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System _and Evolution of Japanese ^Fulgorarid ^Gastropoda ⁹¹

Fulgoraria (PsePhaea?) tessellata sp. ^nov.

モリシマヒタチオビ(新) (Pl,^16,丘gs. 7‑10)

Holotype: NSMT*‑P‑5451 _collected by T. MoRISHIMA ^from the lower Oguchi bed at ^sea coast of Kusbimoto‑machi, Nishi‑

muro‑gun, Wakay争ma Prefecturel) (Pl.16,丘gs. 7, 8).

Referred

^SPecimen: ^GK‑L ⁶²⁷⁵ collected by ^T.

SHUTO ^from the Ashiya formation _;1.tthe sea Coast 750m west of Cape Yawata, Wakita, Wakamatsu‑ku,

kitakyushu City.2)

Diagnosis: Shell _medium sized, slender ^and ^with gently curved shoulder. Surface of whorl smooth

and with ^numerous radial striations ^across axial

striations, hence surface is且nely tessellated. Spire and columella plaits unknown; shell ^probably fusi‑

form with moderately high splre. Subsutural band and axial ^rib ^absent.

Remarks: NSMT‑P‑5451 is 87.5mm ^high ^as

preseryed and 45.3 and 38.4mm ⁱⁿ ^diameters of last

whorl. GK‑L 6275 ^is 75.7mm ^high ^as preserved and

44.8and ^41.1mm ⁱⁿ diameters of last whorl. In the

･absence of axial ribs this species may be close ^to sinziensis, but much differs ^from the latter in _general outline and tessellated surface. ^By ^the ^last charac‑

teristic it may be closer ^to daviesi, ^but its ^true subgeneric position is undetermined ^until ^better specimens ^are obtained.

.Fj

j･‑‑.

∫̲i_I

l I

92 T. SHIKAMA

1952･ Fulgoraria uejii ^MAKIYAMA (MS), ^HuzIWARA, ^OGOSE ^& ^ToMITA. Jour.

Geol. SocI Jap･, vol. 58, nod 684, _p. 418 (list) (Sasage).

Fossi1 Occurrence: UTCM 0067, two shells collected by ^Y. OTUKA from the Sasage bed at Sasage _coast, Sanuki, 6sawa‑machi, Kimitsu‑gun, Chiba Prefecturel); smaller shell

(Pl.

^ll,丘gs. ^7,

8),

^75.6mm ^high, almost perfect in preservation and with columella ^plaits; larger ^one (Pl.ll,丘gs. 5, 6), broken in columella ^tip, 76.8mm bigb and carries ^three columella ^plaits; ^they ^are

treated by OTUKA ^aS Fulgoraria

(psephaea)

sasagensis OTUKA, MS ⁱⁿ 1947,

and ^by ^HuzIWARA, OGOSE and ToMITA aS F. uejii ^MAKIYAMA ^MS ⁱⁿ ^1952.

UTCM‑Y‑0066,･ ^two shells from the ^same locality; ^four columella plaits.

UTCM‑0068, ^a shell from the Nishiyatsu sand bed at Nishiyatsu, Koito‑machi,

Kimitsu‑gun, Chiba Prefecture.2) UTCM‑〟 ^Kcf ^, ^a shell from Nojima

(?),.Yo‑

kosuka City3); shell 53.2mm ^bigb, 21,4mm wide, with three columella plaits;

this shell ^was ^treated ^by OTUKA ^aS F.

(PsePhaea)

yokoyamai OTUKA MS ⁱⁿ 1947. UTCM‑〃Kf‑321 ^, type of F. koshibensis OTUKA, _collected by OTUKA from the Koshiba shell ^bed ^at Koshiba, Kanazawa‑ku, Yokohama City4) _; small sized shell, 65mm high, 22mm wide, ^with ^large protoconch and four columella

plaits･ ^A shell belonglng ^tO S･ HAYASAKA's collection and treated ^by him as

F. inj7ata HAYASAKA MS, from Shimizu, Minato, 6sawamachi, Chiba Pre‑

fecture. Eleven shells

(GIYU),

perfect ^or imperfect ⁱⁿ preservation, collected by members df the Yokosuka City Museum from the Miyata bed at Tsukui, Yokosuka City5) (Pl.ll,丘gs. ^1,2); the largest shell is l16mm bigb and carries three columella ^plaits ^but ^the ^other smaller ^ones ^carry ^four plaits. A shell

(GIYU)

^collected ^by ^K. ^KATO ^from ^the Kaiseikizan bed at Minaminagano, Misato‑mura, Age‑gun,

served but broken in

Y. MATSUSHIMA from Chiba Prefecture7); a

MATSUSHIMA ^from the

Mie Prefecture6); shell is 119.2mm high,血ely _pre‑

protoconch; b/a is.0.33. ^A shell (GIYU) collected by the Kawayatsu bed at Nuda, Kazusa‑machi, Kimitsugun,

fragment of spire. A shell

(GIYU)

collected by Y.

Hasumi bed at Dainaka, Kazusa‑machi, Kimitsu‑gun, Chiba Prefectures); _a fragment _showing four whorls. NSMT‑P‑222 collected in 1872 from the Miocene ^bed at Shizugaya, Kawai, Doki City, Gihu Prefec‑

ture9); shell is much depressed.

Remarks: This species is

rather ^common ⁱⁿ the Plio‑Pleitocene forma‑

tions of ^the Kwanto ^area and treated by _many authors under different new manuscript names.

1) 2) 3) 4) 5) 6) 7) 8) 9)

千葉県君津郡大佐和町(佐貫)笹毛君津郡小糸町西谷

横須賀市野島横浜市金沢区小柴横須賀市津久井

三重県奄芸郡美里村南長野千葉県君津郡上総町怒田同郡同町大中

岐阜県土岐市河合静ケ谷

Sgstern _and Evolution _of Japanese ^Fulgorarid ^Gastropoda 93 GeologLCal Horizon: The Sanuki ^formation of the lower Narita Group;

G血zian to G血z‑Mindelian, ^Ⅰ2･ The Zizod6 bed of ^the lower Narita Group;

G血z‑Mュndelian, Ⅰ2b･ The Kawayatsu ^bed of the upper Akimoto Group; early Pleistocene, Donau‑G血zian, ^Ⅰ‑b･ The Sakahata bed of the upper Seki Group;

late Pliocene, H2･ The Koshiba bed of ^the upper Miura Group; ^latest Pliocene, H2･ The Nojima ^bedof the middle Miura Group,I middle Pliocene, ^Hlu̲̲2. The Fukazawa bed of lower ^Miura Group; lower Pliocene, =1･ The ^Hatsuse (‑Miyata) bed; middle Pleistocene, Mindel‑Rissian, Jlb. The Kaisekizan bed of the lchisbi formation; late Miocene, F2‑3･

Musashia (Nipponomelon) preuostiana magma (KuRODA _and HABE,

1950)

オオヒタチオビ(Pl･ ^ll,丘gs･ ^13J6, ^{Pl. 16,丘g.} 3)

Loc. °it.

1922･ Voluta megaspira ^Sow･, ^YoKOYAMA･ Jour･ Colt, Sci･ Imp･ Univ･ Tokyo, vol.

44, _art･ 1, _p1 50, (Semata).

1926･ Voluta megaspira Sow.･ YoKOYAMA･ 1our･ ^Co11･ Sci･ Imp･ Univ. Tokyo, sec.

2, vol･ 1, art･ 7, p･ 232, pl. 29,丘g, 1.

1928･ Voluta megaspira Sow.･ YoKOYAMA･ Jour･ ^{Coll･ S°i.}^Imp･ Univ･ Tokyo, sec.

2, vol･ 2, pt･ 7, p･ 352 (Nishiyama).

1933･ Voluta megaspira (Sow･), ^T･ ^MIZUC=Ⅰ･ ^Exp･ ^Text Kashima Sheet (list).

1947. Fulgoraria Preuostiana (CROSSE), ^MuRAKOSHI. ^Rep. ^ⅠIId Dept. Res. Inst.

Nat･ Res･, no. 3 (list).

1958･ Fulgoraria _cf･ prevostiana (CROSSE), ^OzAKI･ ^Bu11･ ^Nat, ^{Sci･ Mus･} ^Tokyo, _po1

42, _pp･ 154, 155, pl. 17,丘g.9 (Iioka).

Fossi1 Occurrence: Two shells

(GIYU)

collected by N. IKEYA ^from thd Semata bed _at Semata, Shizu‑machi, Ichihara‑gun, Chiba Prefectu;el,

(Pl.

^ll,

丘gs･

13‑16)･

^A ^broken shell (GIYU) _collected by Y. KANIE and others from the Ninomlya bed at Ninomlya, Ninomlya一皿aCbi, Naka‑gun, Kanagawa Prefec‑

ture2)･ NSMT‑P‑4458, described by OzAKI ^aS Cf. preuostiana ^from the lioka bed at ^a creak of Omate, Unakami‑machi, Unakaml‑gun, Chiba Prefectures);

inner mould of last _whorl and ^a ^part of spire･ A shell (GIYU) _collected _by Y･ MATSUSftIMA from the Sakahata bed _at Oikomi, Seiwa‑mura, Kimitsu‑gun, Chiba Prefefecture4'･ A mould of ^last whorl (GIYU) _collected ^by Y. SEKIGUCHI from the Kurosawa bed at Yamanouchi‑mura,.Hiraka‑gun, Akita Prefecture

(Pl･

^16,fig･ ^3)･5) ^{NSMT‑P‑611} collected by TAKIMOTO in 1899 from Sukegawa, Hidachi City, Ibaraki Prefecture6); inner mould of four shells. IGPS _cat. no.

7442l collected ^by ^S･ MuRAI ^from a river ^{cliff of} ^Yokouchi River, Okura‑mura, Mogaml‑gun, Yamagata Prefecture7); ^a ^fragment of ^last whorl, 51×24mm in diameters･ IGPS _cat･ no･ 74432 collected by S･ MtJRAI from Sunako‑zawa,

1) 2) 3) 4) 5) 6) 7)

千葉県市原郡市津町瀬又神奈川中郡二宮町二宮

千葉県海上郡海上町大間手(水路) 千葉県君津部活和村追込

秋田県平鹿郡山内村茨城県日立市助川

山形県最上郡大蔵村横内川

94 T. SHIKAMA

Furukucbi, Tozawa‑mura, Mogaml‑gun, Yamagata Prefecturel) ; ^a shell frag‑

ment of ^two whorls, 22 and 18mm ⁱⁿ diameters. IGPS cat. ^no. 75681 from Babame, Gojyo‑machi, Minamiakita‑gun, ^Akita Prefecture2); a fragment of last whorl of 25.5mm wide. UTCM‑Y reported ^by YoKOYAMA aS megaSPira from the Nishiyama bed at Hanzogane, Tocbio City, Niigata Prefectures);

fragment of ^two whorls; 55mm high and 40mm wide･ UTCM‑Y from Ha‑

tsuzaki, Hitachi City, Ibaraki Prefecture4) ; fragment of three whorls, 95mm

highand

^40mm wide. UTCM‑Y reported ^by YoKOYAMA aS megaSPira ^from lchinokaya, Nishimaki, Shimonita‑machi, ^Kanra‑gun, Gunma Prefectures) _{; frag‑}

ment of ^two whorls; ^a ^splre 69.5mm bigb and 41.3mm wide. UTCM‑Y from the neigbbourbood of Cbietolplra along the Niikap River, Hidaka,

Hokkaido.6)

Remarks: The specimens from the Semata bed (Pl.ll,figs.

13‑16)

clearly belong ^td this subspecies. The shell (figs･13,

14)

^is ^142Amm

high,

with 5 postnuclear ^whorls, small protoconcb, subsutural band and ^two ^weak columella plaits of last whorl.

GeologLCal Horizons: The Semata bed of the middle Narita Group; middle Pleistocene, MindeトRissian, Jlb. The Ninomiya bed _; middle Pleistocene, Mind‑

elian, Jla. ^The ^lioka ^bed; ^early ^Pliocene, ^Hl. ^The ^Hatsusaki ^formation; early pleistocene, Il･ The Nishiyama bed; early Pliocene, Hl･ The Kurosawa bed;

late Miocene, G.

MusashL'a (Nit)ponomelon) preuostiana salebrosa subsp･ ^nov･

ェゾヒタチオビ(Pl. ^10,丘gs･ ^6, ⁷⁾

Loc. °it.

1950. NeoPsePhaea _magma (KuRODA ^& BABE), ^TAKEDA･ Shinseidai‑no K･enkyu,

no. 4, _p. 13, _pl. ^4,丘gs. 18a, b, 19･

1960. Fulgoraria (PsePhaea) magma KuRODA & fIABE, OyAMA, MIZUNO & SAKA‑

MOTO. Ill. Handb, Jap. ^Pal. ^Mollリpp. 79, 80, pl, 17,丘gs･ 2a‑d･

Fossi1 Occurrence: ^A shell

(GIYU)

collected by the writer from the Anden shell bed at Anden, Koriai, Oga City, Akita Prefecture (Pl. ^10,白gs･ ^6, 7)7),'A shell described by H･ TAKEDA from the Miocene Noya formation at Futamata River, Mitsuishi‑mura, Hidaka‑gun, Hokkaido.8)

Remarks: ^The shell from Anden ^is ^fine ⁱⁿ preservation, 92.2mm

high

and with small protoconch,丘ve postnuclear whorls, eminent keel‑like axial 1)

2) 3) 4) 5) 6) 7) 8)

し山形児最上郡戸沢村古口砂子沢秋田県南秋田郡五城目村馬場日

新潟県栃尾市半蔵金茨城児日立市初崎

群馬県甘楽郡下仁田町西牧市野萱北海道日高国新冠川

秋田県男鹿市五里合安田北海道日高郡三石村二又川

System and Evolution of Japanese ^Fulgorarid ^Gastropoda ⁹⁵

ribs, ^strong longitudinal striation and two columella plaits of last whorl.

The Mitsuishi _specimen is ^a fragment with ^two whorls, 100mm high and 57mm wide, and probably belongs to this subspecies.

GeologlCal IJorizons: The ^Anden shell bed; middle Pleistocene, Mindel‑

Rissian, Jlb. The ^Noya ^formation; Miocene.

Musashia (Nipponomelon) kamakurensis (OTUKA, 1949) カマクラヒタチオビ(Pl･ ^12,figs, ^5‑8, ^ll‑16)

Loc. _°it.

Fossi1 Occurrence: UTCM‑" Kト349a (holotype) described.by Y. OTUKA from the Koshiba bed at Koshiba, Kanazawa‑ku, Yokohama Cityl)･ Nine shells

(GIYU)

collected by the writer from the above‑mentioned locality. A

shell (GIYU)

(Pl･

^12,figs. ^13, ¹⁴⁾ collected ^by ^S. NAKANE from the above一甲entioned locality･ A shell (GIYU) (Pl.12,丘gs. 7, 8) _collected by Y. MATSU‑

SHIMA from the Sakahata bed at Tsujimori, Seiwa‑mura,Kimitsu‑gtln, Chiba

Prefecture2'･ A shell (GIYU) (Pl. 12,figs. 15, 16) _collected by Y. MATSUSHIMA from the same bed at the same locality mentioned above. A shell (GIYU) (Pl･12,丘gs･ 5, 6) _collected ^by ^Y･ MATSUSHIMA from the Kawayatsu bed at Kawayatsu, Kazusa‑machi, Kimitsu‑gun, Chiba Prefectures). ^A shell ^and three fragments of ^spire

(GIYU)

collected ^by H. KAGAMI from the Kan6zan ^bed at Shibahara, Koito‑machi, Kimitsu‑gun, Chiba Prefecture4). A shell

(GIYU)

^(Pl.

12, figs･ ll, 12) _collected by S･ NAKANE from the Koshiba bed _at Hitorizawa, Kanazawa‑ku, Yokohama City5).

Original Description: "It ^is the spelCmenfigured by M. YoKOYAMA aS

Voluta megaspira ^from the Koshiba ^Pliocene, and is a distinct

species. Ful‑

goraria megaspira ^of ^HIRASE ^from ^Sagami ^Bay ^is closely ^allied, ^but ^the latter has a

higher

spire ^and ^a sharper apical angel (about

35o).

^Fulgoraria ^koshi‑

bensis ^is ^a more inflated'shell than F. kamakurensis. F. kamakurensis is 6 whorled･ The two initial _whorls are smooth, ^and ^the axial ^folds ¹⁴ ^on ^the penultimate; ^more than 15 ^on the ultimate whorl and obsolete toward ^the aperture･ There are 4 columella folds, the 2 posterior ^very weak･ The type specimen ^of Fulgoraria kamakurensis OTUKA is 67mm in height, 25mm in

diameter, and 39mm in height of ^aperture.

Remarks: As YoKOYAMA pointed ^out, ^the columella plaits ^are rather variable ⁱⁿ number, ^from 2 to 4･ When there ^are only 2or 3 plaits the shell may be confused with ^young shell ^of preuostiana, ^but ^the _general _outline _of slender form, smaller size, thick shell and obsolete axial ribs ^on last whorl,

1) 2) 3) 4) 5)

横浜市金沢区小柴千葉県君津郡清和村辻森岡郡上総町川谷

同郡小糸町柴原横浜市金沢区永瀬沢

96 rF. SHIKAMA

Table 35. Dimensions (in mm,) ^of kamakurensis･

Sa'mple number

1 2 3 4 5 6 7

55. 3 58. 8 42.9 42.9 40.3 49.3 37.2

20.4 21.9 16.5 15.0 12.9 18.6 13.6

27. 9 27.4 17.9 19.8 19.7 22.3

Total mean

b/a

0.37 0.37 0.38 0.35 0. 32 0.38 0.37 0.36

Number _of _columella plaits ^on ^last whorl

4 2 3 2 2 3 4

Repository

Recent (Okutani)

GIYU, Pl. 12,丘gs. 7, 8 GIYU, Pl. 12,丘gs. 15, 16 GIYU, Pl. 12,丘gs, 5, 6 GIY口, Pl. 12,丘gs. ll, 12 GIYU, Kan6zan

GIYU, Koshiba

0 0 0 0 0 0

c/a

50 47 46 46 49 45

0. 47

Number of

axial ribs in penultimate

whorl 13 18 13 14 15 17 16 16

Number of postnuclear

whorls

4.5 4.5 4.5 4.5 4.0 4.5 4.5

may characterize ^this ^species.

The _majority of the specimens have _not colour markings but the shell (Pl.^12,丘gs. ^7,8) from Tsujimori _carries _colour mark‑

ing of zlgZag pattern. Colu‑

mella formula ^is 2.2.3.4 (f.F, F.F, f.F.F, f.f.F.F),belonging to

β^pattern, ^based ^on ^a‑shell from Kosbiba.

GeologLCal Horizon: The Kosbiba bed of the ^upper Miura Group; latest Pliocene, H2. The Kawayatsu bed of the upper Akimoto Group;

early Pleistocene, Donau‑Gtlnzian, Ilb. The Kan6zan bed of the Akimoto Group; early Pleistocene, Il. The Sakabata bed of ^the Seki Group; late Pliocene, H2.

Musashia

(Nipponomelon)

elongata SHIKAMA ナガヒタチオビ(Pl･ ^15,丘g･ ¹⁰⁾

Loc. °it.

Fossi1 Occurrence: Fragments of ^two shells (GIYU) _collected by S. NAKA‑

NE from the Koshiba bed at Koshiba, Kanazawa･ku, Yokohama City. A splre showing ^three whorls (GIYU) _collected ^by ^{S. NAKANE} ^from ^the ^Koshiba ^bed

at east of Oshikiri, Totsuka‑ku, Yokohama City (east of Ofuna railway ^sta‑

tion).1)

Remarks: The shell from Koshiba ^{is large} sized, 120mm

highas

^preser‑

ved, 46.2mm wide ill last whorl, ^with ^two columella plaits ⁱⁿ it･ Shell is thin, 1)横浜市戸塚区押切東方

System and Evolution of Japanese Fulgorarid Gastropoda 97 slender and ^narrow; ^surface of whorl ^rather ^smooth and axial ribs rather

weak･ Another shell is

much ^depressed, 109･4mm ^high as preserved, ^and

with very smooth surfaces. Columella plaits ^seem ^to be two.

GeologlCal Horizon: ^The Koshiba bed _of the upper Miura Group; latest Pliocene, H2.

Musashia (Nip♪onomelon) _otukai sp. ^nov.

オオツカヒタチオビ(新) (Pl･^12,丘gs. ^9, 10)

Holotype: UTCM‑ Kf collected by Y. OTUKA; the locality unknown.

Diagnosis: Shell small sized, thick, slender and

high

spired, with 4.5 postnuclear whorls. Protoconch _medium sized, its nucleus is situated ^on the left side ⁱⁿ ^front ^view･ On last _whorl, columella plaits ^two, anterior ^one being a little _stronger than posterior; Pattern _of it being f･F. Subsutural band obsolete and ^suture rather deep and ^acute･ Shoulder _not angulated but gently curved･ Axial ribs ^very ^strong, keel‑like and 15 on penultimate whorl.

On splre there are seen numerous radial striations which ^cross axial ribs. In the holotype of 75.5mm high, a is 51.2mm, b is 26.5mm and ^c is 24.6mm;

b/a: 0.52 and c/a: ^0.48.

Remarks: ^This species ^is rather allied ^to angulosa in b/a _and strong axial ribs ^but may be distinguished by less columella ^plaits, smaller ^aperture,

narrower splre and by

unangulated shoulder. ^Be that ^as it may, this is a

species closely related with angulosa.

Musashia

(Nipponomelon)

elegantula ^sp. ^nov.

ワタナべヒタチオビ(新) ^(Pl･ ^14,丘gs. ^5, 6)

Holotype: A shell (GIYU) _collected by T. WATANABE from the Iioka bed at Shiisbiba, Chosbi City.1)

Diagnosis: Shell medium in size,fusiform, rather small protoconcb, ^nucleus of which ^occurs ^on ^the There ^are 6 volutions of teleoconcb, and ^splre ^rather sutural band distinct but ^narrow, and suture rather gulated but gently ^curved; whorls ^a little vaulted.

thin, slender ^and with left side ⁱⁿ front view.

high and ^narrow. Sub･

deep. Shoulder ^unan‑

Axial ribs ^eminent,

narrow, numerous, amounting to 21 in penultimate whorl. ^There ^are de∀eloped

many radial striations ^and cancellated ^on whorls surfaces. ^Aperture ^narrow and small, situated relatively ^ln low position. Columella _plaits few and weak, two on last whorl, F･F, aild the ^same in _prlmary pOStnuClear whorl･ Holotype is l18mm ^high; ^a: ^83･2mm, b: 38.1mm, C: 36.5mm, b/a: 0.46, c/a: ^0.44.

Remarks: This species is rather related ^to cancellata in general outline, but distinguished from the latter by the mode of development of columella

1)銚子市椎柴

98 T. S王1Ⅰ虹AMA

plaits and by the larger number of post nuclear whorls･ In columella plaits, elegantula ^may be ranked between Nipponomelon and Musashia, and it

might

be an offshoot of miensis.

Geological Horizon: The Iioka bed of ^early Pliocene, Hl･

Musashia

(N軸onomelon)

miensis (ARAKI, 1960) ムカシナガヒタチオビ(新) (Pl･^15,figs. 6‑9)

19601 Fulgoraria miensis ARAKI･ Bu11･ Lib･ Art･ Dept･ Mie Univ･, spec. vol., ^no. 1, p. 105, pl. 9, figs. 1, 2.

Type SPecimen: An adult shell described by ARAKI from the Kaisekizan bed in a road‑cut 300m _upstreams from the entrance of the valley ⁱⁿ the west of Yanagidani, Misato‑mura, Age‑gun, Mie Prefecture.1)

Original Description: 〃Shel1 ^large in _size, measuring about 125mm in preserved length, 95mm ⁱⁿ length of body whorl, ^and ^about 45mm in _maxi‑

mum diameter _of body wborl･ Very narrowly ^elongate in shape, second ^and third whorls shouldered but _with nearly straight ^sides, ^the ^body ^whorl gently shouldered btlt its lateral sides moderately expanded and rather abruptly

(/

臥

I l l l I

i

_I//

l /

l / I/

tJ̲‑.,.

′

′ / /

′

∫

Textfig. ll. Musashia

(NiPPonomelon) miensis ARAIくⅠ, restored, ^× 0.6.

curving into basal _part･ Second whorl ^provided ^with about 20 longitudinal ribs which ^are broadly round‑

ed, ^narrower than their interspaces, not much ele‑

vated, ^and provided with ^obscure ^growth lines wbicb

are narrower than their interspaces. Body whorl

with about 18 broad longitudinal ribs, ^narrower than their interspaces, _not elevated, broadly rounded ^and

vanishing towards the lower part of whorl･ Basal

part of whorls almost ^smooth･ Aperture narrowly oval･ Columella more or less straight, weakly curved, provided at its lower part with ^one fold

(observable).

Canal narrowly opened.

Remarks: Spire exceedingly

highand

^there ^are

5 volutions of teleconcb; a/b ^is ^about ^0.49. ^Spire

narrow and slender. Axial _ribs _very distinct and

19‑23 in penultimate whorl; ⁱⁿ ^splre ^it is keel‑like and there

or growth last whorl.

striations.

are developed numerous axial striations lines, which become rather obsolete ^on AIso there are seen some obsolete radial Protoconcb medium sized. Columella plaits ^seem ^to be two in last _and pennltimate whorls.

Stlbsutural band obsolete. This species is much like elongata and clearly ^an ancestral form of it, but ^may 1)三重県奄芸郡美里村柳谷

system and Evolution of Japanese Ftllgorarid Gastropoda 99 be distinguished from it by radial striations.

Referred

^SPecimens: ^About ¹³ ^specimens of ^splreS ^and body whorls

(GIYU)

collected by Y. KANIE from the Kaisekizan bed at Yanagidani, Misato‑

mura, Age‑gun, Mie Prefecture.

NSMT‑P collected ^by ^Z, KuRIMOTO from the Tomlya tufFaceous sandstone bed _at Tomlya, Takeoka, Amaha‑machi, Kimitsu‑gun, Chiba Prefecttlrel) ; large sized shell with 5 postnucelar whorlds. Two shells (GIYU) _collected by the writer ^from ^the Fukazawa bed at Kehai‑zaka, Kamakura City2); small ^sized and 5 postnuclear whorls ^preserved. UT‑È Kc (600511) collected by K･ CtlINZEI from the Kagitori sandstone bed of the upper Kadonosawa formation at Kadonosawa, Fukuoka‑machi, Ninohe‑gun, Iwate Prefecture

(Pl･

^15,figs･ ^8, ⁹⁾³⁾^;

body whorl ^and ^a ^part of ^splre With ^very obsolete axial ribs and ^numerous minute ^radial striations; this specimen may belong to a new subspecies of

mlenSLS.

Geological Horizon: The Kaisekizan bed of lchishi formation; middle Miocene, F2‑3･ The _upper Kadonosawa formation;

middle Miocene, F3. The Fukazawa bed of ^the upper Miura Group; ^late ^lower Pliocene, ^H2. The Tomlya tuffaceous bed of the lower Seki Group;

lower Pliocene, Hl.

Musashia

(NLl卯)onomelon) fujL'motoi (KANNO,

¹⁹⁵⁸⁾ フジモトヒタチオビ(新)

1958. Fulgoraria (PsePhaea) fujimotoi ^KANNO. ^Sci.

Rep. Tokyo Kyoiku Daigaku, sec. c, vol. 6, no.

55, pp, 219, 220, _pl. 7,丘gs. 9, 10.

HolotyPe: TUE‑G*‑5671, collected ^by KANNO from the Ushikubitoge bed ⁱⁿ a river cliff of Akabira ^River, Tomita, Chicbibu City, Saitama Prefecture.4)

Original Description: 〃She11 tall and high spired, slender, very large in size, with about 6 whorls; ^splre ^Very high _and less than twice _as lligh as aperture. Suture slightly lmpreSSed with

narrow shelf around it. Surface ornamented with

axial plicae which ^may be somewhat accentuated above and tend ^to disappear on the body _whorl;

the plicae numbering 14 _on the penultimate ^whorl

'1

∫

′1

/ /

tLtl/LJ̲

Text丘g.

∫

′■

■■∧

12.

(NiPPonomelon)

′

Musashia fujimotoi (KANNO), restored, ^× ^1.

* Institute of Geology _and Mineralogy, Tokyo口niversity _of Education.

1) 2) 3) 4)

千葉県君津郡天羽町竹岡十宮鎌倉市化粧坂

岩手県二戸郡福岡町門ノ沢埼玉県秩父市富田

100 T. S王iIKAMA

and about 16 on the body whorl, separated by interspaces wbicb become wider than the width of ^plicae; close splral striation regularly arranged. Aperture spindle shaped; ^inner ^lip covered by ^a thin callus, ^and provided with ^two columella folds of ^wbicb the anterior ^one is _very _strong, but the other ^is feeble. Canal short,

slightly

^recurved. ^Apical ^angle ^about ^25o. ^Altitude

85mm; altitude of ^aperture, 35mm.‑Maximum diameter, 27mm; minor

diameter, 22mm in holotype.

Remarks: As KANNO pointed ^out, ^this species ^{is rather} allied ^to tokunagai in _general shape, but is distinguished ^by ^a smaller number of axial folds, and

more slender ^splre. Also it _may be distinguished by smaller protoconch, lower _position of ^aperttlre, ^etC. Subsutural band absent and there ^are four postnuclear whorls. Altbou･gb the tip of columella is broken,

b/a

may be 30.5/59.5±‑0.51± _and c/a･､may ^be 25.3/59.5±‑0･43±･ ^Columella plaits of the last whorl ^are weak and ^two, ^that ^is f.F. This species ^may be characterized by low and relatively small sized last whorl, ^very bigb splre and few axial ribs. With regard ^to the subgeneric position this species ^may be included in NL'pponomelon and in some points it_may be situated in the ancestral position of elegantula.

Geological Horizon: The Usuikubitoge bed of the Hikokubo Group; 01igoI Miocene, D‑E.

Musashia (Nipponomelon) tokunagai

(KANEIiARA,

¹⁹³⁷⁾ トクナガヒタチオビ(節) (Pl. 14,丘g.4)

1937. PsePhaea tokunagai KANEIIARA. Bull. Geol. Surv. Jap,, vol. 27, ^no. 1, pp.

16‑18, pl. ^2, ^figs. ^2‑5.

1954. Fulgoraria (PsePhaea) Prevostiana (CROSSE), ^SuIKAMA･ ^{S°i. Rep･} ^Yok･ ^Nat･

UnivリSeC. 2,no. 3, pl. 6,丘g. 26.

1962. Fulgoraria tokunagai (KANEtIARA), ^KAMADA (pars)･ ^Pal, ^Soc･ Jap･ ^Spec･

JapリnO. 8, p. 192, _pl, 21,丘gs. 5‑8.

Holotype: Three shells stored in the

Geological

^Survey ^of ^Japan, collected from the Yunagaya bed at Nagakura coal mine, Yumoto, Iwaki City, Fuku‑

shima Prefecture.1)

Original Description: ‥Shell tall and

highspired,

aplCal angle ^about 25 degrees･ Suture slightly impressed with ^narrow ^shelf around it･ Surface ornamented with axial ^folds, ^which ^may be somewhat accentuated above and tend ^to disappear on the body whorl. Spirally _grooved regularly, also over the folds. Aperture spindle shaped, obliquely notched posteriorly, with ^nar‑

rower anterior canal. Inner lip provided with ^two columella folds and covered

by ^a thin callus, which adheres ^to ^the columella and thickens anteriorly. Canal and ^outer lip missing ^on nearly all the specimens. Holotype

(medium

^size,

lacking apex): ^95mm ⁱⁿ ^height, ^40mm ⁱⁿ ^diameter. ^Paratype (large _size, 1)福島県磐城市湯元長倉炭坑

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