On the New Forms of Paleogene Molluscs・ from Japan

564（52） ON THE NEW FORMS OF PALEOGENE MOLLUSCS・ FROM JAPAN

Katsura OYAMA＆Atsuyukj MIZuNo

Introduction

During this half century，our informations on the paleontology of Pale． ogene system in Japan have been piled up in voluminous amount through the efforts of many authors．H：owever，there remain yet many new forms of molluscs to be clarified for the progress of this science． Here，the writers will describe among them the following twenty－one new Oligocene forms discovere4from the various areas of Japan。

New genus T名o癬伽σOYAMA et MlzuNo，gen．noマ．（in Buccinidae）． New speeies and subspeeies （The names of systems show those from which the holotype occurred）鰯。％ol伽醜6h露OYAMA et MlzuNo，sp．nov．（Setogawa group） Cα妙加oσso驚h伽s乞30YAMA et MlzuNo，sp。nov．（Wakkanabe formation， Ishikari group） Sゆh。磁幡h伽伽αOYAMAetM・zuN・，gP。n・v．（Akabiraf・mati・n，lshi－

kari group） Sゆho鰯齪『銘吻o航σOYAMA et MlzuNo，sp．nov．（Maze formation，Nishi－ Sonoki group）．P蜘40卿7ゑsso嬬乞6sα彦漉OYAMA et MlzuNo，sp．nov。（Shioda fomation，：Nishi－

sonokigroup〉 Sαoo61痂hoh履40θ鯉蛤OYAMA et MlzuNo，sp．nov．（H：iragishi formation，Ishi一． karigroup）ノ46吻（Tグ繊鰯吻）照9σoづOYAMA et MlzuNo，＄P．nov．（Kishima∫ormation， Kishilna group） ∠46伽（∠46珈）sh珈oッα卿碗OYAMA et MlzuNo，sp．nov．（Akabira formatiqn， Ishikarigroup）琢伽s耀傭h露OYAMA et MIz口No，sp。nov，（Omagari fomation，Ombetsu group） L吻σ（ノ406吻）s翻6shJ吻漉OY春M：A et MlzuNo，sp．nov．（Setogawa group） Os舵σ60吻吻7乞s OYAMA et MlzuNo，sp．nov．（Shitakara fomation，Urahoro

group）、C郷s傭ll露6s（C鰯sσ！611づ姻為o吻04σz OYAMA et MlzuNo，sp．nov．（Maze foma－

tion，，Nishisonoki group）

1一（589） 1，ド塁彰！l 地質調査所月報（第9巻第4号）’

I 旨＼唱伽6惚吻（qソ・Z・・4勲）h岬肋OYAMAetMIzuNq・sp・n・蝋Eigiref・rma－ 1』』 tion，Nishlsonbki group）

1．、．L％伽o卿σ郷g襯OYAMA et MlzuNo，sp．nov．（Yamaga formation，Ashiya 旨 group）巨一r 卜』丁勿σsづ解（co％ohoo8z8）わ乞sθoiαo卿礎痂QYAMA et MlzuNo，subsp・nqv・（Akabira 1∴

1・， formation，Ishikari group） 1、1

1「』．P吻7s吻oh加sづs OYAMA et MlzuNo，sp。nov．（Wakkanabe formation，Ishikari

1’「

1』、 group）．」R6吻Zo耀づ卿鰯OYAMA et MlzuNo，sp。nov．（Tokuman formation，Nishi．ノ 1、、，

llF sonoki group）・

いア iNew names ド・αzso舵脚（αzso舵卿o餌sP）πσg伽OYAMA et MlzuNo，nom．nφv．（for助づ60一％∫z仰z sP・rndet・NAGAo，1928） 1 1「1 ’，y6彫 7加癬σ（（加Jooπ名伽）ツoた砂翻碗OYAMA et MlzuNo，nom．nov．（for76刀碗一〇σ擢㍍60％ψ紹ssσYoK6YAMA，1890） 1；

14 ，伽9灘惚伽σ脚OYAMA’etMlzuN・，n・m・n・肌（f・r伽・g燃麟気に MAKIYAMA，var．6伽8伽NAGAo et INouE，一1941）

1、 Materials・of new species and忌ubspecies are all kept in the Geological 1ピP Depart卑entlGe・1・3ica1Survey・fJapan，except．th・se・fα磁…（αz3・一瀦卿o囲s7）郷9襯OYAM：A et MlzuNo and S伽θIJαho勲痂oθ競s OYAMA et MlzuNol th¢formerispreservedin the GeologicalandPaleontologicalInstitute， Tδhoku university，and the latter is in the collection of the GeQlogical and

Mineralogical I耳stitute，Hokkaid6University♂

Sy’stematic Description

GASTROPODA

Family Trochidae

Ge加s M：inolia A．ADAMs，1860

醜％oZ宛魏6h露OYAM：A et MlzuNo，sp．nov．

（Plate I，figs．1a～c）

Holotype：GSJ．Reg．No．5008（lntemal mould，somewhat broken at 尭he apical and apertural parts） Type locality二IIn the vicinity of Ashikubo，Miwa－mura，Abe．gm， Shizuoka－ken．（Setogawa group） Description：Shell sma11，turbinate with four whorls，suture distinct．3 B・dywh・rllargeli尊Hated，sculpturedwithab・utninespiralribsandwider interspaces with one week stria on every one；whorls of spire sculptured 『withab・ut・eig与tspiralribs；aperturesupcircular，6・1umellathickened。 Dimensions of the holotype：Height ca．0．85mm；diameter of the last whor10．84mm Comparison：This lnew sp㏄ies somewhat resembles磁物1毎f観蜘Zα如

2一（590） OntheNewF・rms・fPale・geneM・11us6sfr・mJ寧pan（K・Oyama＆AMizun・）

YoK：oYAMA，1890，upPer Oligocene species from Central Hokkaid6，but differs from the latter in having more slender whorls and fewer spiral ribs on body whor1．Further，it differs from磁●％ol宛s％み伽g1％鰯σKuRoDA et HABE，1952 in having fewer whorls． Geologic range：（寿ower P）Oligocene Geographic distribution： Cent士al Honshi】、

Family Epitoniidae

Genus Cirsotrema M6RcH，1852 Subgenus Cirsotremopsis THfELE，1928

α駕o舵脚（C魏o舵窺ψsJsP）照9襯一〇YAMA et MlzuNo，nom。nov。（Platel，丘9＄』18a～c）

ユ928，ゆ∫！o％伽吻sp．indet．NAGAo，Sci．Rep．，T6hoku Imp．Univ．，Ser． 2，Vo1．12，No．1，p．93（83），p1．15，fig．7． Descriptioh and locality are given originally by NAGAo（1928）。 H：010type： IGPS．Reg．No．36183（broken in the apical part of she11） Type locality：“Beach rocks，west of Hachiman－zaki，Wakita，Waka－ matsu－shi，Fukuoka－ken”（after NAGAo，1928）． Description： “She11．rather sma11；probably high－turreted，penultimate whorl being slightly narro｛ver than the body whorl and slowly increasing in diamete士down－ ward；suture distinct and deep． E貧ch whorl corlyex，10ngitudinally ribbed and spirally striated；ribs9－10in血umber，rathernarr・w，slightly・blique，sharp，Pτ・mine写tand disc・nti且u・usfr・m・血ewh・rlt・thenext，withtheinterspacesHat・and，孕1m・stthrice 、as broad as the ribs；two or three ribs very broad，thick，and roundly flat on top， gr。wingt・sm・・thvaricesspiralstriaeHne，andcr・wded，eachaltematedwith・neo「 two finer striae．Body whorl rather sma11；base smooth and pro▽ided with a bounding kee1；aperturesma11，subcircular，andsurr・unaedbydisc・孕tin“・usthickenedlips；no

defined umbili、cus．” （after NAGAo） Geologi¢range： 76駕蛎αz短宛∂6sあ渉o躍6s zone（upper，01igpcene）

Geographic distribution： Northern Kly丘sh廿

Family Calyptraeidae

Genus Calyptraea LAMARcK，1799

C吻伽α6α’so鰯h伽sJs OYAMA et MIzuNo，sp．nov．

（Plate I，figs．6a，b）

H：010type：GSJ．Reg。No．5030 Type1。cality：Nai6－machi，S・rachi－gun，H・kkaid6（exactlyunkn・wn）・（Wakkanabe formation，Ishikari gtoup） Descripti・興：She111arge，with、threewh・rls；sutures・bscurαSpi「e hlgh，m・re・rless・blique；apex、bluntAperturelargelvery・blique・・nea「1y circular．Surface of the shell om＆mented by many伽Q growth・1ines． Dimensions of the holotype：Height ca10mn玉l major dlameter of body whor129。5mm

3一（591）地黄調奪所・月報（第9巻第9号）

Comparison：This new sp㏄ies is characterized by its high and．oblique3 spire， a箪d is easiIy distinguished from tヒe known species of other forms． Geologic range： Lower Oligocene鞠 Geographic distribution： Central Hokkaid6

Buccinidae

Genus Tromi血ina OYAMA6t MlzuNo，1958，gen二nov． Type species：。肋6乞s伽oZ砂客sノψo吻6％5TAK：EDA，1953

She11℃omparatively large，rather thin，fusiform，withhigh spire。Whorlsl rather high，not v6尊numerous in number with two prominent keβ1s，one ofり which is situated almost on the lower suture． Body whorl generally with two keds as ln T吻hoケo吻ε，but the lower one rarely obsolete． Spiral sculpture except keels and axials not prominent』 Aperture ova1，wi画short canaL Thlsロew genus differs from！▽のi％彫σR6DING，1798，with high spire・

and two（or one）keels． α伽砂6g窺σGRANT et GALE，1931P has two keels，、 butb・th・fthemaresitua㌻eゆthesubsutufalpart・fwh・r玉s． This gellus contains following speci¢s： 24％oぎsケo陀舞sノのo窺謡s TAKEDA，1953

／1／zoお伽o形力乞s hoた々σ躍oαzs乞3HAYAsAKA et UozuMI，1951

ノ知z砿5朗oムゆ乞sゑsh〃診召妬6駕sゑs H：AYAsAKA et MATsul，1951

且7zo客5伽ol砂乞s房oozゴσ如HATAI et KoIKE，1957 ／醜伽8召郷研gσs伽αYoKoYAMA，var．卿わ爾6競s H：AYAsAKA et MA一一

TSUI，1951

1，・醜醜92襯催9αs蜘αYOKOYAMA，1932・ハ吻脇彫召％卿わ611ケ翻郷乞s且AYAsAK：A et UozuMI，1954

ハ彰ゆずz〃z6σo／z％σJoσYoKoYAMA，1932 Pハ吻劾彫α6zoσnσTAKEDA，1953

Genus Sip弛on．alia AビADAMs，1863

Sゆho7zσ1伽ゑsh貌σ7宛鴛σOYAMA et MlzuNo，sp．nov．

（Plate I，丘gs．7a，b，8，9a，b，10a，b），

Holoty’pe： GSJ．Reg．No．5031 Type locality：Upstream of the Tan名an river，Ashibetsu．shi，Hokkaid6．、（Ak：abira formation，Ishikari group） Description：Shel1，smail to medium in size，with four or five whorls l spire low，slightly concave。conica1，each whorl shou1dered and strongly nodose；apicaユangle about seventy de喜rees． Body whorl large，with thirteen sharp nodes on its upper portion；whorl inHated below the nodes，abmptly［ d㏄reasing the inHation about at anterior one一だhird of the whor1，making「・ very weak ridge between。Whorl of spire angula‡e昼with about thirteen nodes at about閣its middle．Spiral cords regularly arranged in altemation ofl

4一（592），当

On the New Forms of Paleogene Molluscs from Japan（K．Oyama＆A．Mizuno）

』4the strongs and weaks，u阜dulated，crossing，with very weak axial ribs l sculpture from the middle to posterior one－fourth of body whorl being very weak：．Aperture obli（1uely ova1，angulated on the upPer，part．CanaI short， nearlystraighl・butthedetailisunkn・wnduet・theill－preservati・n・fshe1L Dimensions of the holotype： Height ca．19．7mm l width of body 『whorl ca．11．9mm l height of body whor1’ca，15mm． Comparison：Sゆh卿召1伽づshJh4吻照n．sp．d近ers from S。3罐盈％舷 MlzuNo，1954，in having many smailer nodes on each whorl and peculiar ・〈）mamentation of body whor1。It so；newhat resembles S．αsα肋郷o％sぱs（NAGAo）， 1928，but the latter has few nodes on the whorls and higher she11。 Also，it Tesembles American S．わ加伽α如 DlcKERsoN，1915and its allies，but it ・differs from、the American forms in having much inHated body whorl and wellde丘nednodeson』eachwhor1． Remark：The neW species are sor践etimes found in the Akabira and －Wakkanabe formations of Ishikari group．on the northem part of the Ishikari ・coa1丘eld，in Central Hokkaid6，together with such brackish molluscan fossils，、as Os舵α，Co癖o漁and段not無6r allied spegies，一Sゆho禰1毎sα肋肋瑠MlzuNo・ This new species may be classed in a new subgenus of Sゆho照1伽associate4 with S．s盈罐％名痂：their morphologic characteristics，namely，the short and nearlystraightcana1，and1・wspire・suggest，貧sわ・inted・utbyM・zuN・（1954），their similarity to the species of Eo吻ho郷1乞α，but『6ur瀕materials can 、be apparently distinguished from the species of the subgenus in having箪o distinctbiangulati・n・fb・dywh・r1；theydi鉦ergfr・mth・sす・fNσss鰯σin lhaving nearly straight and hardly bent cana1． Geologic range：Lower Oligocene Geographic distribution： Central Hokkaid6

Sゆho照1齪吻φo％加OYAMA et MlzuNo，sp。nov。（Platel，丘gs．2，3）辱

1928，C㈱061如吻～sp．indet．d．NAGAo，Sci．Rep．T6hoku Imp．Univ．， Ser。2，V・L12，N・・1，阜122（112）・P1115」gs・42～44・ Holotype： GSJ．．Reg．No．5035 「Type locality：In the sample of “：Kita－tatek6” at the Sakito coal mine，Sakito－machi，Nishi－so血ogi－gun，Nagasaki－ken。（Maze formation，Nishi． sonokigroup） Description：Shell sma11，with five or six whorls l spire high，each whor1、strongly shouldered and nodose l如ical angle about forty一丘ve degrees。 Body whorl large，occupying more than a五alf of the whole she11・two rows of nodes，distinctly biangulated，showing a inconspicuous third，angle below the other two nodes，on each row being arranged about ten nodes l body whofl sculptured with spiral cgrds ih altemation of the stronlgs and weaks becoming very weak on the biangulated part of whorL Whorls on spire

5一（593）地質調査所月報（第9巻第σ号）

orhamented With fine spiral cords，with about nine or ten nodes on the middle・feachwh・rLAperture・bliquely・valwithlangulati・n・Canal rather short，slightly twisted to馳e、left． Dimensions of the holoty甲pe： Height16．4mm十1．5・mm± （broken）ll width of body whorl ca、0．9mm；heig玩of body whor10．9mm＋i．5mm± C・mparis・n：ThisneWspeciGss・mewhatresemblesSゆh・励副伽一冗伽勿面（DlcKERsoN），1917and S．5吻καh6競3（WE入vER），1912in outline of shell，but apparently differs frqm them in having more prominent nodes and distinctly biangulated body whorL 今lso，・the new species shoWs the strong similarity to the species of Eo吻honσ1伽in t恥．morphologic character．． istics、of t丘e shell∫but it is easily distingulshed from them in having higher

shell．

Remark：The several specimens shown．by NAGAo（1928）・under the ，name of C催061伽吻？sp．are feferable to・this new species．This new species is commonly，yielded墨n the76彫7加z6毎ッosh昭碗zone in Northwestern、、KyUsh通・ Geologic range二％駕耽αグ協σッosh24傭zone qower Oligocene） Geographic distribution： Northem KyUshU

Family．Vasidae

Genus Pseudbperissolax』CLARK：，1918

．Ps側40ρ副sso鰍づ¢sα観OYAMA et MlzuNo，sp．nov．

（Platel，丘gs．4，5）

Holotype：GSJ。Reg．No．5037（internal mould l broken in apex anごL apertureン Type locality：Near Shirahama，about700m north to Nakado』Oshima－ machi，Nishi－sonog圭一gun，Nagasaki．ken．（Shioda formation，Nishisonoki group） Description：一She1玉sma11，fusiform，sm60th，bic3rinated with probably 丘ve or six whorls．Body whorl more than half of the whole she11，fairly bicarinated，with fine tubercles on the pos七erior kee1．Whorls of spire shouldered about at the middle．Aperture elongated， ovate－trigona1． DimensiQns of the holotype：Height14mm十l width10mm 、 Comparison：The new species（iiffers from Ps6％4砂醜s30嬬伽h6ず（CoNRAD），・1855in having smaller shell with smaller apical angle Also it is ， distinguished from P．ケ砂ho銘o娩s TEGLAND，1933 in having tubercles on the posterior keel of body whor1．

Geologic range： 1VI6／z6蛎oσ名4♂α∂6sガ∫oゑ465zone （upper Oligocene） Geographic distribution： Northem KyUsh“

’

6一（594） On fhe New Forms of Paleogene Mo11uscs from Japan（K：。Oyama＆A．Mizuno＞

PELECYPODA

Fa卑ily Nuculanidae

Genus Sa¢cella WoopRING，1925

Sαoo61伽ho盈認06競s OYAMA et MlzuNo，sp．nOV．

1953，〈砺o％」σ照sp．form肋々肋づ406n5乞s TAKEDA，Studies on Coal Geology，。

No．3，P』66，P1．6，figs．10，12． 1955，翫o％伽α励ゐh鰯06鰯s TAKEDA（MS）一〇GAsAwARA，Hok．Chish． Y6h6，No．29，P．28，text－ng．2 （no description）．・ Holotype：UH．Reg．：No．m㎞own（right，intemal mould） Type・10cality：In the boring core at the upper stream of Ichihosawa， west of Mt．一Kamui，Utashinai・machi，Sorachi－gun，Hokkaid6．（Hiragishi． formation，Ishikari group） This new species was first cited as〈砺o％Zα％σsp．form1海肋碗40卿s商・ by TAKEDA（1953），who illustrated his destroyed holotype．Then，OGAsAwARA （1955）has shown the specimen identifiable to the TAKEDA’s species as翫6痂α％σ ho海履406競s TAKEDA（MS）．The writers’observations on some specimen鼠 made it sure that the unrecorded species of TAKEDA is widely found in the・ Paleogene of Hokkaid6，and here the writers establish a new speci負c name・ with the specimen shown by OGAsAwARA（1955）as the type． According to TAKEDA，characteristics of this species are as follows： “She11、 moderately large，inequilatera1；posterior elongated end rostrate and pointed，rostrum． slightly recur▽ed；beaks not prominent，10w；anterior dorsal shoulder sometimes one、 half the length of the posterior dorsal shoulder， 1℃unded， and’passing gradually to・

ventra1；escutcheon distinct，with radial striation（P），extending to the end；pallial sinust very sma11，romded in front．Surface omamented with close，fine concentric lines，but－

nearly straight on ventral portion，and nearer to posterior dorsal margin suddenly run－ ning upward，where an obscure，blunt，depressed、narrow area runs from umbone to， the middle part of the posterior ventral margin．This species resembles／V．初81αo’，but the former is much longer and the pallial sinus is sma11er．1， Comparison：This species is very similar to Sα66011σ照8iαφTAKEDA， as pointed out by TAKEDA，but it is distinguishable from t1等e latter in having larger shell with lower beak and wider anterior part．Also，it differs from S．ρs6翻os6」∬％紹如TAKEDA，in having widely rounded anterior border． Geologic range： 01igocβne Geographic distribution： Central Hokkaid6and eastem Hokkaid6

Family Nuculidae

Ge卿s Acila E・et A・ADAMs・、1858 Subgenus Truneacila GRANT』et GALE，1931

∠40伽（T7鰯6σo伽）郷8襯OYAMA et MlzuNo，sp． nOV．（Plate I，五gs．14，15）

1928，。〈砺oz〆α（／10σ1σ）卿づ名πわ」あs var αsh勿α6％sJs NAGAo，Sci．Rep．， T6hoku Imp． Univ二， Ser．2，Vo1．12，No．1，p．21，p1．7，figs．8，9（in part）．

7一（595）ロつ

／地質調査所月報（第9巻第9号）臣 1956，！16吻鰯即oづMlzuNo，（MS）一MlzuNo，Bu11．Geo1．Sur》．Japan，蔭 V・1・7・N・・6・pr28・pL2，β9・1（n・descripti・n）・ Holotype：G＄J．Reg．No．5019（1eft valve l somewhat defaced） Type locality：Ob6，Arita三machi，Nishi－matsura－gun，Saga－ken．（Ki』 shima formation，kishima group） Description：Shell sma11，0bliquely ova1，somewhat compfessedl antero－ dorsal border faint1ゾ arcuated； the－posterodorsal nearly straight，abruptly turning to broadly arcuated ventral border with angle of about120～125？． Surface of shell omamented with Hat－topPed，diver墓ing radial ribs l primary ’bifur“ati・nlinesituateds・mewhatp・steri・rly・nshelllribs・nanteri・r与alf side coarse and，platy，but those on posterior half side somewhat fine l obsolete radi＆1ribbing area．indistinct。 Lunule narrow，small l escutcheon ℃ordate，short．Imer margin of shell smoot耳

檬 Dimensions．：Length H：eight 1・（mm）（mm）

l一，：

lP・ Holotype 16．4 13．0 陛、 Paratype 13。2 9．5 ｝

弾一、 Com自arison：The new sp6cies somewhat resembles！16伽soh％吻σ名漉匙L』、

ll、r ΦALL），1909in its outline，but differs from the latter in having smaller shell

姓L・ ll1『 with coarser radial ribs．Further，the former，1acks rOstral sinus，but the

1、， latter has weak rostral sinus． Remark： NAGAo（1928）establishedハ乙zκz読z（／16薇σ）％z動α扉1づs var．‘zsh砂α一 lyr、 6競s basεd on several specir口ens，but the specimens shown in his figures8

獣L 、and9may belong to the present new species from their characteristics．

l・“ Geologic range： Vり彫万oα74伽ツoshづ4‘zJ zone （10wer Oligocene） Geographic distribution： Northwestem Ky貢shO、

Subgenus－Aeila s．str．

L一∫・／10伽（A6伽）s苑加oツα挽漉OYAMA et MlzuNo，＄P．nov．

（Plate I，figs．16，一17）

H：010type：GSJ．Reg。No．5017（intem亀1mould of rlght valve） Type locality：A branch、of Kakino．sawa，the Penke．poronai river， Penke，Ashibetsu－shi，Sorachi－gun，Hokkaid6．（Akabira formation，Ishikari group） Descripti6n：shell small for the subgenus，moderately inHated，obliquely ’・va1・withapicalangle・f100～110Q・anter・一4・rsalb・rdgr1・ng・slightly arched；P・ster・d・rsalb・rdefsh・rt，nearlystraightqrlfaintlyc・ncave，ab－ ruptly tumed to ventral border with nearly right angle．Rostral sinus dis－ tinct．Surfac60f shell omamented with diverging radial ribs，bei血g very 旨 1ドド fine，crowded l prim＆ry bifurcation line situated sorbewhat posteriorly or

1［

／r， about at the middle of shell l angle of bifurcation about700．Obsolete radial 1ノ ribbing area indistinct．

8一（596） 1 OntheNewF・rms・f♪ale・ge“eM・11uscsfr・mJapan（K． Oyama＆A。Mizuno）

Dimensions 一琵ngth Height Angle of （mm）（mm） bifu1℃ation（o） Holotype 18．1 14，8 ca．700 Par＆type 21．0 17．O ca．700

Co血parison：／16瀕αshづ解oッα窺αづis very，similar to．46露α1》グoθ4吻α万oα㍍翠AGAo et HuzloKA，1941，but distinguished from the latter by the smaller apical angle of bifurcation．Also，it resembles ∠46吻αsh卿6競s（NAGAo），192ε 国 and∠しo伽伽召面s（NAGAo et RuzloK：A），1941，but the new species differs from thef・rmerinhaving丘nerradia！ribsandfr・mthelat聯nhavingless inHated，smaller she11． Remark：This new species is commor庄y found in the so－called ma血e zone of the Akabira formation of Ishikari group on the northeastem area of the Sorachi coal field and also rarely found in the Hiragishi formation near Smagawa coal mine． Geologic rangle： Lower Oligocene Geographic distributio♀： Central Hokkaid6

Family Mytilidae

Genus：M：ytilus LINN重，‘1758

晒ガ伽s辮α伽h露OYAMA et MlzuNo，sp．nov。

（Plate III，Hgs．8a，b，9a，b）

Holotype： GSJ，Reg。No，5q15（right，internal mould） Type locality：Chambetsu．gawa，Ombetsu－mura，Shifanuka．gun，Hok． kaid6．（Oma息arif・rmati・n，0血betsugr・up）

Description： Shell Iarge，elongated，moderately inHated． Dorsal border ’br・adlyarcuated，s・血etimesmakingvery・btuseangle貧tab・utmiddle； ventral bor（1er slightly concave； the posterior regularly arched． Surface omamented，with伽e concentric growth－1ines．Beak sma11，ter土nina1．

Dimensions． Length Greatest width （mm）（mm） Holotype ca。62。0 34。1 Paratype 80．1 39．0 70．0 39．3

Compariso尊：This new species somewhat resembles a living吻≠伽s 64％1σs LINN亘，1758，but differs from it in having larger apical angle．From ハ勿ガJz6s Zz‘o加グ％s YoKoYAMA，1924，the present species is e＆sily di菖tinguishe（1 in having a shorter fornユ． Remark：This』species commonly occurs in the sha116W sea deposits of Paleogene of KUshiro coal field，・accompanied by O3≠紹α607吻画σπs OYAMA et MlzuNo，sp．nov．Also，it is rαrely yielded in the Wakkanabe group of Ishi．

kari coal fleld．

9一（597）地質調査所月報（第9巻第9号）

Geologic range： 01igocene Geographic distribution： Central and eastem Hokkaid6

Family Limidae

Genus Lima BRuGul鳶RE，1797

Subgenus Acesta H．et A．ADAMs，1858 L伽α（！106siσ）sα耀shづ窺碗OYAMA et MlzuNo，sp．血ov．

（Plate I，figs．11，12）

Holotype：GSJ．Reg．：No．5006（intemal mould of left valve，some． what broken at ventral part） Type locality：Vicinity of Ashikubo，Miwa一血ura，Abe－gun，Shizuoka， ken．（Setogawa group） Description： She11 1arge，strongly inequilatera1，rather comlpτessed． elongate（i to antero－ventral side l antero－dorsal bor（ier v6ry long，somewhat

concave， the postero－dorsal one‘short， convex， passing gradually into long，， arcuated postero－ventral border l anterior ear very sma11，posterior ear large，． pot separated distinct！y from postero－dorsal part of sheIL Surface of shelr sculptured by very fine concentric growth－1ines and radial ribs，the latter being strong，not squamated，somewhat round－topPed，separated by wider interspaces，sixteen to twenty．on今in number，of寅hich few being on an一， terior ear． Dimensions of the holotype specimen：Length ca．67mm l height ca、 82mm；thickness ca．7mm（1eft valve） ¢omparison：五伽αsα耀3h伽漉sp．nov．is somewhat s㎞ilar to L．、 s繍hお・wERBY，1888andL・卿・sg繊・sσN・ETLING，ユ901，butisclear1γ distinguished from them in having less mmbered radial ribs and longer anterodorsal bor（1er of shelI． Remark：Th6writers examined ten speじimens referred to this new－

species。These specimens show a slight variation in numbers of radi41ribs； most of them including the holotype specimen have eighteen or nineteen ribs． while other few having sixteen，seventeen or tWenty－one ribs． Geologic range：Lower？ 01igocene Geographic distribution： Central Honsh貢

Family Ostreidae

Genus Ostrea LINN丘，1758 0s加σ60吻協副s OYAMA et／MlzuNo，sp．nov．

（Plate IV，figs．1al b，2a，b，3a，b）

Holotype： GSJ．Reg．No．5001． Typelocality：CliffoftheShi㌻akarari〉er，about200msouthtothe tributary’of the Shitakara river and Pon－shitakara river，north to the『YObets媒

10L一（598） 6n the New Forms of Paleogene MoIluscs from Japan（K．Oyama＆A．Mizuno）

coahnine，Akan－machi，Akan－gun，Hokkaid6．（Shitakara formation，UrahorO

group） Description：Shell of moderate size，ovate，comparatively thick』gently c・血vex，inequivalve．Cardina！areac・mparativelybr・adanter・一aゆ・ster・一l dorsal margins with crenations，but not vermiculation． Inside of ventral margin smooth．Adductor scar situated somewhat subcentrally．Sculpture without prominent radial folds．

Dimensions Length Height （mm）（mm） Ilolotype 46．1 51．5 Paratype 79．5 111．1 64．5 87．2

Comparison：Recent C鰯ssos舵σ4万σ肋鰯s FuJITA，1913（＝“吻％伽づs沖 auct．）、resembles this new species，but the living form differs from the new species by having larger size and lacking crenations on t五e r嘩argin・ Os伽6α 城z吻吻SowERBY，1871has more slender shell and more inequilateral than O．60吻漁7歪s OYAMA et MlzuNo，sp．nov．，but the both may have clos6 relationship to each other， Remark：This new species is richly included in the shallow sea dep・sits・fPale・genethr・ugh・utthqKushir・c・a1丘eldlespりciallyits葺・wsa crowded，occurrence in the lower part of t狙e Shitakara formation，forming a so．called．03舵σbed．Also，it is found in the Akabira formation in the Ishi． kari coal field． Geologic range： Oligocene Geographic distribution：Central and eastem Hokkaid6

Family Crassatellitidae

Gehus Crassatellites KRむGER，1823

Subgenus Crassatellites s．str・ C7σ5s伽ll伽s（C郷sα護θll露6s）ゐo郷04αづOYAMA et MlzuNo，sp・nov・

（Plate IIL figs．1a～d，2a～c）

Holotype： GSJ．Reg．No．5004（conjoined valve） Type locality： In the main incline of the Sakito coal min6，、Sakito． machi，Nishi．son6gi－gun，Nagasaki－ken。（the lowermost part of the Maze 〆 formation，Nishisonoki group） Description：Shell moderate in size for the subgenus，rather，thick・ well inHated，transversely elongated l antero－dorsal margin short and slightly

c。nvex；P・ster・一d・rsa1・ne－c・ncaveunderthebeaklP・steri・rb・rdersub－ ’＼1 truncatedlventralb・rderbr・adlyc・nvexlstrikingridgec・卑cavelyrunni幣9 from unibo to postero－ventral comer．Beak sma11，pointed。Surface of tlle shell omamented with concentric・growth－1ines and fine ribs，the ribs being visible only’at the anterior area of the above－mentioned ridge in immature

11一（599）／

地質調査所月報（第9巻第9号）

l← 教stage of she11．’Lunule narrow，10ng and deep；escutcheon cordate，deep，the β 【both about same in length．Inner margin of she11五nely crenulated．臨 i嵩自 Dir丘ensions of the holotype：Length34．1mm l height22．4mm l thick一

ll、・・ness14。6mm．に賑 Comparison：The new species is distinguishe（1from all the species of 撚 lt ・C名αss碗ll吻s from the Paleogene in Northem Ky亘sh豆in having丘ne crenula． lll・

1，F 』tion of intemal margin．It is somewhat similar in outline to some specimens

彰、・of C〆αss砿611露6s （E％o名πss‘z渉61㍍）ツσわ6づNAGAq， 1928，but it differs in having

寮 the crenulation of the ventral border an（i striking ridge on posterior area of いポ the shel1．Alsαthe new species is clearly distinguished from the living species 鶴霧・C郷ss痂611漉s（（）観ss厩611漉s）％郷s（A．ADAMs et REEvE），1850，in having 鵠 llり士三10nger and more，inHated shel1．

ヒ鵠．1 Geqlogic ra寡ge： 76％6吻σグ碗σッosh躍漉zone（10wer Oligocene） 11 Geographic distribution： Northern Ky且sh貢！・∫

霧

1『1 Family Carditidae

Genus Venericardia LAMARcK，1801 Subgenus Cyclocardia CoNRAD，1867 γ傭7卿剛α（qソolooα名4紛h礎％観OYAMA et MlzuNo，sp。 nOV．（Plate III，丘gs．3a，b）

Holotype：GSJ．Reg。No。5014（right valvO，more or less broken in

’beak）

Type locality： Nakado，Oshima－maqhi，Nishi－sonogi－gun，Nagasaki． ken．（HigirQ formation，Nishisonoki group）

Description：Shell moderate for the subgenus in size，rather thick，、鷺 inflated，slightly higher than long， subcircular；anterior and t）osterior borders 襲 regularlyr・undednearlyi血equallventralb・rder・br・adlyarcuated．Be亀k

ピド 11・ prosogyrous，prominent，at about central part of the she1L Surface of the shell omamented with very fine，concentric growth－1ines and radial ribs l t尊e ribs ab6ut twenty－two in number，rather narrow with bluntly angulated top， separate（i by narrower interspaces，finer an（i more crowded in the posterior partthanintheanteri・rpart・fthesh6111severa1・nes・ntheanteri・r extremity concavely well arcuated．

Dimensions of the holotype：Length20．5mm l height21．3mm；thick－ ness6．5mm（right valve） Comparison：The new菖pecies re＄embles76％7加z4伽銘Oogα耀％s♂s No－ MuRA，1935，a wel1－known Miocene Carditid fossil in Japan，in its outline of the shell and the humber of ribs，but differs from the latter in having more Tounded posteτo－ventral part and wider ribs，Also，it is similar to＄ome ・specimens of珍％67翻z漉α躍伽ゆφo％加NAGAo，1928，from which it is dfs－ tinguishable in having fewer ribs and more rounded postero－ventral part．

12一（600） Onth6NewFgms・fPale・geneM・11uscsfr・mJapan（K．Oyama＆A．M量zun・＞

Geologic range： 76彫π6αz4伽∂65傭oJ46s zone（upper Oligocene） Geographic distribution：Northwestem Ky’｛ishO

76n67卿醜σ（C弼oo召名づ刎ツo々のσ耀♂OYAMA et MlzuNo，nom．nov．

1890，76紹万oσ毎伽60柳紹3sσYoKoYAMA，Palaeontographica，Vol。36，P．、 196，pl．25，丘gs．4a，b （non Cσz4づ如60柳泥ssαREEvE，1843）。 1953，76鰐π6αz4毎（qソo乙oαzκ刎60郷ゆ名召ssαYoKoYAMA－UozuMI，Shin一・ seidai－no－K：enkyU，No．17，P．27，P1．21，figs．168～170． 1953，P76％67勿召名4伽、60吻φz6ssαYo：KoYAMA－TAKEDA，Studies，on Coar Geology，：No』3，pL12，fig．91p1．8，fig．14． Remark：： C礎漉！α60噸紹ssσREEvE，1843（Conch．Icon．，Vo1．1，p1．9， 1fig．46）belongs to 76彫7ぎ6α名4宛，and then it invalidates the YoKoYAMA’sも name．Here the writers introduce a new speci且c name for the latter。 Geologic range： Upper Oligocene Geographic distribution： Central and eastem Hokkaid6

Family Lucini母ae

Genus Lueinoma DALL，1901 L％伽・甥卿鱒OYAMAetMlzuN・・甲n・v・（Plate IV，figs．7a，b，8a～c，9a～c）

1928，Phσ60♂463（五％6初o吻α）sp．indet．NAGAo，Sci．Rep．，T6hoku Imp．、 Univ．，Ser。2，Vol．12，No．．1，p．59（49），pl．10，figs，2，12～14。

1956，L％o伽o卿4σo％≠づ1初召αiσ （CoNRAD）一HIRAYAMA，Sci．Rep．，T6ky’δ1か Ky6iku Daigaku，Sec．ρ，Vo1．5，No．45，p。108，pl。6，fig。8． Holotype：GSJ．Reg．No．5027（conjoined valve） Type locality：r Nittan－Takamatsu coal mine，Mizumaki－maとhi，Onga一、 gun，Fukuoka－ken．（Yamaga formation，Ashiya group） Description：Shell small to moderate in忌ize，suborbicular in outline，ヒalm・stequilaterallP・ster・一d・rsalb・rderfaintlyc・nvexltheahter・一d・rsal slightly concave and s豆orter than the former； anterior and posterior borders・＾ nearly vertical and faintly convex， gradually passing intq regularly arche（1 ventral border． Beak slightly prosogy薗rous，very smal1，pointed，situate（i on． about middle of the shβIL Lunule d6ep，narrow．Surface of she玉l omamented「． with many concentric fine ribs，being separated by’，broad，Hat interstices．

Dimensions Length Height Thickness （mm）（mm）（mm） Holotype’ 25．0 23．1－ 41．0 Para．type 32．1 29．0 16。9 ca，． 4．0 ！6．1 18．5 （leftva1▽e）

ComparisQn：The new species is closely akin to L％伽o卿g60伽卿伽％α （CLARK：et ARNoLD〉，1923，and it is very di伍cult to separate the both species，

13一（601〉地質調査所月報（第9巻第9号） bytheir．・utline，andsurface・mam6ntati・n・H・wever，thepresentspecies differs from the latter in having smaller shell and less prominent and smaller 『beaks．Further，this new species resembles五％σ伽o卿αα6観1伽θσ渉σ（CoNRAD）， 184g，but differs from the latter in having smaller shell with lo血ger antero一

㌧dorsa1，border． Remark：P肋60づ463（L％o吻o吻σ）sp．of NAGA6（1928）is apparently the new s食eciesl and also L％o伽o魏σα6％あ1初6σ如of HIRAY奈MA（1956）are referable to the species．The new species occurs widely’in the％勿6πo礎4乞4∂6s痂o掘6s z・ne「（upPerOli3・cene）inn・rthemandn・rthWe＄temKy“shO，suchasthe Aもhiya group，Meinohama formation，upPer part of Kishima and』Nishisonoki groups，・and no specimen is found in the Iower Oligocene horizons of these areas，Sqveralspeci血ensref6rablet・thisne痴speciesn・wathandh3ve slight difference』especially in the proportion of the Iength and height of the

1・． shel1，but they agree with their small size and the shape of出e she11． Geologic range： 76彫720α名漉4∂6s読o擢65zone（upPer Oligocene）聖 G←ographic aistribution：Northem and noτthwestem KyUshU

Family Thyasiridae

Genus Thy・asira LEAcH，1818 Subgenhs Conchocele GABB，1866

丁勿σs〃α （Co7z6hoα3彪）房s66雄o盟zα猶z房OYAMA et MlzuNo，subsp．nov．

（Plate III，figs．4a，b，5～7）

Holotype： GSJ．Reg．Noい5011（Conjoined valve l shell somewhat broken in anterior part） Type locality：Ashibetsu．shi，Sorachi．gun，Hokkaid6（exactly unknown）．（Akahira密ormation，Ishikari group） Description：Shell rather sma11，．trigonally ova1，slightly longer than 至igh・m・deratelyinHated・withapicalangleab・ut1100・Anter・一d・rsalbgrder nearlystraight・rfaintlyc・nvex，・btuselytumedt。br。adlycurvedventral borderl drawiロg a subangulated arch l tlle postero－dorsal regularly arcuate（1，参b・utthree－sec・nd・rtwice・ftheanter・一d・rsalinthelength．Surface’・f the－shell sculptured by concentriご，rough，an（1irregularly arrahged growth－ 1ines・・posterior surface excaYated－from the upPer side of the beak to the posterior comer，making oblique ridge． The anterior part of the shell excavated like in the posterior one，but it is Iess excavated，with twol oblique， faintridgeunderlunule，

Dimensions ：Length Height Thickness （mm）（mm）（mm） Holotype 29．3 28．5 17．0 Paratype ca．30．0 ca，，29，0 16。0 21．2 21．0 11．0 16．0 14．8

14一（602） On the New Forms of：Paleogene，Molluscs from Japan』（K：・Oyama＆A．Mizuno）

Comparison：The new subspecies is similar to the typical form of T勿σs加6づs6伽CoNRAD，、1849，a familiar species from the upper Oligocene to Recent in Japan，but it differs from the latter in having sma11er，more drcularf・mwithnearlystraight6rfaintlyc・nvexanter・一d・rsalb・rder． Geologic range：Lower Oligocene Geographic distribution： Central Hokkaid6

Family Veneridae ’ Genus Pitar R6MER，1857 P吻プs粥oh勧52sOYAMAetMlzuNo，sp．nov．（Plate IV，figs．1a，bl2～4，5a，b，6）

Holotype：GSJ．Reg、No．5021（conjoined intemal moulds） Type Iocality：In the vicinity of Manji，Kurisawa－machi，Y亘bari－gun， Hokkaid6．（Wakkanabe formation，Ishikari groΦ） Description： Shell large，trigona1玉y oval，moderately・inflated，inequi二 laterallanter。一d。rsalb・rdersh・rt，thep・ster・一d・rsa11・ng，regularlyarどhed，

’the both passing gradually to broadly’arched ventral border．Beak sma11， situating at anterior two．fifth or one．third of the whole she11． Surface or．『namented with fine，rather irregularly arranged concentric growth－1ines． Pallial sinus large，、wide，triangular，pointed at the end．

Dimensions： Length Height （mm）麺m） Holotype 50．0 44．4 Paratype 44．4 38．5

－ 35．3 31．2

－ 49．4 41．2

C6mparison：The new species is very similar to P吻グo彦α4伽σ（YoKo－

YAMA）， 1932an（1 P窃πグツo々の7σ別αづ（NAGAo）， 1928，in outline of she11，but it differs from the former in尊aving less in且ated shell and from the latter in

having pointe（i pallial sinus． Remark：一P伽7sozαoh伽zs乞s sp．nov．richly occurs in the Ishikari lgroup，especially in the Wakkanabe formation・throughout the Ishikari coa1 五eld，and also the writers know its sitnilar occurre燐e in the Iower part of the Shitakara formation，Urahoro group llear the Y丘betsu coal mine in the Kushiro coa1且eld． Geologic range：Lower Oligocene Geographic distribution： Central and ea＄tern？ Hokkaid6

Family Myidae

Genus Mya LINN倉，1758

砥α9劣召ω伽9勉砿9αo♂OYAMA et MlzuNo，nom．nov．

1941，！吻α9名伽伽9勉MAKIYAMA，var．6娩9伽NAGAo et INouE，Jour．

15マ（603）地質調査所月報（第9巻第9号）

Fac．Sci．，Hok．Imp．Univ．，Ser．4，Vo1．6，No．2，p．150，p1．33（2），丘gs．1～4．（nonハ勿4切o％gとz如BRoccHI，1814）． Remark： Acc・rdingt・theC・penhagenD¢isi・n・nZ・・1・gica1N・men－ clature（p．84），the trinomen for fossil form is to be deemed a subspecific name．ハのα g泥”初9ゐづvar．切o％9α如 NAGAo et INouE has、a subspecific rank andispre・“cupi“dby伽β」・難卿BR・ccH・・18141asaprimaryh・m・nγm・ The writers introduce，then，a new name郷即o歪for Japanese form reportedl by’NAGAo and INouE． Geologi“range： Upper Oligocene Geographi6distribution： Southem Sakhalin

Family’Periplomatidae

Genus Peri】Ploma ScHuMAcHER，1817 P6吻lo耀歪θs雄漉OYAMA et MlzuNo，sp，nov・

（Plate I，丘g．13）

Holotype： GSJ．Reg．No．5029（right outer cast）夢 1』 Type locality：Kakinoura－jima，Sakito－machi，Nishi－sonogi－gun，Naga－ saki－ken．（Tokuman formation，：Nishisonoki group） ll Description： Shell large，compressed，transvαsely ova1，inequilatera1，，！ inequivalve，right valve with slightly『higher beak l broadly rounded in front，、，／ truncated behind， ventral border gently arched， the antero一（iorsal broa（11y

ア 1，』

お arched，the postero－dorsal abruptly¢oncave behind beaks． Beaks not pro卑一 1，51 inent，“ituatedatthep・steri・r・ne－third・fthesHe11．Surfacesculptured

11i with numerous growth－lines，and obliqu“fine ribs，strongly wrinkled in the ll、 posterior extremity．

ll Dimensions of the holotype specime辞：Length43。3mm；耳eight3LOmm （in right valve）

ト Comparison：This new species di鉦ers from jP6グ弼o卿の召sshoθ％s6（YoKo－ YAMA），，1924in its posteriorly situated beak and posterior wrinkledもculpture 髪 Geologic range：『V6％露αz而毎∂θsピづ渉o躍6s zone（upper Oligocene） 1・

11、 r Geographic distribution：Northwestem Ky豆shU

l l 護 References ／鼻、

藍 1）HIRAYAMA，K、；Tertiary Mollusca fro血Hikoshima，Yamaguchi Prefecture，Japan．き碁 with Remarks on the Geological Age of the“Ashiya Fauna”，Sci．R＄p、 1『1 T6ky6Ky6iku．Daigaku，Sec．，，C，No．45，p．81～122，3pls，，1956 レ巨に 2）尽uRODA・T・＆HABE・T・；、Chec≧ListandBibli・graphy・f・theRecentMarin3・契 M・11usca・fJapan・ed・andpub・byLe・・W・Stack，P・手～210，1952 3）MlzuNo，A．；On Two New Forms of Paleogene・Gastropods from Hokkaidδ，Japan，， Venヒs・V・L18・N・・2・P・1・1～1・8・6，text一丘95・・1954 1ξ き 11F 4）MIZuNo，A．；A Preliminary Note on the Megafaunal Zones of the Paleogene inl

誌 N・rthwestemKy五shu・Jマpan（f・rC・rrelati・n・fthePale・窪en6F・rmati・n・ § in Japan），Bull．GeoL Surv．Japan，Vol．7，No．6，p．261～270，2pls．，1956 ［ l 16一．（604） l㌧ i 誕

導「．／

On the：New Fomis of Paleqgehe Molluscs from Japan（K：。Oyama＆A．Mi雀uno）．．

5）NAGAo，T．；Paleogene Fossils of the Island of K：y貢shti，’Japan，Pt・2，’Sci・Rep・ T6hoku Imp．Uni》．，Ser．2，Vo1．12，No．1，p．11～140，17pls．，1928’ 6）NAGAo，T．＆HuZloKA，K．：Fossil！10勉from Hokkaid6and Karahuto，Jour． Fac．Sci。，Hokkaid61mp．Univ．，Se1・．4，Vo1．6，No，2，p．113～141，3pls．， 1941 7）NAGAo，T．＆INouE，T．： Myarian Fossils from the Cenozoic Deposits of Hok． kaid6and Karahuto，Jour．Fac。Sci。，Hokkaid61mp．Univ．，Ser．4，．Vo1．6． No．2，P．143～158，3Pls．，1941 8）No殖uRA，S．二Miocene Mollusca from Siogama，Northeast Honsy廿，Japan，Sait6－ Ho－on Kai Mus．Res．Bu11．，No．6，p．193～234，1935 9）OGAsAWARA，K：．：On Some Poronaian Fossils found in the UpPer Part of the Ishikari Group，Hokkaid6Chishitsu Y6h6，No．29，p．28，29，・1955 10）OYAMA』K．：F我milia Limidae，Conchologia Asiatica，Vol．1，Pt．1，P．1ル74，14 Pls．，K：ajitani Shoin，1943 11）RuTH，J．W．：The Molluscan Genus Siphonalia of the PaciHc Coast Tertiary，Bull． Dep．GeoL Sci．，Univ．Calif．，Vo1．26，No。3，p。287～306，2pls．，1942 12）TAKEDA，H．＝The Poronai Formation（01igocene Tertiary）㎡Hokkalid6and South Sakh＆1in，and its Fossil F歌una，Studies on Coal Geology，Hokkaid6Assoc． Coal Min．T㏄hno1．，No．3，p．1～103，18pls．，1953 13）UozuMI，S．30n聖the Ge加s％％o吻α名伽from Hokkaid6，ミhinseidai－no－Kenky廿，No． 17，p．26～30，1pl．，1953 14）WEAVER，C．E．：Paleontology of the Marine Tertiary Formations of Oregon and Washington，Geology，wash，Univ。，vo1．5，p．一1～190，104p星s．，1942 15）YoKoYAMA，M．3Versteinerungen aus der Japanischen Kreide，Palaeontographica，． Vol．36，Nos．3～6，p．159～202，8pls．，1890 16）YoKoYAMA，M．』M611uscan Remains from the：Lowest Part of the J6ban Coa団eld，」・ur。C・ILSci』，、ImnUniv・士6kyδ・V・1・45・Arし3・P・・一32’5pls…♀24 17）YoKoYAMA M．3Tertiαry Mollusca from the Co＆団eld of UryU，Ishika域 Jour． Fac．Sci．，Imp．Univ．T6kyδ，Sec．2，．Vo1．3，Pt・6，p．221～247，4pls．， 1932

本邦産古第三紀化石貝類の新種について大山桂水野篤行要旨

この数年間の研究により，古第三紀層産の貝化石には多数の新種が含まれていることがわか／つた6それらのうち，漸新統産の次のものをこ』に記載する。

新属

7ンo吻雁％OYAMA et MlzuNo，gen。nov．

新種お』よび新』亜種

ル伽o吻翻ohガOYAMA et MlzuNo，sp．nov． C吻飾鷹4so郷h纏sズ50YAMA et MIZuNo，sp．nov． Sゆho郷枷試sh吻n襯αOYAMA et MIzuNo，sp．noヤ．

17一（605）地質調査所月報（第9巻第9号）

Sゆho剛紺吻ρoπ吻OYAMA et MIZuNO，sp．nov． Ps6％40φ爾sso名醐勿sα々α」OYAMA et MIZUNo，sp．nov． Sσ066肋ho々肋劾6％s澹OYAMA et MlzuNo，sp．nov．・ l r z40磁（τ7吻oσo漏郷g襯0’YAMA et MIzuNo，sp．nov．イ46珈（。46勉）3h珈oッ4脚プOYAMA et MIZuNo，sp．nov．区ノ吻伽s耀伽oh露OYAMA et MlzuNo，sp．nov．互耀（z406吻）sα脚3h2耀♂OYAMA et MIZuNo，sp，nov． Os！脚召o吻癩舷s OYAMA et MlzuNo，sp．nov． C燃s碗燃θs（C郷sα魏舵s〉ん伽o磁lOYAMA et MIZuNo，sp．nov． γ6彫7吻グ伽（の6Jo僻4勿）hα7％履OYAMA et MIZuNq，sp．noy』勧吻o耀郷g伽OYAMA et MIZuNo，、sp．no▽． τhッαな加（Co％6hoo碗）δ試超吻o脚吻OYAMA et MIZuNo，subsp．nov． P％σプεo耀oh勿％3澹OYAMA et MlzuNo，sp。novF． P6吻Jo耀勿s盈αi OYAMA et MIZuNo，sp．nov．

新名

α翻名翻σ）α剛瀦9鎚P）π卿・♂OYAM今etMIzuNo・n・m・n・v・，（聯・％纏sp・indet・NAGA・・1928） y碗グ磁グ伽（C夕吻6α鰯α）ッoκoッ卿認OYAMA et MlzONo，nom．nov．（惚瘤7磁7伽）60郷鋼8灘’YOKOYAMA，1890）ノ吻αg紹吻2g々初αg襯OYAMA et MIZuNo，nom．nov．

療（ルゆαg泥ω6初g窺6め％g観αNAGAo et INouE，1941）

18一（906〉 Plate I

1a～C 盈弛o枷is％oh露OYAMA et MlzuNo，sp．no》． Holotype（GSJ。Reg．No．5008）×1．75 ：Loc．：In the vicinity of Ashikubo，Miwa・m翠ra，Abe－gun，Shizuoka－ken．（Se－ togawa group） 2， 3 Sψho郷伽卿汐o％磁OYAMA et MlzuNo，sp．nov． 2 Paratype（GSJ．Reg．No．5036）×1 ：Loc』：Ob6，Arita－machi，Nishi－matsura－gun，Saga－k母n．（：Kishima formation，

：Kishimagr・up） 3 Holotype（GSJ．Reg．No．5Q35）×1．6 Loc二： In the boring cqre of the shaft “Klita－tatek6”， at the Sakito coal mine，Sakito－machi，Nishi－sonogi－gun，Nagasaki－ken．（Maze formation，

Nishisonoki group） 47 5 Pso錫40ρθγ才sso1砿犯so虎厩OYAMA et MIZuNo，sp、novl 4 Paratype（GSJ．Reg．No．5038）×1。6 Loc．： Okuura，’Sakito－machi，、Nishi－sonogi－gun， Nagasaki．ken．（Tokuman formation，Nishisonoki group） 5a，b Holotype（GSJ．Reg．No．5037）×1。85， Loc．二Near Shii・ahama，about700m north of Nakado，Oshima－machi，Nishi－ sonog圭一gun，・Nagasaki－ken．（Shioda formation，Nishisonoki group），

喝a，b Cα砂ヵi昭臨so郷oh初¢s乞s OYAMA et MIZuNo，sp。nov。 Holotype（GSJ．Reg．No．5030）×1 ：Loc．：Nai6．machi，Sorachi－gun，Hokkaid6 （exactly unknown）．（Wakkanabe『

formεしtion，Ishikari group）ぜ 7～10 Sψho郷勧訊sh魏σ吻紹OYAMA et MIZuNO，sp．nov． ‘7a，b Paratype（GSJ．Reg．’No．5033）×1ユ Loc．：Upstream of the Tanzan river，Ashibetsu－shi，Hokkaid6，、（Akabira， formation，Ishikari group） 8 Pa．ratype（GSJ．Reg・No・5034） ×L1、 Loc．： ibi（i． 9a，b Paratype（GSJ．Reg．No．5032）×1．1 ：Loc。： ibid．

ユOa，b Holotyge（GSJ．Reg．No．5031）×1．1 Loc．l ibid．

ユ1，12 〃耀（z46θ蜘）εα耀sh枷召z OYAMA et MIZuNo，sp．nov。

11 Paratype（GSJ．Reg．No．5007）×！ L。c．＝lnthevicinity・fAshik廿b・，Miwa－mura，今be－gun，Shi2u・ka－ken。（Se－

togawa group） 12 H：olotype（GSJ．Reg．No．5006）×0．9

Loc．： ibid． 13 p厩μo脚忽α勧OYAMA et MlzuNo，sP・nov・ H：olotype（GSJ．Reg．No．5029）×1 Loc．： Klakinoura．jima，Sakito．machi，Nishi．sonogi．gun，’Nagasaki．ken．（Toku－＼ man formation，Nishisonoki group）－

’1

一一事 14，15 ∠40吻（T7襯6α6勉）πσg襯OYAMA et MlzuNo，sp．nov． 14 Paratype（GSJ．Reg．No．5020）×1．75 ：Lcc．＝ Ob6，Ar貧a－machi，Nishi－matsura－gun，Saga－kenl（Kishima formation飽

K：ishima group）

15 Holotype・（GSJ．Reg．No．5019）×1．75

1」oc．： ibi（i．

16，17 ノ40吻（孟6勉）εh加oッ翻αガOYAMA et MIZuNO，sp．nov． 16 Paratype（GSJ．Reg．No．5018）×0．93 L・c．：Abranch・f、theTanzanriver，Ashibetsh－shi，H・kkaid6。（Akabiral

formation，Ishikari group） 17 Holotype（GSJ』Reg．No．5017）×1．67

：Loc．： A b1・anch of Kakino－sawa，the Penke－poronai river，Penke，．Ashibetsu一一

shi，Hokkaid6．（Akabira formation，Ish三kari group） 18a～c αグ30加吻σ（α7so舵郷oφs試s～）郷即oズOYAMA et MlzuNo，sp．nov． Holotype（1～∋PS。Reg。No。36183）×2 ：Loc軌：Beach rocks，west of Hachlman－zaki，Wakita，Wakamatsu－shi，Fuku＿ oka－ken．（Wakita formation，Ashiya group）

ひ 09／

η8 9、9／，、駒

η6’

講・蒙、

6 ’oN：‘6 010A ’f oA」nS ’lo∂ξ）。IIロa Plate II

1～3 Os舵α60γ翻呂捌s OYAMA et MIZuNo，sp．nov． 1a，b Holotype（GSJ．Reg．No．5001）×0．89 Loc．： Cliff of the Shitakara river，about200m，south of the junction of the

Shitakara river and the Pon－shitakara river， north of the YUbetsu Coal mine，Akan－machi，Akan－gun，Hokkaid6．（Shitakara formation，Urahoro group） 2a，b Paratype（GSJ．Reg．No．5002）×0．93 Loc．： ibid． 3a，b Paratype（GSJ．Reg．No．5003）×0．94

㌧ Loc．： ibid． oθ

蝋§磯弱

9ど

oど灘i籔雛雛騨

II e膨ld 600N‘6。loA●f oAエnS●lo9｛）’1Ina Plate III

1， 2 C郷s膨Z伽s（C燃εα’β」耽s）々o郷o伽OYAMA et MIZuNO，sp．nov． 1a～d Holotype（GSJ．Reg．No．5004）11a，b ×1．23，1c，d ×1．1 1Loc．：In the lst gallery of the Sakito coal mine，Sakito－machi，Nishi－sonog1・ gun，Nagasaki－ken．（Maze formation，Niるhisonoki group） 2a～c Paratype（GSJ．Reg．No．5005）×1．13 Loc．： ibid． 3a，b 距％痂oα名伽（のoZo6醐伽）hα7％々ガOYAMA et MlzuNo，sp．nov． Holotype（GSJ．Reg．No．5010） ×1．12 Loc．：Nakado，Oshima－machi，Nishi－sonogi－gun，Nagasaki－ken．（Higire forma－ tion，Nishisonoki grouか）

一一4～7 銑ッαs加（Co％oho68Z8）δ魏吻o耀吻OYAMA et MIZuNo，subsp．nov． 4a，b Holotype（GSJ．Reg．No．5011）×0．98 ：Lcc．： Ashibetsu－shi， Sorachi－gun，｝lokkaid6『（exactly unknown）．（Akabira

formation，Ishikari group） 5 Paratype（GSJ．Reg．No．5012）羊×0．9〆

Loc．’一＝’ibid． 6 Paratype（GSJ．Reg．No．5013〉×・り．O I，oc，： ibid． 7 マaratype（GSJ．Reg』No。5014）×0。9 曳． F Loc．： ibid．

8， 9 聯吻s漁6h⑳YAMAelM・zuN・・sp・n・v・ゴ 8a，b Holotype（GSJ．・R6g．No．5015）×0．99 ：Loc．：Chambetsu－gawaダノOmbetsu－mura，Shiranuka－gun，H：okkaid6．（Omagari ’ ！ f・matign，Ombets喚gr・up） ga，b Paratype（gSJ．Reg。Nq。5016）×0．88 ’ Loc．： Sen’no－sawa，ミatombetsu river，ρmbetsu．mura，Shiranuka－gun，Hok－ kaid6．（Shit歌k＆ra formation，Ura．horo group）（79 09 解塑

IIlo‡Bld 6 ’ON ‘6 ●10A of ●△じms ●logD ’Hna Plate IV

1～6 P物7so名αoh初s試s OYAMA et MIZUNO，sp．nov． 1．a，b Holotype（GSJ．Reg．No。5021）×0．94 ：Loc．：In the vicinity of Manji，：Kurisawa－machi，YUbari－gun，Hokkaid6．（Wakkanabe formation，Ishikari group） 2 Paratype （GSJ．Reg．No．5022） ×0．90 Loc．： ibid． 3 Paratype（GSJ．Reg．No．5023）×0．86 Loc．： ibid． 4 Paratype（GSJ．Reg．No．5024）×0．90 1’oc．： ibid． 5 ：Paratype（GSJ．Reg．No．5026）×0．88 ：Loc．＝Upstrψm of the Tanzan river，Ashibetsu－shi，Hokkaid6，（Wakk我nabe

formαtion，Ishikari group） 6 Pa1’atype（GSJ．Reg．No．5025）×0。88 Loc．： Same as Figs．1～4 7～9 五％吻o耀郷g観OYAMA et MIZuNo，sp．nov． 7εし，b Paratype（GSJ．Reg．No．5040）×1．59 Loc．：Southwestem coast of Oshima，Oshima－machi，Nishi－sonogi－gun，Naga－ saki．ken．（Shioda formation，Nishisono：ki group） 8a～c Paratype（GSJ．Reg．No．5028）×1 ：Loc．：Nittan－Takamatsu coal mine，Mizumaki－machi，Onga－gun，Fukuoka－ ken．（Yamaga formation，Ashiya group） 9a～C Holotype（GSJ。Reg。No．5027）×1 Loc．： ibid． o

昭翅

AI o↓Bld 6●oN‘6’loA of o△JnS。10∂D oI1na