a -{t~-1;-i.~~~~~·~~tTransactions and Proceedingsof thePalaeontological Society of Japan
New Seriesl\o. 47

Palaeontological Society of japan
September lOth, 1962

CONTENTS
TRANSACTIONS
Page

432.

Trigoniid from the Tetori Group in the Furukawa District. Central Japan .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shiro :MAEDA 273

433.

Influence of Environment on the Variation of Hatillaria multijormis (LISCHKE) .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ]oji NAGASAWA 277

43:1.

The Fossils and their Habitats in the Neogene Katsuragawa Group, inthe south K wan to Region ........................... ivlunemitsu SUGITA 281

435. Chevrons of Glycymerid Shells ........................... Shozo HAYASAKA 291
J36. On the Genus Cmpinus with Descriptions of two new Species............ .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seido ENDO 298
437.

Variation and Dimorphism of Pac!zymelania (Gastropoda) from the Eocene
of Burma ........................... Tamio KOTAKA and Satoru UOZU:'III 301

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

310

President : Teiichi KOBA YASIII
Councillors:

Kiyoshi ASANO (Editor of •· Fossils"), Riuji El'DO (Planning), Haruyoshi

FUJJ:\IOTO, Shoshiro HA~ZAWA, Wataru HASHIMOTO (Treasurer), Kotora HATAI,
lchiro HAYASAKA, Koichiro ICHIKAWA. Nobuo lKEBE, Teiichi KOBAYASIII,
Tatsuro MATSUMOTO, l'vlasao MINATO. Tokio SHIKAMA (General Affairs), Fuyuji
TAKA! (Editor), Ryuzo TORIYA:O.·IA
Secretary: Tetsuro HANAI
Assistant Secretary : Takeo ICHIKAwA

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. Palaeont. Soc. Japan. ~- S .. :\c. ·17. pp. 273-276. Pl. 4~. Sept. 10. 1962.

--l:.l~.

TRIGONIID FROl\I THE TETORI GROUP IN THE
FURUKAWA DISTRICT. CENTRAL JAPAN*
SHIRO .l\1AEDA
Geological Institute. Chiba University~W. ·,t;;lljjj!~O):f.lfiJiUfgf. Trigoniid:;ltl:~{>yi:~·}",O trigoniid ~~~l.,t.:~*·

jiijJiX~~~!El'il·<? inoceramid, Suculu ~ ~ctl;~:Vipponitrigouia d), ~iil!-:-t.>~.::..=
Sippouitrigonia furukazcmsis ,l: $£ [.,. ii2ttL. t.: .f.c:t-;. C OJlt.0:.:. .Vippmzitrigollia O)~t/tJ~!ti.:. "?l '"C(j"f0)~~~1JD;t t:
WI m gy (!I~
~W~f.:O)\?

in the central part of the Hida mountain·
land. As a result it was found that a
new species of trigoniid occurs together
with Nuczt!a, ammonite and belemnite
in the Sugizak i sandstone, north of Furukawa City, Gifu Prefecture. In thispaper the new species. i.e. lv'iJ>/>mtilrigonia
furukawensis. is described and brief notes
are given on the stratigraphy and phylogeny of Nipponitrigonia.
In the present study, the writer ismuch indebted Prof. T. 1\0BAYASHl of
University of Tokyo who gave the writerconstant advice and encouragement.
and wishes to express his thanks to Dr.
I. HAYAMI of the same University for
his kind help.

Trigoniids bear importance for correlation of the Jurassic formations injapan. Since S. Il'IIAl\lURA (1933! hadreported Niptwnilrignnia sagawai fromthe upper Jurassic Kiritani formation.
the occurrence of trigoniids was foundin the Tetori group at various localities
by the writer. ~ow. six species includ·ing Kiritani species are known as follows:
Nippmzif rif.[onia sagm~~ail(YI-:IL\RA) : Kiritani sandstone l]l.{yof>lwrclla (l'romyophordfa .')Kiritani
iman;urai KnBAYASJII :d1~tnct
Kiritani sandstone
Latitrigouia letoriensis
KoHAYA,.;IIJ: Yambarazaka
alternation
Latifrigoniu orbicularis
KonAYA,.;III: Yambarazaka
alternation.l/yoplwrcl/a (Promyophoreffa)
orienta/is KonA Y ASH 1 andT A~lliRA: Yambarazaka
alternation
Vaugmzia yambarcnsis
KoBAYA,.;III: Yambara
conglomerateJlI..,,."

Ku'"''"

Note on the Stratigraphy
The Tetori group in the Hida mountainland can be classified as below.
ltoshirojTaie alternation of shale andsubgroup
sandstone (200-500 m. thick)Sugizaki sandstone (150-200 m.
thick),
Numamachi alternation of
h.uzuryu
shale and sandstone (!50subgroup
350m. thick)Tanemura conglomerate (250500 m. thick)

Lately the writer (1958) has carriedout a stratigraphical study on the group'fl· * Received Nov. 27, 1961: read at 79th
Meeting of the Palaeontological Society ofJapan on 2·1th September, 1961 at Kanazawa.

278

27·1

Shiro lVL'iEDA

The facies change shows that groupconsists of two sedimentary cycles. The
Numamachi and Taie alternations, composed of fine· to coarse-grained sandstone
and mica-bearing black sandy shale, arenon-marine deposits, and yield Corbicula
LHesocorbicula)tetoriensis,
Vil'ipams
1Sinotaia ?) onogoeusis, Melanoides l'ulgaris
minima and other molluscs and fossil
plants such as Onychiopsis elongata, Cia·
dophlebis denliwlata, C. exiliformis. Podo·
zamites /anceolatus, P. Reinii and so on.
The Taie alternation has been consideredlatest Jurassic in age. The lower partof the Sugizaki sandstone is characterized by the conglomerate and pebbly ar·
kosic sandstone containing small sub·angular pebbles of granitic rocks, chert.
Palaeozoic sandstone and shale. Its upper
part is represented by coarse-grained
arkose massive sandstone. The forma·tion, which is a solitary marine deposit,
yields J.Vij>j)()llilrigonia fumkawensis n. sp ..
lnocerrtlllltS furuluncensis (I. HA YAl\11:
1960, pp. :311<312, pl. 16. fig. 8). Nzu:ula
sp .. ammonite. belemnite and so on. !.
furulww(!}lsis closely resembles the i\laki·
to species (HAYA~II. 1960). The formation
has been correlated to the Mitarai shalei(WAYA: 19·10. i'VIAED:\: 1952) in the i'VIaki·
to area by the inocerarnids and the sedimentary cycle. and is considered probab·
ly Oxfordian in age.
:\!though Nipponitrif[mzia furukmt'Cil·
sis is contained in the lower as \\·ell as
the upper part of the Sugizaki sandstone,
it is very abundant in the lower coarse
sandstone. There N. fumkatcensis isaccompanied by Nucttla sp. and othersmall pelecypods but inoceramid andammonite are seldom found. It is presumed that the species of trigoniid pre·ferred to shallow. conglomeratic or coarse
sandy bottom under strong wave. From
the occurrences of Nipponitrigonia in the
Furukawa and Kiritani areas, it isthoroughly proved that the upper Jurassic
Tetori sea extends in the inner side of
the Eo-Nippon Cordillera (KoBAYASHI:
1941) from the Kuzuryu-tvlakito area tothe Kiritani and Arimine areas throughthe Furukawa area.

Description of Species

Family Trigoniidae LA~IARCK
Genus .Vippollifrigonia Cox, 1952
Nipponitrigmzia fumkazce11sis ~IAEDA,

new species
Plate 4:!. Figures 1-15

DescrijJtion :-Shell small for genus.
subquadrate. trigonal in outline, gently
convex, a little longer than high, inequi·lateral. short and well rounded in front,
produced behind: test thick. Postcro·
dorsal margin short. slightl~r curved. ob·liquely sloping, obtusely angulated withsiphonal margin. which is fairly longand truncated ; ventral margin long,
gently arched. gradually merging withneighbouring margins; anterior marginrounded, shorter than siphonal margin ;antero-dorsal margin oblique and passing
into the anterior. Umbo high. elevatedabo\'e hinge-margin. placed at a point
about one-third of shell length fromanterior extremity; beak distinct andorthogyrate. Disk wide and ornamented\Vith concentric costae which are blunt,
widely spaced, running from disk to area,
and counted about 7 to 9; concentric finelines seen in interspace; marginal angul·
ation obtuse; escutcheon ill-de!ined andsmooth. Hinge typical of Friwmirw. Innerside of shell markedly grooved on disk
and area near marginal angulation, pecies·
ally becoming stouter postero-vcntrally.
J11easurement :- \lany undeforrned
specimens measure in mm as below:

432.

275

Trigoniid from the Tetori Group- - - - - - -ValveSpecimen

LengthR. 619::!101
R. 6192102
R. 61!12103
R. 619210-1
R. 619:!105
R. 6192106

R. 619210i
R. 6192108

R. 6192109
R. 6192110
R. 6192111

I

Left
Left
Left
Right
Right
Right
Left
Right
Right
Right
Left

Width

Height
----

- - -

1-

3

12

10

}? '

~·
12+

11

3.5

10

"

20+

19

5

13

10. 5

3

')

9

7

2

15

13

20+

li

-1
5

'

10

1.5

? -

].1

11

3.5

9

3

11.5

-· :>

-------

Comparison :-All the specimens are
external and internal moulds.
Theygreatly vary in outline, from oblong-ovate
to rounded quadrangular. ~lost of themarc. however, transversely quadrated tri·
gonal. This species is a leading memberof the Furukawa marine fauna. It closely resembles Nipponilrigonia sagmmi (KoBAYASHI. 1957) from the upper Jurassic.
and hardly differs from N. sagazmi ininternal mould. However. it is easily
distinguishable from the species by concentric costae and fine concentric lines
which the latter arc in the anterior partof the disk, and by the little size. Nipponitrigonia JUIIIIJlallni (YEHARA, 1923)
shows a wide variation in outline.
The present species is similar to naumanni. especially by KOB:\ YASIII 11957) from
ProYince Tosa in outline and aspects ofconcentric costae. but they differ in density of costae. outline and size of shell.
Oaurrence :-Sugizaki sandstone in
the Kuzuryu subgroup. the lower division of the Tetori group: the cliff eastof Sugizaki. the valley south of Nonaka
and the cliff north of Nakano in Furukawa City, Gifu Prefecture.
Some Consideration on Phylogeny

Judging from the outline of shell,.the development of costae in disc andthe internal character. it is unquestionable that sagmmi and fumlum'l'llsis are
the nearest relatives. Sagmmi appeared
earlier than fumlwwensis.
Namely,sagmcai ranges extensively from the!\•Iiddle to the Upper Jurassic (1\.oBAYA·
Sill: 1957). while fumkmcansis is limited
to the Upper jurassic !MAEDA: 1958).
Therefore. furuluncensis may have been
derived from sagmmi or sagan·ai-like
form. Cretaceous Nipponilrit:onia comprises smooth and costated forms. The
former is represented by kifaJcliirma andconL'exa, and the latter by naumamti andsakamotoensis. KOBA YASI!I ,]957) pointed
out already that "llilmd1iana could be
introduced from sagal!'ai-like form by theloss of anterior costae". This opinion
can be accepted from the character ofthe ornament in juwnile and adultstages. In another way. com:exa smooth
form may have been originated from thesame sagmNii·likc form. A remarkabletendency for Nippouilrigonia is that theanterior costae were lost and the shellsize became larger in Cretaceous. On theother hand. it may be thought thatuaumanni and sakamotoensis were introduced from furulwwensis-like form hav·
ing concentric costae. Considered fromanother phylogenetic tendency of Nipponi·
trigonia it is certain that concentricShiro M:lEDA

27()

ccstae on disk remained more or less distinct. number of its costae increased bydegrees. and the shell size became larger
in the Cretaceous period.
References
Cox. L. R. (1952) : ~otes on the Trigoniidae.
with outlines of a Classification of thethe Family. Proc. 1Ua/. Soc. London, t•o/. 29.
HAYA:O.!l, I. (1960): Jurassic lnoceramids inJapan. four. Fac. Sci. Unit•. Tokyo. Sec. 2.
!'0!. 12.
KOBAYASHI. T. (1954): Studies on the Jurassic Trigonians in japan, Part I. Preliminary Notes. japan. ]om·. Geof. (.'eogr ..
t·ol. 25.
- - (1957): Some Trigonians from the Hida
Plateau Region, Central Japan. Ibid., 27.
- - (1957) : Nipponitrigrmia and Rutitrigrmia
in Japan. Trans. Proc. Pal. Soc. japan,
lli_ S., No. 26.
- - . :\!oRr, K. and TA:.rL'RA. M. (19.3!-J): Th..:
Bearing of the Trigoniids on the Jurassic
Stratigraphy of Japan. Japan. ]our. Geot.
Geogr., t•ol. 30.
btA:O.IL'RA. S. (1933) : On th? Mesozoic For·mat ion in the Jinzu Tributaries in Toyama
Prefecture. jour. Geol. Soc. Tokyo, t'Ol. ·10.
Xo. 411. (in Japanese)
I wAY A. Y. (1940) : On the Tetori Series inthe Vicinity of Makito in the Upper
Tributaries of the Shokawa in the Province of Hida. four. Geol. Soc. japan. vol.
47, .Yo. 567.
M,\EDA. S. (1952) : A Stratigraphical Studyon the Tetori Series in the Upper Sho·kawa District in Gifu Pref. Ibid .. zoo/. 58,
No. 679.
- - (1958) : Stratigraphy and Geological
Structure of the Tetori Group in the
1-Eda Mountain land. Ibid., twl. 64. ]1./o. 755.
YEIIARA, (1921): On some new Species of
Trigonia from the Lias of !'\agato and
the Cretaceous of Prev. Awa. four. Geol.
Soc. Tokyo. t'o/. 28.
YEIIARA. (1923): Cretaceous Trigmziae fromSoutheastern Japan. japan. four. Geol.
(Jeogr., l'OI. 2.
- - (1926) : Faunal and StratigraphicalStudy of the Sakawa Basin. Shikoku.
Ibid .. 1'01. 5.
- - (1931) : Trigoniae in japan. Iwanami
Lec/ure Series, Geology ami Palaeontology.

Explanation of !'!ale 42

Nipponitrigrmia fumkawensis ~IAEDA, new species
1. Clay cast of left valve. holotype (R. 6192101) x.t: Loc. Sugizaki (ti-~) in Furukawa
City (i!tlilrlJ), Giiu Pref (ii&:Jii.V;l:).
Fig. 2. Internal mould of left valve, holotype (N. 6192101) x4. Loc. ditto.
Fig. 3. Clay cast of left valve. paratype (R. 6192102) x4: Loc. ditto.
Fig. 4. Clay cast of left valve. paratype (R. 6192103) X4: Loc. ditto.
Fig. 5. Internal mould of right valve. paratype (R. 6192104) x2. 5; Loc. ditto.
Fig. 6. Lateral view of the specimen shown in Fig. 5 (R. 6192104) x2. 5: Loc. ditto.
Fig. 7. Internal mould of right valve, para type (R 6192105) x 2. 7; Loc. ditto.
Fig. 8. Lateral view of the specimen shown in Fig. 7 (R. 6192105) X 2. 7; Loc. ditto.
Fig. 9. Clay cast of left valve. paratype (R. 619210G) x-1. 5: Loc. ditto.
Fig. 10. Internal mould of left valve, paratype (R. 6192107) x2. ·I: Loc. ditto.
Fig. 11. Internal mould of right valve. paratype (R. 61!-.12108) x2. 5; Loc. ditto.
Fig. 12. Lllteral view of the specimen shown in Fig. 11 (R. 6192108) x2. 5: Loc. ditto.
Fig. 13. Clay cast of right valve. paratype (R. 619210!-J) x4. 5: Loc. ditto.
Fig. 14. Internal mould of right valve. paratypc (R. 6192110) x2. 7: Loc. South of Nonaka(!l'fl'fl) in Furukawa City, Gifu Pref.
Fig. 15. Clay cast of right valve. paratype (R. 6191111) x4: Loc. Ditto.

Fig.

All the illustrated specimens arc kept in the Institute of Geology. College of Arts andSciences. Chiba University. Chiba.

MAEDA :Trigoniid from the Tetori Group

Plate 42

T/

/

.

..

,<•

,,

~

. ·'·
.. ,. .
~

· ~6

Trans. Proc. Palaeont. Soc. Japan. N. S .. No. '17, pp. 277-280. Pl. -13, Sept. 10. 1962.

4~:3.

I~FLUENCE

OF E~VIRON:\IENT ON THE \'ARIATION OF

BATILLARJA. MULTIFORlv!JS (LISCHKE)*
JO.II NAGASAWA
lnst. Earth Sci .. Tokyo Gakugci University·'J ~ .=..7-0J!ll:'i"-~c.&ti'·;)J.Wi.!J!OJ!t~.': Jjlj@]OJrn5)CC'>';:fili~<c;l-#iiC'I·:"f7.>:fXOJ~ !if f:il
J:([ICI:.-:>L""J ~=--J·1: A. B. C 0::=:!\'l.tc;t}~Lt.:.. :'Eil~(I'·J(C.f:J..Q~. lnl-J"«l.lTr:;t,.QII'iJ;:~.!t!!f;. ~i*J~HA.:. •'J ' .=.. :!- ~ :t 'J '7 ~ =- 7 OJ.§'JO)/ll.!J!~l!!:lirnJ-f~(lij'CT- L L"'. '~, <:. 0 .~.li:!1i!:l'l!if.J1};ffi'J:I:to~ 'L" trnJ [.; L' iS 7.> o ·d1. C'ff.05€1!'1i~lfllc,;!Of ~ ;fL.O (:.0 ftt)Jf Lt:o L
t> t_,t, 'J "') ~ .=.. 7-0J:Jjb;~~::>~(t::~~L'ilS ~· 0 ttOJJtfl>£-{il1'i#~!;l:ffltij(O)~&..t !J ~ ~c;s•:.>-?:;k~~'.!g7}illt/!!:ICiY..HM~i67.> tOJ.~li£:.£~fi..Q,

7Y- iR~i~

Introduction and Acknowledgements

Frequencies of types of B. multiformis

The writer in his previous paper1961) classified Batillaria
multiformis O.ISCIIKE) into three types
according to the grade of developmentof the sul.Jsutural tubercles on theirshells.
It is considered that variation in theshell of B. multijormis may result fromits environment or inherited characters.
There is reason to believe that thevariation of the shell may be a reflectionof the environment as the writer explainsin this paper.
The writer expresses his thanks to
many students of Tokyo Gakugei Uni·
versity, :\Iessrs. ~vlasaharu ISHIKAWA and
Kanji ABE who kindly submitted to him
the samples for study.
Particular thanks are due to Professor Kotora H.>'~TAI of the Institute of Geo·logy and Paleontology of Tohoku Uni·
versity for his advice and encouragement.

and R. cumingi(NACASA WA,* Received Jan. 21, 1962: read Jan. 20.
1962.

ThL' accompanying table shows thefrequency of each type of the Recent
B. mu/tiformis and the closely related
species: Batillaria cumingi ((ROSSE~ which
always found living in association withthe former species in the low tidal zoneof japan.
It may be noticed from the tablethat both the frequencies of the t~·pes ofB. Jmtlliformis and B. cumingi collectedfrom the same locality and influenced by
the same environment show the sametendency e.g. parallel change.
This phenomenon can easily be under·stood to be an effect of the influence ofthe same em·ironment on both species.
If the frequen::y of the types is not
influenced by environment but by in·
heriterl characters. both species collectedfrom the same locality would be expect·
ed to have no relation each other.
As may be known from the annexed
map. the frequency of the types of both
species shows also the same tendency or]Oji N:lGASA II'.·I

271;
Table I.

Frequencies of types of Batillaria mu/tiformis (Ltsctii->E) and JJ. cumiugi (Ctwssr-:).

Localities

frequencies of types of
JJ. mllll~(ormis

No. ofindi\'.

Locality ::\umber:
1. Lake Akkeshi. Hokkaido. 2. Samukawa. Hakodate City. Hokkaido. 3. Yamasedomari. I-lakodate City. -1. Tachimachi-ruisaki. Ilakodate City. 5. Moheji. Kamiiso-gun. Hokkaido. 6. Shikutotsu-misaki. Muroran City. Hokkaido. 7. Etomo. Muroran City. 8. Noheji. Kamikita-gun.
Aomori Prefecture. 9. Ashizaki. t)minato. Aomori Prefecture. 10. ()ma. Shimokita PeninRula, i\omori Prefecture. 11. Shiohama. Kawasald City. Kanagawa Prefe~ture. 1~. Makuwari. Chiba Prefecture. 13. Kurozuna. Chiba City. H. Kohama. Kisarazu City, Chiba
Prefecture. 15. Northeast of Mabori. Yokosuka City. 16. Kurozaki. southwest of l\·liur~

433.

Variation of Batillaria multijonnis (L!SCJ/Kii)('K'fozaki KY'Jo:ri:\

Arao~KF s~

Taira!

Shimabara~&;

Text-fig. l.

!\lap showing localities.

Peninsula.
17. Southwest of jogashima. Miura Peninsula. 18. Southeast of jogashima.
19. Harada. Shirahama. Chiba Prefecture.
20. Harada. Shirahama, Chiba Prefecture.
21.
Ubara. Chiba Prefecture. 22. Enoura. south of ~umazu. Shizuoka Prefecture. 23. Southof Kakizaki. Shimoda. Shizuoka Prefecture. 24. Tokoname. Chita Peninsula. Aichi Prefecture. 25. Akogigaura. Tsu City. Mie Prefecture. 26. lno, Nishiura. Aichi Prefecture. 2i. lkm
south of Ino. :\ishiura. Aichi Prefecture. 28 Takahama, Ishikawa Prefecture. 29. Asbiya.
Fukuoka Prefecture. 30. Wakamatsu. Fukuoka Prefecture. 31. Xakatsu. Oita Prefecture.
32. Tsuruzaki. llita Prefecture. 33. Totaro Bay, Miyazaki Prefecture. 34. Kurozaki. northof Omuda City. Fukuoka Prefecture. 35. Arao City. Kumamoto Prefecture. 36. Taira,1\agasaki Prefecture. 37. Shimabara. Nagasaki Prefecture. 38. ;'{orthcrn coast of Aoshima.
Miyazaki Prefecture. 39. Miyajima. Hiroshima Prefecture. 40. Uwajima. Ehirne Prefecture.
41. Lake Jlarnana (ncar Benten-Zima). Shizuoka Prefecture.

280

fuji .N.-lG,4SAWA

similar change in their geographical distribution. namely, the type of both species collected from the inner part of thebay is generally A (estuary type), butthat from the center or outer part ofthe bay or low tidal zone facing theopen sea is generally of the types designated as B or C as in the case of Tokyo
Bay and Uraga Strait, the lse Bay andthe Atumi Bay. and the Ariake Sea.
But. B. cumingi is liable to change
more sensitively its form than H. multifonnis. for the former species produces
many individuals of B or C type under
the same condition al the same locality.
Such examples were collected fromthe following localities: Kurozaki ncar
Shimomiyata, Miura Peninsula, Harada
at Shirahama and Ubara. Bos6 Peninsula.
south of Kakizaki at Shimoda, Izu Peninsula and 1 km south of Ino, Nishiura.
Aichi Prefecture.
The above facts suggest that themorphological changes of both species

correspond with the change of environment and the cause by which B-C or C
type is concerned is considered to be therather highly saline water rather than
the water temparature. because the typeof B. mult~formis collected from Taka·hama-machi in Ishikawa Prefecture
where the water temperature is not sohigh. is B. and the type of H. cumingi
is C and also the writer found B type
and C type of B. cumingi in Hokkido
where the water temperature is low andthe type of B. multi.fonnis collected fromthe Prehistoric Tokyo Bay· whose watertemperature was rather higher than thatof Tokyo Bay. is generally A.

Reference
J. (1961): The StratigraphicalSignificance of the Variation of Fossil!Jatillaria multi/ormis (LISCHKE). Trans.
Proc. Palaeo11/. Soc. ]t:pan, X. S., No. 48.
pp. 102~ 107.

NACASAW,\.

Explanation of Plate 43
Batillaria mu!t~formis (LISCI!KE)Fig. 1. Type A, Southeast of Jogashima. Kanagawa Prefecture.
Fig. 7. Type A, Nakatu. Oita Prefecture.
Fig. 13. Type A. Kurozuna. Chiba Prefecture.
Fig. 19. Type C. Totoro Bay. Miyazaki Pr~fecture.
Fig. 25. Type B. Takahama·mati. Ishikawa Prefecture.
Fig. 31. Type A. Harada at Shirahama. Chiba Prekcture.
Batillaria cumingi (CROSSE)
Figs. 2- 6. Type A. Southeast of J6gashima. Kanagawa Prefecture.
Figs. 8-12. Type A. Nakatu. Oita Prefecture.
Figs. U-18. Type A. Kurozuna. Chiba City.
Figs. 20-24. Type C. Totaro Bay. Miyazaki Prefecture.
Figs. 26-30. Type C. Takahama-mati, Ishikawa Prefecture.
Figs. 32-35. Type B. Harada at Shirahamn. Chiba Prefecture.

Batillaria multiforrnis (LTSClfKE)

NAGASAWA:

1

2

Plate 43

3

4

8

9

14

15

6

5

10

12

11

7

16

18

17

13

21

22

24

20
19

25

'

26

27

32

3l

28

33

29

~
35

30

Trans. Proc. Palaeont. Soc. Japan, N. S., No. 47. pp. 281-290, Pl. H, Sept .. 10. 1962

-B-!. THE FOSSILS AND THEIR HABITATS IN THE NEOGENE
KATSURAGA WA GROUP. IN THE SOUTH KWANTO REGION*
1\IUNEl\IITSU SUGITA
Geological Institute, University of Tokyo

A-iRtlll1!!~t~0)~11'E.:.~Jmi'£/IH«intO)ft:Q'
tiJ~O)!fEtf»~rc::l=i:t~ffl~~~i'~,I.

CU: L--c.:::.tHHtE) ~~\\J!t L. .!CO)ft:6@.
t; m ~i< illl
the Shimada, Iwatonoyama. Otsuru and
1\akamagawa formations in ascendingorder. Their lithology is shown in table
1. The fossils are found in the Shimada
and Iwatonoyama formations besides
some in the basal part of the Otsuru
formation, although these fossils are notwell preserved. The fossils and theirlocalities are shown in Table 2 and 3.
Since IIA:"'AI had proposed the name,
Katsuragawa conglomerate bed for theconglomerate and mudstone formalion in
1927. many papers were published on
their stratigraphy. The molluscan fossils
in this group, howeYer. have been little
studied but SEKI's work !19371. Fromthe lithology and molluscan palaeontology he reached the conclusion that thegroup was deposited in brackish wateror inland sea. The habitats of the fos-

Introduction

The Katsuragawa group forms a
strip extending from Kawaguchi Lake
to Sagami Lake for about 40 kilometers
along the Katsuragawa valley which runs
easterly between the Kwanto and Tan·zawa \lountainlands. This paper mainly
concerns with the portion of the groupfrom Fujino·~* to Saruhashi**·~. It is composed of mudstone and various conglomerates partly known as " Iwatonoyama
conglomerate bed "or" Katsuragawa conglomerate bed". It can be classified into
* Received Jan. 26. 1962: read June 2,
1962.

** Fuji no Town, Tsukui Distri<:t. Kana·
gawa Prefecture.
**'~ Otsuki City, Yarnanashi Prefecture.

Fig. 1.

Stratigraphical position of fossils.

281

Munemitsu S(i(;JT.l
Table 1.
Conglomerate similar to that of the Otsuru formation.
but with many large boulders of fresh pyroxene
andesite.

Nakamagawa
formation

600m+

Otsuruformation

max.
1200 m+Conglomerate brownish. with thin intercalations of
mudstone: pebbles angular to subangular. ill-sorted
and 20 to 30 em in diameter: mudstone bluish tobrownish and sometimes very coaly: cross-bedding
common.

lwatanovama
formation

600m+
to
3m

Uppermost part : Alternation of conglomerate: changeof pebbles in magnitude.
Main part: Monotonous conglomerate, resembling tharof the upper Shimada formation.

Shimadaformation

max.
100m+

Upper part: Alternation of conglomerate and mudstone;
conglomerate grey to black: its pebbles well rounded.
flat. 2 to 3 em in diameter and sorted well : mudstonesimilar to that of the lower part.
Lower part: Mudstone black to grey and somewhat
bituminous.

Table 2.

Localities of fossils.

I

1---

'

locality 1 Jakotsuzawa. Otuki City, Yamanashi Prefecture
locality 2 Ilinalc, Uenohara Town. Yamanashi Prefecture
locality 3 Yassawa, Ucnohara Town.
Yamanashi Prefecture
locality 4 do.
locality 5 do.
locality 6 do.
locality 7 Shiss;;izi. Ucnohara Town.
Yamanashi Prefecture
locality 8 Shibata. Fujino Town. Kanagawa Prefecturesits of this group are the main subject
to be discussed i 11 this paper.
The Katsuragawa group is nearlysynonymous with the Nishikalsura group
by FuKUDA and Sm;-;oKJ ,19521 in Yamura
and Otsuki areas and with the Katsura·gawa series by KoriA YASHI et at. (1943)
in Uenohara area. Because the materials
in hand are not efficient for chronology.
the writer follows FUKUDA and SmKOKI
for the time being to refer the lower
half of this group to the 1\liddlc 1\lioccne.

Thewriter thanks Professors T.
and T. KI~IURA. AssistantProfessors T. HANAI and T. SATO. andDoctors T. HA:\IADA, K. Cm;-;zEI, I. liA YA:\IIand A. TOKllYAl\IA of the University of
To!< yo for their I< i nd guidance.
KOBA YASHJ.

11.

Fossils and their occurrence inthe lower Shilllada formation

The lower Shimada mudstone forma·
Lion is generally rich in molluscan fos·sits as seen at toes. 1. 2. 3. ·1 and 7.
Locality 1 (jakotsuzawa'
Species :-.lnadara tScapharca; sp.,!lear sp .. Ostrea (Cmssoslreal sp .. Trapez·
iwn sp., Ioauisiel/a sp .. Lucina cf. steam·siana. Pilar? sp., Venempis sp.. Pap/ria
sp .. Clementia nafumwrai, Clementia mille·/eli. Macoma sp.. Tellinides sp.. Diodora
sp., Dendritic coral.
Presermtion :-Often deformed.
Frequency :-l\lost numerous in num·
ber of shells. if compared with otherlocalities of the formation. Ostrea sp. isdominant. Lucina cf. stearnsimw, Trapez·
ium sp .. and Clemellfia ratlreleti are com·mon. The other species are rather rare.

434.
Table 3.

Tlze Fossils of the Katsuragawa Group283

List of the fossils from the Katsuragawa group.

species

locality------------------------------1.-leila (s. s.) divaricata (III:-.:Ds)
Emmcula sp.
l\'ztculana sp.
Portlamlia (Megayoldia) /suruensis SUGITA, n. sp.
Portlanclia (Portlandella) om/a (TAKEDA)
Acar sp.
+
A11adara (Scapharca) sp.
+
G/ycymeris sp.
Chlamys ex. gr. kane/wrai (YoKOY A :I.! A)
Pa/liolum (!Jell'ctopecten) peckhami tairanum (YOKOY.-\:\tA)
Ostrea (Crassostrca) sp.
+
Crassalellites (Hucrassatella) sp.
Corbiwla (s. s.) matusitai St::l.l'K!
Trapezium sp.
+
foanisiella sp.
+
LapltJXIIIIS ~ sp.
+Lucina cf. stetJrnsiana 0\':\:\IA+.. Cardium " sp.
Pilar' sp.
+
Vencmpis sp.
+
Pap/litJ sp.
+
Clementia (s. s.) nalwmumi On:t.;,\+Clemeutia (s. s.) l'flflwleti ]'.,.fABtLLE+
Rae/a sp.
1liacoma optim (YoKOYA~tA)
11laconut sp.
+
Jliacoma .0 sp.
Tclliuicles sp.
+
Dentalium (Fissidentalium) !'emedei SowERHY
Diodora sp.
+
Cocculilza (s. s.) n. sp. ?
Turcicula (Ginel>is) cf. crumpii (P!LSBRY)
Fusitriton oregonesis (REDFIELD)
Gastropod gen. ct sp. indct.
c:\'ClammiiUI ('(/1/('!'l/ata BRADY
Cyclammi11a aff. rzoensis AsA:-:o (n. sp. ?.)flabellum japonicum MosF.t.F.Y
Ahermatypic simple coral
Dendritic coral+
Rhynchonellidac, gen. et sp. indet.
Echinoid. gcn et sp. indet.
Dicotyledonc:-~c a sp.
Dicotyledoneae b sp.

2

3

1

5

6

7

8

+

+
+
+

+

+
+

+

+

+

+

+

+

+

+ +
+

+
+
+
+
+
+ +
+ +
+
+
+
+

+
+

+

+

+

284

Munemitsu SucJTil,lfode of occurrence :-Ostrea sp. forms
several banks in four horizons. !\lostremarkable is the top one. 50 to 60 em
thick and associated with a few indivi·
duals of :lnadara sp., .lear sp., Diodora
sp., and some fragments of various mol·luscan shells and dendritic corals. The
other species are assemblaged with manybroken shells in lenticular form. Intact
shells are generally rare but some ofTrapezium. Pitar. and Clementia vatlieleti
remain bivalved.
Litlzologv :-Bluish gray mudstone or
pebbly mudstone. Sand pipes (1 to 2 emin diameter) are found frequently justbeneath the uppermost Ostrea bank.

Locality 2 (Hinate)
Species- :Hacoma optitJa. Cyclammina
cancellata, Flabellum japonicum.
Presen•ation :-Foraminifers are wellpreserved.
Frequency :-\luch reduced in num·
ber of fossils. in comparison with locality 1. Cyc!ammina caw:e!lata is dominant.
:Hode of occurrence :-Widely scattered. Shell fragments are rare.
Lithology :-Homogeneous. gray andsomewhat bituminous mudstone.
Locality 3 (Yassawa)
Tv·lO types of assemblage are discrimina ted, name! y Portia ndia-Cyda 111mi11a and .'leila· Pal!io'um assemblages.

"Porllandia-Cyclammina assemblage":'>pecies :- P011!andia (Megayoldia)
tsurueusis n. sp .. Portlandia IPortlandel/a)
ora/a, Rae/a sp., klacoma optil'{[, Cyclam·mina cancel!ata, Cyclammina aff. ezoensis(n. sp. ?). Echinoid gen. et sp. indet.
Preseroatiou :-Foraminifers are wellpreserved.
Frequency :-Less numerous than at
locality 1 and also in Acila-Palliolum assemblage of locality 3. Dominant species
are Portlandia tsuruensis. C.w:lammina

cancellata and Cydmmina aff. ezoeusis.
1l1ode of occurrence :-Widely scattered. Shell fragments are rare. A few
specimens of pelecypods are bivalved.
Litlzology :-Homogeneous, gray andsomewhat bituminous mudstone.
.. . lcila·Palliolum assemblage •·Species :-,·leila dil'aricata. Emmculasp., Nuculana sp., Portlandia tsuruensis.
P. o~·ata. G!ycymeris sp., Palliolum (Delectopecten) pecldwmi tairmwm. Crassatellites (Eucrassate/!a) sp.. ··Cardium •· sp.,
Rae/a? sp.. Macoma optiva, Dentalium(Fissidentalium) l'emedei. Cocculina n. sp.,
Turcicula (Ginebis) cf. crumpii. Fusitriton
oregonensis. flabellum sp.. ahermatypic
simple coral. Rhynchonellidae gen. et sp.
indet., Echinoid gen. et sp. indet .. Dicotyledoneae a sp.
Frequency :-\luch more numerous
than in the homogeneous mudstone (Portlandia-Cyclammina assemblage! and lessso that at loc. 1 (.lakotsuzawa i. Dental·
ium vemedei. Palliolum pecNwmi taira·num. :l1acoma uptim and Acila divaricata
are common.
Mode of occurrence:- This assemblage occurs in lenses. Shell fragments
are common. !\lost pelecypods are uni·valved, except !11acoma optiva. Several
specimens of this species remain bivalved.
I.itlzology :-Dirty, grey mudstone
bearing a small quantity of granules ofsandstone and shale. besides volcanic
detritus and other rock fragments. The
mudstone forms several lenticular beds
(about 1 m in diameter! which are intercalated in homogeneous mudstone.
Locality 5 CYassawa!
Sper:ies :-Portlandia tsuruensis, L)•·dammina cancellata, C. aff. ezoensis.
Echinoid.
Frequency :-Less numerous than at
locality 3.
Jllodc of or:currenct? and lithology:-

434.

The Fossils of the Katsuragaum Gtoup

Similcr to those of Porllcmdia·C:rdammina
assemblage at locality 3.
Locality 7 (Shisseizi ·Several thin layers of limestone 110
to 20 em thick) are intercalated in homogeneous mudstone of similar lithology tothat of locality 3. The limestone is impure. somewhat muddy, microcrystalline
and bears some foraminifers including(;fohigerimt. An indeterminable pelecypod is also found in the mudstone.
Ill.

The hahit.ats of the fossils in thelower Shimada formation

In summarizing the above facts. it
is evident that the lower Shimada formation in thE: eastern area 1from Hi nate to
ShibataJ is quite different in facies fromthat of the western area. In the easternarea the Portlmzdia·Cyclammina assemblage is commonly found in homogeneous
mudstone. whik at loc. 1. Uakotsuzawa)
such an assemblage is absent.
The horizontal and vertical clistribu·
tion of the living species in the easternarea are as follows :,-leila diz•aricala :- Pacific Ocean:North-LaLitucle :~o--35'. Japan Sea: N35'45 (KURODA and HABE, 19521, euneritic
to subneritic zone t.TAKI and 0YA\IA.

195-1).
Dlmtalium vemcdei-P : N23 · -3-!
Turcicula crumpii-P : N31 _,n·. J :- :.'-J 12 ·Fusitriton oreJ.[onensis. P : N38' -59·. J :N36"-50'. euneritic to subncritic zone
c:vclammiua cancellata-lndo- Paci fie
Ocean, 140-5000 m (ASANO, 19511
Purtlandia. Nuculana. l'a!liolum and<.---yc/ammina show maximum developmentin outer neritic zone. Ahermatypic corals
arc also inhabitants near the margin of
the continental shelves (J.\V. \VELLS.l9571.
The salinity of the sea allows corals to
dwell. Further the Glohigerina-bearing
limestone at Shisseizi probably indicates285

open sea condition. The fossiliferous
bituminous mudstone suggests that thesea water was not strongly agitated.
Considering the above facts it may beconcluded that the area in question has
been an open sea in a subneritic zone ornear to it.
In the western area occur Ostrea(Crassostrea), Trapezium. Joanisiel!a andLuc:ina. 1-ucina steamsiana lives now inthe tidal to euneritic zone. The brokens:tells are abundant there. These facts
suggest a shallow sea bottom under the
influences of waves or currents for thesite of deposition. In brief. it is reasonable to consider that this area was ina littoral or euneritic zone.
IV.

Fossils and their occurrence inthe upper Shimada formation

The upper Shimada formation consists of conglomerate and mudstone inalternation. Pebbles of the conglomerate
are well sorted. rounded. fiat and 2 to
3cm in diameter. Only one water-wornvalve of Chlamys sp. ex gr. kandwrai ,,·asfound to lie on a bedding plane in theconglomerate at locality -1: it was presumably transported by current together
with fiat pebbles.

Y.

Fossils and their occurrence in thelwatonoyama and Otsuru formation
Several valves of Ostrea !Cmssostrea)
sp. are found in the conglomerate of theupper part of the lwatonoyama formation
at Shibata (Joe. 8!.
~loll uscan fossils are found in the
coaly mudstone in the basal part of the
Otsuru formation at Yassawa doc. 6J.
Locality 6 (Yassawa':
Species :-Ostrea (Crassoslrea) sp ..
Cvrbicula matusitai, Macoma sp., Dicotyledoneae b sp.

286

Munemitsu SUGJT.-1

Preser!'ation :-Often deformed.
Frequency :-Ostrea sp..
Corbimfa
matusitai and Dicotyledoneae b sp. areabundant.
!11ode of occurrence :-Ostrea sp. forms
several banks. Corbicula matusitai often
bivalved and .Hawma sp. are scatteredwidely. Leaves Dicotyledoneae b sp. arc
gregarious and sometimes accumulatedwith Corbicula or Oslrea.
Lit/10/ogy :-Black coaly mudstone
bearing coal patches or lenses and pyrite
grains.
The occurrence of Ostrca (Grasso·
streaj and Corbiwla in the coaly mud·stone indicates brackish condition forthis part. No animal fossils are foundin the other part of the Otsuru formation.

VI.

Summary\lolluscs are main fossils in thelower half of the Katsuragawa group.
The lowest formation or the Shimada
has been deposiled in a subneritic zone
in the eastern area. but in a littoral zone
in the the western area insofar as canbe judged from Lhe fossils and the lithology. The Iwatonoyama formation aboYe
the Shimada formation bears Ostrea
rarely. The lowest part of the Otsuru
formation is rich in Corbicula and Ostrea
at Yassawa. In view of the fossils andtheir mode of occurrences. this area may
be said to have been in brackish condi·
tion.
VII.

Description of Species

Conch. vol. 3. p. 101, pl. 223. fig. 3.
1928. Dentalium Zlemedei SoWER n y. YOKO-

Imp. Geo/. Surt. Rep .. no. 101.

YAiiiA.

p. 68, pl. 5, fig. 12. pl. 6. fig. 6, 6a.
1953. Dentalium (Fissidentalium) l'enwdei So\\'ERBY. I·IABF.. Gen. Japan. Shells. (Pel.
& Scaph.) p. 293. figs. 741. 74~. 743.
1960. Dentalittm (Fissidcutalium) vernedei SoIVERBY. JVlAKIY:\~IA. Pa/eoilt. Soc. japau,
S'p. Pap. 6. pl. 92. Jig. 6.

Dimensions :-(On a comparatively
well preserved specimen 1
length :diameter:

7. 6 em
1.05cm (m::x.).0.2Scm (min.)Remarks :-All specimens are fragmentary except for a nearly complete
one. Compared to D. yo/~n_mmai .MAKJYA:O.IA, the shell is more strongly curved
and possesses finer sculpture and its diameter increases more slowlY. The shellis thick and bent abrupt!;- in a point
near the apex. In view of these features.
the writer identified this specimen with
D. vernedei. It is a common member ofthe recent fauna of Japan. but rareamong fossils.
Occurrence :-C'vliddle l'vliocene. Shimada formation at the locality 2 (.lcilaFalliolum assemblage) at Yassawa on
dirty mudstone associated with Acila
diNtricata. Ennucula sp .. Pal!io!um peckhami tairanm11 and Crassatel!ites sp.

Genus Portlandia MbRCH 1897
Subgenus J1egayoldia VERILL et
BliSH 1897
Port!andia (J\1egayoldiai tsumensis
SUGITA, n. sp.

Genus Denlalittm LIX:\"E 1758
Subgenus Fissidentalium FISCHER 1885

Plate H. Figures. 2-6

Dentalium (Fissidentalium) vernedei

Description :-Shell of medium sizefor genus, inequilateral. moderately inflated. usually slightly Laller than a half
length. Urnbonal profile obtusely angular; umbones slightly· incurved. very

SOWERBY

Plate 44. Figure 1
18-t~.

Dentalium''ernedei

SowERflY,

Thes.

434.

The Fossils of the Katsuragawa Groupslightly opisthogyrous and a little an·terior in position. Postero·dorsal profile
rather strongly concave. Antero-clorsal
profile gently slant, straight from umbo.
describing a semi-ellipse with anterior
and antero·ventral margins.
Ventralmargin strongly convex. Posterior end
some\\·hat truncated. Surface ornament·
ed with fine. weak, regularly spaced
concentric threads.
Hinge. which is comparatively wellpreserved in one specimen consists of astraight anterior row of 25 or 26 denti·
cles and a concave posterior row of 21
denticles. Chevron-shaped teeth form aslightly obtuse angle below the umbo.
Adductor scars and pallial line obscure.
Dimensions:Sp.3cimen
holotype
no. 2
no. 3

length~-55 em
2.36
1. 36

height
1. 3-1 em
I. 28
0.65

inflation
0. 30 em
0. 23

0.20

Remarks:- This species is dis·ti ngu ished from l'ortla!l(/ia ( 1lle{.{ayoldia\
gratiosa IYOKOYA:O.·IA) by the posterodorsal profile bent up.
The present collection contains 15
specimens. 2 of which are bivalved. 3
specimens occurred in Acila· Pa/liolum
assemblage at toe. 2 at Yassawa and theothers in /'m1landia·Cyc/ammina assemblage. ~lost of them are internal moulds.
lkcurrence :-.\1 idclle .ivl iocene. Sh i rnada
formation at the following localities:
locality 2 !Cydammiua·Porl!andia assem·
blage> at Yassawa-the holotype andseveral other specimens in homogeneous
mudstone in association with Rae/a sp.,
!11m:oma optiNI. Cyc!ammina cancellata
and Cyc/ammina aff. ezoeusis (n. sp. ?J ;Joe. 2 u\rila· Pal/iulum assemblagc)-3
specimens in dirty mudstone yielding
Acila dit•aricata. Ennucula sp., Glycymeris
sp.. Pallioum jJecli/Mlmi ta~. Crassa/ellites sp .. J1Jacoma optil'a. Dentalium
L'emedei etc.: loc. 4 at Yassawa-2 speci·287

mens in homogeneous mudstone associated with Cyclammina cmzcel/ata. Cydam·
mina aff. ezoensis. Echinoid gen. et sp.
indet.
Genus Pallio!nm ~[ONTEIWSATO 1884
Subgenus Delectopecten Sn:w.~RT 1930
Pal/io/zmz ( De!ectopecten) peck!zami
taimum ~YoKOYAM:U
Plate -t.l. Figures 7-9
1925. l'ecten lairmzus YoKOY,\\IA. ]our. Col/.
Sci .. Imp. L'nil'. Tokyo. nd. -15. art. 7.
p. 8. pl. I, figs. i!. 9.
1934. Pecten (/'sl'udrmzussium) pecklzami G.-\Eill.
OsE. jour. Geo/. Soc. japan. z·o/. 41. zw.
-186, pp. 125-130. pl. -1. tigs. 1-2.

Dimensions :Sp:'cimen
no. I (left)
no. 2 (left)
no. 3 (left)
no. •I (right)

length
1. 05 emheightI. 07

0. 97 em
0.97

1. 35

1.11
l. 07

Remm·ks :-5 specimens. including aright valve. are at hand. Their ill pre·servation does not admit any detailed
observation. The right valve. hO\vever.
shows irregular concentric undulations
and seemingly lacks radiating lines. The
left \'aiYes are similar to the right except for the flat anterior ear. They area little longer than high. These specimens closely resemble the type specimenof Pecten taimnus YoKOYA~I'It\. They are
longer than Pa!liulwiz peckhami (GABB)of North America.
Typical Pal/io/um peckhami (G.\BB)
occurs in the Pacific Coast of North
America. The materials of '' Pa/liolum
pecldiami ·· and the species allied to it
abundantly occur also in Japan. For
these materials seYeral species ,,·ere proposed (ex. Pecten tairanus YOKOY A:\IA,
Pecten peck!urmi GAIIB, Pecten 1mtanabei
YOKOYA\IA. Pecten beshoensis KURODA),

Munemitsu SUGITA~88

while 0'.!0~1 and lTTASHIRO (1951) contended that they must be united into one
species. The writer regards tentativelr
Pecten tairrmus YoKOYAMA as a subspecies of pecllllllmi.

Genus Clenwntia GRAY 18-17

Clementia (s. s.) nakamurai OTUKA
Plate ·1·1. Figure 12
1925. Clementia speciosa YoKOYA~t.>,. ]our. Fac.

Sci. Imp. Unil'. Tokyo. sec. 2.ml. 1. pt. 3.

Genus Lucina LA~IARCK 1799

Luciua cf. steamsiana OYAMA
cf. 1927. Loripes philiPPiana (REt·:n:). YoKO·
Y.>,:-..tA, jour. Fac. Sci. Imp. Unir. To-

kyo. ser. 2. vol. 1. pt. 10, p. 434. pl.
L. figs. 1-2. (non REEVE)
cf. 1954. Lucina steanzsiana 0YA:I.IA. in T.>,KIand OYAMA, Pal. Soc. japan Sp. Pap.
2. p. 52, pl. 47. ftgs. 1. 2.
cf. 1959. Lw:inasl!•amsiana0YA:I.IA. Ktt~A.Col.
IlL Shells, Japan, p. 13-1. pl. 53. fig.

.

Dimensions :length

height

2. 6 em

2. 2em

2.8
2.5

3. 0
2. 7
3.4

2.8

1938. Clementia mzkamurai On;KA. ]our. Fac.

Sci. Imp. Unit•. Tokyo, sec. 2. z·ol. 5. pt.
I, p. 14. pl. 1. fig. ·l.

Plate 'II. Figuress 10-11

specimen
no. 1
no. 2
no. 3
no. 4

p. 119. pl. 14, flg. 7. (non YotWYMIA.
1923)

inllation
0. 'i em
1.2
0.;
1. 35

Remarils :-~fany specimens werecollected. most of which are, however, so
strongly deformed that their exact identi·
fkation is difficult to be made. Theircommon characteristics are as follows.
The shell is rather strongly inflated.
The postero- and antero·dorsal margins
are subhorizontal. The straight antero·dorsal margin forms a right angle withthe anterior margin and merges with itin a rather sharp curve. From these
aspects the specimens are provisionallycalled Lucina cf. stearnsiaua.
Ocwnence :-1\liddle Miocene. Shima·da formation at the locality l (Jakotsu·zawa) on pebbly mudstone associatedwith ]oanisie/la sp .. Pitar? sp., Fenempis
sp., Papllia sp., Clementia nakamurai,
C/emeutia vathe/eti, etc.

Dimensions:length
4. 5 emheight4. 9 eminflation
1. 5cmRemarks :-A solitary specimen at
hand is similar to Clementia l'aflieleti
MABILLE. In this specimen. however, thepostero-dorsal margin forms a smaller
angle with the antcro·dorsal margin thanin C. ratheleti. The postero-dorsal margin
is arcuate in C. vatheleti. but straight inthis specimen. The latter is more pro·
duced in the ventral side if comparedwith the former. These char-acteristics
are all common to C. nakamurai. By
this reason this specimen can safely be
identified with C. nakamurai.
Occurrence :-\Iiddle Miocene. Shimada formation at the locality 1 (Jakotsu·zawa) on pebbly mudstone associatedwith ]oa11isiel/a sp., Pilar? sp .. Venerupis
sp .. Paphia sp., Clementia mtlzeleti. etc.
Genus Cyclammina H.B. BR.-\DY, 1876

Cyclammina aff. ezoensis ASA:\O(n. sp.?)Plate 4-1. Figu~es 13-15

Description:- Test large, compressed.
planispiral, composed of two or three
volutions. evolute-penultimate volution
well exposed in the umbilical region:
periphery sharply angulated in aperturalview, remarkably lobulated in side view;
chambers eleven or so in the last whorl.
sutures distinct, depressed. sigmoidal; last

434.

The Fossils of the Katsuragawa Groupchamber especially large; wall arenace·ous. surface smooth; aperture inobserY·
able because apertural faces are broken
in all specimens at hand.
Dimensio11s :specimen
no. 1
no. 2
no. 3
no. 4

number oflargerchambers diameter
5.3mm
12
13
4.8
11
4. 5
11
4. 8

smallerdiameter
3.5mm
3. 1
3.8
3 5

Remarks :-These specimens are dis·tinguishished from the various spcci('Sof G)·c!ammia by its lobulated peripheryand its evolute test. C. ezoensis ise\·olute. but this form is more evolutc.
Occurrence :-l\liddle Miocene. Shima·da formation at the following localities;
loc. 2 (Port!alldia·(vdammilla assemblage!
in '{ assawa on homogenous mudstone
associated with Portlmulia tsuruensis.
Raeta sp.. .11amma optiva. Cyclammiua
cance!lata : loc ..J in Yassa wa on homo·
genous mudstone associated with Pori·landia tsuruel/sis. C. crmcellata. Echinoidsp.

Bibliography
AsA:-;o, K. (1951): Illustrated Catalogu.o> ofJapanese Tertiary Smaller Foraminifera,
pt. 10. p. 5-7- - (1951) : Recent and Tcrt iary Cy!ammina
from ]:!.pan and the Adjacent Regions.
Short Papers. IGPS. no. 3. p. 13 2-1.
Fna.:n.\. 0. and S1u:-;oK1. R. (1952) : Strati·
graphic:-.! ::~nd rvlkropalcontological Study289

of the Nishikatsura Group. four. Ceo!.
Soc. Japan. 1'0/. 58. 110. 681. pp. 191-1~5.
HA:-;AI. S. (1927) : Studies of Topographr
along the River Katsura. Tlte (;eographi·
cal Rm·iew of Japan. 1'0!. 3, no. 8. pp. 173-189.
HEDGI'ETII, JoEL W. (Editor) (1957): Treat·
ise on ~Iarine Ecology and Palaeocology
Yol. 1. Ecology. Geo/. Soc ..i.merica . .1Iemoir
61.
KJRA, T. (1959): Colored Illustr::~tion5 of theshells of Japan.
KoHAY.\SIII, T. and his students (19-13): Geology of SeYeral Localities in the Kwanto
Mountainland. four. Ceo!. Soc. Japan. l'OI.
50. /10. 600. pp. 22\J-2-ll.
Kt'ROD:\. T. and HAllE. T. (1952): Check
List of Bibliography of the Re~.:ent Marine
Mollusca of Japan.
l\IJTst·c111. T. (1929) : Geological i\lap ofJapan. Hachioji Sheet (Scale 1:75. 000),
Geol. Surv. of Japan.
- - (HI32) : Explanatory Text of the Geological .Map of Japan. llachioji Sheet.
Scale l : 75000.
0YA\L\, K. (1952):
Palaeoecological Studies
on Pectens. Jliist:illaueous Rep. Res. Ins!.
Natural Resources. 110. 25. pp. 24-30.
- - (1~152) : On the Vertical Distribution of
1\Iarine Mollusca.
The Venus, I'OI. 17.
no. I. pp. 27-35.
S1·:K1. T. (1937): On the lwatonoyama Conglomerate. four. Geol. Soc. ]aptm. t·ol. 44.
110. 530. p. 1000-1008.
SHIRAI. T. (1959) : Tertiary Cyc/ammiua fromJapan. The Cenozoic Researclt. 110. 30. pp.
40.
TAKI. I. and OYA\1:\, K. (1954): i\L-\TAJIROYoKOYA\IA's .. The Pliocene and Later
Faunas from the Kwanto Region in Japan."Pal. Soc. japan. Spec. Pap. no. 2.

291l

lvlunemitsu SUGITA

Explanation of Plate 44
Fig. 1. J)nztalium (Fissidenlalium) z•emedei SowER BY
Joe. 2. Yassawa. x L 5
Figs. 2-6. Portlandia (Jlegayolciia) tsurumsis ScGITr\, n. sp.
2, 3: Joe. 4. Yassawa. x2
4, 5, G: Joe. 2. Yassawa. xl.5 (4. :i: holotype)Figs. 7 -\l. Paltiolum (Deledopecten) ftr!.:khami tairamtlll (YnKoY.-\:\1.\)Joe. 2. Yassawa, x2
Figs. 111-Jl. Lucina cf. steamsia1w OY,\'.JA
Joe. I. Jakotsuzawa. X 1
Fig. 12. Clementia nakamurai 0TLTKA
Joe. 1. Jakotsuzawa. x 1
Figs. 13-15. Cyclammina aff. ezoensis As.-\:'\0 (n. sp. ?)Joe. 2. Yassawa. xlO
Figs. 16-17. Cyclammina cancel/ala BRADY
Joe. 2. Yassawa. X 10

SUGITA:

Fossils in Katsuragawa Group

Plate 4414

17

Trans. Proc. Palacont. Soc. Japan. N. S .. No. 47. pp. 291-291. Pl. 45. Sept. 10. 1962.

H5.

CHEVRONS OF GLYCY:\'lERID SHELLS~SJ-IOZO HA YASAI\A
Institute of Geology and Paleontology,
Tohoku Ur:iversity

surface· and in thin section. of the (;/y·cymeris shells. In this regard. the writer
has paid particular atlention to examin·
ing the .. chevron-type" lOWE:-;. 1959)
ligamenta! ridges.
In this article arc given the resultsof observations on the ligamenta! chevrons as an important character of glycy·
merid shells: by means of these observa·
tions the peculiarity of the Sasage speci·
mens has been understood. Special em·
phasis is given to that the increase in
number of ridges is independent of therate of increase in shell size but is close·
lv related with the age of shell·fishcs,~nd consequently the number of chevron·type ridges can be taken up as an age·determining character.
Here the writer expresses his hearty
thanks to Professor Kotora l-IATAI of theInstitute of Geology and Paleontology,
Tohoku University, for kindly supervis·
ing the present work. Acknowledge·
ments are also due to Drs. Tamio KO·
TAKA and Koichiro !viASUDA, both of the
Tohoku University. for their valuablead vices and suggest ions. and to thewriter's father. Dr. lchiro HA Y:\SAKA of
the Shimane University for his encour·
agement and criticism.

Introduction and Acknowledgt•mcnts
It is known that some of the forma·tions of Pleistocene age in the Boso Pe·
ninsula. Chiba Prefecture. yield abundant
glycymerid shells. Among them. t~hespecimens of Glycymeris yessoens1s (SO·WERHY) from the Nagahama Gravel at
the sea-cliff of Sasage. Osawa·cho, Kimi·
tsu·gun. Chiba Prefecture have fairly
large and thick shells with peculiar Jiga·
mental chenons.
For paleoecologicalconsideration it is of importance to under·
stand whether the large size of the
Sasage specimens is due to the extra·
ordinary growth of normal form (unusu·
al longevity\ or represents merely thenormal adult stage of gigantic form
caused by the unusual rate of shell de·vclopment. For this purpose. discrimi·
nation of the age determining characters.
for example. the genuine annual rings-excluding the other rings such as " dis·turbance rings" of Owro~ (1926. fide
1-IAY!\SHI. 1955) is most convenient. It is
usually difficult. however. to distinguishthem near the shell margin on the outer* Received Jan. 10, 1962: read at 19th:\!eeting of the Palaeontological Society on
2·1th Sept .. 1961 at Kanazawa.
291

2fl2

Shozo HA YASAJ{A
Observations on the ligamenta!
chevrons

Chevron-type ridges or grooves on
the triangular ligamenta! area between
the beak and the hinge line of the glycymerid shells have usually been accepted as one of the fundamental specificcharacters. Generally, however. they
have been taken into account only as
to number and strength observed in theapparently adult specimens; there are
only a few authors who paid attention
to their morphogenctical significance.
such as variability, mode of development.
origin of the chevron-type ligament andSO on L\IAK.IYA:\!A, 1930. 1952; OWEN,
1959).
Obserying the morphological featuresof the ligamenta! area. the following
several points have been recognized. Except for l'estita. a/bo!ineata, reevei, uaka·murai and ciss!zuensis of which triangularligamenta! areas are flat and smooth
after the removal of the chevron-type
ligament materials, the line connecting
the apices of the chevron-type ridges isusually biassed posteriorly in accordancewith the degree of lateral asymmetry ofshell outline, and therefore. the ligamenta! ridges are not equal in numberin the anterior and posterior ligamenta!
areas. For example, in most specimensof rotunda, yessoeusis and Pilsb1yi theligamenta! ridges on the anterior partare one more in number than those on
the posterior. In the Pliocene species
nippouica, a rather small and highly triangular shell, the above-mentioned median line is extremely biassed posteriorly.
and the number of ridges is quite different in the two parts of area (Pl. 45. figs.
4. 5). This does not seem to have any
relation to the asymmetry of the shelloutline. but seems to be an fundamental

character of this species. because someof the lopotype specimens and all the
specimens from the three different localities in the Northeast Honshu have thisvery character.

A
B

Text-fig. 1. Diagram :>howing the three
types of profile of the ligamenta! cheYrons(ridges and grooYes).
Table 1. The breadths of ligamenta!
chevrons and the types of profile of ligamenta! area in eight different species ofGf.,•cymeris.
Species

Breadth (mm)of cheHon

Type ofprofile*goro/wensis
matumorieusis
uipponica
pilsbryi
rotunda/otomiensis
yamasakii:ressoensis

1.0±
0.7-0.8
0.3-0.4
0.3±
0.4-0.5

A?
A?

c
C-A.
B.C

0. 4±

A-C

0.-1-0.5

A-C

0.6-1.0

B-A

The breadths of the ligamenta!
chevrons in the species concerned areshown in Table 1. For convenience. thebreadth of each set of ridge and groove
was measured. So far as the specimens
dealt with here are concerned, the breadth
ranges from 0.3 to 1 millimeter. and appearing to be rather constant in eachspecies. Generally speaking, the breadthvarie.; correspondingly to the shell size

* Diagrammatically shown in Text-fig. 1.

435.

Chevrons of Glycymerid Shells-of each species in the adult stage.
Of the shape in profile of ligamenta!
area of the treated species, three differ~ent but mutually related types arc rccog~
nized (Text-fig. 1). The type of profile
seen in each species is shown in Table
1. Generally, two types are observed ineach species. This character is rather
variable according to growth stage andspecimen-group( population) among others
even in the same species. It is notice·able, however. that the most fundament·
a! is the type A, from which the othertwo types. B or C. are derived.
As the result of the foregoing ob·
servations. it should be noticed that
although there are hardly any percepti·
ble morphological feature of each species.
the breadth of the ligamenta! chevron
and the shape in profile of ligamenta!
area are criteria worthy to note in thespecific descrit>tion of the glycymerid
shells.

cies. the shell size is represented by thevalue of length x height (both in mm).
The number of ligamenta! ridges is re·presented by the number in the anterior
half of the ligamenta! area. The asscm·
bly of the points obtained by such a pro·cedure can be considered to represent the" growth series.. of each species fromeach locality. The specimens here treat·
ed are of G. pi!sbryi, G. rotunda and G.
yessoensis. and all are from two consecu·
ti\'e formations of Pleistocene age atthree different localities in the Boso
Peninsula.
As shown in Text-fig. 2. 11 the rateof increase of ligamenta! ridges referring
to shell~size development is fairly differ·

10

B

w
N

Developemnt of ligamenta! chevror.s

(ii

lO

.J
.J

d 1 Ontogenetic significances of the liga·
mental ridges.
It is well known that the number ofligamenta! ridges increases with thegrowth of shells. i.\IAKIL\:\1.-\ 119301. who
first studies the correlation between theshell size (length) and the number ofridges forming the ligamenta! chevronsof glycymerid shell. pointed out that
there is a case where the correlation
appears to differ in two specimen-groupsof the same species from two different
localities.
The writer attempted to make agraph showing the relation between shellsize and number of ridges of the speci·
mens at hand representing a few differ·ent species. To avoid the factor result·ing from the difference in proportion ofshell outline duC' to the difference in spe·

~

1

I

•

10

II

12

NUM8£R OF LIGAMENTA!.. RIDGES

Text-fig. 2. Graph showing th:;: rela·tionships between the number of ligamenta!
ridges and the shell size in three different
sp:cies of Glycymeris.
A. G. yessoeusis (SowER flY) from the Plei·
stocene Yabu Formation at Azu. Ichi·
hara-gun. Chiba Prefecture. (:\=43)
B- G. rotwula (DL':>:KER) from the Plei·
stocenc Jizodo Formation at Izumi·
yatsu. Ichihara-gun. Chiba PreL:cture.
(X=25)
C-G. pil.~bryi (YoKO\':\~IA) from thesame Formation as above at J iz6do,
Fukuta-cho. lchihara-gun. Chiba Pre·
fccture. (~ =·li)

~!J.J

Shozo HA L!S..U\A

ent from species to species. that is. in theorder of pi/sbl:vi>rotunda>yessoensis, but2) each curve on the graph assumes theforrnof the typical or sigmoid growth·
curve. and shows that there exist. in thegrowth process of each species. twophases, namely self-accelerating and self·
inhibiting; and at the same time thelimit of shell growth is shown. The
growth limit seems to be consistent withthe habit of growth lines which become
closer towards the ventral margin of theadult shell.
It rarely occurs that the point representing the correlation between shell size
and number of ridges extremely deviates
in position on the graph from the general tendency of the species concerned.
In all cases. however. it indicates therelation that the number of ridges is
extremely large in comparison with theshell sizl'. and no inverse relation has
been encountered. Through the exami·
nation on each specimen showing such a
deviation. it has been recognized thatthe growth lines arc much more closely
developed than in the other speci·
mens or nearly the same sizes (Pl. 15.
figs. 8. 9•. and consequently the shelldevelopment of it might have been abnormally suppressed for some reason.
Therefore. it seems plausible to assume
that the above-mentioned deYiation is
the result from that the ligamental
ridges had increased in number independently of the suppressed rate of shell
dewlopmcnt.
Judging from the foregoing. it canbe considered that the rate of increasein number of ligamenta! ridges is rather
constant in comparison with that ofshell size. and is assumed to benearly parallel to the age of the shell·
fishes. To scrutinize whether it is correct, it is necessary to examine the cor·rclaiton between t·he number of ridges

and the true annual rings. But unfortu-nately. the descrimination of true annual
rings is usually difficult as already men·tioned. Thereupon, the wri tcr has used
the .. sectioning method" of l-IAYASIII.
(1955) for age determination (Pl. 45, fig ..
6). According to HAYASill, the numberof subconcentric lines observed in thethin section of the molluscan cardinal
plate corresponds to that of the annual
rings of the shell. and it can therefore
be regarded as one of the age determining characters.
For this observation,.
staining by water soluble eosin is effecti\'e. The results are graphically shownin Text-fig. 3.* where the correlation
between them is represented by a st·raight line {con·elation coefficient: 0.96).
Consequently. the number of limamental
ridges can be regarded as of age-parallel
and to be an indicator of growth stagesof glycymerid shells.
l2i Shell-size of each specimen-group in
relation to the number of ligamenta!
ridges.
As it has been made clear that the
number of ligamenta! ridges is an inclicator of the growth stages, the curves
on the graph showing the relation be·
tween the shell-size and the number ofridges can be regarded as the so-called
growth curves.
Between several specimen groups of
G. yessoensis from various localities andhorizons. considerable differences in therate and limit of shell-growth arc recog·
nized tText-fig. 4: Pl. -!5, figs. 1-3). On
th:- other hand, however. in the selfaccelerating phase of shell-development all the specimen-groups represent* Although it is unknown, concerning G/yr:ymeris. whether the lines obs;:rvc:d in the
cardinal plate arc of annual origin or of theseasonal, il can he safely regarded as a biologic:tl scale of growth stages.

435.

~

Chevrons of Glycymerid Shells

20

z

::J
5::2
~

z
~
z

15

0

(.)

m
:::>

x

10

X

..J

(f)

IJ..

0

a::
~

5

~

:::>

z

0

f
e

NUMBER OF LIGAMENTAL RIDGES
Text-fig. ::!. Graph showing the relationship between th<.: number of ligamenta!
ridges and the number of subconcentriclines of growth observed in thin section ofcardinal plate (see Pl. -15. fig. fi). Glycymeris
yessocusi:< (So\\'EIWY) from the Plci~tocenc
Yabu formation ;,t t\zu. lchihara-gun. Chiba
Prcfcctun;. (N=:~3)

nearly the same ,-alue of the shell-size
against the number of ligamenta! ridges.
i.e .. similar courses of development. And
the same relation is also recognized in
specimen-groups of G. rotuuda ~Text-fig.
5!. Consequently the relation between
the shell-size and the number of liga·
mental ridges is considered peculiar tothe species as the self accelerating phaseis concerned.
Among the four specimen-groups
shown in Text-fig. -!. the Sasage speci·
mens represent the extreme!~, high limitof shell development in comparison withthe other three. Uut the numbers ofligamenta! ridges near the growth-limit
arc nearly equal (10-11) to that of theShibikawa specimens which have a low·

NUMBER OF LIGAMF.NTAL RIDGES

Text-fig. 4. Graph showing the relationships between the number of ligamenta!
ridges and the shell size in three different
specimen-groups of G. yessoensis.
A-Sasage Coast. O~awa-cho. Kimitsu-gun.
Chiba Prefecture. Nagahama Gr:n·et.
Pleistocene.:. (N = 41)
B-Azu. Ichihara-gun. Chiba Prefecture.
Yabu formation. Pleistocene. (:\=-13)
C-Anden Coast. Oga City. Akita Prciecture. Shibikawa Formation. Upper
Pliocene. (:'\=i5)

est rate of growth and the smallest sizes.
Therefore. the large size of the Sasage
specimen is judged to be due not to thelarge longevity as seen in the case ofbank-building Ostrea giJ;as TtWNBERG(HA YASAKA, 1960) but to the much more
rapid rate of shell development which
seems to be consistent with the great
thickness of the shell. Because or the
deficiency of specimens, the abovc·statedShozo l!AYASAKA

29()

results can not be examined in compari·son with the Recent ones. but a compari·son with them from various localities orenvironments will serve as a basis forconsidering their paleoecological meaning.

A(3) Helation between the convexity of

""
N

u;

10

shells and the rate of shell-develop·
mcnt.
The mean values of I he convexityof the shells in each specimen-group areshown in Table 2. In this table, the

.J
.J

""05

/

.

'

t

tO

"

It

ll

NUMBER OF LIGAMENTA!. RIDGES

Text-fig. 5. Graph showing the relationships between the number of ligamenta!
ridges and the shell size in two different
specimen-groups of G. rotuuda.
A-Ninomiya. Naka-gun, Kanagawa Pre·
fecture, Ninomiya Formation. Upper
Pliocene. (N =25)
B-Izumiyatsu. Ichihara-gun. Chiba Prefecture. Jizodo Formation. Pleistocene.
(N=25)

Table 2. The mean values of the convexityof shells in each sp;;:cimen-group.
Spo:c:.:ies
yessoensis
yessoensis
ro/111ula
yessoensis
pilsbryi

I

Specimengroupl\lean value ofshell-convexity

Sa sage
Azu
Izumiyatsu
Shibikawa
Jizodo0.528 (N=41)
0.661 (N=-!3)

0.682 (~=25)
0. 73-! (.\' =i5)
l. 566 (N=47)

Explanation of Plate 45(All figures are in natural size except for the fig. 6)
Figs. l-3. G!_w:rmeris yessoensis (SoWERBY).
Showing the difference in size between thespecimens representing the three different specimen-groups. which are equal in numberof the ligamenta! chevrons with each other, and therefore, of nearly the same growthstages. la-b. Anden Coast, Oga Cit}', Akita Prefecture, Shibikawa Formation, Upper
Pliocene; 2a-b. Azu. lchihara-gun, Chiba Prefecture. Yabu Formation. Pleistocene; 3a-b,
Sasage Coast. Osawa-cho. Kimitsu-gun, Chiba Prefecture. Nagahama Gra,·el. Pleistocene.
Figs. -!-5. Glycymeris nipponica (YoKOYA~IA). The median line of the ligamenta! che\rrons isextremely biassed posteriorly and the number of ridges is quite different according to
the area, anterior or posterior. 4a-b. Sawane. Sado Island. Niigata Prefecture, Sawane
Formation, Pleistocene; 5a-b, Sea Coast at the south of Kanita. Higashi-tsugaru-gun.
Aomori Prefecture, Pliocene.
Fig. f). Thin section of cardinal plate of G!ycymcris ycssoensis (SowERBY) from Azu. in which
the sub-concentric lines of growth are observed. The results of observation on the Azu
specimens are shown in the Text-Jigs. 1. 2 and 3. (x17)Figs. 7a-b. G!ycymeris pi!sbryi (Yoi<OYAT\IA). Specimen from ]izod6, Fukuta-cho. Ichihara-gun.
Chiba Prefecture. Jiz6do Formation. Pleistocene.
Figs. 8-9. Glycymeris rotunda (IJL::-:KER). Comparison between the normal (Figs. Sa-b) andabnormal (Figs. 9a-b) specimens of nearly the same sizes, showing the differences inconcentric growth-lines and in number of ligamenta! ridges. Both specimens are from
Izumiyatsu, lchihara-gun, Chiba PrefeCture, Jiz<ido Formation, Pleistocene.

H ;u -AS, !KA :Chevrons of glycymerid shetls

Plate 45~,

- --- J .,

lb

2a

2b

5b

KU MAGA I

photo.

Sa

9a

Sh

9b

435.

Chevrons of Glycymerid Shells

convexity is represented by the valueof Depth/Length x Height. and the specimen groups of the same or the different
species are arranged according to therate of shell-de\·elopment.
From the above table. it is easily recognized that the more rapidly the shellsize increases. the less is the shell-convexity among either the same species ordifferent species. This suggests that themode of shell-secretion may change \Viththe rate of shell growth.
Summary1) There has been recognizedthrough the observation both of surface
and in profile little difference in the morphology of the ligamenta! grooves andridges, but the peculiarity to each species
occur only in the breadth of grooves.
2) The rate of increase in numberof ligamenta! ridges is nearly parallel tothe age of the shells. and consequently
it can be regarded as an indicator of thegrowth stages.
3i The specimen-groups of Gf\•cymeris yessoensis from various localities
and horizons have their own growthlimit of shell size. and the numbers ofligamenta! ridges are almost equal near
the growth limit.
1\ The growth curves of several
specimen-groups of the same species fromvarious localities appear to have branched off from a common trunk, and therefore. concerning the self-acceleratingphase of shell-development, the relation
between the shell-size and the number ofligamenta! ridges is peculiar to thespecies.

2915) It is recognized that the more
rapid the shell-size increase. the small·er the shell-convexity among either thesame species or different species.
6) The large size of the " Sasage
specimen " is judged to haYe been re:;ulted not from longevity, but from themuch more rapid rate of increase inshell-sizes which seems to be consistent
with their striking thickness.
7) For lack of specimens. the above,;tated results could not be comparedwith the Recent ones, but a comparison
with them from various localities orenvironments will serve as a basis forconsidering their ecological meaning.

References cited
I·IA YASAK.\, S. (1960) : Large-sized oy~ten;from the japanese Pldstocene and their
paleoecologica; implic:nions. Sci. Rep. Tolloku Unit>., 2nd Scr. (Geol.). Spec. Vol ..
So . .J. pp. 356-370. pis. 37-38. 7 text-figs.
liA Y ASH r. T. (1955) : Studies on th(; age de·t~rmining characters of the shdl-lishes.
I. Observation by sectioning of the shell(l). Bull. Hohkaido Regioual Fish. Res.
L'!b., no. 12. pp. l-6. text-figs. 1-3. pb. 1.
2.
M.-\KIY.-\~IA. }. (1930) : On th:: y:uiation ofth,; fossil Gl.H:rmeris yes.~oens:s. The Venus,
mi. 2. 110. 3. pp. 107-116, te!xt-figs. 1-3.
tab!;;:; 1-3. 1 pl.
- - . (1932) : On th: muntion of the fossil
G/ycymeris rotunda. Trans. Proc. Palaeont.
Soc. fapau. N. S .. no. 5. pp. 131-138. t"xt·
figs. 1-5. tables 1-7.
OwE:-:. G. (1959) : The ligam<.:nt and digestivesyst:.~m in th;; Taxodont bivalv·.:s.
Proc.
Mdac. Soc. Lon doll. t•ol. 33. pt. 5. pp. 215:!23. ligs. 1-7.

Trans. Proc. Palacont. Soc. Japan. N. S.. No. ·17, pp. 298-300. Pl. 46. S..:pt. 10. 1962

4:~6.

ON THE GENUS CARPINUS WITH DESCRIPTIO~S
OF TWO NEW SPECIES*SEIDO ENDOTokyo National Science Museum

f:t.1;vt::'~.7.J /li.W:-::>PT:6~<:>2!frJ.ll\:l)~c~:
C. c ::." cf:t.1;vi::.'~.7.J 05/.~fll!li~940ftJs-0:f.1:<:ft.$£f;l<:rlli L-. -i:-0).*$7}1;1:7 ::17 :lti!CEJ;l~ L-:lt.~.:-8-11U1l!c 3 - o ·:;'':lt!IC~-7-

f!i!~ ~ -rt '-0,:/&b~Po{t.Ef!Hi~ 80 .fill <Is 'J.tfi~t'f;!C~M "? -rilf~1li L-. -;t,·~-=-~~IC!;t!J;tJ: \ J:f:JNfri!tiC~<:f!l!;;£-~).lljj- {,C. cl;l:miffi-z:j) {);6{, W{it]\{~jiC:~ "? L"ill5.!1J'2: ;h,i.L@;*ggO)=1iliCD,j-\[g{;t 3 ~!:tJ: "? 'L~ '-0 ;;j{} :/7 ffiO) b O){;t),j!~O) '!_,0);61~~ 'o B;j>:O)J:./ljl¢~!!t~O).il!!l!b';,.; 3 ~O);J,T!JO) !t.E:f.l>§~~ <HL. k-Q) m..tl11iJD:)i·:~O) b 0) IC .t ( {l;tn' Z>, :lt.ifijc@:O)l.:Jt•N!UJ>;~L-OtJ!i!:nt.:'J'~{;t:}/;1P,!U],~tJ:t,O)<:tlJ.5t:~c.\P.:b~tJ.)

The existing species of the genus
CmjJinus are about 40 in number. all ofwhich are limited to the northern hemi·
sphere in its distribution: many of them
now exist in east Asia.*·~ There are only
two species now exist in North America
and Europe. In well developed involucres.
both of the American species, Cmpimts
caroliniana, and the European species.
CmjJimes betulus are trilobed. while inthe many Asiatic species are generally
simple with some of the exceptions. forexamples, C{//pinus tientaiensis, C. Iondo·
niana. C. poilanei. C. lanceo/ata. and C.

* Recdv"d Jan. 26, 1962: read Jan. 20.
1962.

** 22 species exist in China (Among these
species. 3 spedes nrc common with Japan.)5 species exist in Japanese Islands.
7 species exist in Korea. (Among these
species. 2 species are common with Japan.
one species is common with Manchuria andNorthern China. respectively.)
5 species exist in Taiwan.
4 species exist in Central Asia.
1 species exists in Atlantic North America, Europe. l\-Ianchuria and Northern China.
respectively.
2~l8

ii

~

~

j£!

laxitlora. etc. The geological records areabout 80 species from the Eocene to the
Pleistocene (BERGER. 1953: SAJ{GE:-\T,
1916; H u and CmJN. 1933: 'VV!:-IKLER.
190-l). in age. and reached its maximum
development in the l\liocene age: and in
the Palaeogene age. the reliable records
arc comparatively rare. The involucresof Carpinus grandis UNG. (KRAUSEL. 19l9,
pl. 3. f. 4, pl. 9. f. 2) are similar to
Cmpiuus wroliniana. and Carpinus lzons/mensis (E;-.;no. 1950. p. 56. pl. 6. f. 6)
from the lower Pliocene formation of
Kawanishi·mura. Yama·gun. Fukushima
Prefecture is also similar to Cmpinus
caroliniana. Our l\liocene species Carpinus
nipponica 1E;-.;no. 1950. p. 53. pl. 6. f. 8)
from the upper Miocene of 1\ishizawa,
Al<iu·mura near Sendai. japan. is rather
similar to Cmpinus belulus than Cmpinus
camliuiana.
In short. the similar fossils to Cmpinus
caroliniaua and to Carpiuus betulus existed in the ;\Iiddle Tertiary period (theupper :\Iiocene or the lower Pliocenei atthe northern Honshu of Japan. while C.
caroliniana now exists only in the south·
eastern North America. and C. betulus in

436. On the Gem1s Carpinus
the middle Europe to Persia.

Carpinus Shimokmmrai E:--:no, n. sp.
Plate 46. Figure 8

Cmpiuus Talwoi ENDO, n. sp.
Plate 46, Figure 6

Description :-Involucre ovate in shape.
about 0.8cm. long, and OA em. in maximum width. apex acute. base rounded ;margins roughly serrated; stipc and seed
not preserved. Texture coriaceous. Primary nerves 5 in number craspedodrome,secondary nerves thin and obscure. Areolation thin. meshes quadrate or polygonal.
Remarks :-It is not always easy to
distinguish the every species from thefossil leaves of genus Carpinus. but
it is sometimes easy to identify the
species from the involucres. Thl' in,·o] ucres of Carpinus japonica fJL. aresomewhat similar to the present one. but
the latter is smaller than the formers.
Another allied one is the simple (notlobated) involucres of CarjJinus !axU7ora
I3r.. but these are larger than the present
one. Some of the simple (not lob;tted)
involucres of C[npinus caroliniana WALT.
are another likely one. but the present
involucre is thinner and smaller than theformers.
As already stated. the fossils of
genus Carpinus occur from the Eocene
to Ph:istocene in age. The present in·volucre may be the progenitor of Cmpinus
japonira. because its leaves occur fromthe same horizon of the Ishikari group,and because it is very simple. smallest
and similar to the involucres of the
Miocene Carpinus protojaponica (E~oo.
1950. p. 52. pl. 6, f. 2) which are alsosimilar to those of Carpinus japonica.
Lomlity :-The river bank of Lhe Yu·bari RiYer. Shimizusa\\'a. Yubari·citv.
Hokkaido. japan.
·
Horizon :-Woodwardia formation.

299

Description :-Leaves oblong-ovate tolong-ovate in shape, length 13cm.±,width 3 em.± ; apex acuminated. baserounded. petiole not preserved; margins
finely duplicate serrated. teeth extended
into slender spines; midrib slender andstraight. secondary nerves numerous.
closely spaced. slightly curving upwards,
parallel, 20 or more pairs. subopposite oralternate. arising at ca. 40' in the middleof the leaf, the angles slightly moreacute below. extremities bearing 1 or 2
small abaxial branches. branches entering second order teeth; tertiary nerves
irregularly percurrent; areolation rather
coarse. Texture subcoriaceous.
Remarks :-The present material issomewhat similar to the existing CmPi·
nus japonir.a BLU:\IE. but the former
much longer than the latter. Anotherallied species is Cmpinus fmtema LES·QLIEREUX.
which was described by
LESQUEREIJX (1883, p. 152. pl. 27, f. 12141, from the Oligocene of Florissant,Colo .. U.S. A. (i'viACGt:--:tTIE, 1953. p. 97,
pl. 26, f. 1-31. It may be probably theprogenitor of the existing Carpinus
japonica IlL.. because the involucre of
the CarPinus Takaoi ENDO occurs fromthe same horizon of another locality.
The involucre of Cmpinus Takaoi aresomewhat similar to the young involucres of Cltipinus japonim I3I.lJME.
Locality:- The upper course of the
Enhorokabetsu, a tributary of the Yubari ri\·er. Yubari·city, llokkaido. japan.
Ilorizon :-\Voodwarclia formation.
Literatures
W. (1953). Studicn zur Srstcmatik
und Gcschichtc der Gattung Carpinus.
not. Noli$er 1!153, lliifte 1. Lund.

BERGER.

:300

Seido ENDO

- - (HJ53). Eine neue Carpinus-Art aus dem
Oberol igor.iin des Rhein Iandes. op. cit ..
Hiz/le 3. Lund.
E:--;Do. S. (1940). A Pleistocene flora from
Siobara. Japan. Sci. Rep. Tolwku Imp.
Unit• .. 2nd ser. 21, 1. Sendai.
- - (1950). On the fossil Carpinus fromJapan and Korea. Short Papers, I. G. P. S ..

.Vo. 2.
- - (1955), leones of fossil plants fromJapanese Islands. .. Sangyo Tosho Co.,
ltd."
HEER. 0. (1856). Flora fossi lis Helvetiae II.
lie. II. II. and Cuu:--;. H. (1927. 33). leones
plantarum sinicarum I. III. Shanghai.

KRXt:sEt... R. (1919). Die Pflanzen des Schlcsischen Tertiiirs.
1vL<\CGJ:-JITJE. H. D. (1953). Fossil plants of
the Florissant beds. Colorado. Carnegie

Jnst. Washington Pub .. No. 599.
NAGEL. K. (1916), Betulaccac, Fossilium Catalogus II. 8. Berlin.
SARGEI"T. C. S. (1915). Plantae \Vilsonianae.
Vol. II .
U:-;GER, F. (1852). Iconographia plantarum
fossilium. Denkschr. K. :lkad. d. Wiss.,m:~tluwturw. Kl. 7. \Vien.
WJ:"Kt..ER. H. (190,1). Bctulaceen.
In A.
E:"GLER:
Das Pflanzenreich IV. 61.
Leipzig.

----- -·-------------

Explanation of Plate 46
1. Carpinus caro/iuiatta WALT. (Pennsylvania U.S. A.) x 1
Existing specimen, for comparison.
After \V. BEHGER: (Studien zur Systcmatik und Geschichte dcr G:lttung Carpinus
p. Hi. Aff. 6, F. F. 1953.)
Fig. 2. Carpinus graJI(/is UNG. X 1
After O.HEEr~. (BEER. 0. · Flora fossilis Helvetiac II. p. ·10, F. 12. Pl. LXXII. 1856.)
Fig. 3. 11. Caryinus betulus L. X 1
Existing specimen, for comparison. Alter \V. BEHGER. a. (BERGER. W.: op. cit .. p. 11,
F. D. Abb. 4. 1953.) 11. After A. E:-JGLER. (A. El'o;GLER: Das Ptlanzenreich. IV. 61,
Bctulaccac (H. Wtl'l<t..AR) p. 39. F. G. a. 1904.
Fig. •1. Carpinus pro/ojaponica Exoo. X 1
Afler S. E:--:oo, (E:-;oo. S.: leones of fossil plants. pl. 35. f. 16. 1955. and, On thefossil Carpinus from Japan and Korea, Short Papers J.G.P.S. No.2. p. 52. 1950.)
Fig. 5. Carpinus japonica Bt..l::--.rE. x 1.
After S. E:-.:oo (E:--;oo. S.: A Pleistocene Flora from Siobara. Japan. Sci. Rep/. Tolwku
Imp. Uniz•. 2m/. Ser. Geology, z•ol. XXI, ]\io. 1. p. 55. pl. VI. F. 4. 1940.)
Fig. 6. Carpinus Takaoi Exoo. X ca. 2 (n. sp.)
Locality: The river bank of the river Yubari. Shimizusawa. Yubari-city. Hokkaido,japan.
Fig. 7. Carpinus nipponica E:-.:oo X 1
Locality: ~ishizawa. Akiho-mura. Near Scndai. Japan. (Miocene Age) After S. E:-:oo:On the fossil C'Jrpinus from Japan and Korea. op. cit., p. 53. pl. 6. F. 8. 1950.
Fig. S. Carpinus Shimokau:arai E:-;oo. X 1 (n. sp.)
Locality: The upper course of the Enhorokabctsu river. a triburarr of the river
Yubari, Yubari-city, Hokkaido. Japan.
Fig. 9. Carpinus honshuensis Ei'DO. X 1
Locality: Maki. Kawanishi-mura. Yama-gun, Fukushima Prefecture. Honshu, Japan.
(Lower Pliocene?) After S. E:--;oo. (E:--JDO, S.: On the Fossil Carpinus from Japan, andKorea. op. cit., p. 56. pl. 6, F. 6. 1950.)
Fig. 10. Carpinus tientaiensis CuENG. X 1
Existing specimen. for comparison. After \V. BEHGEH. (BERGEH. ·w.: Studien zur
Syste matik und Geschichte der Gattung Carpinus. op. cit., p. 16, Aff. 6. F. A. 195:t)Fig.

E N DO:On the genus Carpinus

Plate 4G
2

1

4

6

10

11

Trans. Proc. Palaeont. Soc. Japan. N. S.. No. 47. pp. 301-309. Pi. 47. Set>t.. 10. 1962

-t:ri.

VARIATIO);' AND DDIORPHIS~l OF PACHY2V!ELANI.4.
(GASTROPODA) FROM THE EOCENE OF BURl\IA*
TAt\110 KOTAKA
Institute of Geology and Paleontology
Tohoku University
and

SATORU UOZLlr-.11
Dep;:rtment of Geology and i\lincralogy
Hokkaido Uni':ersityc ,~,. 7t/jl'fr*frH/.' P::d1.n1lel:mia (~l!) O)~~c=-~!11: .lt ~- ,~,.-,., tJ v '7 J:XrnO)J:£\;~
w~~~••~n~•*-K*u•aO)~w. M~ft~~~~ =•~O)~a~~L~~. ~fill P<:d:ymelania lwf,·wmw ~mol!,\ L t: o1]\ ll'li R; :}( · ,i.\1. 11:
ffi

Introduction and Aclmowledgements
A number of fo5sil organisms werediscovered from the strata of Eocene age
during the geological survey of the coal·
field5 of Burma at the request of the
1\lineral Resources Development Corpora·tion in 1958. under the direction of Pro·
fessor Rinji SAITO of the Geological In·
stitutc, Kumamoto University and l>r.
Satoru L'ozr:-.11. These strata are deve·
loped in the Kalewa coalfields in northern
Burma. Among .the specimens there wasfound a new species of Lhiarid gastropod,
here described as Padlymclcmia kaleu'l/lut.
The strata which yielded the present
materials correspond to the shallow
water deposits of the "Yaw Shales" or
the Yaw Stage which is characterized
by certain fossil remains indicating the
Eocene age.
'~' Rec;:ived Jan. 26. 1962: read at 80th
Meeting of the Sxi;:ty at Fukuoka: S-.:pt. 18.
1961.

At a glance. the thiarid specimens
seem to consist of two different typesof surface sculpture, that is. one showsa smooth or spirally sculptured surface
and the other a nodulous surface except
on the knife edged spiral keel on theadapical margin of the whorls. How·ever, the characteristics just mentioned
shO\\. gradation from one specimen to theother. This may suggest a certain kindof the sexual dimorphism in one valid
species.
The writers express their deep ap·
preciation to Professor Rinji SAITO of
the Geological Institute, Kumamoto Uni·
versity for his kind permission to study
the fossil gastropod specimens and forthe information concerning their occur·
renee.
Acknowledgements arc also due toProfessor Kotora llATi\I of the Instituteof Geology and Paleontologr. Tohoku
University and Professor .\'lasao iVIIiSATOof the Department of Geology and \lin·eralogy, Hokkaido University for theirencouragement and suggestions. They

302

Tamio KOTAKA and Sr!loru UOZUMI

are also indebted to !VIr. Kimiji KUMAthe photographic \\·ork.

GAI for

Geological Setting
The name. Yaw Shales or Yaw Stagewas first introduced by COTTER (1941a,b) for the fossiliferous rocks typicallydeveloped along the '{aw River. one ofthe principal tributaries of the lrrawad·
ely south of its confluence with the Chin·
dowin RiYer. of the Pakokku District.
In this district the strata of the Yaw
Stage arc all marine in origin and chara·cterized by marine molluscs and Num·
mulite foraminifers of Eocene age. The
lithological characteristics of the ·· 'Yaw
Shales .. show remarkable change lateral·ly. and in the northern- and the northernpart of central Burma the strata containcoal-seams. ancl the marine deposits
wedge out northwards and grade up·
wards into sandstone which has beencalled the Pegu coal-bearing formation,and can be thought to be of the margin·
at facies of the Tethyan sedimentationin the present region during the later
Eocene Period.
In the district above mentioned. thestrata of the Yaw Stage are subdivided
into three stratigraphic units. These
are informally called the upper coal-bearing formation. the middle sandstone. andthe lower coal-bearing formation in descending order, and are underlain with
conformity by the Eocene Pondaung
Sandstone. mostly terrestrial in origin.
The new species is from the Kalewa
Coal \line in the Mawhataung area near
the small tributary of the !vlittha River,
one of the tributaries of the Chindowin
River. The exact horizon of the fossil
gastropods is the upper coal-bearing for·mation (Eocene Yaw Stage) in the Kalewa coalfields of northern Burma.

t..AOS
I
I··+--...

7AI

'

f

- ... _...

........

c .. ~,~lnAIVet
ID·!rrO!ra!MyD~tllc!~A·Irr~yRive·~Cil·I'.GtCNIQI Rlvlt

I

I

LI'

,

(

I

..

,

,~-~\'\,rI\ i~Mt··l.llln&lu'-'C:Mando!oy
P I"'IIc*);u

R:A,ftOOOI\SlFt;St•tona Rlv•r
St~A.SGJ•ur. Al'.tt

)~>'

,,

1

.:

Fig. 1.

-

\I
....

.'

Index l\lap of Burma.

Systematic Paleontology
Family Thiaridae
Subfamily Thiarinae
Genus Pachymelania E. A. S:-.JITH. 1893

Type species (lV!onotypel :- Nerita
aurita 0. F. t\li.iLLER. 1776. Recent, Belgi·
an Congo. Africa.

Paclzymelania E. A. S:-.IITH. 1893, Concho·/agist, vol. 2, pp. 141-142 fuon vidi,fide
WENZ, 1939, p. 7171. : wm WHITE, 1895;

non COSS?.IA:\:'\. 1909).
Claviger HALDE:\IAN:\.1811. Amer.]ourSci.,vo!. 41, pp. 21-23 1110/l PREYSSLER,
1790).
Vibex GRAY. 1847. Proc. Zoo/. Soc. London,

437.

Variation and Dimorphism of Pac/zymelania

ro!. 15. p. 192 (non 0KE:'\, 1815).
Hemipirena RO\'ERETO. 1899, A.tti Soc.
Lingustica. IJO{. 10 (non L•idi. fide
WE:'\Z, foe. rit.).
Clm•igerina ?viARTENS. 1903. JYiss. E1:gelm.
Deutsc/z. Tiefsee-Exp., Ml. 7 (non L•idi,
fide WENZ. loc. cit.).
Itameta IHERING, 1909. Jour. Conrltyl., vol.
57 (non vidi. fide \VENZ. loc. rit.\.
Diagnosis:- According to WE:-.:z11939;. the diagnosis of the genus is asfollows:.. Gchause ma13ig groB bis ziemlich groB.
fcstschalig, g;etiirmt: Umg;ingc mit rnehr
order weniger kraftigen axialen Rippen
und Spira!Hiden. -rei fen. -kielcn oder Hackerunci Knotenrcihen: Mi.indung klein. eifi>rmig.
oben gewinkelt: Aul3enrand obcn eingebuchtet. in der :vlittc vorgczogcn. unten mehroder weniger kurz rinnenartig: Spindel verdickt: Spindelrand mehr oder wenigcr breitumgeschlagen. schwielig;: Deckel schmal. mit
fast geradem Spindelrand. pauci spiral. mit
randlichem. der Basis genahertem Nukleus."

Remarks :-The genus Pac!Lymelania
has hitherto been known only from thewest coast of Africa where it lives in
the lagoons or estuaries. For the reason
the discoYery of the present new species.
Pachymelania kalewmw does not only extend the distribution of the genus. but
also is the first fossil record of the genus.
The species known from West Africa arethought to be direct descendants of kale·
zcana. judging from their ontogeny andzoogeography as will be described in thefollowing pages.
Pachymelania kaleww~a KoTAKA and
UozmH, n. sp.
Plate 47, Figures la-llb

Diagnosis :-Shell medium to large,
solid and heavy, turreted. Protoconchrather small. but details unknown be·cause in all examined specimens lack
nucleus. Post-nuclear one or two whorls
rapidly increasing in size and then gradu·

ally growing. W'horls straight, slightly
convex to concave in profile except onknife edged main spiral keel on adapicalmargin of whorls. Spire rather straight·
sided and composed of six to eight post·
nuclear whorls. \\'horl surface with spi·ral striae or/and more or less prominentspiral row of beads or granules on middle
and adapical part of whorl and surface
sometimes almost smooth. These beads
or granules sometimes composed of moreor less strong longitudinal riblets on
younger whorls. Base of whorls withthree to ten, fine but prominent spiralstriae or cords. Aperture oval in shape.
with more or less prominent anal canalon adapical margin of it or about main
spiral keel. outer lip entire with no sinuous depression. inner lip with smooth
callus, and without siphonal canal on
abapical margin of apenure.
Repositm)• :-Syntypes: IGPS* coiLcat. nos. 79323-1""11 and L. H** Reg.
Nos. 13696 (a-i).
Comparison :-Although the writers
unfortunately could not refer to S!IIITH's
original work, the diagnostic character
presented by WENZ (1930) and I\'rCJ\LES~:1950), safely assign the present specimens to the genus Parhymelania.
The Lype species of the genus. Parhyme!ania aurita UviULLER !, primarily allo·cated to the genus Nerila by the original
author, described and illustrated fromthe coasts of Belgian Congo and Portu·
guese Angola by subsequent authors:PILSBRY and BEQUAERT. 1927. WE:'\2.1939
and NICKLES. 1950) is distinguished fromthe present new species in the surface
sculpture of the whorls. The shell of* Abbreviation for the Institute of Geology and Paleontology, Tohoku University,
Sendai. Japan.
** Abbreviation for the Department of
Geology and Mineralogy, 1-lokkaido University,
Sapporo, Japan.

304

Tamio KOTAKA and Satom UOZUMITable 1.

Specimen No.

forma

Measurements (in mm).

L

I

B

PB

- - - - - -IGPS 1
U.II. a00

43. '1'13. 9

U.H. b

0
0

43. 0
53 5
46.4

IGPS ZIGPS 3
IGPS 4U. H. c~PI~ ~~----R_e_m_a_r_k_s_
8. 9

16. 1

14.7

14.8

(!)

14.8
19. 0

17.0

9. 7

8

47. o
62.4

18. 0
20. 0

12.4
20. 2

9.6
10.7

18.4
15.4

11. 8

U. H.

e - - - Tran· @I
6--l-J.-11.

I

15. 7

47. 0
52.8

IGPS

!sition1

9.8
I 9. 7
I
10.6
8.5
9. 0

e

u. H. dIGPS 5. li. 0
I

I

U.H.

i

IGPS 11
IGPS 12

19.3
19.8

17.0
18. 3

16. 9

-f-----x-1~
X] 7. 4

57. 2·- i 20. 2® I 46. 2

IGPS 7
U.H. g
IGPS 8IGPS 9IGPS 10

18. 9

1<1.2

8. 5

20. 6
18. 5

18. 2

10. 0

X

X

38. 4

X

18 7

X

42. 0
38. 5
37. 3

X

65.2

X

37.6

21. 2
12.3

X

1

16. 0

14. 3
14.6

younger whorls andbase lacking

aperture broken

8.8

16. 0

47. 1
52. 9

I

I

17.3

11.5

15. 0
18 4

8. 1

13.4
13. 1

6.8
8. 4

20.5

10.0

12.3

7. 1

9. 9

'

Symbols in the column of forma: See Table 2
L : Total length of shell
B: l\·laximum breadth of the body whorl
PB: Maximum breadth of the penultimate whorl
PH: Height of the penultimate whorl

the type species aurita is ornamented
with a spiral row of strong nodes on
about the middle of the whorl surface
instead of the sharp spiral keel on theadapical margin and spiral cord or
granule spiral rib on about middle of thewhorl surface.
Pachymelania lnyonensis (GRAY) reported from the Ivory Coast of Angola
is a form allied to the present one, but
Gray's species is ornamented with two
spiral rows of prominent nodes.
Pachymelania fusca (Gl\IELIN) described and illustrated by Nrcu!:s (1950) andreproduced here (Figure 2) and also fromthe Ivory Coast of Angola is a form
mosr similar with the present one in thegeneral shape of the shell and the surface ornamentation. but the former has
different feature of the ontogeny during
the course of the shell growth as is shownin the following pages. From the Ivory
Coast. the variety quadriserita tGRA Y J
was recorded and illustrated in association with the species by the same author.
but the variety shows the surface ornamentation of the young Jitsca and has
no spiral cordings except on the base of
the body whorl.

437.

Variation and Dimorphism of Pachymelania

Fig. 2. Pachyme/ania fusca
Gmclin, Recent, West Coast of/.;,;;i;~~~~,., Africa. (after NicKLEs. 1950)

10 mm

Variation:....:... The variations in thegeneral shapes of the spire and thewhorls are not so prominent as alreadyshown in the specific diagnosis, however,the present species has considerably wide
range of variation especially in the surface sculpture of the whorls.
Among the specimens examined. twoare rather short and have the spire
broader than the others ; and two shownearly flat whorls profile whereas theothers exhibit slightly convex to concave profiles.
All of the specimens now at handare ornamented with the main spiral keelon the adapical margin of the whorls
and the other parts of the whorls show
sculptures which can be classified into
three types in general.
The first type is here called theforma o:. and is further subdivided into
three forms. that is those with, a) smoothsurface. b) smooth or with very finespiral stria on the adult whorls but \Viththe spiral row of fine beads in the younger stage of shell growth, which changes
into fine spiral stria or becomes obsolete
and sometimes disappear in the adultstage, C) ornamented with one or two·spiral cords throughout the whorls except on the protoconch.
The second one is the forma /3. andis ornamented by the presence of a prominent spiral row of beads or granules

305

continuing throughout the surface of thewhorls. In two specimens belonging tothis form, the beads or granules are verystrong and form longitudinal riblets on
the younger whorl surfaces.
The third type comprises forms transitional between the first and second
types and is represented by specimens
ornamented with beaded spiral cord.
The following table shows the composition of the variants in the surface
sculpture of shell.
Table 2. Surface Sculpture and Dimorphism.
.,

1

·

orma .

I

forma a:tran· /on11a! sitionfJ

e [01' -;2 -11--

Symbol
0 I tt' I-Number of --~---jzi3
indi,·iduals I 4

Explanation of symbols :0: Surface sn1ooth(!) : Surface with a spiral row of finebeads in the middle stages of theshell growth
8: Surface with one (or two) spiralcord(s)®: Surface with beaded spiral cordx : Surface with prominent spiralrow of granules

The sculpture on the base of the
body whorl consists of several spiralstriae and cords which are also variablein number and strength, they range fromthree to ten in number.
Ontogeny :-The ontogenetic changeof the surface sculpture of the present
species can be divided into three types(I to 111) from the characters of the spiralsculptures except on the knife edged main
spiral keel. These types are idealized
and diagramatically illustrated in Textfigure 3.
The third type or Type III is represented by the shells (considered to bevariants) ornamented with more or lessprominent spiral sculptures in the adult,

30(iTamio KorAKA and Satoru UoZUJJI
101IGPS coli. cat. no.79323 -I............... -·n

IGPS coli. cat.no.79323-3- - - - ////lt/1//f/1/1 II I 1/ ///1'/ /1/1 Pfi/J'Jit' J?p '111/(J()PQI p Do coG o o Ooc.

m

IGPS ooll.oat.no.79323-ll

WN.• Whorl number
Fig. 3.

P•Protooonoh

Diaphragm showing Three Types of Ontogeny.

and belonging to the forma fJ, the transi·tion form. and the variants of the forma
a based upon the surficial ornamentationin the adult stage of shell growth. The
ontogenetic change of this type is shownin the following way. On the first or
second post-nuclear whorl. just preceding
the appearance of the main spiral keelon the abapical margin of the whorl,
more than 10 to 15 fine beads forming
spiral row begin to occur at about a little
adapical to the abapical suture of thewhorl, and these continue to grow andbecome str~ng and increase their number
in consequence with the growth of thevolution. Sometimes. the spiral beads or
granules appear immediately following
the appearance of the main spiral keel.
and further, the fine spiral cord appears
to occur just adapical to the abapicalsuture in the middle or adult stage of
growth. The numbers of the beads or
granules on each whorl decrease withthe shell growth.
In the second type or Type II whichis represented by the forms characterized
by the surface ornamentation of thevariant belonging to the forma a, thesituation is somewhat different fromType III. The spiral row of fine beads isalso present in the early stage of growth
as in the case of Type Ill, but this row
becomes obsolete and is changed intofine spiral stria and sometimes disappears
with the growth of two or three volutions. and even the spiral stria disappears
in the adult stages. The smooth form of
the forma a is the first type or Type
L In this case no other spiral sculptures. except on the main spiral keel andsometimes very fine spiral striae on theadult whorls, appear during the courseof the shell growth.
Pachymelania fusca (G~IEI.I:-.;) fromthe west coast of Africa is one of theforms most allied with present new
species in the shape of the spire, and in
sculpture. Especially the adult surface
ornamentation is indistinguishable fromthe smooth variant of the forma a of

437.

the present species. The ontogenetic
change of fusca is, therefore, described
below in comparison with those of theforms belonging to the present species.
In the earliest stage of the shell
growth of the second or third post-nuclear whorl. the surface is ornamented
with fine longitudinal riblets about six
or seven in number in the mentioned
whorls. These riblets become granularwith the shell growth and form three
spiral rows of beads or granules. Thisfeature of the surface ornamentation
suddenly disappears in the middle stage,
and more or less sharp, strong and weakspiral keels begin to occur on both sidesof the adult whorls, just abapical to theadapical suture. and just adapical to theabapical one respectively. And the baseof the body whorl is sculptured with
about six spiral cords.
Remarks 011 DimmPI1ism :-As shownin the preceding pages. the specimens
dealt with can be subdivided into eightgroups from the adult features and ontogenetic changes of the surface ornament·
ations. Correlation of those groups isshown in Table 3. and although there
may be some overlap of the groups inthe classification, it adequately shows
the relationships.
Table 3. Correlation between Surface
Sculpture and Ontogeny.

'

Ontogeny' tran- forma
sit ion _E_

forma ((

Surface
Sculpture

0

@

II

:307

Variation and Dinwrphism of Pachymelania

·c

0

X

III

At a glance. these seem to indicate
the mixing up of two or three different
species so far as the surface ornamentations are concerned. The results of thestatistical analysis on the morphologicalparameters of the shell shown below(Table 4) and the surface characteristics
exhibiting the gradual change without
any gap between each grouping given
above. however. suggest the intimate
relationship between each specimen
examined, and the difference in thesurface sculpture may be from sexual
difference.
Table 4. Result of Statistical Analysis.
(Level of significance: 0. 05)
B/LxlOO

t

:-

N

7

8

M

37. 17750.463

12. 2145

54.8632

~~--

f:

ut

-2.

2.447

1

N

9

-M.

~

I
I

t

2. 36538. 046-46. 3-08-131. 409-69. 517-

Range

-2.

PII/PBxlOO

I

I

9

~9·!_~~ --. ·I,

56. 750

11. 117235.7390

2. 306

2.306

Range -31. 243-47. 443

1

42. 39s-n.lo4

The writers, therefore, consider thatdimorphism exists in one valid species
and thorough studies on the Recent form
is necessary to confirm whether the dimorphism is sexual or due to some otherphenomenon.
And to clarify the phylogenetic
trend of this peculiar gastropod genus,
the thiarid species of the Tethyan region
during Cenozoic time should be restudied. The probability of this group as agood indicator of the sedimentary facies,
paleogeographical reconstruction, and as
material for faunal migration within thesaid region can be inferred from theevidence presented in this article..

Tamio KuTAK:i and Satont UOZUMIReferences
CJJHIBilER, H. L. (1934): The geology of
Burma. xxvii+538 pp., 26 pis., 37 text.figs.
MacMillan and Co., Ltd., London.
CossMA:-IN, M. (1909): Essais de Paleoconchologie Comparee, vol. 8, 248 pp .. 6 pis .. 87
text-figs. Paris.
CoTTER. G. de P. (1914a) : Notes on the valueof Nummulites as zone fossi Is. wi lh a
description of some Burmuse species. Rec.
Geo/. Sun'. India, val. 44, pt. 1. pp. 52-84.
pis. 1-3.
- - (1914b) : Some newly discovered coalseams ncar the Yaw River, Pakokku District, Upper Burma. ibid .. pt. 3, pp. 163185. pis. 5-12.
GRAY. ]. E. (1847): A list of the genera oi
Recent mollusca. their synonyma andtypes. Proc. Zoot. Soc. London, 1'0/. 15. pp.
129-219. (inaccessible)
HALDE:I.IA!"N, S. S. (1841) : Observations on
the Mclanians of LAMARCK. .4mer. jour.
Sci., 1•ol. 1 '1. pp. 21-23. (inaccessible)
IJJEIU:"G, H. vo:-. (Hl09) : Les l'vJelanides
americains. ]our. Concl!yl .. !'o/. 57, pp. 298316. (inaccessible)

l\1ARTENS, E. vo:-.: (1903): Die bcschaltcn
Gastropoden der Deutschen Tiefsee-Ex·
pedition 1898-1899. ll'iss. Ergebtz. Deutsch.
Tiefsee-Exp., 1•o/. 7, pp. 1-180, pis. 1-5.
(inaccessible)
NlCKL~:s, M. (1!!50): Mollusques testaces
marins de Ia Cote occidentale d'Afrique.
.l!an. Ouest-Ajricains. 1•ol. 2, pp. 1-269, 464
text-figs.
PII.SBRY, H. A. and BEQUAI,RT, ]. (1927) :The aquatic mollusks of the Belgian
Congo, with a geographical and ecological account of Congo malacology. Bull.
.timer. "Uus. Nat. His/., Neu.: York. vol. 53,
110. 2, pp. 6!!-662. pis. 10-77. (inaccessible)
REED. F. R. C. (1949): The geology of the
British Empire. 2nd ed. i-ix+1-764 pp.,
26 text-figs. Edward Arnold and Co.,
London.
RovERETO, G. (1899): Primi rierche sinonimische sui generi dei gastropodi. .4lti Soc.
Lingustica, l'fll. 10, pp. 101-110. (inaccessible)
SAITO. R. (1961) : Depositional environmentof the coal fields of Burma. jour. Assoc.
1\/ining Geologists, japan, tml. 11. IIOS. 4 541). pp. ~86-291. 6 text-figs .. 4 tables. (inJapanese with English abstract)

Explanation of Plate 47(All ligures in natural size)
Pacllymela11ia kalewana KoTAKA and Uozu~11. n. sp.
Figs. la-b. Syntypc. IGPS coli. cat. no. 79323-3.
Figs. 2a-b. Syntypc, U. H. Reg. No. 13696 (c).
Figs. 3a-b. Syntype, U. H. Reg. No. 13696 (d).
Figs. 4a-b. Syntype, IGPS coiL cat. no. 79323-5.
Figs. 5n-b. Syntype. U. H. Reg. No. 13696 (e).
Figs. Ga-b. Syntype, IGPS coiL cat. no. 79323-6.
Figs. 7a-b. Syntypc. !GPS coiL cat. no. 79323-10.
Figs. Sa-b. Syntype, U. H. Reg. No. 13696 (f).
Figs. !la-b. Syntypc. · U.JI. Reg. No. 13696 (g).
Figs. lOa-b. Syntypc, IGPS coiL cat. no. 79323-11.
Figs. lla-b. Syntypc, IGPS col I. cat. no. 79323-7.
All specimens were collected from the Kalcwa Coal Minz in the Mawhataung area ncar
the small tributary of the Mittha River. one of the tributaries of the Chindowin River, ~orthern
Burma. (CoiL R. SAITO and S. UozUl\11, 1958)

Plate 47

b

6

b

8

b

h

437.

Variation and Dinwrphism of Pachymelania- - and Uozu~u. S. (1959): Geological reconnaissance of the coal-fields of Burma.
jour. Soc. ilfining Geologists, japan. !!O{. 9,
no. 35, pp. 179-189. 25 text-figs. (in Japanese)- - and-- (1961): Some considerations on
the stratigraphy of Burma (Fourth Report)-The depositional characters of thecoal·bearing formations in Burma. Kumamoto four. Sci., Ser. B. Sect. 1 (Geol.), t•ol.

30!)

4, 110. 2, pp. 90-105.
Sr-.IITH, E. A. (1893) : On the generic name tobe applied to the ll/erita aurita of M1:LI.ER
and other allied species. Cmu:hologi.~t. 1ml.
2, pp. 141-142. (inaccessible)
WENZ, W. in ScHI;>;DEWOLF. C. II. (l~ditor)(1939) : Gastropoda, Teil 3, pp. -181-720,
text-figs. 1236-2087 itt " Handbuch der
PaHiozoologie, Band 6 ". Gebriider Borntraeger, Berlin.

310
PPOCEEDINGS OF TilE PALAEONTOLOGICAL SOCIETY
OF JAPAN

B;.$:i!i~%~~~ 81 @l(~€;;fi.

1962 ~ 6 ~ 2 B~**~ill!~l!llitlln~ft~;::.t;.,.,·-c!JIIoo~.nt:,. . . . . . . . . . . . ?\1. ::\AKA:"O & K. 0KA~IOTO
Lima (Acesia) sp. Q)~'E

A'f-rm!f.lftlll~ffiQ)
1~0v·-c($4:<~ 27 il)A
Verbeeininae from the Inferred Wolfcampi·
on Limestone in the West of Ryoseki.
Kochi Prefecture. Japan. Crt~) ....... .
.............................. K. lstiiZAKt
Lower Carboniferous Bryozoa from the Omi
limestone. Japan. Parts 1 & 2. (ft<i'il:) ..
• . . . . . . . . . . . . . . . . . . . . . • . . . . . S. SAKAGA:\11

Brachiopods from the Late Jurassic Nakano·sawa Formation in Fukushima Prefecture, japan. Crt~) .............. K. MoRt
A Dibranchiate Cephalopoda from the Rifu
Formation. crt~~) ............ Y. BA:-IDO
Note on Some Triassic Gastropoda from the
Rifu Formation at Hamada. Miyagigun,
Miyagi Prefecture, japan. Cftml:) ..... .
............................ S. HAYASAK.-\
Trigonioides from the Tctori Group. ((\':~).............................. S. MAEDA
Some molluscan fossils from the Upper
Mesozoic Yoshimo Formation ..... Y. 0TA
Clz/amys and Venericardia from the "Ashi·ra Group" in the Yuya-wan Yamaguchi
Prefecture. Southwest Japan .......... .

........................ EBt:r~

The Fossils and their habitats in the Neogene Katsuragawa Group in the South
Kwanto Region. Crt~.) ........ M. St:GITA
On the Dentition Formulae of Heterodont
Pelecypoda ..................... I. HAY A:-.H~twmmm~-'t-Vil&7=it:ul:-::>"·-c....... .

... .... .. ........ .... ...........
1I;ltltiiiH'htBWlt::91i'E1illl.l1!!*~f-tit'E 1:-::>"t'...................... m* li·~fO!I~m~*

It·

New Species of Gadus from the Pliocene ofjapan. C(\';;r,~) .... K. HAT At & T. KoTAKR
On the genus /ker with description of New
Species ........................... S. E:-.:oo~p~~7Arrem~~Q)ii~~~~JtJ~ i1'J 1:.:t.i!\Q)~Mt·J!iif~ c M.ilt"-'ifiii'F!E~~Q) ~f(•JQ)~ft'....................... -~fti!~=:!!U!Jf;t.iiTQ)m.f.!!:JM'l~ ~ JtM.iltUt~ . -~EB~~
iTJL!f,!.Q)~~ ....................... -~* :£;¥i1Htii'1:.l&~:(/)-2:,(1)/l!Jiii1............ 0Ji(}.:!/J
n:;t.:Q)-/=7*i!.:::.&J'!ffi ............. -~*Bam lites facies 1.:-::> It· -c .... t.a*ilM •1HMiB':Em~~~~~*~Q)~~~~~~~Q)M~~~.h
I:OO~i' o ti1:.:fm~EI1P.if!ll!l!l · .... -~f'i-A:M

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(1962, Jan. 20)

Article 19.
Article :!0.
Artide ::!1.
Article 2:!.
Article 23.
Article 2-1.
Addendumf§lj

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CONSTITUTION
of the
PALAEONTOLOGICAL SOCIETY OF JAPAN
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ArticleArticle