above mentioned species. thosefrom Daishaka are of small size andfew in individual number, while thosefrori1 Tsurugasaka are of lar~er sizeand common in individual number.
From Daishaka, S. No1.tt:RA and K.
HATAI (1935) Iwve reported the occurrence of llemitlzyris psittacea (GMELI1')
a~d Terebratalia cct·emzica (AoA:o.ts and
REE\'E)-

1. Hemithyt·is psittacea (G:-.tELI:-> ). This
species is rare in the Daishaka fossil
zonP., where it occurs only as broken or
isolated valves. In the Tsurugasaka
fossil zone it is found commonly either
as isolated or intact valve!:. In living
state, this species inhabits the seas of
the northern hemisphere, where it isfound from the tidal zone down to about
167 meters. It prefers a clean coarse
sea bottom.
2. Coptotlty1·is adamsi ( DA v1oso;o.; ). AI-...... Daishaka fossil zone. andthough this species was found in bothfossil zones, each localities provided onlya single specimen. The size of the specimen measured about 7.2 mm in width,
6.8 mm in length and 3.8 mm in thicl<ness; they have about 18 radial ribs inthe middle part ot the ventral valve of
the Tsurugasaka specimen and about
14 of the same in the Daishaka specimen.
This species is known to inhabit a sea
bottom consisting of fine to coarse
grained material providing it not bevery muddy. The depth to which thisspecies is known to extend at prerent,
is from the tidal zone to about 37 fathoms, and is one of the most common
species of Brachiopoda known from
northern Japan. This monotypic genus
is common in the tranquil watersof Mutsu Bay, Aomori Prefecture, but
becomes less common in Matsushima
Bay, Miyagi Prefecture. and by goingBrachiopoda from the Daishaka and Tsurugasaka Fos.>il Zones

still further south, the number of indiViduals is much decreased, and at Onahama Bay in the ·southern part o~'Fukushima Prefecture, collecting isdifficult. Therefore, judging from thefrequency of occurrence, size of shelland type' of radial ribs, it seems thatthe types of these brachiopods resemble
those in M~tsu ?ay, the thermal conditions during Daishaka and Tsurugasaka
zones was cooler than that 'of present
day Ma~s~shima Bay, the environmental
conditions correlating with the. Mutsu
Bay, but deeper.
3. Tcrebratult'na. japonica (Sowr:RnY).
This species is commonly found in the
Tsurugasaka fossil zone, and the ribs of
the younger specimens are rough anddistinct. In living state it is known tobe distributed entirely around Japanand has been recorded from depths of
75-336 meters on the continental shelf.
This species seems to prefer a sandysea bottom.
4. Terebratalia coreanica (AoAMS and
REEvE). This species is represented byonly fragments of the isolated andbroken valves of both valves, but ofdifferent individuals. The specimens(restored) are smaller than those now
living in Mutsu Bay, Aomori Prefecture.
This common shallow water brachiopod
is related to bottom control, but thermal
barriers seem to have but little effectto its distribution. It ranges from 44296 meters on the continental shelf ofJapan where the predominating bottom
material consists of fine sandy mud.
5. Terebratalia gouldi (DALL). This
species is very abundant in the Tsurugasaka fossil zone. In living state, thisspecies inhabits on bottoms consistingof mud within the range of 60 fathoms
to about 612 meters on the continental
shelf.
6. Laquezes rebellus (SowERBY ). This

species is abundant, but generally occurs
as broken and isolated valves. Partaking to a sea bottom consisting of fineto coarse materials, this species has adepth range of 40-499 meters in the seasaround Japan.
· T~ese both fossil zones must be re~og.
nized as the massing type of the so·called ··Sweeping" accumulation in theoceanic shallow water. While theftowlngs of the wide 'spread may not be'considered because· of the species andthe physical conditions that the fossils
are derived from them .. They may beseemed as the para-autochthonous fauna.being accompanied with the allochthonous one. and therefore, the sedimentary
enviroments of these zones may beconsiderable in general.
Namely, from the above mentioned
data the Daishaka fossil zone can beinterpreted as containing a brachiopod'
fauna which suggests, (a) accumulation
in a sea \Vith a depth probably less than
80 meters, which is the most favorable
minimum depth for the brachiopoda it
contains, (b) the thermal conditions
may be compared with present day
Aomori Bay but were deeper than th:c.tand, (c) the paucity of species seems
to indicate that prevailing conditions
were not favorable for the flourishingof brachiopoda. The Tsurugasaka fossil
zone is characterized by, (a) an assemblage which accumulated in a sea witha depth probably between 120-170
meters, (b) the thermal conditions weresimilar to that of the Daishnlm fossil
zone but deeper, (c) the assemblage
consists of species which take to a muddy bottom and those which flourish ona sandy sea bottom, (d) and finally thegeological age may be Pliocene fromthe absence of extinct forms, the evidence afforded by the other fauna ofForaminifera and Mollusca etc., and by10

Jiro KoTCH

the stratigraphic position of the fossil
zones.
Reference
K. (1937). The stratigraphic significance of Tertiary Brahciopoda. japan.
]our. Geol. Geogr., Vol. 14, 11os. 1-2.
- - (1988), The Tertiary and Recent Brachia·
poda of Northeast Honsyu, Japan. Saito
Ho-on Kai Mus., Res. Bull., No. 10.
- - (1939), A note on a Cenozoic Brachiopoda,
Cop/athyris grayi (DAVIDSON).
The
jubilee Publicatiatt it1 the commemorationof Prof. H. Yabe's 60th Birthday.
- - (1940), The Cenozoic Brachiopoda ofJapan. Sci. Rep. Tohoku Imp. U11iv., ser.
HATAI,

2. Vol. 20, pp. 1-413.
- - (1950 ). Brachiopoda from Jizodo, Chiba
Prefecture. Short Papers. IGPS., No. 1.
NoMURA, S. and HATAI. K. (1935), On two
species of Brachiopoda from the Daishaka,shell beds of Daishaka. Aomori·ken. Saito
Ho-on Kai Mt1s., Res.Bull., 110. 5.
- - (1985), A Review of the Brachiopod Pale·
ontology of Northeast Honsyu, Japan.
Saito Ho-011 Kai Mus., Res. Bull.. 110. 5.
- - (1936), On Some Fossil Brachiopoda from
Akita Prefecture, Northeast Honshu,
Japan. Saito Ho-ott Kai Mus., Res. Bull.
110. 1 o. pp. 183-194.

rL\ Y ASAKA, I. (1933), Copt athyris grayi aomori·ensis fossils. ]apmt. ]our. Geol. Geogr.,Vol. 10, 11os. 3-4, pp. 125-128.

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 25, pp. 11-16, Pl. 2, April 30, 1957

307. FOSSIL AND RECENT SPECIES OF THE GENUS
PANOMYA FROM JAPAN*
SABURO KANNOTokyo University of Education:<$:;f\lggf~:ri~l.:.l'.li!~ Pa11omya ~1.:.-0\.'"C: :<f;:;fll!m Pm1omya )!j,i.:.--?I.,"Cii. ;:tt-~~;m~:m!
4 fiR. 1t;ooo 2 mn:fil!!r~*L-c"'t.:.o;. ;:nt?l.:."?1..,-c:f!J~lML. ~n::. 1 ~.m!~Jm~Lt-:. tJ::to:<t;:;fllr::.
:t-o~-t7.> Pm1omya ~O):fll!.1l{ll~HV.c l?tH::.:!tl!f.!l!i¥Jf.)-:ffi~~lMLt.:.
11' JE.f ~ f!ll

2. P. turgida DALL, 1916. Proc. U. S. Nat.
Mus., vol. 52, ·110. 2183. p. 416.
3. P. beringia11a DALL, 1916. Ibid., p. 416.
4. P. 11ipponica NOMURA and HATAI. 1933,
Saito Ho-011 Kai Mus., Res. Bull., tiD. 5. p.
20. pl. 1. figs. 7a-b.
5. P. simotome11sis 0TUKA. 1934, Bull. Earlhq.
Res. Inst .. 110. 12. pt. 3. p. 621, pl. 44·, fig~.
66a-b.
6. P. izumo NoMURA and HAT AI, 1938, fapmz.
four. Geol. Geogr., vol. 16, 11os. 1-2, p. 6.
pl. 1, figs. 2a-b.

Introduction

In this paper is given a brief summary of the Japanese fossil and Recent
species of the Genus Panomya and a
description of a new species of fossil

Panomya.
The writer wishes to express his
thanks to Profs. Haruyoshi FuJIMoToand Kotora HATAr of our Institute, fortheir guidance and encouragement.
Thanks are also due to Messrs. Shigeru
AoKI and Hiromi T AKAI of our Institute.
for kindly offering some specimens to
the writer. The writer is also indebted
to Dr. Isao TAKI, Natural Science
Museum, and Mr. Sunao OcosE, Tokyo
University, for their kind informationon the bibliography.

Nos. 1-4 in the above list are living
species and the remaining ones are
known only as fossil, but recently T.
HABE (1955) lumped such Japanese
Recent species as" P. turgida DAr.L " andP. tzipponica NoMURA and HATAI into P.
amp/a DAr.L.

Review of the previous works

Distribution and Ecology

The following fossil and Recent species of the geuns Panomya have beenreported from Japan.

The present genus is rather rare in
Japan both living and fossil. However,
the geological distribution of its living
species seems to be restricted to the
Pacific coast of northern Honshu (themain island of Japan). the Okhotsk andthe Bering Seas.

1. P. ampla DALL, 1898, Trm1s. Wagner Inst.
_Sci., vol. 3. pt. 4. p. 883.

"' Read June 20, 1956; received June 21, 1956.
11

Saburo ·KANNo

12·According toT. KuRoDA and T. HABE
(1952), the Recent species are distributed
along the Pacific as follows;
P. ampla DALL N. lat. 50°-68°, "P.
turgida DALL" ~. lat. 43°-56°, P. beringiaua DALL N. lat. 39°-64°, P. ttiPpottica NoMURA and HATAI N. lat.
39°.
Thus. from the known geographicaldistribution it may be said that thepresent genus is boreal in habitat.
The living species of Panomya areusually buried in muddy bottoms comparatively offshore in cold water. andare not known to bore into rocks.
The fossil species of Pattomya inJapan dale back to the Miocene of
Izumo, Shimane Prefecture, (N. lat. 35°26'), which is the known southern limit
in Japan. the Miocene of Shiogarna,
Miyagi Prefecture (N. lat. 38° 14' 48").
the Miocene of Kurosawa, Akita Prefecture (N. lat. 39° 14' 35'1) and the Pliocene of Suenornatsuyama, Jwate Prefecture (N. lat. 40° 171 30'') Accordingly,
the distribut:on of the fossil species isapparently more south than that of the
Recent one. The fossil species ofPatwmya are usually entombed in finegrained sandstone or mudstone.
The present genus first appears in
the Inferior Oolite in the United Statesof America, Europe and India. However, so far as Japan is concerned, theoldest record seems to be in the Mioceneof Izumo and Shiogama, P. izumo andP. simotomensis occur.
The next
younger occurence is in the Pliocene of
the Suenomatsuyama and the Nakamura
mudstone (S. KANNo, 1955) where P.
simotomettsis and P. gigautca KANNo,n. sp. occur. No Pleistocene species ofPatzomya have been reported fromJapan.
Systematic Description

Family Hiatellidae
Genus Panomya GRAY, 1853
Panomya GRAY, 1853, Figures oj Molluscus
Animals vol. 5, p. 29.
Pm10mya G1~AY, H. and A. ADAMS. 1858, The
Ge1zera oj Recent Mollusca. vol. 2. pp. 351,
659.
Prmopaea MENARD, F. STOJ.JCZKA, 1871.
Palellotzfologia bulica, ser. 4. vol. 3, p. 85.
Panopaea. ME:SARD, L. REEVE. 1873. Monograph of the Genus Panopaea, pl. 5, fig. 7.
Pm10mya MENARD, s. P. WoonWARD, 1880,
Manual of the Mollusca, pp. 492-493.
Panomya GRAY, W. H. DALL. 1898, Trans.
Wagmr hzst. Sci. Phil.. vol. 3, pt. 4, p.
832.
Pmzomya G1~AY, T. HABE, 1952. Genera ofJapanese Shells. 110. 3, p. 233.

Genotype :Panopaea norvegica

SPF.~­

GLER, Recent.
According to W. H. DALL (1898), thegenus Pmzomya has the following characters; •· Shell solid, large, irregular,
with a single cardinal tooth under thebeak in each valve: the pallial line of
unconnected, rounded impressions : theanimal larger than the shell, with large,
united siphons, diverging slightly at thetips and covered with a wrinkled coriaceous epidermis."
Remm·ks : The present genus issomewhat related to the genus Mya
LINNE 1758, but it can be distinguishedtherefrom by having the pallial line of
unconnected, rounded impressions, asingle cardinal tooth in each valve. nochondrophre, and external ligament.
The present genus is also related to thegenus Panope MENARD, 1807, but it canbe distinguished from the latter by having a medial depressed area, radialbounding folds, more shorter and noncylindt ical shell, and the pallial line of
unconnected, rounded impressions.
According to F. SToLJCZKA (1871),

Fossil and Rec~nt Species of the Genus Panomya from Japanthe present group had been referred to
the genus Glycimeris of KLEI:-; (1753,
Tent. Meth., p. 130) based upon the
Norwegianspecies.
Subsequently,
LAMARCK struck with the pecular characters of BRoN's Jl.fya glycimeris (=Chamaglycimeris ALDvANv), proposed a new
genus Glycimeris in 1799. However, a
few years back, when MENARD (1807)
proposed his name Panopaea, LAMARCK
dropped the name Glycimeris. The namePanopaea was proposed by MENARD in
1807 for a Tertiary species, \vhich hecalls P. Faujasi, but which has been
proved to be identical with the Recent
species Panopaea glycimeris of BRoN, or
Panopaea Aldvatzdi of MENARD.
H. and A. AnAMS (1858) referredthese species to the genus Glycimeris,
retaining the name Panopaea for P.
J. E. GRAY
norvegica of SPE:-<GLER.
(1853) defined the genus Patzomya anddesignated Pmwpaea norvegica SPENGLim
as the type.
According to W. H. DALL (1898),
ME:-<ARD publi~hed a separate of his paper on Panope. dated January, 1807. inwhich the name ended with the single
vowel" e".
Thus, so far as the generic name isconcerned, LANAIKK's genus Glycimeris(1799. non KLEIN 1753) seems perfectlyin accordance with our present system
of nomenclature. However, it is very
confusable because of DaCosTA's genericname Glycymeris, 1778, which is based
upon a taxodont mollusc. Thus, thegeneric name Pmzope as established by
MENARD in 1807 should be regarded a
substitute for Glycimeris LA:-.tARCK.

Panomya ampla DAI.t.. 1898
Panomya amp/a DALL, 1898, Trrm. Wagmr Free
lnst., val. 3, p: 883.
Panomya ampla. 0LDRovn,1324. Stanj. Univ.
Pub/., Geol. Sci., val. 1. 110. 1. p. 207. pl.

13

10. fig. 3.
Panomya amp/a, ABBOTT, 1951, Amer. Sea
shells, p. 454.
Pa11omya amp/a, HABE, 1955, Pub/. Akkeshi
Mar. Bioi. Sta., 110. 4. p. 21, pl. 5, figs.
3-4.

Pauope (Panomyo) amp/a. GRA:ST and GALE,
1931. Mem. San Diego Soc. Nat. Hist .. val.
1, p. 426, pl. 21, figs. lOa-b.
Panomya arctica turgida, KINOSHITA, 1937, Rep.
Fish. Surv. Hokkaido Fish. Exp. Sta .. no.
41, p. 30, pl. 9. fig. 53.

Pauomya turgida. HABE. 1952. Gen. Japan. Shell,
110. 3. p. 233, figs. 606. 607.
Pa11omya 11ipponica NoMl.:RA and HAT AI. 1935.
Saito Ho-011 Kai Mus. Res. Bull., 110. 5, p.
20. pl. 1. figs. 7a-b.

Remarks : The so-called Japanese
species Panomya ampla, P. turgida andP. nipponica are merely transitional
forms as pointed out by T. ILo\nE (1955).
These three forms seem to be local orvarietal forms of a single species. Evidently, the figures by various Japanese
workers closely resemble one another(see text-figure 1).
DistributimJ: North of N. lat. 39°
along the Pacfic coast of Japan, Okhotsk
Sea and Aleutian Islands.
Panomya beringiatza DAn, 1916
beri11gia11a DALL. 1916, Proc. U.S.
1\'lzl. Mus., val. 32, 110. 2183, p. 416.
Pa11omya arctico turgida, CLARK, 1932. Bull.
Geol. Soc. Amer., val. 43, pp. 823, pl. 17,

Pa~romya

figs. 6. 9.

Remarks: The characteristic features of this species are thin, less cylindrical, large, and rather shorter shell.
Length. 130 mm; height, 80 mm: diameter, 50 mm.
Distribution : North of N. lat. 39°
and eastern Bering Sea.
Panomya simotome11SiS 0TuKA, 1934
Panomya simotomensis

0TUKA. 1934, Bull.

14

Saburo KANNO

Earthq. Res. lnst., vol. 12. pt. 3, p. 621.
pl. 49, figs. 663.-b.
Panomya simolomensis, NoMURA. 1935, Saito
Ho·Oil Kai. Mus., Res. Bull .. 110. 6, p. 223,
pL 16, fig. 12.
Panomya simotomensis, 0TUKA, 1941. jour.
japan. Assoc. Petrol. Tech .. vol. 9, 110. 2.
p. 153, fig. 1, on p. 148.

Remarks : The present species is arather small type in the genus. This ischaracterized by the angle of the radialfolds which are about 45°, and thebeaks being situated at the anterior
third of the shell.
Distribution: Shimotomai, Nidatori,
all in the vicinity of Fukuoka·machi inlwate Prefecture; Chiganoura, Shio·gama-shi in Miyagi Prefecture; Naka·
Nango, Sannai-gun, in Akita Prefecture.
Geologic range : Middle Miocene·
Lower Pliocene.
Panomya izumo NoMURA and1-IATAI,

1938

Pmwmya izumo No:.tURA and HATAI. 1938.
japa11. jour. Ceo/. Geogr.. vol. 16. tzos.
1-2. p. 6. pl. 1, figs. 2a-b.

Remarks: This species is distinguished from P. simotomensis 0TUKA,
by its higher and shorter shell outline,
and the beak which situated more cen·tral in position than the latter. MoreReg. N'o.
5600
5601
5602

Length130.5
ca. 137.0
ca. 112.0

Height85.5
98.0
ca. 76.0

Remarks: Two specimens with both
valves intact and three single valves
were examined.
This species is easily distinguishedfrom such fossil and Recent species as
P. simotomemis, P. izmno, and P. ampla

over, this species closely resembles
DALL's P. ampla in the quadrate shell
outline, buf precise comparsion is difficult owing to the insufficient numberof specimens at hand.
Distribution : Fujina, Tamayu-mura.
Yatuka-gun in Shimane Prefecture.
Geologic 1·ange : Miocene.

Panomya gigantea KANNo, n. sp.
Pl. 2, Figs. 1, 2a -b.

Shell large, rectangular in outline.
inflated, gaping widely behind; anteriorbroadly rounded; posterior subverticallytruncated; ventral margin almost straight, being parallel with the posterodorsal margin. Beak situated at about
4/10 from the anterior, rather small.
somewhat swollen, turned-in and directed
forwardly, not touching one another.
Surface ornamented with concentric,
irregular undulations or rude concentriclines of growth, and the whole surface
with short, irregular, minor striations;medial portion of valves depressed andbounded by two radial folds, of which
the anterior one is almost vertical tothe ventral border; angle of these two
folds is about 40°. Inner surface andhinge not observed.
Dimensions (in mm) :Thickness

Valve

Type

25.0

Right
IntactHolotype
Para type". deformed
specimenca. 50.0

II

by its extremely larger and higher shell(see text-figure 1). The present species,
so far as the form ratio is concerned,
rather resembles P. beringiana and P.
turgida. The other species hitherto
reported from Japan seem to be alliedFossil and Recent Species of the Genus Pm1omya from Japan

15

X

130

120

1!0

100

+
60
7
X

5')

.\1

•

20

30

e9

40

50

60

70

HEIGHT

so90

Text-figure 1. Graph showing the form ratio of PatiOtiiJa giganlea KANNO,n. sp., and the known fossil and Recent species of genus Panomya.

1.
2.
3.
4.

P. giganlea KA:>:NO, n. sp.
P. beriugiana DAr.I.
P. turgida DALL
P. turgida of KI:-;osniTA
5. P. amp/a of GRANT and GALE
6. P. ampla of HABE

7. P. amp/a of OLDROYD
8. P. 11ippouica NoMURA and HATA1
9. P. izumo NoMURA and HATAT
10. P. simotomemis 0TUKA
11. P. simotometJSis of NoMURA
12. P. simotomensis of 0TUKA fromNaka-Nango.

to the Aleutian species, P. ampla.
The present species occurs rather
rarely from the Pliocene Nakamura
mudstone which is compcsed of grayish.
pumiceous sandy mudstone. The new
species occurs in associated with
Patbwpecte1z sp., Fulgoraria sp., andEchi11araclmius sp. The specimens withboth valves intact are buried in thestrata in their natural position. Fromsuch evidence, it is inferred that thepresent species was not transported toits site of burial. therefore, it may indicate the thermal conditions of sea inwhich it lived. The writer considers
that the molluscan fauna of the Nakamura mudstone indicates cold water.
These facts perfectly agree with thethermal conditions indicated by the
Tatunokuchi fauna (S. NoMURA, 1938).
Reg. No. 5600 (Holotype), 5601 and
5602 (Paratype).
Locality : Railway-side, about 400
meters south of Kornagamine station,

16

Saburo KANNO

Shinc11i·machi, Soma-gun,Prefecture.

Fukushima

References
ABBOTT, R T. (1954), Am~rican Sea shells.
AnAMS. H. and A. (1958), The genera of
Recent Mollusca. vol. 2.
C!.ARK, B. L. (1932). Fauna of the Poul andYakataga Formations (Upper Oligocene)of Southern Alaska. Bull. Geol. Soc. Amer..
vol. 43, pp. 797-846.
DAI.I., W. H. (1898), Contribution to the
Tertiary Faunas of Florida.
Trans.
Wagner Free lt~sl .. Sci. Philo .• vol. 3. pt. 4.
- - (1916). Diagnoses of New Species ofMarine Bivalve Mollusks from the Northwest Coast of America in the Collectionof the United State National Museum.
Proc. U.S. Nat. Mus., vol. 52. 110. 2183.
GRAr-;T, U.S. and GALE. H. R. (1931). Catalogueof the Marine Pliocene and Pleistocene
Mollusca of California and Adjacent Re~dons. 111em. Srm Diego Sci. Nat. His! ..
vol. 1.
IlABE. T. (19·12). Genera of the Japanese
Shells. 110. 8.
- - (1955). Fauna of Akkeshi Bay. no. 21.
Pelecypoda and Scaphopoda. Pub/. Akkeshi
Mar. Bioi. Stat., no. 4, pp. 1-31.
KANNo, S. (1955). Geology of the Environs
of Kaneyama-machi, lgu-gun, Miyagi Prefecture. (in Japanese) Res. Bull.. Ceo/. Mill.

In$[., T.okyo Univ. Educatio11, no. 4. pp. 11-23.
KI:-<OSHITA. T. (1937), CataloJUe of the Shell
Bearing Molluscs from !Iokkaido, no. 2.
Rep. Fish. Surv. Hokkaido Fish. Exp. Sto.,
1W. 4, pp. 1-3}.
NoMURA, S. (1985), Miocene Mollusca fromthe Siogama. Northeast Honshu, Japan.
Saito /Jo-otJ Kai Mus .. Res. Bull , no. 6, pp.
193-234.
(1938), Molluscan Fossils from the Tatunokuchi Shell Bed Exposed at Goroku
Cliff in the Western Border of Sendai.
Sci. Rep. Tohoku Imp. U11iv .. 2nd ser., vol.
19. tlO. 2. pp. 236-275.
- - and HATAI. K.(l938). Fossil Mollusca
from Neogene of Izumo. fapall. four. Ceo[.
Ceogr.. vo!. 16, nos. 1-2. pp. 1-9.
OLDROYD. I. S. (1924). The Marine Shells
West Coast of North America, vol. 1.
Sta11[ Univ. Pub[., Ceo[. Sci., vol. 1. 110. 1.
OTVKA. Y. (1931), Tertiary Structures of theNortheastern
End of the Kitakami
Mountainland. lwate Prefecture. Japan.
Bull. Eorlhq. Res. lust .. vol. 12, pt. 3. pp.
566-638.
- - (1914), On the Fauna of the Neogene
between Honzyo and Kurosawaziri. four.
fapa11. Assoc. Petrol. Tech., vol. 9. 110. 2,
pp. 85-107.
REEVE. L. (1873). Monograph of the Genus
Panopaea, Conchologia Iconica.
STOLICZKA. F. (1871), Cretaceous Molluscaof Southern India, vol. 3, Paleonlologia
bJdica. ser. 4.

Explanation of Plate 2(All figures in natural size)
Fig. 1 Panomya gigontea KANNO, n. sp .. paratype.
A left valve showing surface ornamentation.
Figs. 2a-b. Panomya gigantea KANNO, n. sp., holotype.
a. Right valve, surface more or les,; worn.
b. Apical view of the same.

S. K ANNo : Fossil and Recent Panomya

S. A or<r photo.

Plate 2

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 25, pp. 17-20, Pl. 3, April 30. 1957

308. TWO CARBONIFEROUS CORALS FROMOKAYAMA PREFECTURE*
MASAO MINATO
Geological and Mineralogical Institute. Hokkaido University
and

KEIJI NAKAZAWA
G.:ological and Mineralogical Institute. University of Kyoto=of~':'~"""=.fi'"7[U!]UJ*<l){ipj{;ft!JilllmJ::M: lili]Ulllll:fif Jim. ±fl. /j'*~JMBj{iJi<l) Amygdalophyl/rmr gigatlteum.,..,.,'69?=(YABE et HAY ASAKA) c ~ .!'!m. {£(;t. /j'*~~im<l) Clisaxophy/lum awa MIN ATo subsp. atetsuetrse
subsp. nov. -a-~11~-t .7!> o Riiif<l)~ftl.:. "?I., -c 'tm~c7)ail;~ .7!> :0:. c t 1.:.15~*C~I1<1) t <1) t ;7,..t..:i"'o~~lEI!Jii·~iR*=:

KA: On the identity of Echigophyl/um
YABE et HAYASAKA (1924) and Amygda/ophy/lu;n DUN and BENSON (1920)
etc., four. Ceo/. Soc. ]apa11, Vol. 46, p.

Amygdalophyllum giganteum ( YABEet HAYASAKA) and Clisaxophyllmn awa
MrNATo subsp.
atetsuense nov. aredescribed. The former was newly foundin a limestone developing at Niiyabara,
Tsuchihashi, Niimi City, Okayama prefecture, while the latter was collectedfrom the tufaceous limestone whichcrops out near Morikuni, Niimi City,
Okayama prefecture.

!"39.

1955.

Amygdalophyllum giganteum, Mit-:ATO:
Japanese Carboniferous and Permian
corals. four. Ji'ac. Sci., Hokkaido Univ.,
ser. 4. Vol. !X. No. 2, p. 149, pl. 17,

Fig. 9: text·tig. 16.
It is far from doubtful that thepresent specimens now in concern are
wholly conspecific with Amygdaloplzyllttm giganteum (YABE et HA v ASAKA)
described and figured by HAYASAKA
from the Carboniferous limestone ofOmi district.
The writers have directly comparedthem with the holotype specimen now
deposited at the Inst. GeoL and Palaeont., Tohoku Univ., Sendai.
Echigophyllum giganteum was firstestablished by YADE and HAYASAKA
based on the coral specimens derived

Description of Species

Amygda lopllyllum gigan teum
(YAnE et HAYASAKA)
Pl. 3, Figs. 1, la. 2.
1924. Echigop/Jy/lum gigatlteum, HA YASAKA :On the Anthracolithic limestone. etc.,
Sci. Rep. Tohoku Utriv .. ser. 2, Vol. 8.
No.1, p. 20. pl. 4. Figs. 5. 6. 7. (On theplate there were misnumbered as 9. 10

and 11. respectively.)
1939. Amygdalophyl/um gigatrteum. HAY ASA-

* Read June 20, 1956; received June 25, 1956
17

18

Masao l\hNATO and Keiji NAKAZAWA

from the limestone of Omi district, Niigata prefecture. This species. however,
was later transferred into the genus
Amygdalopllyllum by HAYASAKA whoclaimed the generic identify of Eclligopllyllt!m with Amygdalophyllum. Thus
the generic name Echigophyllum has
been abandoned.
The present senior author once fol·
lowed H,,YASAKA's view with slightdoubt, and is now of the same opinion.
The columella of Amygda/ophyllrmt
gigatzieum is observed to be composedof numerous lamellar tissues. a very
obscure median plate-like structure andseptel lamellae-like tissues. The men·tioned encircling lamellar tissues in ·thetransverse section are never the usual
axial tabellae.
In the specimens presently at hand,the columella is consisting of numerous
concentric lamellar tissues, and lessnumerous septal lamellae-like structures,
besides the obscure median plate. al·though the concentric lamellar tissues
are occas:onally discontinuous and inter·
rupted by a tmsting crack due to thedeformation of the specimens.
The concentric lamellar tissues inthe transverse sections appear as atabellae-like strucutre in the longitudinal section; they are steeply ascending towards the imaginary medianplate.
However. in the usual species ofgenus Amygdalopltyllttm including the
genotype, the concentric lamellar structure is not so conspicuous in thetransverse section of the columella as
in the present specimens and in theholotype of Amygda/oplzyllum=EchigoPhyllum giganteum. Thus the structureof the columella in Amygdalophyllum
giganteum must be regarded to be muchdifferent from that of the usual speciesof Amygdalopltyllum.

Furthermore the dissepiments of thepresent specimens as well as those of
the holo':ype specimen of Amygdalophyllmn gigantcum are quite characteristic, in the pattem of their arrangement.
The dissepiments of this species.
especially near the outer wall arearranged in neither concentric nor
angulo-concentric pattem, but they are~arranged along the septa with convex
sides faced inwardly.
Geological age: -Middle Carboniferous?
This species has been regarded until
present day to indicate the Upper Lower
Carboniferous or Middle Carboniferous
in age, but the new specimens were
found in association with Waagerwphyllum, the latter of which is a quite defor·
med specimen and in ill-preservation,although it is quite nearly related tolVaagenophyllum akasake1tsis (YABE),
the Permian species.
It is an open question, whether theformer species is a derived fossil broughtin the Permina limestone as a pebble
or not, when the WaagNwpltyllum
limestone was deposited.
Reg. nos.:- 12460. 12461. Hokkaido
Univ., Department of Geology andMineralogy.
Clisaxoph~•llum

awa MrNATO,subsp. atetsuense nov.
Pl. 3. Figs. 3. 4.

Corallum simple, corallite ceratoid,slightly CUT\'ed ? fairly large in size.
The septal number, calicular diamete1
and the diameter of the columella ofeach stage through the ontogeny of one
specimen ate tabulated below :Two Carbonift!rous Corals from Okayama Prdecture
Sept:il number
31
31
36
36
33
38
40
40
43
43
45
45

calicular diameter
15.0 mm
16.0
18.0
22.0
26.0
28.0

Thus, the major septa increase in
number as the corallite grows. andbecome as many as 45, which areobserved to be always alternating withthe same number of minor septa. Dissepimentarium very narrow or almost
lacking in the early stage. while it
becomes much wider in the mature
stage.
The columella is not solid in the
neanic stage.
In cross section. it isobserved to be composed of the primordial columella or median plate- likestructure as well as septal lamellae- andaxial tabellae-like structures, all ofwhich show quite fibrous tissues.
Also very fine vesiculate structure
are developed in this stage around theprimordial columella, and in the outermost part of the columella. The feature
is closely allied to the vesiculate columella observed in the corallites of
Clisaxop!tyllum azva MtNATo.
Next. the sep';al lamellae-like structures become less distinct, and coarsely
arranged vesicles develop well on bothsides of the mectian plate ; in themature stage. the columella come toconsist of highly convex vesicles arranged concentrically, with their convex
sides faced outwards.
The feature is much like the columella of Clt'saxopltylltem awa MtNATo
in the transverse section, as above
stated, although there are observablevery fme and short trabeculae-likeridges radially arranged in the columellaof the present species now in concern.

I~

diameter or cotumella
3.5mm
3.5
5.0
6. 5
9.5
10.0

The septa, either major or minor
ones, are very thick near the outer wall.
They gradually become thin distally inearly stage. However, the major septa
show somewhat rhopaloid in the mature
stage, while such feature is never observable in the minor septa even in themature stage.
Cardinal septum is slightly shorter
than the other major septa; it is notuniting with the median plate of thecolumella. Also the median plate is notconnected with the counter septum at
any time in the ontogeny of the corallite, so far as observed.
Dissepiments numerous, slightly angular or sub-angulo-concentric in arrangement. Wall rather thick.
In the longitudinal section the dissepimentarium is very wide in themature stage where numerous dissepimental vesicles are arranged in morethan 10 rows., with their com·ex sides
faced inward near the tabularium, andupward as well as inward near theouter wall. The vesicles are variable insize, according to their situation; near
the outer wall they are very large in
general, while they are smaller and subequal in size near the tabularium.
Septa with septal gratings are also
clearly discernible in the longitudinal
section like the case of the cross section.
Columella in the mature stage consists of very sinuous median plate andquite numerous small vesiculate tabellae
which are ascending towards the medianplate, their convex sides being faced
outwards as well as upwards. Most of

.20

Masao MINATO and Keiji NAKAZAWA

these structures are strengthened byorganic deposits.
Also there me observable numerous
short ridges which are sporadicallyarranged in the columella, to diverge
from the median plate. Their structures
a1 e observed in cross section as if trabeculae-like structures.
Tabulae not complete, rather sporadically arranged, counted 7 in a spaceof 5 mm, which are horizontal or gently
inclined outwards.
Remm·ks :-It is almost beyond doubtthat the present form is most like
Clisaxophyllum awa MINATO, but theformer is distinguishable from the latterin having trabeculae-like ridges in thecolumella. besides septal gratings.
In the holotype of Clisaxoplzyllum-------- -------- ----

awa MINATo, it is now ascertained byrecent re-examination that such trabeculae-like ridges in the columella arealso developed, although they are neverso prominent as in the present form.
However there is no sign of the presenceof such definite :septal gratings in
Cli'saxoplzyllmn awa MINATo.
Geological rauge :-Middle Carboniferous.
Reg. 11os. :-12452-12459, Departmentof Geology and Mineralogy, Hokkaido
Univ.
Reference
M. MINATO:
Japanese Carboniferous andPermian corals. ]our. Fac. Sci .. Hokkaido
Univ., ser. 4, Vol. IX. No. 2,:1956.

-------- - - - - - - - - - -Explanation of Plate :~Figs. 1. la. 2. Amygdalophyllum giganteum (YABE et HAYASAKA) 1: (Cross section of corallite.
x3.0) Reg. no. 12461. 2: (Cross section of columella, x5.0) Reg. no. 12461.3: (Longi·
tudinal section of corallite. x 3.0) Reg. no. 12462, Loc.: Niiyabara, Tsuchihashi. Niimi
City.
Figs. 3. 4. Clisaxopllyllum awa l\hNATO var. atetsuense var. nov. 3: (Longitudinal section ofcorallite, x 3.0) Reg. no. 12453. ·~: (Cross section of corallite. x 5.0) Reg. no. 12454,
Loc.: Morikuni, Niimi City.

MINATo and NA KAzAwA:

M. MI NATo

photo.

Two Carboniferous Corals

Plate 3

Trans. Pro::. Palaeont. Soc. Japan. N. S.. No. 25, pp. 21-25, Pl. 4, April 30. 1957

309. SOME MOLLUSCAN FOSSILS FROM THE EASTERNPART OF THE TANZAWA MOUNTAINLAND"
MATSUTARO SHIBATA
Kyo!Jashi Upper s~~ondary Chemical School

'1'1'

.p

1'tiRtll~'!4!g).r.>1t:S: ftfRtli!JI!I::~N'5-t~~7' -ii-1!1!\"itftJ,i?~Hi-t ~1ti51:: --?1. '1:': it. -t-el:. : ·~~w.'iti:~J..o *~tt. $!1f!~lftJ,I?il¥.lli-t~1t;:et;:.-.,~, ,-c:I!JtiM t..t-:f!*· ~i?t-:1:: 3 rif~Z.~c:-ht-:~~liC.lf~L-f-::o t.cio, ::$:ilfirmUfl~1t~·u. ll£i** · !ttf\l!!tt·~~.W:frtl?;tt."t:l.'7.>o ~t-:. $llli~"i
1lf~~.liil;il•l? Lepidocyclitw tZipponica HANZAWA tl;~.ei!.ttnt-:o t.tl.i?~~fl~i> c};: L."t:. ;$:!If!
li,'l'/iif~~J'lo'lfft, ~ .t V:~Jt;:. ""'JI. '-!: ~ ~Zz L. t.:o~ EE f.!: :t !'!&

(Crassostrea) gigas THUNBERG, and Venericardz'a panda (YoKOYA~IA): from the]ike formation were found ? Gibbula sp.
indet .. CoPiothyris grayi (DA\·msoN) and
Echinoidea gen. sp. indet.: and fromthe Fudojiri formation. only Lepidocy·clina nipponica HANZAWA and Gastropoda gen. sp. indet. were discovered.

Introduction

Reports in which the fossil mollusca
from the so-called l'VIisaka series in theeastern part of the Tanzawa mountain·
land have been listed but neither descri·
bed nor illustrated are those by MrTsucHr(1932), WATA::>~ABE, MrKA~II, Oso and
SmNoKr (1952), and Sm:-;oKr and MrKA·:-.11 (1954).
The discovery of Lepz'docy·clina nippo11ica HANZAWA by MrKA:~u(1955) is noteworthy.
The paleontological evidence of the mentioned
authors seem to be insufficient for determination of the geological age and correlation, because their lists are not supplemented diagnostically.
The writer was fortunate in collect·
ing several characteristic fossils fromthe Ochiai formation. The following
species were discriminated. namely:
Haliotis (Eulzaliotis) koikei SmaATA, n.
sp., Tegula (Chlorostoma) narusei Sm·
BATA, n. sp., Tegula sp. indet., Turbo(Batillus) carnutus SoLANDER, Astraea(Pachypoma) omorii SHIBATA, n. sp.,!l!ytilus cfr. grayanus DuNKER, Osirea

Acknowll~dgements!-or suggestions and help in many
ways the :writer wishes to thank thefollowing gentlemen. Profs. Haruyoshi
FuJJ1\IOTO and Kotora HATAI of the In·
stitute of Geology and Mineralogy,
Tokyo University of EducaLion. Messrs.
Masae O.MoRI, Sabur6 K.o\Nr-;o, Katsumi
HrRAYAMA, Shigeru AoKr and Hiroshi
UJIIE of the same Institute, 1\Iessrs.
Kiyoshi KmKE, Yo NARUSE and Tokihiko
MATst:oA of the Geological Institute,
University of Tokyo, Mr. Hisashi IsmWARA, teacher of tl:e Second High Schoolof Hosei University.
Stratiitraphic Sequence-----· - - - - -* Rea1 Jan 21, 1956; received June 4, 1956.

The geological successions are as21

22

Matsutaro St!IBAT.-\

Aikawa sub-group

I

fault
mainly composed

Ochiai formation (350m)

I fossiliferous .

of conglomerate,

I ----- ------ -mainly comJ)('sed of an alternation
formation (390m)of sandstone and mudstone, fossiliI ferous.
I~ I ...
.

0.
;::J

]ik~

0

~

«!

~

r.!

~

-;
rJl

--

-

-

-

r.!

«!

--------- - ~
;::J

E-<

>.

rJl
;::J
C/)

-

-----

- - - - - ---I mainly composed of an alternation

Yataro formation (535 m)

N

:::

I
I

- -

of sandstone and fine tuff.

--

63awa formation (800 m)

mainly composed of an alternationof tuff (perhaps iron saponite tuff)
and hard shale.

Fudoiiri formation (938 m)

mainly composed of an alternation' of sandy shale and lappili tuff. fossiliferous.

II

6yama sub-group

follows:
The stratigraphy of the northeasternand eastem part of the Tanzawa
Mountainland will be reported in detailby )~HIWARA in a later paper.
Fossil localities

The fos."3il localities of the Ochiai
formation are along the Hayato-gawanear Ocbiai, Miyagase-rnura, Aiko-gun,
Kanagawa Prefecture. Those of the}ike formation are around Hayato, Toyamura, Tsukui-gun, in the same Prefec':ure, and the localities of the Fudojiri
formation are near the dam of the
Ochiai electric power station, Toya-mura,
Tsukui-gun, also in Kanagawa Prefecture.
Geological age and correlation

The fossil fauna from the Susugaya
sub-group, as a whole, comprises warm
\Vater inhabitants largely composed ofthose of rocky shores. Lepidocyclitza
occurs throughout the Susugaya sub-group. From thermal conditions andthe occurrence of Lepidocyclina, thepresent group has characteristics common to those of Tertiary of Chichibu.
particularly with the Chichibu-machi
group. Therefore. the writer bellevesthat the Susugaya sub-group may safely
be correlated to the Chichibu-machi
group.
It may be added that the discovery
of Lepidocyclina from the base of the
Fudojiri formation is evidence sufficientfor stating that the Susugaya subgroupis not older than the lower Miocene.
Systematic Description

Genus IIaUotis LINNE:, 1758
Halioti1i (Euhaliotis) koikei
SmBATA, n. sp.
Pl. 4. figs. 3a, 3b.

Sheil large, rounded oval in outline,
moderately convex. distance of maxi-

Some 1\Iolluscan Fos3ils from the Eastern Part of the Tanzawa 1\Iountainland

mum height from margin about equal
to one-third of greatest length, surface
sculptured by subequal cords with
subequidistant interspaces and broad
oblique wavy wrinkles: distance of apex
from margin equal to about one-seventhof greatest length: perforations on dor·sal border, the last four holes abruptly
but roundly elevated, the shape of theholes ellipsoid. other holes rounded inshape and nodulously elevated.
Dimensions:· Reg. No. 5280* (Bolotype) Maximum length 108 mm., minimum length 85 mm. (ca.), convexity 45
mm. (ca.).
Locality a11d formation :-Road-side
along the Hayato-gawa near Ochiai,
Miyagase-mura, Aiko-gun. Kanagawa
Prefecture. Ochiai formation.
Comparisons and affinities :-The present species closely resembles Haliotis
naevosa iVI.-\RTY:-.1 and H aliotis gigantea
CHEMNJTZ. But ·it differs from the former by having less rolling of perforations, and from the latter by the following points, that is, 1) more rolled perforations. 2) lower elevation of every
hole, last four holes ellipsoid in sha~e.
3) highest point leans towards apex. 4)
spiral cords subequal. interspace.<; subequidistant.
Remarlls :-The specific name is dedicated to Mr. Kiyoshi KoiKE who gave
me some instruction. Although theoccurrences of fossil H aliotis are very
rare, the following reports are known:KocHJBE (1882) briefly described andfigured Haliotis gigantea CHE.l\JNITz fromthe Taga Miocene: YoKoY A'-IA (1925)
illustrated Haliotis gigantea var. llamtschatkana Jo::us (=Haliotis kamtschatkana koyamai MAKJY.-\:>.IA) from the* All of the specimens are preserved in thecollection of the Institute of Geology andMineralogy, Tokyo University of Education.

23

Shigarami PliOcene: MAKJYA:-.JA (1927)
described Haliotis. kamtschatkana koyamai n. subsp. from the Shigarami
Pliocene: KutwnA (1931) listed Haliotis
kamtschatkana lwyamai MAKIY A:\JA fromthe Shigarami Pliocene; NoMURA and
NuNo (1932) described Haliotis lwmtscluztlwna glabrosa n. subsp. from theYugashima Miocene: NO!t.tURA (1940)
described Haliotis (Smzhaliati.s) japonica
REEVE from the Moniwa Miocene: \VATANABE, ARAJ and HAYASHI (1950) reported Haliotis (Satthaliotis) n. sp.
from the Haraya Miocene: " 7 .-\TA:-.IABE,
MmAllll and SuzuKI (1952) listed Haliotis
kamtscltatkaua glabrosa No:-.wRA andNIINO from the ltami Pliocene: and.
HANZAWA, HATAI, lwAt, KrrAML'RA andSHIBATA (1953) listed !ialiotis japo11ica
REEVE from the Moniwa Pliocene.
Genus Tegula Lr-:ssoN. 1832

Tegula ( Chlorostoma) narusei
SnrBATA, n. sp.
Pl. 4. figs. la, lb. lc.

Shell trochoid. more or less deformed,
whorls four in number, protoconch
missing: upper two whorls smooth, longitudinal plicae developed on the surfaceof the penultimate whorl, but reduced
to mere oblique axial threads on thelast whorl: upper two whorls somewhat
compressed and the lower two whorls
steep: aperture depressed, rounded trigonal in outline, outer lip sharp. peripheral. margin rounded; one strong toothon the inner lip: sub-umbilicated.
Dimensions:- Reg. ~o. 5277 (Holotype)
Height 35 mm., diam. 35 mm.
Locality and for~nation :-Along the
Hayato-gawa near Ochiai, .Miyagasemura, Aik6-gun, Kanagawa Prefecture.
Ochiai formation.

24

Matsutaro SHIBATA

Comparisons mzd affinities :-The present species is allied to T e/[ttla n. sp. 2
reported by WATANABE, A~<AJ and HAYASHI from the Tertiary deposits of the
Chichibu Basin, but it differs by theabsence of longitudinal plicae on thelast whorl.
Remarks :-The specific name is dedicated to Mr. Yo NARUSE, who gave me
various instruction.
Genus Astraea (" BoLTEN ")RomNG, 1798

Astraea (Pachypoma) omorii
SumATA, n. sp.
Pl. 4, figs. 2a, 2b, 2c.

Shell trochoid, depressed, large, conicpyramidal, solid, thick, broader thanhigh; surface of whorls flat. declined,
sculptured by oblique axial plicae, theplicae weaker on the upper but stronger
on the lower where they become somewlmt crossed; peripheral margin anguIated; on the lower surface sculptured bynine spiral cords, with alternating weakknotted and smooth cords; the columella base somewhat elevated, umbilicalarea somewhat concave;
aperturesquarely rounded in outline, outer lip
sharply inclined, basal lip thin; columel-

Ia som.ewhat concave, smooth, toothlike swelling on lower part.
Dimensions:-Reg. No. 5276 (Holotype) Height 61 mm. (ca.), diam. 65 mm.
Lncality and formation :-Same asabove.
Comparisons and affinities :-The
present species resembles Astraea(Pachypoma) inaequalis moiztereyensis
but it differs by the following
points, that is, 1) being broader thanhigh, 2) larger apical angle, 3) ninespiral cords on the base. 4) squarely
rounded aperture, 5) peripheral margin
not carinated.
Remarks :-The specific name is dedicated to· Mr. Masae OMoRI who helped
the writer in his study.
The first record of this subgenus
Pachypoma as fossil in Japan is by OzAKI (1954) who described an interesting
species from the basal conglomerate of
the Pliocene deposits in Tyosi City.
The present record is the second one inJapan.
OLDROYD,

Bibliographys., HAT,\!, K., l\\'AI, ] .. KITA·
N. and SHII3ATA, T. (1953). The
Geology of Sendai and its Environs. Sci.

H.\NZAWA,
MURA,

Rep. Tohoku Univ. Se11dai. Japan. 2nd ser.,vo/. 25. p. 7, Table 5.

Explanation of Plate 4
Figs. la-c. Tegula (Chlorostoma) 11arusei SmBATA, n. sp. Holotype, Reg. No. 5278. a. Apicalview x 1, b. Apertural view x 0. 85, c. Umbilical view x 1
Loc. Along the Hayato·gawa near Ochiai, Miyaga>e-mura. Aiko·gun, Kanagawa Prefecutre.
Figs. 2a-c. Astraea (Pachypoma) omorii SHIBATA, n. sp. Holotype, Reg. No. 5276. a. Apical view
x 0. 89. b. Apertural view x 0.89. c. Umbilical view x 0. 92.
Loc. ditto.
Fig3. 3a. b. Ha/iotis (Euhaliotis) koikei SHmATA, n. sp. Holotype, Reg. No. 5280. a. Apical view
x 0. 81, b. Dorsal view x 0. 81.
Loc. Road-side along the Hayato-gawa near Ochiai, Miyagasemura. Aiko-gun, Kanagawa
Prefecture.

M. SmsATA: Molluscan Fossils from Tanzawa

Plate 4

Some Molluscan Fossils From the Eastern Part of the Tanzawa Mountainland
HATAI, K. and NrSIYAMA, S. (1952). Check
List of Japanese TettiaT}" Marine Mol·lusca, Sci. Rep. Tohoku Imp. Univ., Smdai,]apa11. 2ttd ser., Special volume no. 3, p.
206.
MAKIYAMA, J. (1927). Preliminary Report on
the Tertiary Fossils from Kamiminochigun, Shinano, Chiky1t (Globe) vol. 8, no. 2,
p. 188, Pl. III, fig. 4.
MrKAMI, K. (1953a). Lepidocyc/i11a nipponica
from the Ochiai formation in the Eastern
Border of the Tanza wa Mountainland,
four. Geol. Soc. ]apm1, vol. 61, no. 717,
p. 274.
(1955b), Geology of the East Margin of
the Tanzawa Massif, Sci. Rep. Yokohama
Nat, Utliv. Sec. II, no. 4, pp. 41-64.
MrTSUCHI, T. (1932). Explanatory Text of theGeological Map of Japan, scale 1:75,000,
Hachioji. Imp. Geol. Surv .. japan, p. 34.
NoMURA, S. and NnNo, H. (1932), Fossil
Mollusca from Izu and Hakone, Sci. Rep.
Tohoku Imp. Univ., Smdai, Japan, 2nd ser.
vol. 15, no. 3. p. 21, Pl. XII (II), fig. 12.
OLDROYD, I. S. (1927), Marine Shells of theWest Coast of North America, Sta11j. Univ.
Pub/., vo/. 2, Pt. Ill, p. 165, Pl. 108, figs.
5, 6.
OzAKI, H. (1954). On the Paleontology of theBasal Conglomerate of Pliocene. Kanto
Region, Bull. Nat. Sci. Mus. (Tokyo), N. S.
vol. 1. (110 34), p. 12.

25

REEVE, L.A. (1845). Conch. Icon., vol. III.
Haliotis, 74 pis.
SHINOKI. R. and !vhKAMI, K. (1954). Structureof the Northeastern Border of the Tanzawa Mountainland (Pt. 1), Studies fromthe Geol. a11d Mitleral. Inst., Tokyo U11iv.
of Educatio11, 110. 3. pp. 117-123.
TRYON, G. W. (1890), Man. Conch., vol. XII,
p. 84, Pl. 7, fig. 42.
WATANABE. K., ARAI. J. and HAYASHI, T.
(1950), Tertiary Geology in Chichibu
Basin. Bull. Chichibu Mus. Nat. Hist. 110.
1. pp. 29-92.
- - , MrKAMI, K. and SuzuKI, S. (1952a),
sedimentation of the Shirahama Group·
Geology of the Eastern Region of Shimoda
Town, four. Geol. Soc. ]apa11, vol. 58, no.
678. p. 95.
- , - - , 0No, K. and SHrNOKI, R. (1952b ),On the so-called Misaka series of theEastern Part of Tanzawa Mountainland.
Ibid. no. 681, p. 218.
WEINKAUFF, J, C. in MARTINI U. CHEMNITZ(1883), Conchyl. Cab. Bd. VI, p. 26, Taf.
4, Fig. 1, 2.
WENZ, W. (1937), Handb. d. Palaeoz. Bd. 6,
Teil. I, p. 171.
(1938). Ibid. Teil Il, pp. 306, 361.
YOKOYAMA, M. (1925). Tertiary Mollusca
from Shinano and Echigo, ]our. Foe. Sci ..
Imp. U11iv. Tokyo. sec. II. vol. I, Pt. 1, p.
8, Pl. I. figs. 11, 12.

Trans. Proc. Palaeont. Soc. Japan, N. S.. No. 25, pp. 26-30, Pl. 5, 1 text-fig., April 30, 1957

310.

A MIOCENE FOSSIL CRAB, PARATYMOLUS YABEI N. SP.
FROM NAGANO PREFECTURE*
RIKIZO IMAIZUMI
1st College of Arts and Sciences, Tohoku University------~-:lH!fJJil:rWmW"fft;J:;f:}!E:JII. "fft'1'~~:1ttl!dmi7J~.m11t:){(:JII.~J: IJi!il:l!l....f-: Paratymolus yabei
n. sp. ~lm~l..... i-17J~llll~17Jilir~il:~:@B'~-e~Q.:. c~:mt.:t.:o ~17J P. pubescms lt. P. yabei
l::l!!~L.. P. yabei :b>l?j!{tL.t..:~17Jc~k.l?;tL. W~O)JI.,~:OO~li P. sexspit~osus ltiii!Jt.fi:IIJll;:;tf!Y.
L.f.:*~c~k.l?tLF.>o ~~$1::1t.n!!m17Ji'fiJmUf1:f!:~;tL"CI.'~ffil;til:~.;,o~~.,. 311 ~o·~:JR1Jit

ltllroduction :-Emeritus
Professor
Hisakatsu YABE kindly brought the fossil
crabs frorn Chiyo-mura, Shimoina-gun,
Nagano Prefecture to the writer for his
study. The fossil crabs were collectedby a school boy of the Chiyo Primary
School on April 12, 1949 and later they
were passed to the band of Mr. Yoshikatsu SmMAOKA of the Yokohama
National University, who was in thecourse of the stratigraphic field workaround Chiyo-mura. These fossil crabs
were studied by Dr. Tune SAKAI and
Dr. Tokio SHIKAliiA of the Yokohama
National University who determinedthem as a new genus and a new species,"Ti'yocarcimts bifidus ", though theirdetailed description was not given.
The writer visited the locality of thefossil crabs. in spring of 1956, observed
the occurrence, and collected otherspecies of fossil crabs. The fossil crabs
are well preserved, showing their finestructures, and belong to the ParatymoJus, which has hitherto never been

* Read June 16, 1956;

reported as a fossil.
Acktzowledgements :-The writer isdeeply indebted to Emeritus Professor
Hisakatsu YAsE who gave the specimen
to the writer and has constantly guided
the writer's study. Thanks are due to
Dr. Tokio SmKAMA and Dr. Tune SAKAI
who advised the writer for the further
study. The writer wishes to express
his thanks to Professors Sboshiro HA~­zA WA, Kiyoshi AsANo, Kotora H.nAI
and Kenzo YAGI Tohoku University,
for their continuous encouragements.

Family Majidae ALcocK
Subfamily Inachinae ALcocK
Genus Paratymolus Mums, 1879
Mnms, j. E:lward. 1879. On a Collection ofCrustacea made by. Capt. H. C. St. ]OHN,
R.N., in the Corean and Japanese Seas,
Proc. Zoo/. Soc. London, pp. 21, 45. and
46, Pl. II. Fig. 6.
SAKAI. T .. 1988. Studies on the Crabs of Japan,
Ill, Brachygt~atha, Oxyrhyt~cha, pp. 207209, Pl. XXI. Figs. 1 and 2.

received July 9, 1956.

26

A Miocene Fossil Crab, Paratymolus yabei n. sp. from Ka5ano Prefecture.

Paratymolus yab'ei, n. sp.
Pl. 5, Figs. 2-8, TeX:t-fig. 1

Carapace elongate pentagonal andpostero-lateral borders of the carapace
longer than the antero-laterals. The
ratio of length to width is 5 : 4. Surface
uneven and regions indistinct. Rostrum
large and acutely bilobated. The eyestalk is exposed. Two strong spines at
the antero-lateral border, one on theanterior angle of the hepatic region islarger and another smaller one behindof it is acute and directing forward.
The postero-lateral parts of the carapace
are not completely preserved. Protogastric region and the anterior part ofthe meso.gastric region are covered with
granules. The granules on the former
region are rotmd and larger than thoseon the latter. Epi-branchial and mesobranchial region are also covered withsmall granules. Granules on the posterobranchial region are obliquely oblong,and under magnification, these oblong
granules have two or three small granules on the crests.
Antero-lateral, lateral, posterior partof the postero·lateral and posterior border are rimmed with granules. Antenna
seems to be long. Thoracic sternum isrelatively narrow. Chelipeds are moderate in size, fingers are longer thanmanus. movable finger with three or four
blunt teeth. narrower than immovable
finger, and has a longitudinal row of
granules on its outer-upper part. Carpusof the cheliped has a spine on its innerdistal angle.
Pereiopods long andslender, merus long and broad, with alongitudinal groove on its postero-outerpart : carpus short, propodus broad atits distal half. shorter than dactylus ;dactylus narrow. The· first and fourth
pereiopods are longer than the second
and the third. Minor structure of the27

compound eye is well preserved, andsquare facets are about 20 p. in diameter.
Dimemions (in mm) :-Length ofcarapace, 8-9; with of carapace, 6-7;
length of cheliped, 4; length of appendage, IG-13.
Locality and geological horiznn :North cliff in the ground of the Chiyo
Primary School, Yonekawa. Chiyo-mura,
Shimoina-gun, Nagano Prefecture. IGPS
loc. no. N-5, lat. 35° 25' 2" N., long. 13i 0
51' 58". 6 E., middle part of Yonekawa
formation, Tomikusa group l\liocene.
Repository :-IGPS coli. cat. no. 79485.
Occurre1zce and preservation :-There
are about twenty specimens in the slab
which is 65 mm x 195 mm in size. The
lithology of the slab beating_ the fossil
crab, is dark brownish gray fine siltstone.
Laminations are indistinct and perhaps
very thin, about 2 mm. thick. Between
the natural parting, the rock is massive
q.nd has concoidal fracture. Most of thespecimens are the impressions of thecarapaces and some of them have been
doubly pressed by its theracic sternums
with the abdominal somites on theimpression of the carapaces. The fossils
occur within so uniform and homogeneous matrix that the minor structuresuch as the compound eye is wellpreserved, and the carapaces haveretained some of its original relief.
Some specimens show the sternums withthe abdomens of male, which are replaced by the carbonate material. Depression of the sediment has produced
considerable spreading and distortion.
Some of the specimens compressed
obliquely and the sternums with theabdominal somites are displaced fromthe impressions of the carapaces, but
the directions of the displacements are
not constant.
The impressions of carapaces are
separated from their sternums andRikizo l~tAIZUMIText-figure 1-Paratymolus yabei. n. sp., showing dorsal view. thesame specimen as figured in pl 5, Fig. 4.

abdominal parts, and therefore the~pecimens bearing ventral parts musthave their impressions of carapaces
under the venbal surfaces. Regardlessof whether the specimens show theirdorsal views or their ventral views, thefossil crabs on the handspecimen always
lay their outer surfaces of carapaces
down on the surface of the slab. It is
concluded from this fact that thesefossil crabs had been living on someplane of sediments. and were embedded
later without an upside down arrangement. Almost all the specimens havetheir appendages. These facts suggestthat they were rapidly embedded in thesediments after death without agitation.
The field observations show that thehorizon of the fossil crabs, Paratymolus
yabei is restricted to two or three metres in thickness, probably, in the middle
part of the Yonekawa formation. The
fragments of the appendages of thefossil crabs, Paratymolus yabei occur
from two or three thickness of siltstone
but such well preserved specimens as inthis slab are limited to some parts ofthe thin laminae. These specimens offossil crabs are the same in size or haveattained the same stage of growth.
These grouped assemblage of the fossil
crabs is thought to be resulted fromtheir ecological condition.
At the north cliff in the ground of
the Chiyo Primary School (Fig. 1), a
white siltstone is exposed lying conformably on this dark brownish graysiltstone bearing Paratymolus yabei.
Another species of the fossil crabs rarely
occur here with accompanied with theabundant mollusc remains, such as
So!emya tokunagai Y., and Yoldia( Yoldia) laudabilis Yot<., Lt"nthia 1tipponica YosmwARA, and plant impressions
such as Accr, Querc:ts, and algae.
Callitmassa sp. aff. inornata NAGAo
and H uzJOKA was reported from theAt·akida formation, which is correlated
to the Yonekawa formation, at Idozawa,
Furujyo, Tomikusa-mura, Shimoinagun,*l (Smt<AMA, 1954, p. 87, Pl. VII,
Fig. 6, List 16). The carpus of this
---

---~-

A Miocene Fossil Crab, Paratymolus yabei n. sp. from Nagano Prefecture.

specimen is shorter than the manus, but
Callianassa inonzata has the carpus of
the cheliped that is longer than the
manus.
This specimen is nearer to
Callianassa titaensis NAGAO than to
Calliatzassa i11ornata, and the specimen
perhaps may belong to a new species
different from these species. Tymolus
sp. also was reported from the Awano
formation, which conformably overlies
the Arakida formation, at Shonosawa.
Mombara, Tomikusa-mura, (SHIK.-niA,
1954, Pl. VIII. Fig. 7, List 16).*2 This
specimen seems to belong to Tymolus
kamadai IMAIWMI, collected from the
Miocene Numanouchi formation, at east
cliff of Kosuganotsutsumi, Takalru-mura,
Iwaki-gun, Fukushima Prefecture andMisaki, Ena-machi, Iwaki-gun.*3
Remarks :-From Japan. two Recent
species of the Paratymolus have been
known, Paratymolus pubescens MrERs,
1879 and Paratymolus sexspinosus MrERs,
1884. The former is known from various
parts of the sea bottom, 10 to 100 metres
deep, south of the Tokyo Bay. Sagami
Bay, Izu Peninsula of Shizuoka Prefecture, Mie Prefecture; Kagoshima, Nagasaki, coast of Kyushu and to Thursday
Island, northern extremity of Queensland.
and the Gulf of Siam, and the latterfrom rocky or weedy ground, not far
from the shore line, Shimoda of Shizuoka
Prefecture, India and Australia.
The rostrum of Paratymolus pubescens is larger than that of Paratymolus
sexspitzosus, which is indistinctly biloba-*2 ~F fJl»!!llllt.'f:f;i:ftt!i~r~J.Il{EE / iTUi~~ w*3 tiJiiJJII!l.;sJJ,tmi9i~:M,Hf~M~]!(u"ii~ i!IT=-mzrJ:Jri!P!filt7

2Q

ted, but is smaller than one of Paratymolus yabet'. The eyestalks of Paratymolus
pubescens is longer and slender thanthose of Paratymolus sexspitzosus, andthose of Paratymolus yabei are long andstout.
The anterior hepatic spine of Pm·atymolus pubescens is smaller than theposterior one, which is large and acute,
but in Paraty11zolus yabei, the anterior
one is larger and broad at its base andthe posterior one acute and directing
more forward than the one of Paraty·molus pubescens.
In Paratymolus sexspitzosus, there are
two projections on the hepatic region
and the anterior projection is larger
than the posterior one. In the generaloutline of the carapace, which is more
important feature than the eyestalk or
the sizes of lateral spines, Paratymolus
yabei is nearer to Paratymolus prebescetzs
which is far longer than width and ofwhich one specimen is 7.5 rnm in lengthand 6 mm in width. Paratymolus sexspitzosus is slightly longer than wide,of which one specimen is 10 mm inlength and 9.5 mm in width.
Theanterior width of the carapace ofParatymolus pubesce1tS is almost thesame as the width of the postero.
lateral part but the anterior one of
Paratymoltts sexspitzosus is wider thanthe postero-lateral part of the carapace.
In these features, Paratymolus yabei ismore nearer to Paratymolrts pubescem;
than to Paratymoltts sexspinosus. These
relations of the features suggest,hypothetically the following phylogeny
about these three species.

Paratymolus yabei;; ......... ··· ............ ... Paratymolus pubescem··· ......... ··· ... Paratymolus sexspinosus

soRikizo biAIZUMIParatymolus pupescens has more dose
relations of the phylogeny~to Paratymolus yabei than to Paraty'inolus sexspino·sus, and the latter is the one that has
not evolved from Paratymolus pubescens
but branched from Paratymoltts yabei,as the time of tremble, as Paratymoltts
pubescetts evoluted from Paratymolus
yabei.
The eyestalk of crab is related to thehormone gland controlling the ecdysis
and comparatively important organ.
One can see the orthogenetic change ofthe eyestalk among these three species,that is, in Paratymolus yabei the eyestalk is large, in Paratymolus pubescens
eyestalk is sle11der and in Paratymolus
sexsPi1_zosus it is small. There is nosuch relation as above described in thesubordinate feature as the lateral spines.
Square facets of the compound eye ofParatymolus yabei are about 20 p. indiameter and smaller than the facets ofthe compound eye of Astacus spinirostritts, which the writer has reported
1938 from the Lycoptera davidi formation, Upper Jurassic or Lower Cretaceous, at Nieshutsekow, near Lingyuan,
Jehol, (IMAIZUMI, 1938, Pl. XXIII, Fig.
10); the diameters of the square facets
are about 50 p..
- -References
MIERS. J. Edward (1879). On a Collection ofCrustacea made by Capt. N.C. St. ]OHN.
R.N .. in the Corean and Japanese Seas,
Proc. Zoo/. Soc. Londotr. pp. 21. 45 and 46,
Pl. II. Fig. 6.
IMAIZU:-.n. Rikizo (1938). Fossil Crayfishes
from Jehol, Sci. Rep., Tohoku U11iv .• Seco11dSer. (Geol.). Vol. XIX. No.2, pp. 173-178,
Pis. XXII and XXIII.
- - (1952). A Miocene Crab, Tymolus kamadai n. sp. from the Numanouchi Formationof the Joban Coal·field, Tram. Proc.
Palet:t. Soc. ]apatl, N. S .. No. 7, pp. 201204, 5 Text-figs ..
NAGAO, Takumi and HUZIOKA, Kazuo (1938),
A ~ew Species of Cal/iat1assa from the
Neogene Tertiary of Hokkaido, ]our.
Facult. Scie. Hokkaido U11iv .. Ser. IV, Vol.
IV. Nos. 1-9, pp. 63-67, Pl. VI.
NAGAO, Takumi (1941). On Some Fossil
Crustacea from Japan. jour. Facult. Scie.
Hokkaido Univ .. Ser. IV, Vol. VI, No. 2,
pp. 85-lO:J, Pl. XXVI.
SAKAI, Tune (1938). Studies on the Crabs ofJapan, III, Brachygtzalha. O:cyrhyt:cha. pp.
19-l-364. Pis. XX-XLI. 56-Text-figs ..
SHIKAli!A, Tokio (1953). On the TertiaryFormations of Tomikusa in South Nagano
Prefecture, Sci. Rep. Yokohama Nat. U11iv ..
pp. 71-108, Pis. IV-VIII. 16-lists. 2-Textfigs.

--- ------------------------

Explanation of Plate 5
Figure 1. North cliff of the ground of Chiyo Primary School, Yonekawa, Chiyo-mura, Nagano
Prefecture.
Figures 2-8. Paratymol11s yabei, n. sp.
2. Slab bearing specimens, nat. size.
3. Well preserved specimen showing dorsal view. in the left of the slab, x 3.
4. Impressions of carapaces, showing dorsal views. specimens in a part, a little to thecenter of the slab, x8/3.
5. A specimen showing ventral view in the right of the slab, x 3.
6. A specimen showing ventral view in the right of the slab. x 8/3.
7. Fragments of a cheliped and an anterior part of carapace with eyestalks, in the rightlower border of the slab, x 2.
8. Square facets of compound eye of the same specimen as figured in fig. 7, x 18.

R. fM A I ZU MI : Paratymolus yabei, n. sp.

1

Plate 5

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 25, pp. 31-39. Pis. 6-7. 2 text·figs., Apr. 30. 1957

311.

AMUSSIOPECTAN IITOMIENSIS (OTUKA) AND ITS ALLIESFROM JAPAN*
MASAHIKO AKIYAMA
Geological and 1\lineralogical Institute, Tokyo University of Education

Amussiopectetl iitomiemis (OTUK A) (: -=t o:>ili~fil!l:::. "?1. '"C : *~5'!J'Z.llt.liJ ;M/IIlfJ;~tJ' I? Pecten
iitomiemis OTUK A (: t.. "C%~ t..tdt."El'i!Ht Amussiopecletl ~~:::.~ t... Amussiopecten hyugaensis
SHU TO (t~c l"i.J-fl!l~~i .: :_ c :zomJi!i L, -=t"o:>:j!j:j;ClfU~fT"?t.:o "f. t.:, ;;f;:RJto:>f!go:> 3 .N!~1JJ.ll1t!ft

L, -=ttL I? o:>;fA~B :Z.~ l?tJ,I:::. Lt.:otl\ ill mE ~locality should be referred to anotherspecies.
Amussiopecten planicostulatum (NoMURA and Nmw) was first described by
S. NoMURA and H. NnN<> in 1932 fromthe Shirahama group at Ichiya near
Yugashima, Izu Peninsula, but no subsequent record of occurrence has been
published.
Amussiopecten yabei (NoMURA) was
first described by S. NoMURA in 1933
from Taiwan.
Recently, T. SnuTo (1955) described
Amussiopf!cten lzyugaensis SnuTo andAmussiopecten praesignis (YoKOYAMA)
from Hyuga, Miyazaki Prefecture, anddiscusseq their stratigraphic significance.
The writer studies some specimensof Amtt!isiopecten praesignis which areprobably topotypes, many individuals of"A. pra_esignis" and some of "Pecten
iitomiens,is 0TuKA " from the southernfoot of Mt. Minobu, Yamanashi Prefecture, and some of A. planicostulatum
fro:n Abuzuri, Zushi City, Kanagawa
Prefecture.
As -the result of his study, it becomes
clear that the topotype specimens of.. Pecten iitomiensis 0TUKA " represent
Amussiopecten iitomie1lSis (OTuKA),

The genus Amussiopecten has beenreported from many localities of Japanand Formosa (Text·fig. 1).
Amussiopecten praesi'g1tis (YoKoYA1\IA) was first described by M. YoKOYAMAin 1922 from an unknown locality. In
1926 he pointed out ··that its locality
lies somewhere in Southern Totomi ",Shizuoka Prefecture. This species isalso recorded by the same author fromthe Lower Byoritsu beds in Taiwan(1928) and Tonohama in Tosa (1929).
As was pointed out by T. KuRODA (1931),
the specimen recorded from the former
locality should be referred to anotherspecies. In 1932 S. NoMURA and H. NnNo reported the present species fromthe Nawachi gold mine, Izu Peninsula,but this specimen also represents another species. S. NoMURA and N. ZINBO
recorded this species from the Shimaziri
beds, Okinawa in 1936. Y. 0TUKA also
reported the present species from theTanna tunnel, Shizuoka Prefecture(1933), northern foot of Mt. Minobu.
Yamanashi Prefecture (1934), and southof Murono, Shizuoka Prefecture (1938),
but the specimens from the second* Read June 20, 1956;

received Sept. 8,

1956.
31

Masahiko AKIYAMA~

32

.
130

140

Text-figure 1. Map showing the distribution of the genus Amusliopectetr in Japan and Formosa.
0: A. praesignis (YoKOYAMA). x : A. iitomiensis (OTUKA). e: A. planicostulatum(NOMURA and Nmm). A: A. yabei (NoMURA). 1. Shizukawa sandstone. 2. Zushi
formation. 3. Yugashima group. 4. Shirahama group. 5. Hamaishidake conglomerate.
6. Dainichi sand. 7. Tonohama group. 8. Takanabe formation. 9. Miyazaki group.
10. Shimaziri beds.* 11. Byoritsu beds.

* It is questionable whether these specim!!ns can be assigned to Amussropecten praesignis(YoKOYAMA).

including the individuals from thenorthern foot of Mt. Minobu which Y.
0TUKA (1934, 1936) once assinged to A.
praesignis, and that Amussiopecten
hyugaetzsis SnuTo is a synonym of thisspecies.
In this paper the writer ~ discusses
the above mentioned four species andclarifies their variations and interspecificrelationships.

Acknowledgements are due to Dr.
Haruyoshi FuJIMOTo, Dr. Kotora HATArand Mr. Masae OMoRI of the Geologicaland Mineralogical Institute, Tokyo
University of Education, for theirvaluable su'!gestions and reading of thismanuscript. Thanks are due to Mr. S.
AKAGI, Mr. T. MATSUZAKI and Mr. T.
OMORI, for co-operating with him in collecting some of the present specimens.

Amussiopectan iitomiensis (OTUKA) and Its Allies from Japan

Family Pectinidae
Subfamily Anrlisiinae
Genus Amussiopectett SAcco, 1897
Amttssiopectetz praesigttis (YoKOYAMA)Pl. 7, Figs. 5. 6.
1922 Pecten praesig11is, YoKOYAMA. four. Geol.
Soc. Tokyo, vol. 29, 110. 530. pp. 1-2, pl.
5, figs. I-8.
1926 Pecten praesig~zis, YOKOYAMA, jour. Fac.
Sci., Imp. Univ. Tokyo, Sec. 2, vol. 1, pt.
9. pp. 357-358, pl. 40. figs. I. 2; pl. 4I,
fig. 1.

1931 Amussiopecten praesignis. KuRODA, Ve1ms
vol. 3, appe11dix. pp. 76-77, fig. 80.
1938 Amussiopecten praesignis, 0TUKA, jour.
Fac. Sci., Imp. Univ. Tokyo, Sec. 2, vol.
5, pt. 1' pp. 6-7, pl. 1. fig. 2.
1955 Am11ssiopecten praesignis, SHUTO. Trm1s.
Proc. Pa/aeo11t. Soc. ]apa11. N. S .. no. 20,
pp. 103-104, pl. I7, figs. 1, 3.

The six specimens collected by thewriter and his friends from the Dainichi
sand, · Shizuoka Prefecture take thefollowing description.

33

Shell large, rather thin, longer thanhigh, orbicular in outline; right valve
more convex than the left; both valvesradiately ribbed. Right valve equilateral.
with 16-17 broad, elevated, flat-topped,
straight ribs, which become gradually
lower towards the ventral and the lateral
margins, and sometimes bifurcate at thelateral borders and sometimes are
single ; interstices narrower than ribs
themselves; internal ribs 13 pairs in
number, wide and flat at the beginning
but later becoming prominent and concave to have prominent ridges on bothsides: interstices becoming as wide as
the ribs at the ventral border. Growthline weak but distinct. Ears subequal;
anterior ear being somewhat wavy andwith weak but distinct byssal notch.
Hinge line wing-like. Left valve almost
flat, ornamented with external andinternal ribs and growth liJ!es; external
ribs rounded and as wide as interstices.
The measurements are shown in
Table 1 (in mm.).

Table I

Reg. No. _L_.-:~ ~ J\~~:_~~~~~-1-l_in_g_ei_L__N_;o_ibs_·_of_, __i_~~i~-~- '_V_a_l_ve_
15391--- 104 I 102

14

5392

93

80

8

5393
5394
5395

114 : 108
66
64
84
73

7
10
8

I

:

46

.98

't

I

36

I

. 86

.13
. 09

95
.97
.87

. 07
.15
.10

I

48
.

Remarks:-This species is characterized by the rather thin, large shell which
is provided with 16-17 elevated, flattopped, bifurcating. radial ribs whichhave prominent ridges on both sides.
The ribs become obsolete towards theventral and the lateral margins and arebroader than the interstices.
The
umbonal angle exceeds 120 degrees. It
is noteworthy that the bifurcating ribs
are hardly recognized in one specimen

.4-1
. 52

17
16

127 :
127 I

R.
R.

I R.
I

.43

16

120 '

R.

R

and the ratio of height to length of theshell varies between .86 and .98.
The specimen figured by M. YoKoYAMA (1928) from Lower Byoritsu beds
shquld not be included in this species,
as was suggested by T. KuRoDA (1931).
The specimens reported by Y. 0TUKA(1934) from the Shizukawa formation
should be assigned to A. iitomie11Sis(0TUKA), and the one recorded by S.
No:.IURA and H. Nm;o from the Nawachi

34

Masahiko AKIYAMA

gold mine may be also included in A.
iitomiensis.
Locality and horizon :-In the tunnel
near Nishiyama. Haranoya-mura, Ogasagun, Shizuoka Prefecture : Dainichi
sand.·
Repository :-The Geological andMineralogical Institute, Tokyo University of Education. Reg. No. 5390-5395.
Distribt~tiotz*: - 1)
Hamaishidake
conglomerate, Shizuoka Prefecture: 2)
Tonohama group, Kochi Prefecture;3) Takanabe member, Miyazaki Prefecture.

Amussiopecten p!atzicostulatum(Nol\WilA and NnNo)
Pl. 7, Figs. 2. 3, 4.
1932 Pecte11 pla1ricostulatus NoMURA and NnNO. Sci. Rep., Tolzoku Imp. U11iv., 211d.
Ser., vol. 15, 110. 3, p. 117, pl. 12, figs.
2. 3. •l. 5.
1952 Anmssiopecte11 p/atricostulatrmr, HATAJ
and NJSHIYAI\IA, Sci. Rep., Tolzoku Imp.
U11iv., Spec. Vol., No. 3, p. 116.

The original description of Amus·
siopecten platzicosttelatum (No:o.mRA and
NnNo) is as follows.
"Shell large, about 110 mm. in height,
compressed, length nearly equal toheight, subequivalve, subequilatcral ;sides straight, with margins smooth :umbonal angle about 110 degrees. Test
rather thin. Right valve ornamented
by 18 low. rounded, subequal ribs which• This species was reported from the
Neogene of Tanna tunnel (OTUKA 1933)
and from the Shimaziri beds (NoMURA
and ZDmo 1936), but thes: specimens
were not figured, so it is questionable
whether they can be assigned to thisspecies.

are sometimes dichotomous or branching : in some specimens the ribs arealmost obsolete near the ventral mar.
gin; interspaces subequal, very shallow,
much narrower than the ribs, rarely
provided with interstitial riblets; wholesurface covered by numerous fine growthlines and a few stronger periodic ones:
hinge line less than one-half of disklength. Ears subequal in length ; anterior ear rounded in front and ornamen·
ted by almost obsolete radials as wellas concentric lines of growth ; byssal
notch rather shallow and broad : posterior ear is obliquely truncated, ornamented by only concentric lines.
Leftvalve quite similar to the right except
for almost unequal ears." The four
specimens of the right valve and asingle one of the left which were collected by the writer ·from the Zushi
formation at Abuzuri, Kanagawa Prefecture take the following description.
Shell large, rather thick, longer thanhigh, orbicular in outline; almost equilateral and inequivalved: umbonal angle
llQ-120 degrees.
Right valve with 1518 broad, rounded, straight ribs, whichbecome gradually obsolete towards theventral and the lateral margins and are
rarely provided with interstitial riblets;interstices much narrower than ribs
themselves. Internal ribs with prominent ridges on both sides at the ventral
side. The shell surface has fine distinct
concentric lines near the ventral margin.
Ears subequal and wing-like; anterior
ear larger than posterior one.· Byssal
notch shallow but distinct. Imperfectly
preserved left valve with low, rounded,radial ribs which are as wide as interstices and provided with interstitial
riblets. Concentric Jines are weak but
distinct.
The measurements are shown in
Table 2 (in mm.).

35.4mussiopectetl iitomiensis (OniKA) and Its Allies from Japan
Table 2.

0

R::9~ -.l-i~i-\ : I
5398
5399*
5400

!

I

-----~-

94
91
106
-

92

87
95

D.

[Hinge
line

7
11
9

46

9

55

48

H/L

D/L

Hinge/L

.87
.98
.96
.90

.07
.11
. 10
.09

. 49
.53
. 52

No. of
ApicalRibs -~~~ Valve
--18
110
R.
15
110
R.

18
17

120
120

R.
R.

-- '

Remarks :-This species is characterized by the rather thick. large shell which
is provided with 15-18 low, rounded,radial ribs and with interstitial ribletson the left valve. The ribs become
obsolete towards the Yentral and thelateral margins, and are much broader
than the interstices.
The umbonal
angle is less than 120 degrees.
Th~ type specimens have sometimes
dichotomous ribs which are never recognized in the present specimens from theZushi formation. The left valve (NoMuRA
and NnNo 1932, pl. 12, fig. 5) to which
S. NoMURA and H. N11No assigned their
specimen may belong to the right valve.
Amussiopecten praesig1tis ( Y oKOY AMA) is closely allied to this species, but
the former has more elevated, fiattopped, radial ribs, larger umbonal angle
and broader interstices which are neverprovided with interstitial riblets.
lAJcality mzd lzorizmt :-Abuzuri, Zushi City, Kanagawa Prefecture; Zushi
formation.
Repository :-The GeologicalandMineralogical Institute, Tokyo University of Education : Reg. No. 5396-5400.
Distributi(m :-Shirahama group near
Yugashima, Izu Peninsula.
Amussi"opecten yabei (No:-..IURA)

The type specimens figured by S.
preserved. S. NoMURA
pointed out that it is distinguishable
from A. praesignis by the numerous
internal ribs, however it may be suggested from Text-figure 2 that his
specimens should be included in A.
planicostulatum.
NoM(;RA are ill

Api l Ar~
0

140

1ao
1.20

110

IOC

10

I~

Text-figure 2. Variation diagram of the apicalangle to the number of ribs with regard toright valves of four species of Amussiopectm.
0: Amussiopectetl praesigtlis (YoKOYAMA).
x : A. irtomienSIS (OTUKA). e: A. planicostu/atum (NoMURA and NuNo). D.: A.
yabei (NoMURA).

1928 Pecletl (Amusimn) praesignis, YoKOYAMA,
Imp. Ceo/. Surv. ]apa11. Rep .. No. 101, p.

96. pl. l!'i, fig. 1.
1933 Pecten (? Amussiopecte11) yabei NoMURA.
Sci. Rep., Tohoku Imp. Univ., 2nd Ser..
Vol. 16. No. I, p. 59, pl. 2. figs. 3. 4.

* This specimen was collected by teachersof natural science al the Meguro Fourth.Middle School in Tokyo, to whom thewriter expresses his sincere thanks fortheir gift of it.

.36

Masahiko AKIYAMA

Amusswpccten iitomiensis (0TUKA)
Pl. 6, Figs. 1. 2, 3, 4. 5, 6; Pl. 7. Fig. 1.
1934 Pecten iitomiensis 0TTJKA, four. Geol. Soc.
Tokyo. Vol. 41, No. 492, pp. 566-567,
text-fig. 1.
1934 Amussiopecten praesigm. 0TUKA. ibid., p.
567.
1936 Amussiopecten praesignis, 0TUKA, Geogr.
Rev.. Vol. 14. No. 12, p. 978.
1952 Patinopecten iitomiensis, HATAJ and NISI·YAMA, Sci. Rep., Tohoku Imp. U11iv .. 2nd
Ser.. Spec. Vol .. No. 3, p. 110.
1955 Amussiopecten hyugaetiSis, SnuTo. Trans.
Proc. Palaeont. Soc. Japan, N. S., No. 20.
pp. 105-108. pl. 16. figs. l, 2. 3, 4, 5; pl.
17, figs. 2. 4, 5.
Specimen 1; (R. G. No. 1879)
Specimen 2; (R. G. No. 1880)height50
57

Ribs 14-15 in number.
The apical portion of this species isflat and resembles Pecten laqueatus
SowERBY.
Ears are simple and triangular; byssal notch indistinct. Radialribs rounded and become gradually
flatter and obsolete towards the ventral
and the lateral margins. The interstices
narrower than the ribs themselves."

Y. 0TUKA 0934) assigned some ofthe scallops from the Shizukawa formation to Amussiopecten praesignis(YoKOYAMA) and Pecten iitomietzsis
0TUKA, but as the result of the writer's
study, it becomes clear that they represent the same species, Amussiopecten
iitomiensis (0TuKA).
The original description of "Pecten
iitomiensis 0TuKA" (in Japanese) is asfollows.
" This new species resembles
Pecten nagattumana YoKOYAMA, but theformer has a flatter and higher shellthan the latter. Patitwpectetz yessoensis]AY is allied to the present species, which
has narrower and shallower interstices.
The measurements are as follows;
length47
t9

thickness
6.5-5mm. (one valve)
6.5mm. (one valve)

The specimens collected by the writerfrom the Shizukawa sandstone take thefollowing description.
Shell large, rather thin, varying inoutline from opithocline to prothocline
through orthocline. Right valve a little
convex, slightly curved near the beak,provided with 12-15 low, rounded.
straight ribs, which become obsolete

Explanation of Plate 6
Fig. 1. Amussiopecten ii!omie11Sis (OTUKA), Topotype, Reg. No. 5312, Right valve, x 1. Loc. near
Kannon·bashi, west of Hayakawa-bashi, Nakatom:-machi. i\Iinamikoma-gun. Yamanashi
Prefecture.
Fig. 2. AmilSSiopectell iitomieusis (OTUKA), Reg. No. 5315, Right valve, x 2/3, Loc. Osozawa,
Nakatomi-machi. Minamikoma-gun, Yamanashi Prefecture.
Fig. 3. Amussiopecten iitomiensis (OTUKA), Reg. No. 5316, Right valve, x 1/2. Loc. Same asabove.
Fig. 4. Amussiopecteu iitomiensis (OTUKA), Reg. No. 5317, Right valve, x 2/3, Loc. West of
Oharazima. Nakatomi-machi. Minamikoma-gun, Yamanashi Prefecture.
Fig. 5. Amttssiopectell iitomiemis (OTUK A), Reg. No. 5324. Inner surface of right valve. x 2/3. Loc.
Osozawa. Nakatomi·machi, lVIinamikoma-gun, Yamanashi Prefecture.
Fig. 6. Amussiopecten iitomiensis (OTt.iKA). Topotype, Reg. No. 5311, Left valve. x 1, Loc. Near
Kannon·bashi, west of Hayakawa-bashi Nakatomi-machi, rviinamikoma-gun, Yamanashi
Prefecture.

M. A K I YAMA:

Amussiopecten

Plate 6

37

Amussiopecten iitomiensis (OTUKA) and Its Allies from Japan
Table 3.
Reg. No.

5311
5312
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5326
5327
5328
5329
5330
5332
5333

~~Hinge

H

L.
1-

_ _
· _

•
1

50

48
42
107
134
118

10

48

99
119
98

9
7
7

76
41
59
49
42
98
59

8
5
7
5
3
12
7

line

!

H/L

I Hinge/L

I

I

1.04
1.10
. 93
.87
. 83

28
22
60
48

.58
.52

. 45
.41

55
89
52
71

fi2
50
Bl

69
45
94
56
35

81

45
71
I

I
I

57
35
81

8
7
4

26
26
30

37
28
20

I

I

I
I

.84
i
.79 I
.83 I
.79
.84
.70
.85
1.00
. 76

I

1.09 I

1.00
1. 00

gradually towards the ventral and thelateral margins: interstices much narrower than ribs themselves. Internal
ribs have inconstant width and prominent ridges on both sides near theventral bol'der.
Concentric striations
weak but distinct. Ears subequal. anterior one being somewhat wavy and withweak but distinct byssal notch. Hingeline wing-like. Left valve flat, ornamented with 11-12 round-topped. radialribs and a few interstitial riblets:interstices broader than ribs at the upper
half of the disc ; on the other hand,near the ventral side interstices as wide
as ribs.
The measurements of the selected
specimens are shown in Table 3 (inmm.).

Remarks :-This species is characterized by the rather thin, large shell
which is provided with 11-15 rounded,

No. of
Ribs

13
12
13
14
15
11
H

.50

.39

15
14
13
15
13
15
13
12
15

. 52

11

.42
.60

14

I

14

Apical i I 11equi- Valve
Angle • larity * i

105
.44
112
.52
I
102 I .62
.43
115
120
.46
120
115
.45
120
.40
120
.54
120
. ·12
120
. 49
137
.33
.4.0
117
100
.38
110
130 ' .59
110 : .47
100 ' .50
110
.4fi

R.

L.
R.
R.
R.
L.
R.
R.
!

I

I

R.
R.
R.

I
I

R.

I

R.

R.
R.
R.

L.
R.
R.

I

straight. radial ribs. The ribs become
obsolete at the ventral and the lateral
margins, and are much broader than
the interstices. The present species, as
was pointed out by T. SnuTo (1955),
has variable characters. Above all, theshell outline varies from opithocline toprothocline through orthocline and from
.33 to .62 in lnequilarity.
Amussiopecten hyugaensis SuuTo issynonymous with this species.
A. praesignis (YoKOYAMA) is closely
allied to the present species, but thelatter has less numerous, rounded, radial* Inequilarity :-This term is propos:'!d by
the writer to express a degree of an
inequilateral shell.
'Ve draw a perpen·
dicular from th:'! beak to length-line ab,where the point a is at the anterior, andcall a point of intersection c. Here, ac/
L is defined as " I nequilarity ".

Masahiko AKIYAMA

38

ribs which never split into riblets andthe interstices are nmch narrower.
A. pla1licostulatum (NoMURA and
NuNo) is also allied to the present
species, but the latter has less numerous
ribs which never split into riblets.
Geological significance :- T. SnuTo
has stated that " A. lzyugaetzsis " occurs
from the lower part of the Miyazakigroup in south-east Kyushu, while A.
praesigtzis is found from the upper horizon of the Takanabe member. Considering the above mentioned facts and themorphological relationship of these two
species, it may be suggested that A.
praesigtzis is derived from A. iitomiensis(A. hyugaettsis).
If this is true, theShizukawa sandstone (OTuKA 1955) inYamanashi Prefecture which yields A.
iitomiemis may be Upper Miocene inage. Unfortunately, the writer has had
no chance to examine A. praesignis (?)
reported from the Sagara formation, but
in the future, he wishes to collect andstudy those specimens and to clarify thephylogenetic relationship between A.
Pmesignis and A. iitomiensis.
Y. 0-ruKA (1938) stated that thefauna occurring in association with A.
praesigtzis and Veneri'cardia panda----.-(YoKoYAMA) is characteristic in theLower Pliocene deposits along the Pacificcoast of Japan. The genus Amussiopectm. therefore. is to be considered tohave valuable stratigraphic significance.
Localities and horizon :-Osozawa andnear Kannon-bashi in Nakatomi-machi
and Oharazima in Minobu-machi, Minamikoma·gun, Yamanashi Prefecture:
Shizukawa sandstone.
Repository :-The Geological . andMineralogical Institute, Tokyo University of Education. Reg. No. 5311-5313,
5315-5324, 5326-5334.
Distribution*:- Lower part of the
Miyazaki group.
Literature Cited
KuRODA, T. (1931), Catalogue of the Japanes~
Mollusca (in Japanese). Venus, Vol. 3,(appendix).
NoMURA, S. (1~33), Catalogue of the Tertiary
and Quarternary Mollusca of Taiwan. Sci.
Rep., Tolzoku Imp. U11iv., 211d Ser.. Vol. 16.
No. 1, pp. 1-108, pis. 1-4.

* The specimen recorded by S. NoMURA
and H. NnNo from the Nawachi goldmine, Izu Peninsula may be assigned tothis species. ronsidering that it has lessnumerous ribs.

-- ... - - - - - - - - - - - - - - - - - - - - - - - - - - - -Explanation of Plate 7
Fig. 1. Atmlssiopecteu iitomiemis (OTUK.-\). Reg. No. 5318, Left valve. x 2/3. Loc. Osozawa,
Nakatomi-machi, Minamikoma-gun. Yamanashi Prefecture.
Fig. 2. Amussiopecten plauicostulatum (NoMURA and NriNo), Reg. No. 5400, Right valve, x 1/2,
Loc. Abuzuri, Zushi City, Kanagawa Prefecture.
Fig. 3. Amussiopecten p!atricostu/atum (NoMURA and NuNo), Reg. No. 5399, Right valve, x 1/2.
Loc. Same as above.
Fig. 'l. Amussiopecten plauicostrllatum (NOMURA and 1\uNo), Reg. No. 5396, Left valve, x 1, toe.
S:~me as above.
Fig. 5. Amussiopecteu praesiguis (YoKOYA:O.tA), Reg. No. 5391, Right valve, x 1/2, Lo;:. In thetunnel near Nishiyama, Haranoya·mura, Ogasa-gun, Shizuoka Prefecture.
Fig. 6. Amussiopecte11 praesig11is (YOKOYAMA), Reg. No. 5392, Right valve, x 1/2, Loc. Same asabove.

M . AKIY AMA:

Amussiopecten

Plate 7

Amussiopecten iitomicnsis (OTUKA) and Its Allies from JapanNOMURA, S. and NnNo, H. (1932), Fossil
Mollusca from Izu and Hakone. Ibid ..
Vol. 15, No. 3, pp. 169-192. pis. 11 ·12.
- - and Zt:mo. N. (1936), Molluscan Fossils
from the Shimaziri Beds of Okinawazima.
ibid.. Vol. 18. No. 3, pp. 229-265. pl. 11.
OTUKA, Y. (193•1). Some Fossils from theNorthern Foot of Mt. Minobu and the
Hayakawa Tuffite of Hakone(in Japanes.:).
Jour. Geol. Soc. Tokyo. Vol. 41, No. 492,
pp. 562-568.
- - (1936}, Geological Investigation of the
Fuzimiyama Fault Scarp in the South·
western Part of Yamanashi Prefecture (inJapanese). Geogr. Rev., Vol. 14, No. 12,
pp. 969-984.
- - (1938), Neogene Fossils of the Ihara
District, Shizuoka Prefecture. Japan. Jour.
Fac. Sci .. Imp. Univ. Tollyo. Sec. 2. Vol. 5,
pt. 1. pp. 1-19, pis. 1-2.
- - (1955). Shizukawa Group and Tertiary

39

Crustal Movements in Japan (in Japanese).
Bull. Eartlzq. Res. hrst .. No. 33, pt. 3. pp.
4•19-169.
SnuTo, T. (1935). Amussiopecten from the~[iyazaki
group, l\liyazaki Prefecture,
Japan. Trmrs. Proc. Palaeo11t. Soc. Japml,
N.S., No.20, pp.l01-110, pis. 16-17.
YoKoYAMA, M. (1922), On a new species ofPecten from the Neogene of Japan. Jour.
Geol. Soc. Tokyo, Vol. 29, No. 530. pp.
1-2. pl. 5.
- - (1926). Tertiary Mollusca from Southern
Totomi. four. Fac. Sci .. Imp. llniv. Tokyo,
Ser. 2. Vol. 1, pt. 9. pp. 313-364, pis. 3841.
- - (1928). Mollusca from the Oil-Field of
the Island of Taiwan. Imp. Geol. Surv.
Japa11, Rep. No. 101. pp. 1-112. pis. 1-18.
- - (1929). Pliocene Shells from Tonohama,Tosa. ibid. 1\"o. 104. pp. 9-17, pis. 7-8.

40

PROCEEDINGS OF THE PALAEONTOLOGICAL SOCIETY
OF JAPAN

rs*tl.?!:.!/fJJ!!f-~ 1956 ~A~J 1957 <1f-2 JJ

9 s JfCJ.ltx~l!l!~tffl:r&j(~~~~'L~""'-c~tm
L.fc: (~~:f'f 38 tJ)o <1f.~tcb"NT .Oh~:Mz
t;tc•Jmml'l~<D.im !J 1:~-0o
1. Lower Permian fusulinids from the Shiroiwa Limestone, North-western part of 6me.
Nishitama-gun, Tokyo-to, Japan (ftlt!C) ........ .
...... Sumio SAKAGAMI and Toshikazu 0MATA
2. Preliminary Report on the Classificationof the Halysitidae ............... Takashi HAMADA
3. m1f~tiMi-:to J: V':id!J'~Htrfl$1:. Favosites EIK~~flc .:t-O)tliiiWj~t::.~....,il:li (ft*M). ..................................................fiiJEE I'Y EF>
4. :ltJ::Ill~im Sciophyllum (I'YMJilllfMl) (ft!'l)...................................................... ~ IE~
5. Occurrence of Jurassic Burmirhynchia
BUCKAMAN from Japan ... Akira ToKUYAMA
6. On some Triassic Spiriferinids from the
Sakawa Basin, Prov. Tosa ... Akira ToKUY AMA
7. On some New Species of Palinopecletz
from the Tertiary formations of Chichibu
Basin, Saitama Prefecture. Japan ................. .
.. . .. .. .. .. . .. . .. . .. . .. .. .. .. .. .. .. .. .. .. . .. . Saburo KANNO
8. The Molluscan Fauna from the Environsof the Zenkoji Hotspring, Nagano Prefecture,
Japan ... Saburo KANNO and Tsuneo TOMIZAWA
9. Cretaceous Pennatae Trigonians in Japan.......................................... Mitsuo NAKANO

io. Radulotzeclites. a New Pectinid Genll!Y
from the Liassic Kuruma Group in Central
Japan ....................................... ltaru HAY AMI
11. Liassic Chlamys, Camptonecles and otherPectinids from Kuruma Group in Central
Japan ...................................... .ltaru HAY AMI
12. Additional New Genera and Species of
Trigonians from the· Jurassic of Soma, North
Japan ... Teiichi KOBAYASHI and M: TAMURA
13. Some Trigoniaris·from the Hida·Plateau
Region, Central Japan ...... Teiichi KoBAYASHI
14. Nipponitrigonia and Rulitrigotzia in Japan....................................... Teiichi KOBAYASHI
15. Trigonian Faunule from Mindro in thePhilippines ..................... Teiichi KOBAYASHI
16. Bemerkungen zur systematischen Stellung von Motzotis. Etztomotzotis, Claraia. Emlzorphotis und einigen anderen Triasgattungender "Pteriidae" (~!!) ... Koichiro IcHIKAWA
17. Cambrian Fossils from PeninsularThailand ........................ Teiichi KOBAYASHI
18. tt~U'Iillilli o:> itEit.!R1ftO)--t/ifll::. -?1., -c...................................................... ,i;Jill.j~;flr
19. Some Notes on a rare Species Triceratiwn simplex J. Brun ( fta) ... Wataru IcmKA w A
20.

J;l!~~gg*C~im7t'I3HtE ......... 1Jf~B=fl~mt!YBOi/4~
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Change in Constitution
On the occasion of the Annual Meeting of the Palaeontological Society of Japan, held at
Tokyo, February 9, 1957, it was decided upon to revise Article 1 and Regulation for Publication
3 as indicated (in italic) below.

Article 1. Name.

The Society shall be known as the Palaeontological Sot'iety of Japan.

("The Society is a section of the Geological Society of Japan" will be omitted.)
Regulations for Publication.
3.

Manuscripts (includiue of text-figures. maps and tables) will be limited to 8 printed

pages (less tha11 18 type-written pages).