a -tt~~f.~~~•*"·i~tTransactions and Proceedingsof thePalaeontological Society of Japan
New SeriesNo. 10Palaeontological Society of Japan
July 31, 1953

CONTENTS
TRANSACTIONS
231. Variation of Japanese Anadara granosa ... ..................... Tamio KoTAI<A 31
232. Fossil Assemblages of Molluscs and Branchiopods of Unusually Large
Sizes from the Permian .............. Ichiro HAYASAKA & Shozo HAYASAKA 37
233. Miocene Foraminifera from the Shintotsugawa Area, Kabato-gun, Hok·kaido.......................................................................... Kiyoshi AsANo 45

President:

Hisakatsu YABE

Councillors:

Kiyoshi AsANO, Riuji

ENI>o, Haruyoshi FuJIMOTo,

E:-~oo(Business and Accountant), Seido

Shoshiro

Nobuo II<EBE, Teiichi KoBAYASHIHANZAWA, lchiro

HAYASAKA,(Editor), Jiro MAKIYAMA, Tatsuro

MATsuMoTo, Tsuneteru OINOMIKADO (Publication), Tokio SHIKAMA,
Koiti SuzuKI, Fuyuji TAKA! (General Affairs), Hisakatsu YABE.

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

,•Trans. Proc. Palaeont. Soc. Japan, N. S., No. 10, pp. 31-36, 2 text-figs., Pl. 4, July 31, 1953

231. VARIATION OF JAPANESE Anadara granosa*
TAMIO KOTAKA
Tohoku University, Sendai*~i!E

Anadara granosa V~$<;-*:tl.lliHI:Ti.&V:m'l:. Anadara grmzosa VJltiJIIJV*fi!¥.: r'**

1'r l- t~ o if~lttt-J!:v.:fb. ;;, !'!'fl.: J: !1, ~:.!M~lii.lmiv~~ a: Jllv •"L. i!ffJtll. il],v~~··~I1"->W:WU ~ ~ .!: ~fft
1E l- 1c 0 ' : 7 "' - IJ - l.t. ·~l]Jj£ l- JJ, < ' JL~I?".>*Ml!~ ~ li1 "' J: <i~~-r Q tV:> a:~~ l-t-c 0 H/L lk.V:
C/L 1:1:, tll9JJ;;:lJ'·fit.r L .!:, 1T~illtr. H, .&V:~VJ.IiH~s-< !::>.Vev·o,?l,.!:, IJ~~llli.!:"->M~ C.!:
VJ11:.~~>¢o -fl~JMIIiJ.!: VC. *810. lBJi!LI:~-?tO~!l/,f,'f;>}:f2UJ1Ja:h.1o: 0 C.tl-!::>l:l:JLH-:: overlap
vcF..; IJ. 4Hl"fv~ll 1.:: 1.:t. itliti'I(JJ-:: fiiJt~tJ·VJW.lf*D: ;£."? t-c c Mt)]; ~ t1- o o tdciii"v k.ti:l!l:.&v:::.XVJ ~l"lli'tc
fFlv•C..!: J: U-lJrfll!i:IZJJI]L, A11adara obessa 1X7.>Wrfillv~[!~a:fftr?t;: 0 1)• i'Wi N~cher of radial ribs, and the other twovarieties to Anadam granosa. In 1938,
H. G. ScHENCK and P. W. REINHART separated the Japanese Recent form fromthe typical granosa by the less numberof ribs, more elongated shell outline andrather narrow umbones. For this typeof shell they proposed the name to bis·
enettsis and added that this occurs inJapan also as fossil. T. KuRoDA and T.
HAnE, from their observations on Recent
material, treat bisenenesis as a subspecies of Attadara granosa.
To determine the limits of variation andtaxonomic values of the shells hitherto
referred to grattosa and bisenensis
in Japan, a survey of the statistics ofthe conchometry of these shells was
made. The mathematical values obtain·
eel from measurements of length, heightand convexity were considered by theformula of the rejection-ellipse. The
results in terms of position and rangeof the variation are as shown in figure
2, in which the respective localities ofthe measured specimens are given.
Heartiest appreciations arc due toProfessor Shoshiro HANZt\WA for encour-

INTRODUCTIO~

The so-called Anadm·a granosa is acommon Arcid pelecypod in the Pleistocene deposits of the l\1iura and Boso
Peninsulas in the Kwanto area, theFuruya shell beds in Shizuoka Prefecture,and occurs in the raised beach deposits of these Peninsulas and in otherregions. It is also commonly foundin the shell mounds distributed from
Miyato-jima in Matsushima Bay, Miyagi
Prefecture to Kyushu along the Pacificboaderland. As living it is known fromthe littoral zone of the Setouchi, Okayama Prefecture, Ise-Bay, Mie Prefecture; and Ariake Bay, western Kyushu.
It is known that the fossil and Recent
forms have remarkable variations in the
shape, thickness and other character ofshell. J. B. P. A. LAMAI<CK recognized
three varieties of the species, namely,a, b and c. Of his species, L. A. REEVE
allocated LAMARcJ.:;'s var. a to Anadararhombca (BoR:-1) which is said to be
characterized by having a greater num-

* Read June 22, 1952; received Aug. 28, 1952.
31

Tamio KOTAKA

32

agement and also to Professor Kotora
I-IATAI for his contiguous guidance during the course of the present study.
Thanks ara also due to Professor T.
btAI, Fisheries Institute and Professor
I. MoTOMURA, Institute of Biology, bothof the Tohoku University for_ their advices concerning biological statistics.
During this study, specimens havebeen received from the following persons
to whom acknowledgements are due,
Mr. T. HABF. and F. UTsUMI, Zoological
Institute, Kyoto University; Mr. H. OzAKI,Tokyo Science Museum; Mr. K. SuYARI,
Geological Institute, Tokushima University ; Dr. I. TAKI, Onomichi Marine Laboratory, Hiroshima University; and tothe officials of the Fisheries Experimental
Stations of Fukuoka and Saga Prefectures.

margins of the shell; the height (H) by
the maximum distance between two lines
parallel with the hinge line and in con·tact with the ventral margin and the
top of the umbo; and the convexity (C)is defined as the distance from the planeof the inner margin of the shell to themost inflated point on the outer surface.
These dimensions are measured carefully
with callipers, and the values are counteel to the degree of 1/20 mm.
RF.JECTION·ELLIPSF.

Brief notes on the rejection-ellipse arc
quoted as follows.
Let us denote, hereupon, H/L by x,
Cji. by y, and let
and y be meanvalues respectively. Then the equationof the rejection-ellipse isx,

D

METHoD m> l\1EASUREMEt-;T

Arcid shells are characterized by having a straight hinge provided with serial
teeth. This taxodont character is important in taxonomy ::md is also convenient
for a conchometric study. As shown in
Fig. 1, the more accurately measurable

Fig. 1

dimensions are chosen ; that is, the length(L) of the shell is represented by the
maximum distance between two lines
perpendicular to the hinge line and incontact with the anterior and posterior~·o =(N-2)N {"' (2 J(N+l)-

'Pll

-)?
x-x"

-2(/J,2(x-x) (y-y)+r/J;>2(y-.Y;2} ............... (1)where, f/Ju = :E (x-x) 2 , r/J12 = ~ (x-x)(y-y), r/J22 = ~ (y-y) 2 ; J = r/Jur/J22-f/J~~;N : number of specimens: F 0 : the valueof F, in the F-distribution under thetwo degrees of reedom n1 = 2, nz= N-2,
and level of significance (0.05); x; andy; are each measured values (i = 1, 2, 3,
4, ........• N).
In the equation (1), let h = x-x, ~ 2= y-y, then (1) is introduced into a11 ~i+2ar2 ~1 h+ a22~~ = 0, in general.
Whereupon, the inclination (8) of thelong axis of the rejection-ellipse is givenby the following equation;
tan 20and the lengths of the two axes are
two real roots ofX?.-(au+a22) X+(au a22-atz) = 0.

.,

Variation of Japanese A11adara granosa
RESULTS A!':D CoNSIDERATio~s

The results of calculation are shownin Table 1 and Figure 2. In Table 1,
the samples without the values of B. aand b do not indicate the true valuesof the equation of the rejection-ellipse,
because of some of the measurements of
H, C, or L are inaccurate due to damageof the shell by subsequent agencies as
erosion, water·worn etc.
As shown in Figure 2, although therejection-ellipses, which represent theposition, range and tendency of variation of the so·called Jap:mese fossil andRecent granosa and bisenensi's, overlap
each other and thus suggest a continuouschange of shell shape between the fossil
and Recent forms, they can be divided
into three groups. That is, Group 1
represented by the rejection·ellipses ofDutch Borneo and Minato silt (1), Group
2 by that of Kojima Bay and Ariake
Bay and Group 3 by that of Okinawa,

33

Minato silt (2) and the Byi>bugaura
formation.
Judging from the arrangement of therejection·ellipses, it is inferred that the
granosa or bisenensis of Japan can bedivided into three forms according totheir shell profiles.
The first form is shown by the ellipses
for Dutch Borneo and Minato silt (1)in Figure 2; this form may be safely
assigned to Anadaragran.osa (s.s.), based
upon the morphological coincidence with
L.A. REEVE's description of the species
The second form which is represented
by the ellipses of Kojima Bay and Ariake
Bay has an elongated shell profile, rather
narrow and low umbones and less num.ber of ribs as has been pointed out by
H. G. ScHENCK and P. W. REINHART; thisis Anadara grattosa bisenen.sis ScHENc~
and REINHART. The third form is represented by the ellipses of fossil and semifossil forms from the raised beach deposits of Okinawa· Island, Minato silt (2)

100

95

90

ss~

00.

Fig. 2. Graph showing the Rejection-Ellipses (Level of significance;0.05) of the specimens from Each Localitie!j.

34

Tamio KoTAKA
Table 1

No.

--

N

Horizon or Age

y=C/L

63

78.0

342

- - --- ----62

-10
3.
..
- - --------

..

4.
5.
6.
7.

--8.

Shell mound
Minato Silt (1)Raised Beach ?
Minato Silt?
(2)
Taito Shell
Hed R. B.

781

38.7

19'2.51ll

80.1

11°321

39.5

82.7

40.5

34°56.51

33
-

83.2

30

S2.1

38.4
-·-

400

------

nl

fr3.7

61

87.0

39°41 1·16.1

30°381

g. b.

76.1

12.7

g. b.

37.2

15.5

g.

19.1

8.4

31.1

15.0

g.

-----g.

--- --24'55 1

73.8

55.5

0.

17.9

o.

--45.4450

51.3--- ---

-

18

85.'1

45.1

..

7

86.4

·16.7

Shell mound

10

85.5

·15.3

13.

Yurakucho F.

25

81.5

379

14.

Narita F.

10

84.9

38.7

11.

38.1

--~

40°28.51

-12.
--

75.2

--- ----

36°18.5'

Byobugaura F.

g. b.

-

ol3.7

10

16.0

--

--- - - - - - - - - -8..1.9

9.

6t3

15°51

-

---

Remarks

a

--

..

2.

b

0
-

J~ecent

1.

x=H/L

----

---

37

59.7

33.2

0.

58.4

19.3

o.

114.3

38.0

o.

-

42°20.51--- --------- ---- ----

- - - ----

(o.)
-

(g.)

---0: lnclin:~tion of the long axis
a : Length of the long axis }of the r~jection-ellipsc.
b : Length of the short axis
g b.: Anadara grai!0$0 bisenensis
g.: A. granosao.: A. obessa
Table 2

No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.

Locality
Kojima Bar. Okayama Prefecture.
Ariake Bay, Saga Prefecture.
, Fukuoka Prefecture.
Dutch Borneo.
Horinouchi. Yoro-mura, lchihara-gun, Chiba Prefecture.
Co:tSt of Kazusaminato-machi. Kimitsu-gun, Chiba Prefecture.
Coast of Nago-machi. Kunigami-gun, Okinawa Island.
Coast of Sanuki-m:tcbi, Kimitsu-gun, Chiba Prefecture.
Coast of Okayoshi-machi. lsumi-gun, Chiba Prefecture.
Kamisawa-nakamura, Totsuka-ku, Yokohama City, Kanagawa Prefecture.
Atoyamada, Totsuka-ku. Yokohama City, Kanagawa Prefecture.
Tsukumo, Okayama Prefecture.
Near the Funabashi race-course. Funabashi City, Chiba Prefecture.
Otake-machi. lnba-gun, Chiba Prefecture.

(g.)

Variation of Japanese Anadara grauosa

and Byobugaura formation. Although
the morphological characters of H/L and
C/L more or less overlap those of Auadara grauosa biscnensis, the very thickshell and more than 84% of C/L seem
to warrant the proposal of the newname of Anadara obessa.
It is interesting to find two types ofshell among the samples from the Minato silt. The specimens from Minato
silt (1) were collected from the exposurenear the coast of Kazusaminato-machi,
while those of (2) are uncertain because
they were collected from the shore andare thought to have been washed out
from a submerged different horizon ofprobably of the Minato silt. According
to the oral information of Mr. F. UEDA
who made a pioneer stratigraphic workon the Miura and B6s0 Peninsulas, theMinato silt contains two horizons of

Anadara.
The atTangement of the ellipses offossil and semi-fossil forms and theirrelation to those of the forms as shownby groups 1 and 3 in the figure suggests
migration and a type of differentiationof species or phylogenetic development,
but details wiJI be reserved for another35

opportunity.

DESCRIPTION OF NEW SPECIESFamily Arcidae
Genus Anadara GRAY, 1847
Subgenus Tcgillarca IREDAI.E 1939

Atzadara (Tegillarca) obessa
KOTAKA, n. sp.
Pl. 4,

Figs. 1a-·6c.

Description: Shell thick, large in size,
quadrate in outline, posterior bordermore or less straight; equivalve, inequiIateral, heart-shaped in lateral view,
ventral margin squarely rounded ; urnbona! region swoll':'n, beak more or lessincurved and directed anteriorly ; ligamenta! area broad, arcuately trigonalin profile, sculptured with five chevronshaped grooves; surface with 17 radialribs cross with concentric growth lines,
anterior part of shell with 12 strongly
granulated ribs and the posterior with
5 smooth ribs which are slightly broader
than their flattened interspaces in width.

Measurement :
Valve
R.
R.
R.
L.
R.
R.
L.
L.
L.
R.
L.

Length715
f.4.35
57.0
55.1
53.0
52.0
51.6
51.3
50.0
48.7
47.25

Height
€4.15
52.0
520
52.4
4865
45.0
45.4
4t9
4·1.4
42.25
44.0

Convexity
32.35
29.4
27.2
27.1
24.67
22.75
23.15
21.73
24.0
21 0
23.1

Numberof ribs
17

17
17
19
17
18
17
16
17
17
19

H/L
89.8
88.5
91.2
95.0
91.9
86.5
88.0
87.5
83.8
86.8
93.2

C/L
45.3
45.7
47.7
492
46.6
43.8

Holotype
Paralype

44.9
43.2
48.0
43.1
486

..

36

Tamio KoTAI<A

HolotyPe : IGPS coli. cat. no. 66356;
Coast near Nago-machi, Kunigami-gun,
Okinawa-Island. Derived from the raisedbeach deposits,
Remarks: Anadara rhombea (BoRN)(L.A. REEVE, Conch. Icon., 1844, sp. 12)
from the Chinese Seas and Ceylon pos·sesses a similar shell profile, but is dis·tinguishable from the present species bygreater number of radial ribs and shapeof umbones. Anadara (Anadara) lwlw·
hataensis HATAI and NtsiYAMA (19119, pl.
23, figs. 8-10) from the Miocene Susahara
formation of Toyama Prefecture is dis·tiriguished from the present form by the
sculpture and number of radial ribs,
posterior slope and profile of ligamenta\.area.
LITERATURE CITED

HAMAl, I. and ITO, K., (1950). Systematic
Relative Growth in Molluscan Shells (2),Potamididae. (in Jap:mese). Venus, vat.
16, 11os. 1-4, pp 57-63.
HAMAl, 1., (1951), Systematic Relative Growth
in Molluscan Shells (3), Buccinacea andLand Shells. (in Japanese). Venus, vol.
16, tiOS. 5-8, pp. 104-111.
HATAI, K. and N!SIYAMA, S., (19·t9), New
Tertiary Mollusca from Japan. ] ourn.
Pa/eo11t .• vol. 23, no. 1, pp. 87-9't
HUXLEY, J. S., (1932), Problems of Relative
Growth. Metlmerz & Co. Ltd., Lo11don.
MASUYAMA, M., (19·~9), Methods of small
Sample Statistics and Planning of Experiments. Revised Edition. (in Japanese).
Kawade-Shobo, Tokyo.
REEVE, L.A., (1844), Conchologia lconica, vol.
2, Monograph of the Genus Area .
SCHENCK. H. G. and REINHART, P. W .. (1938),
Oligocene Arcid Pelecypods of the Genus
Atzadara. 1l1em. Mus. Roy. d'Hist. Nat. deBelgique. 2me ser., fasc. 14, pp 1-73.

Explanation of Plate 4
Figs. la·ld-Anadara (Tegitlarca) obessa KoTAKA, n. sp. x 2/3. Holotype, IGPS coli. cat. no.
66536. Lee. Coast near Nago-rnachi, Kunigami-gun, Okinawa Island. Raised Beach Deposits.
Figs. 2a-2d-Anadara (Tegillarca) obessa KoTAKA, n. sp. x 2/3. Paratype, IGPS coli. cat. no. 66536.
Figs. 3a-3c-.4nadara (Tegil/arca) gratzosa bisenensis SCHENCK and REINHART. Topotype, JGPS
coli. cat. no.
. Loc. Kojima Bay, Okayama Prefecture. Recent.
Figs. 4a-4c-Anadara (Tegillarca) granosa LINNE. IGPS coli. cat. no. 13229. Loc. Coast of
Kazusa-minato-machi, Kimitsu-gun, Chiba Prefecture. Minato silt, Holocene.
Figs. 5a-5b-Atladara (Tegillarca) gra~zosa LINNE. IGPS coli. cat. no. 41659. Loc. Dutch Borneo.
Recent.
Figs. 6a-6c-Anadara (Tegillarca) obessa KoTAKA, n. sp. Saito Ho-on Kai Mus. Reg. no. 6703.
Loc. Coast, W of Sanuki-machi, Kimitsu-gun. Chiba Prefecture. Minato silt. Holccene.
(All figures in natural size unlcs3 otherwise stated).

KoTAKA : Anadara granosa

5b

PLATE 4

6b

6a

-

Trans. Proc. Palaeont. Soc. Japan, N. S., 1\o. 10, pp. 37-44, Pl. 5, July 31, 19S.1

232.

FOSSIL ASSEMBLAGES OF MOLLUSCS AND BRACHIOPODS OF
UNUSUALLY LARGE SIZES FROM THE PERMIAN
OF JAPAN*
ICHIRO HAYASAKA
Holtkaido University and Kanazawa Univer.:ity
and
A

A

SHOZO HAY ASAKA
Tohoku University

ti!l:.'ll!J~;~-c:t;t. A!Hf.f11lifiiH'>1tc -?v• c:: t . .'(: vJ~~ ·!·1tl'lll;t/'it-'<Nf:t~"J~@!: t.c-::> "C ~ • <> ~:. l':;k!{~ttl "->7il.t, .i!liiU "->if!J:a: 'J· t.r v· tc Vl t.c v) tJ· • .v t !l ~;lit~ t~o t.:'Wh•t.r ._ • .t ? tc.lli? o .:: "->/J.. --c:, ~x.!iLVJ;
7.1df,(crJ{O;!l'lliPF. "->JJ:;kt.d~#Ili"->~ffi c. tlii* 1 ilr~!tK ili:v·~UI:!tl!.:hiJii J)[l;J;:;:CJliii.li<l'tl crJUl~H c IJ:,
~ ~ L-v·1§1J·c:a:,7, ?o ;HC"'C:I;t, ~~~~ "->l'I*Illii!t:'lll'lm!:'ll t, =~t:i.!"J t vrC:ib <>.:: c "->l,W)H: 1~t1'1to
7c Vc. c t, (, t ~ f!!.V;llb{jlitt (IMVO:'() Ti1;.;~·;·to1'~1. ·)~"->II• K;lffiff~ ~ tL "C v• o ~HI.~ 1... HJS'~·c: <t;c.t~.~~"Jml·HKMi"<>ll"lf*~·ri*'.::'&J-H tcum:. -·WIJ!!'llVJm!M,.::fft.:r, t"->c L·ct~D.~c ..JJ!Jol:
1.-"C J!td:, ~~·;~·.}, ffl.;{!: UJf\\Jjf<Oftf-H~ f/t'-:> "C 1;1:, JJAfJ!J-'L'li~fflt~ f: _l)dz 0 f.itt,r, j{{:t}\ li: ( V:;fL 'fc j_tjtf!.
-V\<1.>i~ltiti'C/)!U·r.·vJ*,'i:!J!:c L-cm.l.t.tt.tcf~l'l1nl:l*@"'J!o-'~ tv.n:ibo :l:v· '/J·,

Jl:t oolllrt.'JU.r!~H1~U~;k1f;'lt;t_m ~ ~.tL:~:r.>BJHXC/)*G~Cf)lliJi'tc ·;·;t. i?..t"L-<>oc *''i&aL-1!}oiC(4 1-.!ti-Jlii•J,t.!fi~i)':;:;)

T. WAKIMlZU ( 1902), who briefly accounted for how tlwse fossils were found in
the mother rock. In the upper part ofthe "Black zone" which is the 4th frombelow of his 8 "zones," altogether estimated to be about 500-600 meters inthickness, there are thin beds of " very
impure," black limestone, rather earthy
and brittle, having a tendency to cleave.
These beds are usually not more than
30 em. thick. It is in these beds thatW AKIMizu collected his excellent lot of
specimens described by the senior auther.
These fossils have been found at Kinshozan very abundantly since long before
W AKlMizu's time, and consequently many
specimens are found in the natural his-

It is well known to the geologists andpaleontologists of Japan that the Fusulina- limestone of Kinshozan. Akasakamachi, Gifu Prefecture, yields, or at least
yielded, abundant fossils of several species of molluscs of enormous sizes at a
certain bed of the limestone sequence.
Although known for a very long time,
this faunule had not been paleontologically studied until the senior author ofthis paper described a part of it in 1925.
The study was suspended for about adozen of years, and then continued in
Taiwan (HAYASAKA, 1938-43).
Kinshozan has been visited by manygeologists and p:tleontologists, and studied
biostratigraphically by some of them.
But nobody has ever explained the modeof occurrence of these huge molluscs but.. Read Sept. 27. 1952; received Oct. 27, 1952.

37

,

38

tchiro HAYASAKA and Shozo IiAYASAIC-\

tory collections of schools, not to say of
universities and museums. They were
supplied by specimen dealers. It is said
that the specimens occur rather rarely
these days. The molluscs are found inassociation with large specimens of Neo·schwageriua globosa Y ABE and someothers, which are often compressed into
ilat discs. Other fossils found together
are a few brachiopods (HAYASAKA, 1932)and corals (Y ABE et HAYASAKA, 1915 ).
The geological age of the faunule is latePermian. The black, bituminous lime·stone forms a part of the uppermost of
the 4 Neoschwaget·ina zones into which
OzAWA (1927) once divided the whole se·quence of the Fusuliua-limestone of Kin·
shozan according to the different dominant
species; namely, in descending order,
Zone of N. (Yabeina) globosa YABE
Zone of N. margaritae DEPRAT
Zone of N. craticu/ijera SCHWAGER
Zone of N. (Cancel/ina) 11iPPonica OzAWA

Another Permian fauna which equals
the foregoing one in point of being com·posed of extraordinarily large individuals
is the brachiopod assemblage from thelimestone of Kuzu region in the Kwanto
mountainlaml near Utsunomiya city. In
this region a Fusuii1la·Iimestone formation occupies a wide area, and theforaminifer;; are collected very abundantly at many localities. Mammalian re·mains arc also rich in the limestone
caves developed here and there (SHIKA·
MA, 19t9). At a few quarries several
species of brachiopods of enormous sizes
were collected by the senior author in arather thin (about 15m.), black, bituminous bed of limestone, exposed around
Kadosawa in a small tributary of the
Nagano·gawa, West of Nabeyama. The
descriptions of these fossils, also by thesenior author, were published in 1933.
At these localities the black brachiopod-

limestone bed does not contain fusulinids,
while they are very richly found in thegray limestone bed overlying the former.
This fact, combined with the generalolder, Carboniferous aspect of the generalthat are mostly represented by new
species, made the senior author regard
the faunule upper Carboniferous, thoughrather hesitatingly (HA YASAKA, 1933, pp.
1~16). In reality he was deeply con·cerned about the fact that the huge
specimens are confined to the bituminous
rock just like in the case of the motherrock of the molluscan assemblage ofhuge individuals of Kinshozan, Gifu Prefecture. However, it seems there aresubsequent field observations by somegeologists by which the geological age ofthe brachiopod fauna is claimed to be
Permian. According to the kind oral in·formation of Sabun) YosHIDA, Kushiro
Branch of the Hokkaidl> College of Lib·
era! Arts (Gakugei Daigaku), whocarried out field surveys in the Kuztl
region a few years ago, the black, bituminous limestone with huge brachiopods,
but without fusulinids, is continuous withthe gray Fusulina-Iimestones both aboveand below in the immediate neighborhood of Yamasuga, about 5 km. south of
Kadosawa, and close to the town ofKuzu. We are indebted to YosHIDA for
several specimens among which there are
two of Orthoticltia japo11ica from Yamasuga (Pl. I, Fig. 2). Once NAGAo andMI:-;ATO reported that they had foundpieces of Fusu/ina·limestone at the footof a cliff formed of the blacl{, bituminous
limestone in the neighborhood of the ex·posure of Kaclosawa where the brachiopods had been collected. It is they thatfirst cast doubt on the Carboniferous ageof the brachiopod fauna. That the branchiopod-bed and the overlying Fusuli11abearing limestone are stratigraphicallycontinuous was recognized in Kadosawa

Fossil As;emblages of Molluscs and Brachiopods of Unusually Large Sizes

region : no evidence of a physical unconformity was recognized between them.
Thus, it now seems clear that the Nabeyama fauna also is of Permian age,.
although it may not be synchronous withthe molluscan fauna of Kinshozan.
Almost all the other occurrences ofPermian macro-faunas in Japan are in
the Kitakami mountains in northern
Honshft. There the fossils are, even if
found in limestones, of ordinary sizes,
as if to correspond to the non-bituminous
nature of the rock'>.
Here, we will enumerate the membersof the two assemblages of unusuallylarge fossils from the two regions refer·
red to above. Measurements given are
the miximum values obtained of thespecimens so far studied by the seniorauthor.
(*indicates specinwns not unusual in size.)(1) The Kinsh\lzan fauna, Gifu
Prefecture.

A. Pelecypoda: (H. height : L. length; inmm.)
Liebea sinensi.~ FRECI!. H, 46: L, SO
Myophoria japonica HAYASAKA II, 35; L,
45

Paral/elodo11 obsoletiformis HYSK.

H, 22;

L, 48

SolenomorPho clegontissima HYSK. H. 90;
L, 240B. Scaphopoda : ( L, length ; D, diameter inmm.)
Denta!ium akasakensis HYSK. L. 150; 0.17
D. monzatum HYSK. L. ca. 220; D. ca. 24
D. (Piagiog!yota) hcrcu!eum DEKON. L,
200; D, 22

C. Gastropoda: (H, height; W, width: inmm.)
Bc/lcroPhon jonesia11us DF.KoN. H.130; W,
124 (Pl. L, Fig. 1) This is the largest
specimen of this species we have evercome across with. This specimen hap·39

pened to be in the collection of the De·
p:trtment of Geology and Mineralogy,
Hokkaido University. together with several
other kinds of fossils.
*B. jonesianus var hiu!ciformis HYSI\. (Only
1 sp~cimen) H. ca. 30; W, ca. 32*P!eurotomaria aff. multicarinatus Mi\NSUY.
(Only 1 specimen) H. ca. 65: W. 60
P. Yokoyamai HYSK. H. 180; W, 160
Murchisonia Yabei HYSK. H. 400; W, 130*So!enopsis multicostata llYSI<. H. l4; W. 5.5
NaticoPsis Wakimizui HYSK. H. 140; W. 120*N. minocnsis HYSK. H, 40; \V. 30*N. fa[ciata HYSK. (Only 1 specimen) H,
14; W. 12*N. cf. Pracalta WANNER. H. 45; W, 35
Naticella japonica HYSK. H, 8.6; W, 6.2
Traclzydomia magna I!YSK. H. 68. \V, 61
T. conica llYSK. H 92: W, 75*SPirompha!IIS Yabci HYS;<. H. 1'1; W. 4

As far as the material examined isconcerned the specimens of ordinary sizes
arc very few in number of individuals
except the last one. Spiromphalus is a
new genus very much like such small
forms as Zygop/eura or Pseudozygop/eurain point of size and external characters.
This species abounds in the bituminous
limestone. It was suggested that theyalso might represent unusually large
forms of what is ordinarily much smaller. It is also possible, however, that
this species is indifferent to changing
environmental factors or conditions adverse to other gastropod kinds. Although
Spiromphalus Yabei is a small gastropod,
yet it is as a whole larger than speciesof Pseudozygopleura described by KNIGHT(1913).
At any rate. it is fascinating to lookat these sp-cimens gathered together,because the dominant and more numerous
members are extraordinarily large, andalso the shells are all very thick andmassive as is recognized in the pictures given in the papers describingthem.

lchiro HAYASAKA anc.l Shozu HAYASAKA

40

(II)

The Nabeyama fauna, Tochigi
Prefecture.

This is a brachiopod fauna in which thefollowing species have been recognized. (L,length; W, width D. depth: in mm)
Orilwtichia )aPonica HYSK. L, 9:1; W, 97;
D, 61
0. japonica subsp. striata HYSK. L. 75; W, 88
Enteletes acutiplicatus HYSK. (Only 1 specimen) L, 36; W. 39; D. 34
Meekella gigantea HYSI\. L. 100; W, 127;
D, 90
Orthotelitza planoconvexa HYSK. (Only 1
specimen) L, 45; W, 55
0. eusarkos A!HCH subsp. lata HYSI\. (Only
1 specimen) L. ca. 65; W, ca 88; D, ca. 40(?) Davisiella comides (SOWERHY) subsp.
(Only 1 specimen) W. 170
Streptorhynchus sp. indet. W, ca. 40*Produclus (Echinoconchus) defensus (THOMAS). W, ca. 45 testimation)*Spirifer aculiPiicaltts HYSK. L. 35; W. 41*Squamu!aria sp. L, ca. 37; W, ca. 40*Marlinia sp. L, 35; W, 33

This assemblage also gives a deep impression of magnificence when seen in
an array.
In paleontology assemblages of dimunitive fossils seem to have attracted atten·
tion of scientists, and much has been
discussed, and many theories propounded,on· the cause of such assemblages. On
the contrary, assemblages of giant invertebrates seem to have occurred rather
rarely. Occurrences of certain enormous
individuals are on record, however, andvarious explanations have been tried.
DAcQUE (1921), for instance, cites theoccurrence of Oligocene Natica crassalina
in different growth sizes, namely, thespecimens preserved in coarse sand facies
are twice as high as those found in muddy matrix and considered as normal in
growth. The same author mentions asfactors stimulating unusual growth thechanges in temperature of the sea water,
isolation and protection from enemy onislands particularly in case of terrestrial
animals, and so on. The relation between
the growth size and the chemical properties of surrounding sea water issummarized by him as follows ; animals
grow larger in calcareous facies, smallerin pyritic facies. and those in phosphatic
facies are intermediate in size (DAouf:,
1921, p. 37).
There may be many such cases andmany such explanations in geologicalliterature. For the understanding ofsnch phenomena we have refer as muchas possible to the observed facts andresults of experiments in the ecologicalstudies of life in Recent seas. We musthave knowledge on the effects of sediments and sedimentation, chemical,
physical and biological influences of environmental factors on life. In thisconnection we find G. E. MAcGINITE's(1935) studies on the" Ecological Aspectof a California Marine Estuarry " very
instructive and suggestive. In this paper
1\fAcGINITE gives the details of his very
thorough observations during many years
at Elkhorn Slough. It contains manyfacts that are important for geologists
and paleontologists for their paleoecolo·
gical interpretations and explanations ofthings ar.d phenomena at hand. In connection with the problem of dwarf invertebrate assemblages, however, one of therecent papers of Cwun (1948) is very
instructive. In this paper he deals withthe assemblages of dimunitive fossil
brachiopods on record in America. Various cases are analysed, and different
theories scrutinized. After careful consideration he assumes that the following
three cases are possibly responsible for
dwarfed assemblages. Namely,
1) Assemblages of dwarfs (dimunitive adults)
due to physiological retardation of growth,2) Mechanical segregation due to moving
waters,Fossil Assemblages of Molluscs and Brachiopods of Unusually Large Sizes

3) Assemblages of immature specimens arrested in growth or killed young by the changeof evironmental factors.

The three causes Cunm assumes possible for the production of dwarf assemblages similarly function in gJVmg rise
to giant assemblag£s. That is:41

mally large in response, or adaptation, tocutain particular ecological conditions orenvironmental factors.
Thus, our problem is reduced to what
the environmental condition or conditions
can be which provoked unusual growthof the fossils under discussion, on the assumption that such really did exist.

1) Assemblages of unu5ually large individuals

resulted !rom the physiographical acceleration of groy. th.
2) Mechanical scgreg:ttion of giants by moving waters,3) Asscmbl:tges ol individu:.ls gr.Jwn unusuallylarge under changing environmental factors.

Of these three possiblilities 2 may beleft aside with our giant assemblages,
becanse they have particular compositions, one being chietly molluscs and theother almost exclusively* brachiopods,
and contain many smaller species in association. Mechanical segregation does
not seem to have played any importantpart in these cases. 1 and 3 may be
dealt with as in an intimate mutual relation. The influences of the changing
environmental factors may affect organisms through physiological processes
Consequently these two possible causes
may be regarded as a continuous seriesof processes.
Strictly speaking, however, the sameenvironmental factors, or their changes,
may call forth more or less different
responses in different organisms. For
this AMEMIYA's (1928) ecological researches on the Japanese oysters, which
will be referred to later, is suggestive.
Our faunas can be regarded as assemblages of individuals which grew abnor*By the .:ourtesy of S:~buro YoSHIDA we could
see a picture of a Pleut·otomaris-like gastropod
he found in the black. bituminous, brachiopodlimestone of the Nabey.:una region. The
specimen will be examined in a near future.

The environmental factors that haveinfluences upon marine invertebrates aremany as is discussed by 1L\cGINITE, but1) the chemical and physical nature ofwater including salinity, ~) the depth of
habitat, and the character of bottom,
may include most of them. In our cases,
the depth and the bottom characters arerather easy to guess. The majority ofmolluscs and brachiopods are not deep·sea dwellers. The fossils under consideration are embedded in bituminous limestones, which are sediments rich in organic
matter, that is, s:lpropelk, and depositedunder stagnant condition of water, as
is explicitly defined by KRUMBEIN andSLoss in their recent trearise. Such sediments are formed in coastal, shallow
seas, poiisibly seculuded at least partly
from open ocean as almost b.1sins.
The salinity comes into consideration.
"In this regard we find in GRABA:J ( 1931)
an interesting example, as we alreadyquoted by the senior author in his Nabeyama paper. In his voluminous monograph on " the Permian of Mongolia"
GRABAu described numerous species ofof fossils including brachiopods andmolluscs among others. According to
him these molluscs and brachiopods dominantly show dwarf characters, that is,they are as a whole smaller in size than
the same or a~lied forms known from theother parts of the world. lie tried tofind explanation of this phenomenon in
the analogous Rec<'nt ecological facts
observed in and around the Bay of Pe-

42

Ichir6 HAYASAKA and Sh6z6 HAYASAKA

chili, north China. On studying marine
molluscs living in the Bay of Pechili, andcomparing them with the corresponding
forms living outside the Bay, he assured
that the former are decidedly smaller
than the latter. This is considered byhim chiefly due to the subnormal salinityof the Pechili water caused by the greatamount of fresh water poured in by the
Yellow River. Of course it is not only
the fresh water that is brought into the
Bay by the Yellow River, but there isan enormous volume of f1ne debris car·ried down from the loess countries upstream: this must have some important
influence upon the life in the Bay.
GRABAu's (1931) conclusion concerning
the subnormal growth of the lVIongolian
Permian marine invertebrate fauna isthat the Permian sea in that region wasof a similar character as the Pechili Bayof to-day, the salinity of the water having
been subnormal as compared with thatof the more open sea of the other partsof the world.
The significant bearing of the change
in salinity of sea water on the life ofmarine invertebrates is exemplified in
AMEMIYA's (1928) ecological studies on
the oysters of Japan, as mentioned above.
He made observations and experimentsin the natural habitats and in laborato·
rium concerning the effects of changeof salinity on the growth of oysters ofseveral kinds. From his conclusive remarks we like to quote that:
1) there is the optimum of salinitY ;either too high or too low has an unto·
ward effect upon reproduction, and 2)
the suitable salinity for development inexperimental studies coincides with theactual salinity of the natural habitat of
the full grown oysters.
To speak of the optimum, it must bein each of the environmental factors, intheory, and, consequently the relation
between environmental factors and or·
ganisms is a quite complicated matter.
But if the conclusions of AMEMIYA on
the Recent oysters hold true to a considerable extent with the other marine
invertebrates both living and fossil, thenwe can not expect a high salinity as thefactor stimulated the molluscs andbrachiopods to grow unusually large, as
the senior author assumed in his Nabeyama paper, in this case the term
growth meaning the uormal continuouschanges from young to adult. It is because an unusually high salinity is anadverse condition for the animals to live
under, just like a subnormal salinity
causes damages to life. As a matter offact the Zechstein faunas of Europe are
known to be dwarfed because of theZechstein sea having been too high insalinity (MAcGINITE, 1939). Perhaps acase observed by 1-·fAcGINITE on California shore may be mentioned here as an
example of the lethal effect of abund·
ant fresh water flowed into a shallow
sea on the life therein. There may be
many such cases which are useful data
for the study of paleoecology. By wayof referring to MAcGrNITE, he gives aninteresting account of his observation on
the effect of bottom material on thegrowth of Schizohaerus 1tuttali in Elk·
horn Slough, California (MAcGINlTE,
1935 &' 39 a). The individuals living onloose sandy zone are the largest in growth,
those on the heavy clay soil the smallest,
and those inhabiting the Zostera groundintermediate in size. This almost cor·
responds to the case of Oligocene Natica
cmssatina referred to by DAcQulb ( 1921),
cited above.
Concerning the problem of unusuallylarge growth there is very much more
to be investigated and contemplated.
First of all we have to look for examples

Fossil Assemblages of Molluscs and Brachiopods of Unusually Large Size

comparable to the Japanese occurrencesof the Permian assemblages discussed inthis article. Ecological observations in
the actual seas and inhabitants there
must be extended to the assemblages of
unusually large growth. At the present
stage of our knowledge, however, we can
not but try a tentative conclusion, that
there is the possibility of the gigantic
Permian fossil assemblages being theresult of pathological plumpness, that is,
hypertrophy. This, in turn, is consideredclosely related with the saproplelic natureof the marine sediments which were deposited in certain basins of lirnitccl
extensions. Hypertrophy, in passing, isoften a symptome of extinction of theanimals. The so-called Anthracolithic
fauna of Balia Maaden in Asia Minor(ENDEIH.E, 1900) also is in part, at least,preserved is a bituminous limestone, andconsists of some huge specimens of gastropods (Pleurotomaria, JHurdu'sonia) andDmtalium. The huge forms in this faun:t
also have symptomes of hypertrophy, andmay represent an occurrence comparable
to some extent with the )ap:tnese ones.
One thing interesting to note before
concluding this note is that in l\·fongolian
Permian dwarf fauna Spirifcrs alone arerecognized by GRABAU (1931) to be innormal size of growth. The reason is notclear at alL Among the fossils of theJapanese Permian faunas also Spiriferidsof Kinshozan and those and a Productus
of Nabeyama are of sizes generally con·sidered as normal, as is evident in thelist of species given elsewhere. This is
an interesting coincidence. This may be
explained for the time being that Spiriferids are stable, and mor<l resistantagainst the adverse life conditions thanthe other groups of brachiopods, this
explanation involving some unsolved pro·blems. However, the similar differential

43

adaptation may take place in some othergroups of marine invertebrates, as issuggested by some minute kinds of fossils foun::l as members of the assemblagesof giants.
REFERENCESAMEMIYA, I. (1928) :-Ecological Studies ofJapanese Oysters, with Special Reference to
the Salinity of their Habitat>. four. College of Anric., Imp. Univ. Tokyo. vol. 9.
110. 5.
CLOUD. P. E, Jr. (1948) :-Assemblages of Di·
minutive Brachiopods and their Paleoecological Significance. four. Scdime11tary
Petrology, t•n/. 18, 110. 2.
DACQUf:, E. (1921) :-Vergleichende biologische
Formenkunde der fossilen niederen Tiere,pp. 174-176. textfig. 48. This is a p:1rt of
the author's very elaborate discussion on
the fundamental form and the size of body("Grundform und Korpergr(h>e der TypC'n.")

DAC<)UE, in his "Organische 1\Iorphologie undPaliiontologie" (:935), remarks that :momalously large forms (Riss~nformen) do notoccur in the earlier stagrs of evolution of
any group3 or particu'ar lineages of animals( p. 202). This means that the gigantic
growth is on the way to extinction
ENDERLE, j. (1900) :-Ueber eine Anthracolitische Fauna von Bali a .Maaden in Kleinasien.
JJeitr. z. Palaeontol. Oestcrr-Unga1t1s 11. d.
Orients, Bd. 13.
GRABAU. A.\V. (1931) :-The Permian of Mon.
golia; Nat~<ml History of Central Asia, vol. 4.
HAYASAKA. 1. (1925) :-On Some Paleozoic
Mollusca of ]:lpan, I. Lamellibranchiata andScaphopoda. Science RePorts. Tohok11 Imp.
Univ .. 2nd scr. (Geology). vol. 8. no. 2.
- - , (1932) :-0:1 three Brachiopod Speciesof the Subfamily Orthotetinae in theFusr~lina· Limestone of Kinsboz:m, Aka·saka·Mati, Prov. Mino, Japan. Mem. Fac.
Sci. and Agric., Taihoku lm. Univ, Tmwa11,
vo/. 6, 110. 1. The three species describedin this paper are not from the black, bituminous zone but from a lower one. But
in this paper on older Japanes~ note de:~lt

44lchiro IIAYASAKA and Shf>zii IIAYASAKA

with the occurrence of 3 Reticularias and a
Terebratuloid (?) in the former is reviewed.
HAYASAKA, 1. (1933): -On the Upper Carboniferous Brachiopod Faun1 from the
Nabeyama Region. Totigi Prefecture,
Jap:m. Mem. Fac. Sci. Agric., Tailzoku Imp.
Univ, Taiwa11, vol. 6, tto. 2.
- - , (1938) :-Two Species Trachydomia fromJapan. /\femoirs. Faculty of Science andAgriculture, Taihoku ImP. Univ., Taiwan,
vol. 22, 110. I.
- - . (1939):-Spirompha/us, a New Gastropod
Genus from the P.:rmian of Japan., Ditto,
1/0. 2.
- - . (19l3) :-On Some Permian Gastropods
from Kinshuzan, Akasaka-Mati, Gihu Prefecture, pt. 1 (the only part published).
111cm. Pac. Science. Tailzok11 Imp. Univ ..
Taiwan. scr. 3. vol. 1. 110. 2.
KNIGHT, J. B. (1913) :-The Gastropods of the
St. Louis. Missouri, and Pennsylvanian Outlier: The Ps"udozygopleurinae. founwl ofPaleontology, t•ol. 4. SuPPlement .1. Spiromplwlus is a small species. but still it islarger than species of PseudozygoPleum.
KRUMREIN, W. C. and Sr.oss, L. 1.. (1951) :Str:.tigraphy and Sedimentation, p.l46. The
authors remark that in bituminous organicrock> " There is a complete range fromslightly organic to highly organic sediments.
Moreover, distinctions between humic andbituminous s:-iments are not always clear ..
... " In our cas? neither of the limestones
have been chemically studied.
MACG!NITE, G. E. (1935) :-Ecological Aspectsof a California Marine Estuary. Amer.
Midland Naturalist, vol. 16, 110. 3. Theremay be many other, more recent works
by this author on the similar subjects.
We refer only to those within our easyreach.
- . (1939) :-Some Effects of Fresh Wateron the Fauna of Marine Harbor. Amer.
Mit/land Naturalist, vol. 21, 110. 3.
- , (l!l39a) :-Littoral l\brine Communities.
Amar. Midland Naturalist, vol, 21, 110. 1.
NAGAO, T. and MIN ATO, M. (194..1) :-Parafusu/ina kaerimizuensis aus der unterhalb
der Brachioponden-Zone liegenden Schicht
in der Gegend von Nabeyama. four. Geol.
Soc. ]aPall. Vol. 50. 110. 601.
OZAWA, Y. (1927) :-Stratigraphical Studies ofllw Fusulina Limestone of Akasalm, Province Mino. ]om·. Fac. Sci .. Imp. Ut~iV.
Tokyo, ser. 2. vol. 2. Part 3.
SlllJ{AMA, T. (19t9) :-The Kuzuu Ossuaries:
Geological and Palaeonotological Studil's of
the Limestone Fissure Deposits, in Kuzuu,
Totigi Prefecture. Sci. Rep. Tohokr1 ImP.
Univ .. 2ud ser. (Geology), vol. 23.
WAl\lMIZlJ, T. (1902) :-The Limestone Formation of Kinshozan, Akasaka, Province
Mino (in ]lp:mese). four. Gcol. Soc. Tokyo(JaPan,a{lerwards), r:o/.9, pp.71-75; 163169: 205-212; 331-339; 1 pl.
YARE, II. and HAYASAKA, I. (1915) :-Palaeozoic
Corals from Japan. Korea and China. four.
Geol. Soc. Tol1yo, vo/. 22. Romingeris (?)
Kotoi and Lmzsdaleia ( WaagenoPizyllum)
a!Uisal~et~sis are described.

Explanation of Plate 5
Fig. 1. Bellerophon jmzcsianus DRKoN!NCK. Natural size. This is the largest specimen we haveseen, but we have no reas~n to say that this is the largest specimen of this species hitherto
discovered at Kinshozan. because it is not pn~sible for us to examine all the specimens in various rep'>sitories in Japan. This specimen measures 130 mm. in height and 124 mm. In width.
Many other specimens we have had chance to see are, on an average, not much smaller than
3/4 in height of the specimen here pictured.
Fig. 2. 01thoticlra japouica IIA YASAKA. Natural size. This is not to represent the largest size of
this species. but i3 pictured to show one of the specimens discovered at other locality than
Kadosawa where the original material of the Nabeyama fauna was found. This and a few
other specimens were collected by Saburo YoSHIDA in the black, biteminous limestone developed at Yamasuga. Here the bituminous limestone does not contain fusulinids, and lies between
Fusulilla·limestones with Parajusuli11a kaerimizue11sis. YoSHIDA presenttd to us several specimens of this species he collected at Kadosawa \vhich used to he very popular at this place.

HAY ASAKA

and HAY AS A KA • Fossil Assemblages

KUMANO photo.

PrAT E

5

Tran3. Proc. Palaeont. Soc. Japan, N. S. No. 10, pp. 'J.S-54, 18 text-figs., July 31, 1953.

233. MIOCENE FORAMINIFERA FROM THE SHINTOTSUGAW A
AREA, KABATO-GUN, HOKKAIDO*KIYOSHI ASANO
Institute of GeoiJgy and P.1leontology, Tohoku University:ft7¥i!t~<.P11S.tJi-t·ntJJIJl!!~"J rt~~ifrfffl!ltllf: f.rHitJJijjp,!~vJIF.fJf:l::ti!!i~~MU.!: ~-H!tJII M*0') ~. t!\ ~~(!fi ">fi i'L!lu: J,;J ~r.z: t Q) :r it€ t... 1~~;~:. JlfJ'/'i·c.n? tt '1:-~»:tb r.c ;W;Il! O'J~tiJillf-.t.'5tl1 :$liif.l O'Jfft O.li'tK ~ Jt;; .t~- Q "'t"b b '> ;0:. :f: 0') 5 "b 1.:: •11 ~iltKJ:R b h. Q fl'fl!lt S"tr c l: »·I>. !it'J:~- a- rJ 1 $1Cf11'1rl.!t, 1~ ~ 2: .l:l'$t(J11fllt l:. L tr: o :f: ;tL b "J :flfL·x· »· ;u c K5f tt ; tt.::. ;0:. rilr1";· tr· ; ~.:t ~HI
< v.

a:

.!b..ifri.fm"JtitE:@!it~·l!'b./1-"('~·?.o

i~

!Jlf

i,Jf

The Nishitoppu group consists of two
formations. The lower, Soshi fo:·mation
rests nnconformably on the Kabato
Paleozoic complex and contains megafossils, such as Ostrea, but no Foraminifera. The npper, Wakkauenbetsu
formation, m::l.inly consisting of (brkgray or black siltstone, contains a richforaminiferal ass:!mblage at many outcmps around Yoshino-machi, Shintotsugawa-mura, Kabato-gun. The localities,
which yielded the Foraminifera herein
reported, are :Introduction
This paper tre:1ts smaller Foraminifera collected by Prof. S. HANZAWA
and Mr. S. h.uNISIII from the Shintotsugawa area, Kabato-gun, Ishikari province, Ilol<kaido, in 1950.
A condcnced summary of the Tertiary
stratigraphy of the said area CIIANZAWA
and lMANISHI, 1951) is as follows:
Oshirarika group (Pliocene)......... Unconformity ........ .
Shintotsugawa group (Upper Miocene)
Gakuem;awa formation; siltstone intercalatin~~
tuffaceous sandstone. conglomerate at thebase. 250 meters.
Chashiparomanai formation ; siltstone. -120300 meters.
Toppu form:J.tion ; alternation of siltstoneand shale, sandstone at the base. 350-300
meters.
Rukushubetsu formation; tuff, sandstone,
conglomerate. 75·5 meters.
......... Unconformity ........ .
Nishi-toppu group (Middle Miocene)
Wakkauenbetsu formation; siltstone interca·
lating sandstone and conglomerate. 500
meters.
Soshi formation: tuff, sandstone, con·glomerate. 100 meters.
......... Unconformity ........ .
Kabato Paleozoic complex

IMANISIII Loc. No. 151 : Toppu river cliff:! km southwest of Yoshino-machi
Loc. No. 526: Nuttapu-river cliff, 2 km,
north of Yoshino-machi
Loc. No. 531: Nuttapu-river cliff, 2.5 km
north of Soshi, Yoshino-machi
Loc. No. 787 : Hamamasu, 0.5 km northof Soshi, Yoshino·machi
Loc. No. 868: Penkepetan-river cliff, 2 km
s~uthwest of Kokuryo, Uryu-muraLoc. No. 1017: Wakkauenbetsu-river cliff,
0.6 km west of Yoshino-machi
Loc. No. 1018: Wakkauenbetsu-river cliff,
0.8 km west of Yoshino-machi
Loc. No. 1022:
lnuno-s:~wa,
Wakka,
Yoshino-machi
Loc. No. 1028: 0.6 km west of lnunosawa, Wakka, Yoshino-machi

45

46

Kiyoshi AsANO
Loc. No. 1029: 0.7 km west of Inuno~"lWa, Wakka, Yoshino-machi
Loc. No. 1930: O.!lltm west of Inunosawa, Wakka, Yoshino-machi
Loc. No. 10·t3: Rukushubetsu·river cliff,
1.3 km southwest of Yoshino-machi
Loc. No. 1049: Rukushubetsu-river cliff,
2 km southwest of Yoshino-machi

The Shintotsugawa group, consistingof four formations, overlies unconformably
theNishi-toppu
group.
Foraminifera are common in all of theformations of this group except thelowest, Rukushubetsu formation. The
following localities have yielded Foraminifera dealt with:
Rukushuhetsu formation
lMANJSIII Loc. No. 322 : Rolwgosen-rivercliff, 3 5 km southwest of Gakuen,
Shintotsugawa·muraLoc. No. 835: Oshirarika-river cliff at
Gorobuchi, 4 km southeast of Kokuryo,
Uryu.mura
Toppu formation
lMANISIII Loc. No. 76: Sopuchi-river cliff,
1.7 km west of Yoshizawa, ShintotsugawamuraLoc. No. J..J,6: Toppu-river cliff, 1.2 km
sout:h of Yoshino-machi
Loc. No. 175: Rokugosen-river cliff, 3 km
south of Gakuen, Shintotsugawa-muraLoc. No. 176: Hokugosen·river cliff, 3.2 km
south of Gakuen, Shintotsugawa·mura
I.oc. No. 208: Yongosen-rivcr cliff, 1.5 km
southeast of Gakuen, Shintotsugawa·mura
Loc. No. 231: Icnigosen-river cliff, 3 l<msoutheast of Gakuen, Shintotsugawamura
Chashiparomanai formation
lMANISIII Loc. No. 88: Sugiharadani-rivercliff, 2.5 km west of Sopuchi, Shintotsugawa-muraSugiharadani-river cliff,
l.oc. No. 89:
2.6 km west of Sopuchi, ShintotsugawamuraLoc. No. 170: Rokugosen-river cliff. 2.8 km
south of Gakuen, Shintotsugawa-muraLoc. No. 326: Rokugosen-river cliff, 4 km
southwest of Gakuen, Shintotsugawa·mura
Loc. No. 330:
Hachigosen-river cliff,
Chashiparomanai, Gakuen, Shintotsugawa-muraLoc. No. 503: Toppu-river cliff, 0.5 km
east of Yoshino-machi
Loc. No. 1076: \Vakkauenbetsu-river cliff,
Yoshino-bridge, Yoshino-machi
Loc. No. 1106: Yoshitsu-sawa. Oshirarikariver, Shintotsugawa-muraGakuenzawa formation
lMANlSBI Loc. No. 378: Gakuenzawa-rivercliff, 3 km
northwest of Gakuen,
Shintotsugawa-muraLoc. No. 507: Nutappu·river cliff, 1 km
east of Yoshino-machi
Loc. t{o. 516: Toppu·river cliff, 1.5 km
east of Yoshino-machi
Loc. No. 1082: Nuttapu-river cliff, 0.9 km
east of Yoshino-machi

Here, the writer expresses his cordial
thanks to Prof. S. HANZAWA and Mr.
S. lMANISHI for submitting their collections to the present study.
Faunal Consideration
An analysis of the composition andrelative stratigraphic ranges of theforaminiferal assemblage fromthetreated area reveals that, (1) the
Wakkauenbctsu
foraminiferal
assemblage is quite distinct from those of
the overlying Shintotsugawa group andthat, (2) the characteristic associationof the Japanese Miocene Foraminifera,
especially of the oil-fields in Akita,
Yamagata and Niigata prefectures also
occurs in Hokkaido.
The Foraminifera from the Wakkauenbetsu formation (Table 1) consistsof 51 species. These species indicatethat the formation was deposited in themedium-depth zones, such as in the
neritic or bathyal. Of the species,

Miocene Foraminifera from the Shintotsugawa Area, Kabato.gun, llokkaido
Table 1.

~1ties--- .
Specie!'Ammobaculilcs sp.
Ammodiscus sp.
Angulogeri lltl l111ghcsi
BathysiPhon sp. (A)BathysiPhon sp. (B)
Bolivina 1111t·gi11ata
Bulimi11a i t1jlata
Buli milia ot•ata
Cassidulina laevigata
carina/a
Cassidulina margareta
Ci/Jicidcs akncrirmus
Ci/Jicidcscf. a/lamiracnsis
Cibicides cf. lobatu/us
Cyclammina ctmccllala
Cyclammitm czocnsis
Cyclammitla inci.m
Cyclammina Pusil/aDentalina sp.
Discorbis sp.
Ehrcnbergina nolocnsis
Entosolct:ia squamosa
Enloso/enia sp.
G_audryina sp.
Globignitlfl spp.
Gyroiditw soldanii
Hap/oPizragmoidcs
canoriemis
HaPlaPhragmoides ret:zi
IfaPioPhragmoides
trullisotum
LagetJa striata
Martinottiella communis
Nodosaria sp.
Nonion PomPilioides
Nonio11 sp.
1\.'onione//a lzonzawai
P/ec/ofrondicu/aria
japonica
1'/cctofrondicularia
mioceuica
Plectofrondicularia sp.

47

Foraminifera from the \Vakkauenbetsu Formation.
151 1526

531

787

-

-

F

R
-

-

-

-

-

-

-

-

-

R

-

-

-

A

F

-

c
-

F

-

-

-

-

-

86B

1017 1018 1022 1028 1029 1030 1043 1049

1-

-

-

-

-

R

-

-

-

-

F

-

-

-

R

-

-

R

-

-

-

-

F

-

-

-

-

-

-

-

-

R

-

R

-

-

-

-

R

-

-

-

-

-

R

-

-

-

-

-

R

F

-

-

-

-

-

-

-

-

-

F
F

-

-

F

-

-

-

-

R

-

-

-

-

R

-

-

-

R

R

-

-

-

-

-

R

R

R

R

R

R

R
R

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

I~

-

-

-

-

F

-

-

-

R

R

R

R

-

-

-

-

c

-

-

c

-

-

-

-

R

R

-

-

-

R

-

R

c

-

-

R
R

-

-

-

R

R

-

-

-

-

-

-

-

-

-

-

-

R

-

R

R

-

-

c

-

-

-

-

-

-

-

-

-

-

-

-

R

-

-

-

-

F

R

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

R

R

-

-

R

n

-

-

-

-

R

-

-

-

-

-

-

-

R

-

-

-

-

R
R

-

R

-

-

R

R

F

-

-

-

R

-

-

-

-

-

-

-

F

-

-

-

-

-

-

-

-

-

-

-

F

-

-

-

-

-

-

-

-

-

F

R

-

-

R

-

-

-

-

I

-

-

-

-

1~

-'

-

-

-

-

-

-

-

R

-

-

-

F

-

-

-

-

-

-

-

-

-

-

-

-

R

t--

-

F

-

R

-

R

F
-

-

-

-

-

-

-

-

-

-

-

-

R

-

-

-

-

-

F

-

-

A

-

R

-

-

-

-

Kiyoshi ASANo

48

~~
.
. Specres

Localities-~--------~-~

151 526 531 787 8f8------- _ _ __ _ ___Pullmia bulloides
Pt1/lenia sp.
Quinqueloculina sp.
Robulus calcar
Robulus sp.
Rotalia locltigitm.~isRotalia yubariensis
SpiroPlectammina
11iigataensis
Textularia sp.
Trochammi1w niPPonica
Trochammina cf. pacifica
U11igerina proboscidea
Uvigerina subPercgl'ina
Valvulincria niPPouica

R

R

R

c

F

1~17! 101811022 1028 102911030: 1043 1049!I
--

-i

F

-

-

R

-

-

-

-

-

-

R
R

F
F

R

-

R

-

-

-

-

-

-

R
F

-

-

-

-

-

-

F
F
R

R

F

-

F

-

-

-

-

R

-

R

-

-

-

c

F

A

A

-

-

F

F

c

-

c
-

c

R

F
R

R
F

-

-

c

-

-

-

-----

--i

-

-

F

----

'

I

-

-

-

R

-

A

-

-

R

A: Abundant, C: Common, F: Few, R: Rare.

SPifoPlcctammina uii'gataensis, Bathysiphon sp. (A), Tt·oclzammiua nipponica.
n. sp., 1/aplophragmoides irullisatum,
Plectofrondiczelaria japonica, n. sp.,
Nonionella llanzawai, n. sp., Valvzelineria
uiPPmzica are represented by a large
numb:!r of individuals. These species
except for the ones described herein as
new to science are commonly found in
the so called " Black shale " formations
in Akita, Yamagata and Niigata
prefectures. LithologicaiJy, the Kubikiformation in Niigata prefecture, Funakawa formation in Akita and Yamagata
prefectures, and Wakkauenbetsu formation under consideration arc very
similar, consisting of mainly black orgray siltstone. Their similar lithology
and correlative foraminiferal assemblage
suggest that they may have been
deposited under similar environmental
condition of the medium-depth zones.
The " Black shale" formation often
intercalates locally tuff or agglomerate.
Where intercalation of volcanic material
occurs (Loc. Nos. 526, 531 and 1017),

somewhat different assemblages arefound in the silty part; for example,
large forms of Cyclammina, T~ ochammi11a, or Bathysip!tou, such as, C.
ezocnsis, C. cmzcellata, T. niPPo11ica or
B. sp. (A) are found to be dominant
and no calcareous Foraminifera arefound in association. This suggeststhat the larger forms Cyclammiua,
Tt·ochammina or BatllysijJ!tmz prefer amuddy sea bottom, due to volcanic
activity or other agencies. It the Recent
deposits around Jap::m, smaller forms ofarenaceous Foraminifera are usuallyfound to be accompanied with calcareous
Foraminifera, but larger forms of
Cyclammina
cancel/ala was foundabundantly in only one station (H 113,
Lat. :!5° 151 1011 N., Long. 140° 46' E.),
off Bi>sb Peninsula, by the S6yo-m::truof the Fisheries Experimental Stationin Tokyo, during her oceanographicalobservations and dredge operatio:l on
the continental shelf of Japan. The
bottom characters of the station wasrecorded as gravels and clays and the·~9fvliocenc Foraminifera from the Shintotsug;>Wa Area. Kabato-gun, llol:kaido
Table 2.

depth was given as 196 meters. The
ecological factors* govering such anabnormal fauna has not yet been
ascertained.
The foraminiferal assemblages fromthe Shintotsugawa group are ecologically more diverse than those of the
Wakkaucnbetsu. Foraminifera from the---Species

Table 3.

Foraminifrra from the Rukushubetsu
Formation.

----- -------~_§>ecies

J ocalities-

Cri/JroelPhidittm imanislzii
HoPfoPhragmoides spp.
Trocllammina niPPonica

322 835- -- F--c
F

Foraminifera from the Toppu Formation.
Localitit;~---

Ammobaculites sp.
Bulimina ova/aBulimina Pyrula
Cassidulina laevigata cathtata
Cyclammi11a cancellataG)'clammina incisa
Epanides sp.
Epjstominel/o japonica
Globigerina spp.
c;y,·oidina soldanii
HaPlaphragmoides ca11ariensis
HaPloPhragmofdes lm/lisatum/tlfar/ino/tie/la COIIIIIIIWiS
No11ion PomPilioides
Nonionel/a miocenica
Pu/lenia bulloides
Spjroplectammi 11a niigataensis
Trochammiua uiPPonica
Troclwmmit1a ct. Pacifica

_I

76

1

l<l<i 1175

1;--1~- ~-II

R

-

176

208

231

R

c '

c

c

c

F

R

R

F
R

R

F

R

F

R
F
R

F
R

-R
F

c

F

R
R
R

F
F

R

A: Abundant, C: Common, F: Few, R: Rare.

* R. M. STAIN FOR fll stated iA his letter tothe writer (Nov. 3, 1951); ·'My conclusion
has been that the ecological factor causing
such an abnormal fauna is turbidity of thesea water. The turbidity may be due torapid deposition of shaley sediments as in apiedmont facies or in a graben-trough, or in
an area of rapid !loculation of clay colloids,
off the mouth of a big river. The fossil
examples which I have studied in several
countries S'em to give support to this idea.
but I have never encountered a Hccent
fauna of the same type which could be used
to check my deduction."lowest, Rukushnbetsu formation consistsof littoral forms (Table 2), but thosefrom the Toppu, Chashiparomanai and
Gakuenzawa formations (Tables 3-5)
are mainly neritic or bathyal types, as
represented by the Buliminidae, Cassidulinidae and Globigcrinidae. There
are also abnormal faunules consisting
only of larger forms of arenaceous
Foraminifera in some localities (Loc.
Nos. 208, 835, 1106).
In general, the Shintotsugawa forami-

50

Kiyoshi AsANO
Table '1.

Foraminifera from the Chashiparomanai Formation.

--------88
89
170 326 330 503 1076 1105
I- - - - - - - - - - - - - - - - - - I

Batlzysiplzon sp. (A)Bulimina i11jlata
Bulimi7Ja ova/aCassidulimz laevigata carina/aCassidulimz margarcta
CribroeiPhidium imanishii
Cyclammina cancel/ala
Dentalina sp.
EPislominella japonica
EPouides sp.
Globigcrina spp.
Hapiophragmoides amarieusis
HaPioPizragmoidcs tmllisatum!vfarliuottiella communis
Nonioue/la cf. Pulclzella
Pulfenia aPerlula
Qui7Jqueloculina vulgaris
SpiroP/ec/ammiua uiigatacnsis
Troc/wmmina uiPPouica
T10chammi11a cf. Pacijica11
Ut·igcri1W sp.

F

R

I

c

c

R

R

F
R

c
I

-

F

F

R
F
F

c

R

R
F

R

F
F

R

F

F
R

F

R
R

R

F

R
F

F

R

R

F
R

l ____ - - - - - -RFR

C: Common, F: Few, R: Rare.

niferal assemblages, although
theybelong to four rock-units, are distinct
from the underlying Wakkauenbetsu
assemblage ; Cribroelphidium imauisllii,

Nonionella
miocenica,
Epistomitzellajaponica, Nmziotzel/a cf. pulclzel/a andVirgulit~ella mioce11ica are characteristicin
thisgroup, while Nonionella
hanzawai, Plectofrondicularia jajJonica,
P. miocmica, Bolivina marginata, Rotalia
tochigieusis, R. yubariensis and Valvu·
lineria 11iPPonica are limited to the
Wakkauenbetsu (Table 6).
Thus, there is a sharp line! between
the faunas of the Wakkauenbetsu andShintotsugawa, which seems to berelated to the unconformity between
the two.

Age Consideration
A geosyncline was formed along theJapan Sea coast in the middle Miocene
age, in which the Onnagawa siliceous
shale, Funakawa black shale and theKitanra alternation of sandstone andshale and its equivalent formations were
deposited (S. J-iANzAWA, 1!:151). The
Wal<kauenbetsu formation, as abovestated, is correlated to the Funakawa
black
shale
and
the
overlying
Shintotsugawa group to the Kitaura
formation.
In the middle and late
Tertiary, however, a pronounced pro·vincialism affected the faunas, and thestratigraphic ranges of Foraminifera ofthese ages vary in different. areas evenin the same geosyncline, thus it is very

l'vtiocwe Foraminifera from the Shintotsugawa Area, Kabato-gun, Hokkaido
Table 5. F raminifera from the
Gakucnzawa Formation.

difficult to determine the geological age
according to international standard.
However, a comparison of the present
assemblages with those of regions inwhich the foraminiferal sequences havebeen studied in detail is useful in~bowingthedistribution of thecharacteristic species over wide areas.
The Gakuenzawa for~lminiferal assemblage which is the youngest foraminiferal sequence of the treated area
contains species which are dominantly
found in the Upper or Middle Miocene
formations of the Northwestern America,such as Nouiouella mioce11ica andVirguliuella miocenica.
Furthermore,
the Gakuenzawa Foraminifera consistsof many species which are usually foundin the geosynclinal deposits of theNorthwest Honshu.
Thus, in conclusion, it can be said
that the Shintotsugawa assemblages
represent the Upper Miocene for.uniniferal sequence of the Japan Sea Coast,~- . _ _:ocalities 137811 £071516110821- - - -~ ~--~~-~

SpeCJes

AF I CR

Bulimina om/aBuli.'ll.ina Pyru/aComusPira sp.
EPislominclla jaPonica
Globigcrina spp.
G/omosPira sp.
HaploPhragmoides sp.
Lagena perluc•daNoniou pomPilioides
Nonionella mioccnica
Nonionclla cf. Pulclwl/a
Pullcnia sp.
Spi mPlcctammi na
niigcllaensis

A

R

R'
Rl
R
R!

-I

~I

R

c
c
c c

R
A

R
R

c c

R

c

Trochammina nipPonic,lTrochammina cf. pacifica
Ut•igerhw cf. hoo/si
Virgulinel/a mioccnica

F
F

R
R

51

F

A: Abund;mt, C: Common, F: Few, R: Rare.

Table 6. Stratigraphical Distribution of the Characteristic Foraminifera fromthe Shintotsugawa Area.
~u-

Formations

Gakuenzawa! Chashiparomanai

Localities

507 546 1082189 326 330 lt07f .175,176 231
R
R

c c

-

-

~

-

-

-

-

F

~

-

~

-

-

c c
R
- - I- F R c cI- - F- c - - - - - - - - - - - - - -

-

-

A

R

-

-

~

~

~

~

~

I

-

R

-

-

-

-

151 787 102210·1:l!Ot9

-

-

-

-

F

-

F

-

-

c
-

-

-

F
-

-

-

-

c

F

-

-

-

R

R

-

-

-

~

~

-

-

~

~

-

-

-

-

~

-

~

-

-

-

-

-

-

-

I-

-

-

-

-

II

-

-

I

~22

-

-

-

I

\Vakklllcnhetsu

ku.

-~;-

-~~~

SpiroPiectammitw
niigatacusis
Vi rguliuei/Cl mioccnica
Nonionella cf. Pulchclla
Epistomiuella japonica
Nonionclla miocenica
Cribroc!Phiclium imanishii
Boliviua m~rgiuata
Nouionella ltanzawai
Plcctojrondicularia
mioccnica
Plectojrondicular:ajaPonica
Rotalia tochigieusis
Rota/ia yuborirmis
Va/ullttfineria 11ipponica

Toppu

I

- - - -

A: Abund:mt, C: Comn}On, F: Few, R: Rare.

.

-

-

-

F

- -

- c
- I R

R

A

F

F

F

R
F

F

c c

R
F

1\iyoshi ASANO

52

while the underlying Wakkauenbcts·t
can be correlated to the Funakawa andKubiki and is Middle Miocene.
Description of New Species

Nonionella llauzawai AsAKo. n. sp.
Tt•xt-figs. 4 a ..c.

Test sub_globular, slightly longer thanbroad, consisting of. about 7 chambers,arranged inequilaterally,
increasing
rapidly in size as added, much inflated,ventral lobe of last chamber extending
across umbilical area nearly to pe·riphery, with several small lobelcts at
margin; sutures depressed, gently
curved; wall smooth; aperture at baseof apertural face. Length up to lmm.
Ho/otype: Institute of Geology andPaleontology, Tohoku University coli.
cat. no. 75286. Hamamasu, 500 m. northof Soshi, Yoshino-machi (Lat. 43° 3'1' 30'1
N., Long. 1H0 431 30'1 E.), Wakka·-~~~~~----~----~-

ucnbetsu formation, l\fiddle Miocene.
Remadls: Differs from both N. globosa
Is !II w ADA and N. turgida digital a
NoR\' ANG by the more globular test ofwhich ventral lobelets are not completelys~·parated from each other.
This is acharacteristic species in the Middle
Miocene Wakkauenbetsu formation of
Hokkaido.

Cribroe/Pilidittm ima11isllii AsANo, n. sp.
Text-figs. 11 a, b.

Test planispiral. compressed, peripheryrounded, slightly lobulated ; chambers
10-15 in last coil, umbilical region
somewhat depressed, often filled with
granular !>hell material ; sutures gently
curved, depressed in later ones, retral
processes usually indistinct, short andnumerous ; wall smooth, somewhat
inflated; aperture low openings at baseof apertural face, with small circular·----

Explanation of Text-ligures
Figs.
Fig.

1-2.
3.

Figs.
Figs.
Figs.
Figs.
Figs.

4 a-c.
5 a-c.
6 a, b.
7, 8.
9, 10.

Figs. 11 a, b.
Fig. 12.
Fi.~.

13.

Fig. 14.
Fig. 15.
Fig. 16.
Figs. 17 a, b.
Figs. 18 a, b.

BathysiPhon sp. (A) x 25 Loc. no. 1049, Wakkauenbetsu Formation
SpiroPfectammina niiga/acnsis AsA:so and lKOMATA x25 Loc. no. 1049, \Vakkauenbetsu Formation
Nonioncl/a hanzawai ASANO, n. sp. x 25 Lac. nu. 787, Wakkauenbetsu Formation
Trochammina nipponica ASANO, n. sp. >< 2.5 Loc. no. 1028, Wakkauenbetsu formation
Nonionel/a cf. Pulchel/a HAD.\ x 25 Lac. no. 507, Gakuenzawa Formation
Bulimina ova/a n'ORBH;NY x30 Loc. no. 507, (;almenzawa Formation
P/ectofrondicu/aria jaPonica AsANo, n. sp. x :~o Loc. no. 1049, Wald<auenbetsu
Formation
Cribroc!Phidium imanishii AS,\!'\0, n. sp. x 25 Loc. no. 89, Chao;hipJromanai
Formation
Bulimina iujlata n'ORRIGNY x30 Lnc. no. 151, Wakkaucnbetsu Formation
Uoigerina Proboscidea SCIIWACER x40 Loc. no. Hl49, Wakkauenbetsu Formation
P!ectofromlicularia miotenica CUSHMAN x 25 Loc. no. 10-19, Wakkauenbetsu
Formation
Ptcctofrondicularia sp. x 23 Loc. no. 151, Wakkauenbetsu Formation
Virguliilella mioccnica Cl!SIIMAN and Pol\T0:-1 x30 Loc. no. 507. Gakuenzawa
Fornution
Rotalia /ochigicnsis UCIIIO x 25 Loc. no. 151. Wakkauenbetsu Formation
Noniom/la miocc11ic.1 CUSHMAN x 25 Loc. no. 1082, Gakuenzawa Formation

53

Miocene Foraminifera from the Shintotsugdwa Area, Kab:tto-gun, Hokkaido

4 c

4 b

4a

2

1

6 b

6 a
5 b
5 a

11 b

10

11 a

7

16

15

17 a

17 b

18 a

18 b

54

Kiyoshi ASANO

pores on central portion of aperturalface. Diameter up to 1.4 mm.
Holotype: Institute of Geology andPaleontology, T6hoku University, coil.
cat. no. 75287. Sugiharadani, 2.6 km
west of Sopuchi, Shintotsugawa-mura,
Kab:tto-gun (Lat. 43° 3::!1 50'' N., Long.
141 o 50' E.), Chashiparomanai formation,
Upper I\1iocene.
Remarks: Differs from C. czocnse(AsANo) by the smaller test of which
the umbilical region is not so strongly
umbonated.
This is perphaps anancestral form of C. ezoetzse. It also
occurs commonly in the Nakayama
formation in the Joban Co:ll-fielcls.

Trocltammina mppouica AsANn, n. sp.
Text-figs. 5 a-c.

Test much compressed, hrge, composed of two coils, periphery angled :chambers 5 or 6 in last coil, increasing
r:tpidly in size as added, very slightly
inflated; sutures somewhat depressed,
slightly curved ; wall arenaceous, smoothly finished ; apertureindistinct.
Diameter up to 1.5 mm.
Holotype: Institute of Geology andPaleontology, Tf,hoku University coil.
cat. no. 75288. 600 m west of Inuno-sawa,
Wakka, Yoshino-machi,
Kabato gun(Lat. 43° 35' 40'' N., Long. 14 t 0 42 1 30'1E.), Wakkauenbetsu formation, Middle
Miocene.
Remarks: This form may be easily
distinguished from allied species by thelarger and much compressed test, consist·ing of only two coils. It occurs widelyin the "Black shale " formations ofNorthwest Honshu.

P/ectofro11dicu!aria jaj1onica AsANo, n. sp.
Text-figs. 9, 10.

Test elongate,

narrow, compressed,

periphery with 3 sharp platelike c1.rinae,
one in the middle, the other two
perpendicular to the middle one, broadsides concave or flat, diverging gradually from initial end which is round or
sometimes pointed ; chambers numerous,
early ones biserial, later ones uniserial,
low; sutures strongly 1imbatc, notdepressed, usually transparent at middle
portion ; wall smooth except early portion
which is provided with short c~stae.
Length up to 2 mm., breadth about
0.3mm.
llolotype: Institute of Geology andPaleontology, Tohoku University coil.
cat. no. 75289.
Rulmshubctsu-river,1.3 km southwest of Yoshino-machi,
Kabato-gun (Lat. 43° 351 N., Long. 141 o
43' 20'' E.), Wakkauenbetsu formation,
Middle Miocene.
R emarl~s: Differs from P. californica
CusHMAN by the strongly limbate
sutures. This is a characteristic species
in the Wakkauenbetsu formation of
Hokkaido.
Reference
ASANO, K. (1951), Recent and Tertiary
Cyclammina from )ap:m and the AdjacentRegions, Short Papers. Ins/. Geo/. Pal.
Tohoku Univ .. no. 3. pp. 13-24. p1s. 3, 4.
- - , (1952). Foraminifera from the Miocene
Takinoue Formation near Momijiyama,
Hokkaido, Ib:d., no. 4, pp. 47-51, pl. 6.
CUSHMAN, J. A. and Stewart, R E. and K. C.
(1947), Five Papers of Foraminifera fromthe Tertiary of Western Oregon, Oregon
DePt. Ceo/. llfin. Ind.. Bull. 36, pp. 1-110.
pis. 1-13.
HANZAWA, S. (1950), Tertiary Paleogeographyof North Japan, Sho1t PoPl't's, Ins/. Gco/.
Pal. Tohoku Univ, no. 2. pp. 74-98. 4
text-figs.
. and IMANISHJ, S. (1951). Geology on
the Shintotsugawa Area. Kabato.gun, Hokkaido, Report to the Ptrolcum E:cP/orafion
Advmceme11t Committee of foPatz (MS).
l<r.F.INPE!.L, R.M. (1938), Miocene Stratigraphyof California, Am. Assoc. Petr. Ceo/., pp.
1-450, pis. 1-22.

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CONSTITUTION
of the
PALAEONTOLOGICAL SOCIETY OF JAPANARTICLE 1. Name
The Society shall be known as the Palaeontological Society of Japan. The Society is a sectionof the Geological Society of Japan.
A-RTICLE 2. Object
The object of the Society shall be to promote the study of palaeontology and related sciences.
ARTICLE 3. Achievement
The Society in order to execute Article 2 shall ( a) issue the Society journal and other publi·
cations, ( b ) hold or sponsor scientific lectures and meetings, and (c) sponsor collecting or
field trips, and lectures.
ARTICLE 4. Membership
The Society shall be composed of persons who are active of interested in palaeontology or
related sciences, a!ld shall be known as regular members, honorary members, and patrons.
ARTICLE 5. The members of the Society shall be obliged to pay annual dues to the Sodety, forwhich they shall enjoy the privilege of receiving the Society's journal and of submitting
pap~rs which have been read and discussed at the meetings for publication in the Society's
journal.·ARTICLE 6. Administration
The Society shall haye the following organizations for its administration.
(a) Gener.ll.meeting. The general meeting shall be composed of the Society members. Morethan one tenth of regular members shall be present to hold general meetings. Administrative affairs shall be decided during the general meeting.
(b) President. The president shall be elected from among the regular members. The president
shall represent the Society and supervise its business matters.
(c) Council. The council shall be composed of councillors who are elected from among theregular members. The council shall discuss administrative affairs.
(d) Business council. The business councillors shall be elected from among the council members, and shall administer business affairs.
(e) Officers shall be elected by vote of returned mail ballots, as a general rule.
ARTICLE 7. Amendments to the constitution shall be by decision of the general meeting.

By-Laws and Administration
ARTICLE 8. The Society's journal shall be issued three times a year.
ARTICLE 9. Regular members shall be persons who have knowledge, experience, or interest inpalaeontology or related sciences.
ARTICLE 10. Patrons shall be selected individuals or organizations who give special support to theobjectives of the Society.
ARTICLE 11. Honorary members shall be persons of distinguished achievement in palaeontology.
The council shall nominate honorary members for decision by the general meeting.
ARTICLE 12. Applicants for membership to the Society shall submit their full name, mailing address, date of birth, occupation, and name of school from which they graduated.

Dues
ARTICLE 13. Rates for annual dues of the Society shall be decided during the general meeting.
Annual dues for regular members is Yen 400.00 (domestic members) and U.S. $2.00 (foreign
members). Patrons are individuals or organizations donating more than Yen 10,000.00 an·
nually. Honorary members are free from obligations.
ARTICLE 14. The Society income shall be from membership dues and bestowals.
ARTICLE 15. The Society shall have one chairman, fifteen councillors, and several business councillors, whose term of office shall be two years. They may be re-elected.

Addendum
ARTICLE 1. There shall be four business councillors for the present.
ARTICLE 2. The Society journal shall be issued three times a year for the present.