九州大学学術情報リポジトリ Kyushu University Institutional Repository

Family Puzosiidae from Hokkaido and Saghalien : Studies on the Cretaceous Ammonoidea from Hokkaido and Saghalien-V

Matsumoto, Tatsuro Faculty of Sciences, Kyushu University

https://doi.org/10.5109/1524119

出版情報：九州大學理學部紀要 : Series D, Geology. 5 (2), pp.69-118, 1954-10-30. 九州大学理学部 バージョン： 権利関係： Mem， Fac． Sci，， Kyushu Univ，， Ser． D， Geology， Vol． V， No．2， PP．69－118， text・figs．1－6， table 1， plates 9－23，0ctober 1954

Family Puzosiidae from Hokkaido and Saghalien

（Studies on the Cretaceous Ammonoidea from Hokkaido and Saghalien－V）

By

Tatsllro MATSUMOTO

Introduction

There are a number of forms referable to the Desmocerataceae in the Cre・ taceous deposits of Hokkaido and Saghalien． They are grouped in four families， Desmoceratidae， Puzosiidae， Kossmaticeratidae and Pachydiscidae． Some of the important members of the 6rst and last groups have been described in Iny recent paper（Appendix勿T． M．（Editor）1954）． I treat here the second group． Although it would be desirable to give a de丘nition of the‘‘Family Puzosiidae”， there are certain unsettled questions relating to the extent and status of that group， so that I shall not discuss the matter at length here． However we have a series of forms which constitute a fairly easily recognizable natural group． The main purpose of this paper is to describe them systematically． In connexion with the description of our material some necessary remarks on foreign specimens will be included． In aconcluding chapter I shall give my preliminary view on the‘‘family”． The material which I have studied is mainly my own collection which was obtained in connexion with my stratigraphical work． The specimens are preserved partly in the Geological Institute， University of Tokyo（GT．）and partly in the Department of Geology， Kyushu University（GK．）． As to the localities， horizons and stratigraphical problems readers are requested to refer to the previous papers（T．M． 1942－43and also T． M．（Editor）1954）． I have fort皿ately been able to exarnine fully the original material of JIMBo（1894）， YABE（1909）and KAwADA（1929）in the Univer・ sity of Tokyo． Some of the collections in tbe Department of Geology＆Mineralogy， Hokkaido University and in Hokkaido Mineral Resources Survey（‘Chikashigen－ Chosajo’）， Sapporo have also been examined． After I had prepared a draft of this paper and photographs of our specimens I visited London（1953－54）and had an opportunity to observe specimens which are preserved in the British Museum（Natural History）， Geological Survey＆ Museum of Great Britain and Mr． WRIGIIT’s collection． 70 T．Matsumoto

Systematic Description Order Ammonoidea Superfamily Desmocerataceae Family Puzosiidae SpATII，1922 Genus Pμ208『αBAYLE，］878

1ン2りθ sρθoゴθs： ノ1〃2〃20〃カθs s〃妙Zα〃z〃α∫％s ScHLUTER， 1871 （＝ノ1〃2〃20ηξ’θsカ10κ〃10∫〃5 BAYLE，1878，κoκSowERBY，1827）． Gθκ〃ゴoD似g〃os£sごDiscoidal and rather evolute shell， consisting of many whorls which are compressed and elliptical in cross section and have an arched venter． Umbilicus of moderate size（30－40％of diameter）surrounded by a perpendicular wa11 with a subangular umbilical shoulder． Periodic， more or less flexiradiate， con・ strictions showing a forward projection on crossing venter． The ventral part of the whorls is ornamented with subcostae or fine costae which run nearly parallel to constrictions． The inner part of the flanks is almost smooth． Suture・lines in early stage of growth are similar to those of immatureルZε膓o〃oグ㌘s and in later stage of growth have a large and asymmetrically tri丘d L， unusua11y small U1，0blique or recurved U2 and remarkably descending elements of subdivided U3（＝S）． Rθ勿oグんs：The generic name was proposed by BAYLE（1878， explanation of pls． xlv and xlvi）without description of diagnosis． Of the three species figured by BAYLE as 1）〃20sゴα，ρ1耽〃膓α如was selected by H． DouvlLL丘（1879， p．91）as type． BAYLE’s 6gure of‘‘ヵ1α〃〃1α如”shows that he interpreted that species too widely and in fact his figure represents a species previously described by ScHLUTER （1871， P．4， P1． ii， 五gs．5－7）as／1〃2〃20κ力杉s sμbρ1α〃〃Zα∫〃s． There is therefore a case for regarding ρ膓α〃〃α’〃sSowERBY as debarred from selection as type species on the grounds that it was not one of BAYLE’s syntypes， but the question requires a decision by the Inter・ national Commission on Zoological Nomenclature苦． For the time being I fo110w Dr．

SPATH’s interpretation （1923， P．42）． The genus varies to some extent in compression and involution of whorls and also in curvature and strength of the constrictions；the features vary with growth and are modi6ed by condition of preservation． Therefore careful comparison at each growth．stage is necessary for the precise speci6c identi丘cation， while in too many cases only sma11， presumably immature specimens have been treated． However in the present state of our knowledge the genus seems to be divided into two subgroups， which are defined here as subgenera．

Subgenus P〃20sグα（s． s．）

D飢g％osεs：The outer whorl of the fu11－grown stage is essentia11y similar to the inner whorls but with obsolescent ornamentation．

＊Mr． C． W． WRIGHT proposes to refer the question to the Commission（personal communica・

tion， May，1953）． Family Puzosiidae from Hokkaido and Saghalien 71

Subgenus Anapuzosia， nov． （ex MATsuMoTo，1938， MS．κo勿．〃〃4．）

乃φθ功θ6ゴεs： 1）〃205εαb〃ε〃o吻〃汐γαANDERsoN，1938． D飢gκosどs：The adult body chamber is ornamented with periodic， flared or tuberculated， strong ribs of little or no Hexuosity． About a half century ago Professor JAcoB， who examined carefully the change of characters at different growth－stages， described some interesting specimens with a peculiar ornamentation on the large adult body chamber under the speci6c name P〃20sξα勿αyoガαηα（JAcoB，1908， P．38， pl． vi，丘gs．1－4）and remarked that P〃20s化 がo〃〃α’αfrom Basses・Alpes， which is as large as his〃2⑳oグ切伽， never shows such astrong ornamentation． P〃20s∫αs〃bμα〃〃1α加（ScHLihER）， the type species of Pμ20sゴo， is represellted also by fairly Iarge specimens， one of which exceeds over 300mm． in diameter（Sc肌6TER，1871， P．5）． P〃20sゴαo磁ε〃sゴs KossMAT， which is closely allied to 1元s〃bがo〃〃σ∫α， reaches again to a very large size， being 285 rnm． in one example． However neither author observed in these large specimens of Pz’20sらthe particular ornament of JAcoB’s 〃2¢yoガα〃α． Fortunately I have been able to study a large specimen of P2420sどαfrom the Cenornanian of England， about 20cm・． indiameter（in GRIMsDAI，E Co1L Brit． Mus．（Nat． Hist．）， without reg． no． but with GRIMsDAI，E’s no． 1551）．Although it is water worn and still septate near its preserved last part， it shows normal ribbing of s励♪1α捌1α∫α・type on the venter and there is no trace of periodic， flared ribs． Our four species of Pκ205飢， described below， includes fairly large specimens of 200mln． or over in diameters but they never show strong periodic ribs， while som、e of our Puzosiids of later date， described in later pages under 〃吻bo『τ〃αs， do have that peculiar ornament on the adult body chmber． Unfortu・ nately I have failed to discover皿mistakable examples of A〃⑳〃20sどαfrom Hok・ kaido and Saghalien． However in the Albian（UpPer Horsetown group）of California there is another interesting example of Aμαρμ20sゴα， P． b∂4ω20砂θ川z6夕αANDERsoN （1938，

p．185，p1．41，丘gs．1，2；？pL 40， fig．3）， whose large outer whor1， about 160 mm． in diameter， has strong Periodic ribs， although without the pripheral tubercles of JAcoB’s〃2⑳oグ『⑫α． I designate here 1三力〃εκσ砂θη彦〃グσANDERsoN as the type species of∠伽ψμzosどo， since the specimens of JAcoB’s勿4yoタゴα伽are nomenclatorially doubtfuL苦

＊ Recent authors in France（FABRE，1940；BREIsTRoFFER 1936，1947）seem to have made it clear that d’ORBIGNY，s type of幼のo吻批came from the Cenomanian and the species could range down to the Albian， while JAcoB，s precise stratigraphic work （1907，1908）tells us that his只． 伽夕o加姻is rather common in the Lower to Middle Albian and is replaced by P．ヵ1ακ〃～鋤・ sκ地1αμ〃！α彪in the UpPer Albian and Cenomanian． JAcol3 recorded the occurrence of his Iarge 別のo酩ηαin the 4εη’αZμ8・zone． BRElsTRoFFER（1936， iηBEsAIRIE）regarded the small specimen of JAcoB’s〃2のoγ∫o％α（1908， P1． vi， fig．1）as a variety （boη〃21〃り of P〃20s紐4舵刀s’θ4存PARoNA ＆BoNARELLI． Thus the question remains whether JAcoB，s large別α夕o夕i醐αis identical with ・4〃2〃20痂’θs〃2⑳o万α〃od’ORBIGNY， P砿osω4％ηs’θ4ガPARoNA＆BoNARELLI or otherwise． 72 T．Matsumoto

Thus the distinctness of、肋ψ〃20s’αfrom Pμ20sゴo（s． s．）is justified as far as the well preserved specimens are concerned． However the inner whorls of the two groups are essentia11y similar and the special ornament of∠4〃O〃20s『αdid not affect the immature she11． There my be some distinction even in the immature shells， but I have failed to find good criteria． Prof． JAcoB and other authors remarked that」P．沈¢yoプZ碗σis less flattened than 1元がα〃〃1αZα（－s％bヵ1α％〃α∫のand in the former the lateral lobe（L）is regularly tri6d and somewhat deeper than E while in the latter it is distinctly asymmetric and much deeper than E． P． bκε〃卿θηωγαANDERsoN is also round whorled and has the suture of‘乃砺〃2α〃『・type’． The whorl shape however changes with growth and in different species． For instance I fortunately had an opportunity to observe a number of English specimens belonging to P． s加ヵεZ SpATH， which is said by many authors fairly sirnilar to P． 〃2の70夕ω〃α（d’ORBIGNY）． In this species the whorl is as high as broad and rounded in section at diameters over 50mm． but is sometimes higher than broad and rather flattened at diameters below 40mm or so．（JAcoB’s immature specimen‘zη4yo夕ら〃o’ （1908，pl． vi， fig．1a， b） belongs rather to the latter category．） Indeed 1三 s〃αカθξ might belong to∠肋4餌20sξα， but the largest specimen hitherto known is the one 6gured by SpATH（1923， p1． i， fig．12a， b）with a diameter of 83 mm．， so that we cannot decide whether it belongs to Pμ20s化（s． s．）oれ4批φ〃20W． Meanwhlle只 o〃θ〃s〆sKossMAT， which is an example of P〃20s似（s． s．）de丘ned above， has somewhat inflated fianks as compared with P． s〃bヵ1αη〃10ωand P．1りZακμ10∫α． The suture seems more reliable than whorl shape but in the smaller immature specimens there is no essential difference between the two subgroups． The depth， width and cur・ Vature of the constriction may be useful for speci6c distinction but not always so in subgeneric separation． Thus、most smaller or immature specimens are in practice hardly separable into the two subgroups． However the peculiar character in the outer whorl is， as e）ζ一 plained above， more than specinc． Therefore the subgeneric sparation is， in my opinion， apPropriate at least for the time being． Anyhow it is necessary to search for better specimens so that the character at each growth．stage may be clari丘ed in

every specleS． 1）Zs〃ゴb〃’‘oκ： There are four new syecies of P〃20sゴα （s．s．）in the Cretaceous of Hokkaido and Saghalien． One of thenl occurs also in India and other provinces． These species indicate that the stratigraphic range of the genus is very long both in the Japanese province and in India， that is Neomiyakoan， Paleogyliakian and Neo・ gyliakian， namely Albian， Cenomanian and Turonian． The geographical distribution of P〃20s伝is also world wide． In Europe the genus has been known in Albian （mainly Middle and Upper Albian）and Cenomanian， but in my opinion there are a few Turonian species which are referable to this genus， as will be discussed below． Family Puzosiidae from Hokkaido and Saghalien 73

No example of．肋ψ〃20sゼαhas been discovered in Hokkaido and Saghalien． In Europe and California it begins to apPear from the Lower Albian． The upPer limit of its range is still uncertain．

Subgenus P〃205ゴα（s． s．）

2P〃宕osゴαSz4bco2rβαタゴ6α， SP， nov．

（ex YABE，1927 MS．〃o吻．〃％4．）

P1．9， fig．1a， b；Pl．12， fig．1．

〃αZ〃ゴα1：Holotype， GT． L370（H． YABE’s Col1．）from Ikushumbets gorge， Lower Ammonite Beds of YABE（main part of the Middle Yezo Group in MATsuMoTo’s revision）somewhat below the Mikasa Sandstone． Paratypes 1－3， GT．1－671 and GT．1－672 from the same locality（Ik－6－2）as the holotype（T． M． Co11．）and GT．1－2632

from Iocality N327b， zone Kz－Mh in the Naibuchi Valley， South Saghalien（T． M． Co11．）． Other comparable specimens of rather poor preservation are GT．1－2631 from loc．1－69－2， zone Kv（a large fragment）；GT．1－2628， Ioc．1－205p derived froln Kv； GT・1－2629，2630， loc．1－69－1， Kv in the Aikawa Valley， South Saghalien（T．M． Co11．）

and GK． H 1222 from Ioc． Yl81p， bed Ilb2（or Ilb1）in the Shiyubari Valley， Ishikari

Province， Hokkaido（T． M． ColL）．

Mθαs％グε勿θ勿s：

Specimen Diameter Height Breadth（B／H） Umbilicus（％） GT．1－370 173．5 59．0 （34％）

〃 〃 150．5 63ユ 43．5（0．ε9） 48．8（31．4％） GT．1－2632 183．0 81．2 ？41．0 （051） 58．7 （32％）

5ρεo琉碗9〃os£sこ Species of 」P〃zosゴα characterized by highly compressed outer whorls which have flattened， nearly parallel Hanks and rapid growth in height． External half of whorls numerous， narrow and sharp subcostae， while the internal part f the Hanks is nearly smooth， except for faint flexiradiate striae extended from some of the external subcostae． Periodic constrictions gently sigmoidal and with a considerable forward projection on the ventral area． Rθ勿α夕んs： The frequency of the constriction varies with age and individuals． In some there are only 40r 5， in others 6 in one volution． Asmall specimen with a diameter of 44．O mm， which came from the same bed as the holotype， certainly represents an immature stage of the species． This has sharp subcostae on the ventral half of the whorl． In this stage the typical Pκ20s『α・ type pattern is not manifested in the suture－1ine and it is similar to that illustrated suture・1ine of 〆1〃oカ〃20sら 〃2¢yoグゴακα （d’ORBIGNY） （JAcoB，1908， P．25 text fig．13； SARAslN，1898， p．797， text fig．20）， which also belongs to an immature stage and resembles that of MθZ6〃oグ舵s． The adult sheli of the present species has a charac．

teristic suture－1ine with a large and asymmetrically trifid L， curved U2 and remark・ ably descending elements of subdivided U3． 74 T．Matsumoto

The present species is closely allied to P％20sらZαんθゴPopovIcl・HATzEG（1899， p． 12，p1． ii，五g．2）from the Lower Cenomanian of Rumania， but seems to be distin・ guished by less frequent constrictions， a little wider umbilicus and somewhat broader whor1． However exact comparisen is di伍cult as the Rumanian specimen is second・ arily deformed． P％20sらco〃ψ夕εssαKossMAT（1898， P．119， P1． xviii， fig．4）（＝ノ1〃2〃oκゴ∫θs 4κ瑠α SToLlczKA，ユ865， p．143， p1． Ixxi， figs．6，70nly）from the Lower Utatur group of India is somewhat similar to the present species in the compressed whorl and slight subcostation but is distinguished by its more compressed form， wider umbilicus， slower growth of whorls and more strongly projected subcostae． Although the speci丘c name，且s％boo夕bα耽αwhich was given by YABE（1927， p． 41（15），1isted only）， seems to suggest some alliance with 1）αプψ〃205ゴατoγbα夕加（GRos・

souvRE，1894）， of a higher horizon， there is no close relation between the two species． SHIMIzu（1935， P．176）probably wished to reject such a confusing name and intellded to give another name， P．’召κ〃Zs SIIIMIzu， but that is also invalid because the mere mention of its resemblance to 1）．掘〃θJ PopovIcl・HATzEG is no valid description．苦 As

Ihave examined YABE’s original specimen and not had access to SIIIMlzu’s collection， Iadopt YABE’s MS． name which has become already familiar to Japanese geologists． Ocoκ〃ρκce：The holotype and paratypes are from the upper part of the Neomiya・ koan and Infragyliakian of Hokkaido and Saghalien， approximately equivalent to the Upper Albian． Comparable specimens are from other parts of the Neomiyakoan．

Pz4zosゴαoグゴθ〃∫α1ε， sp． nov．

P1．13， figs．1，2a， b．

刀4α’〃化1： Holotype， a large shell whose outer and inner whorls have been detached： GK． H 1225 from Iocality Y420c， bed IIn（10wer part of the Saku formation）in the Shiyubari Valley， Ishikari Province， Hokkaido． Paratype， GK． H 1224 from Ilp， lower part of thc Saku formation in the Shiyubari Valley．（T． M． Co11．）

Mεαs％夕ρ〃2θκ∫s：

Specimen Diameter Height Breadth（B／H） Umbilicus（％） GK． H 1225（at mid． age） 126．3 50．0 38．7（0．775） 43．3（34％） KossMAT，1898， pl． xxii，6g．2 80．0 32．0 23．0（0．72） 26．0（32％） CHoFFAT，1898， pl． xvii， 125．0 57．0 40の（0．70） 34．0（27％） fig．2， xviii， fig．1

Sρεα1βc4ゴ㎎κosZ5： Aspecies of P〃20sらcharacterized by relatively compressed whorls， narrowly arched venter， numerous， regular，丘ne and narrow costae on the external half and the prorsiradiate course on sides and conspicuous forward bend on the periphery of the costae and the constrictions．

＊ The speci丘c name P擢osiαZ伽硫is now used for a different species from the Albian of Angola（Haas，1942）． Family Puzosiidae from Hokkaido and Saghalien 75

Rθ勿α夕んs：The specimens at my disposal were once listed as a variety of P〃20s’α 9姥4α勿α（FoRBEs）（T． M．1942－43， P．233 and elsewhere）． Indeed they are so closely allied to those described under that speci丘c name by KossMAT（1898， P．118， pL xvi， 6gs．2a， b，3）that their speci6c identity is undoubted． Minor differences between ours and KossMAT’s are found in the proportion between height and breadth of whorls and in the width of umbilicus in proportion to diameter． The Japanese form is slightly broader and also slightly more widely umbilicate than the Indian one． The two geographica11y separated forms should be distinguished subspeci丘cally since these minor but constant differences are found in the characteristic features of the species． The Japanese holotype is far larger than the mustrated specimen of Koss・ MAT and is nearly smooth in the outermost part． The fact can be regarded as a difference in growth・stage． KossMAT himself mentioned the presence of a large shell in India． The question remains whether or not KossMAT’s illustrated specimen is speci丘・ cally identical with FoRBEs’original one． Although I have not yet observed the former， I fortunately had quite recently an opportunity of examining the latter， owing to the kindness of the authorities of the British Museum（Natural History）． The specimen（BM．10487）is unfortunately poorly preserved alld its outer whorl is so deformed that the curvature of its ribs and constrictions are apparently quite different betweell the side illustrated and the opposite one． （The ribs and constric・ tions on the unillustrated side have only gentle forward curvature．） As its ribs are not so narrow nor so dense as those of the clearly illustrated specimen of KossMAT， the two must be speci丘cally separated． It is rather similar to‘‘P〃20sゴα”沈4ρ吻6が6α KossMAT， as Dr． SPATH（1921， P．47）has already pointed out， but its deformed con・ dition， as well as somewhat worn surface， prevents us from precise identification． At any rate KossMAT’s specimens should be transferred from P． g醐4α勿αto E o〃6％桓1θand are here called Puzosia orientale kossmati， subsp． nov．， on the grounds of the above mentioned difference of subspeci丘c value． The holotype of the sub・ species is， of course， the i11ustrated one： K（）ssMAT，1898， P．118（183）， pl． xvi（xxii），

五gs．2a， b． Similarly Pκ05ゴαcf．9％4α勿o（FoRBEs）from the Turonian of Portuga1（CHoF・ FAT，1898， P．82， pl． xvii，6gs．2，2；P1． xviii，69．1）may be another example of P． oW〃》α1θんoss吻o彦ゴ． On the other hand“P〃20siαg微4α勿α（FoRBEs）”from Madagas・ car（BouLE， LEMolNE＆T由vENIN，1906－7， pp．20，21， pl． iv，丘gs．4，4a，5，6）seems to me cornposite and needs further study． Dθs勿oo〃os g協4α勿αYoKoYAMA，1890（P． 184，pl． xviii， fig．14；p1． xix， fig．5a， b）belongs to a quite different species， as will be described below．（See∧花ψ〃zosκ∫幼o〃ゴoα（SpATH）．） P据os化oグゴθκZα1e is allied to P〃zosらs％6007bα〃oαin its compressed whorl and 丘ne subcostation， but is distinguished by the more prominent forward bend of the costae and constrictions． Probably the former is a descendant of the latter． 76 T．Matsumoto

Pz偬osら〃2元〃〃Z de GRossouvRE，1894 （＝／1〃2〃20κ〃ρs乃θ夕〃eκs£s Sc肌UTER，1872， non 1867）from the Upper Turonian of Europe， which was regarded as identical with KossMAT’s‘P g協4α吻α’by several authors， including KossMAT himself， is indeed closely allied to the inner whorls of the present species but is still more compressed （b／hbeing O．52，0．580r O．64 as compared with O．77 in typical oグゴεκ加1¢and O．700r O．72in oグゴθ〃劫Zθん05s〃2励のand has elliptica1， instead of rather convergent， whorls， so

that I regard it a distinct species， though allied to the present one． Contary to the views of the above authors SpATH（1922， p．128）not only admit the speci丘c distinct・ ness but furthermore placed it in his 71夕αgo4θ5初06θプαs． I cannot agree with this generic reference because of a considerable morphological difference from the type species of that genus， whereas a close a伍nity to P． oγ’ε〃劫1εand」らs〃bc〃カ〃πα strongly suggests us the reference to Pμzo5切． Mr． C． W． WRIGIIT kindly showed me aspecimen in his collection from the Chalk Rock（Upper Turonian）of England which is also closely allied to P鵬05どαoグ『θ〃ω1θand P．勿元〃θグゴ． Thus P〃20sらseems to have survived up to Turonian and is a persistent genus． 066％グプθκ6θ： Lower part of the Neogyliakian in Hokkaido， Japan， apProximately Lower Turonian． P． oγゴθ〃Zα1e〃oss勿oがis reported from the Trichinopoly group of India， without exact statement of its upper or lower part． CHoFFAT’s comparable specimen from Portugal came from Lower Turonian．

P〃20sゴαoタゴε〃拍12初’ε夕〃2ε4ゴαKOSSMAT

P1．12， figs．2and 3．

1898．Pμ20s辺gαμ4α別αvar．伽’〃耀4iαKossMAT， p．116（181）， pL xvii（xxiii）， figs．3a－c．

Mα’〃鋤：GK． H 1223 from Iocality Y137， bed Iln， Shiyubari Valley， Ishikari Pro－ vince（T．M． Co11．）．

S％65ρραφ64化g〃05‘sごClosely allied to the typical form of the species but dissimilar in the frequent development of flexuous long ribs， besides numerous short externaI ones， after the middle growth・stage． Rρ勿αγ〃s：The Japanese specimen is very similar to the Indian form described by KossMAT， but is somewhat larger and has less Hexuous Iong ribs． The feature can be ignored as a minor change with growth・ages and individuals． The development of Ionger ribs might suggestメ4〃s〃耽〃αs， but the large shelI from Japan does not show the difference in strength of major and minor ribs， On the other hand this form is rather akin toル7θ5ψ〃20sゴα夕〃6α夕θ〃sθ（JIMBo）emended below， in which longer ribs are more frequently developed but are as narrow as the shorter ribs． Probably the present from represents a passage stage from P〃zo5どα oグゴθ川αZθ（s．s．）to』4θsρρ偏os祖夕〃6αプ6κsε． From this assumption the subspeci丘c distinctness can be justi丘ed． 060〃夕7ρκoθ：KossMAT’s original specimen was reported from the Lower Trichinopoly group of South India． Our single specimen came from the Iower part of the Neo・ Family Puzosiidae from Hokkaido and Saghalien 77 gyliakian in Hokkaido， just corresponding in age to the Indian one．

P〃20siα κψρo多2『co， sp． nov．

Pl．10， fig．1；P1．11， fig． la， b， c．

ル1ατ〃鋤：且010type， GT．1－3191 from locality T547p， bed Ilb in the Abeshinai・Saku area， Teshio Province， Hokkaido（T． MATsuMoTo ColL）． Other examples from the same area are GT．1－3188 from Iocality T549r， bed IIb；GT．1－3198，10c． T861e， Ilb （Iower part）；GT．1－3199，10c． T25， IIb；GT．’L3200， Ioc． T230P， Ilb；GT．1－3229， Ioc． T652a， IIb． GK． H 1221 from locality Y141， bed IIk in the Shiyubari Valley， Ishikari Province， Hokkaido（T． M． Coll．）． GT．1－2638， Ioc． N38， zone Mho・Mh1；GT．

1－2637，Ioc． N69－70p， zone Mho（？）；GT．1－2636，10c． N69－70p， Mho（？）；GT．1－2635，10c． 134（Aikawa）， zone Mho；GT．1－3766， Ioc． N308g， horizon Kz－Mh；GT．1－3767， loc． IIIc， zone Mho， all at or near the basal part of the Miho group in the Naibuchi Valley and adjacent area in South Saghalien（T． M． Coll．）．

ル♂eαsκγθ初θ〃Zs：

Specimen Diameter Height Breadth（B／H） Umbilicus（％） GT．1－3191 243．0 100．0 63．0（？）（0．63） 75．0（30．8％） GT．1－3189 82．5 54、0 （0．65） GK． H 1221 83ユ 51．7 （0．62）

5φ¢o砺64ゴαgκ05ゴs： Species of P〃20sゴσcharacterized by fairly large size， rapid growth of whorl height， gentle flexuosity of constrictions， ribbing of moderate strength and the occasional development of somewhat longer ribs in mature stage． Costae and constrictions show a distinct forward bend on the venter． Dθsc夕幼〃o〃：Shell discoida1， Iarge when full grown；whorls rapid in growth， much compressed， with a fairly narrowly arched venter and with only slightly innated 且anks． The width of umbilicus slightly exceeds 30％of a diameter． OverlapPing of whorls nearly a half． The immature shell is ornamented with numerous fine subcostae on its externaI half． In the adult stage the ornamentation becomes somewhat stronger， the costae being narrow and sharp of equal breadth on the ventral area but of unequal length． The longer ribs reach more or less nearly to the umbilical margin． Constrictions fairly frequent， shallow and broad． Constrictions and ribs gently Hexiradiate， show・

ing a distinct forward projection on the venter． The large outermost whorl is nearly smooth， the ribs being obsolete．

Suture・1ines are of typical Pκ20sゴα・type． Rε勿αグ〃s：The present species is fairly similar to P酩os化s〃bヵ1α〃〃αZα（Sc肌uTER） from the Cenomanian of Europe． It is however somewhat more compressed， more rapid in growth of whorls and characterized by the development of longer ribs in Iater stages． In this respect it is somewhat nearer to a typical from of a new genus （Mθsψκzos級加α猶cαdescribed below）of somewhat later date． 78 T．Matsumoto

The longer ribs remind us the major ribs of、4％s〃働ε〃αs but they are not so broad（strong）nor so frequent as in that genus， while in the large outermost whorl the smoothing of ornament takes place as in typical P〃zoW． Thus the species is interesting in that it foreshadows／1〃sが〃c〃αs on one hand and another allied new genus（ル7εsρρ〃20s似described below）on the other． As its new character is not so much stabilized as in either of the two genera， it should be

better included in Pz420siσ．

P〃20sψ04どρ〃sZs KossMAT英（】898， P．112， pl． xvi figs．5a， b，4， PL xviii， fig． la， b），

even the larger illustrated specimen of which is said to be the inner whorls of a very large form， is closely akin to the present form， but is somewhat broader and more inflated． Moreover we do not丘nd in KossMAT’s description mention of such long ribs as are observed in the later whorls of P〃zo5化〃鋤o〃cα． 06c〃〃杉〃6θ：Zone Mho of the Naibuchi Valley and adjacent area in South Saghalien， common；Bed IIb（from its base to middle）of the Abesbinai Valley and adjacent area in Teshio Province， Hokkaido；Bed Ilk of the Shiyubari Valley in Ishikari Province， Hokkaido． Summarizing the above， the species is common in the Paleo－ gyliakian（approximately Cenomanian）of Hokkaido and South Saghalien． Asingle specimen， which fs similar but not precisely identical to the present specles， was found at Iocality N308g， zone Kz－Mh of the Naibuchi Valley．

Pκzosどα （～） α勿6ゴ9κα， sp． nov．

Pl．10， figs．2，3a， b．

五勿∫ε〃α1：Holotype， GT．1－2639 from Iocality N309d， zone Mho， Naibuchi Va11ey， South Saghalien． Its outer whorl is partly broken away and the figures are of the same individual． GT．1－2640， loc． N 74b， z皿e Mho；Several other specimens from the Abeshinai Valley， Teshio Province are also before me：GT．1－3189， Ioc． T7b， top

of bed Ilb；GT．1－3190， loc． T28p， bed IIb・c（β）；GT． L3197， Ioc． T27－28p， IIb－c（β），

etc．（T． M． Coll．）

Mθαs％グρ初ρ〃Zs： Specimen Diameter Height Breadth（B／H） Umbilicus（％） GT．1－2639 Ca 200 80 52（0．65） 65（32．5％）

Dθscγ幼∫『o批 Similar to 1）〃20siα万ψρo励6αbut the Ionger ribs are more frequent， more flexuous and appears in earlier growth・stage than in that species． Rθ初α夕〃s：This species might be referred to五名εso1う鵬os化described below， but from its quite intimate relation to P％20sゴακ幼ヵo励6αand its longer ribs being still infre・ quent and indistinct near the umbilical margin as compared with those of typical Mε5ψ砿05化，it is here provisionally included in Pκ20sゴα． Anyhow it is an interest． ing intermediate form between typical IP％osゴαand Mε5ρρ〃gos’α．

＊ In agreement with Dr． SPATH I think it better to regard KossMAT’s form as an inde・ pendent species from the European one． Anyhow it has more a伍nity to P． s功ρ1α吻1ατα （ScHLUTER）than to P．カ1αηκ～α’α（SowERBY）． Family Puzosiidae from Hokkaido and Saghalien 79

06τμタグ吻6θ：Zone Mho in the Naibuchi Valley， South Saghalien and the uppermost part of bed IIb， IIb・c（β）and IIc（α）of the Abeshinai・Saku area， Teshio Province， Hokkaido． Thus the occurrence of this intermediate species is in the upper half of the Paleogyliakian．

Genus Mesopuzosia， nov． （ex MATsuMoTo，1938， MS．κo沈．κ〃4．）

1＞ρθsρε¢どes： 」砿6soZ｝〃zosゴα1りαcるβ6α， SP． nov． Gθ〃〃‘6碗αgκos玩 Similar to P〃20s級in shell form and suture．line but with much better developed costae． In the middle and adult stages of growth many of the costae（including both longer and some shorter ones）extend below the middle of the Hanks and are of equal strength on the outer half of whorls． Although there are Ionger and shorter ribs， the differentiation to broader（or stronger）and narrower ones is not found as in Po2rαρμ205’ごz（s． s．） or in ／1z6sκ〃参6ε夕αs and the costation is relatively regular． The shell often attains a huge size and in the last whorl the ornamentation disapPears． Rθ〃2αグ〃s： Besides the type species JレZoεsψμ205ゴα 幼4bφα6がcα （KossM、、T）and 」兄 夕〃bαγθ〃s¢（JIMBo）emended below are the examples of this genus． There is also another new species（M∂6κ5ゴcosZo∫α）． These species are similar to certain species of P〃zosωin their immature stage and there are somewhat intermediate forms． Thus 1〕〃20sゴαoγゴ¢励α1θMATsuMoTo， with subsp．物’〃批4仇KossMAT， is apParently apassage form between P〃zos’αs〃boo夕bαグ加（YABE MS．）MATsuMoTo and 1膨sψ〃・ 203飢ツκb〃θ〃sθ（JIMBo）and P酩osゴακψ♪o〃磁MATsuMoTo and its ally， P．α励ゴ9〃α MATsuMoTo， shows intermediate characters between P〃205らs％～ψ1α〃〃1α∫α（ScHI，UTER） or P・04ゴθ〃sゴs KossMAT and ルZ6sψ〃20sゴα 吻4ψαcがcα （KossMAT）or Mカααiβoα （described below）． M6sψ〃zos仇occurs abundantly in the Neogyliakian or Turonian and less com・ monly in the Urakawan or Coniacirnヵ1κs Santonian of Indo．Paci丘c realm， while Pκzos似ranges from Albian to Turonian． Mθ5ψ〃20siαcan thus be regarded as a direct descendant of true P〃zosゴα． To make the distinction of this genus from P〃ψ〃20sZσand∠肋s励ゴo〃os clearer Iinclude here a de丘nition and remarks of those two genera， although there are no examples of them in our collection．

Genus Pα夕ψκ20s飢NowAK，1913

乃ヵ¢5ρθoゴεs： So〃κθグαZゴα4α〃bγερZ de GRossouvRE，1894． Geκ〃‘64ゴSg勿s‘s：Similar to P据osらin general character and distinguished by the unmistakable separation， at Ieast after the middle growth・stage， of the costae into two different types；they consist of numerous， externa1， short ones and Iess 皿merous， Iatera1， Iong and broad ones which reach， or nearly reach， the 80 T．Matsumoto

umbilical margin． Often the Iatter branch into two or three of the former on the ventral area． The ribs are nearly rectiradiate on the side and rather suddenly， but sometimes rather gradua11y， curved forward at the ventrolateral edge， forming ventral projection． On the huge last whorl the major lateral ribs persist as broad， coarse， widely separated ones but the external ribs are obsolete．

Genus∠4κ5ガ励6θγαs， SPATH，1922

7＞カθSρεcゴes： 〆1〃2〃20〃ゴZθs o％5’¢〃ゴSHARPE，1855．

Gθκ〃ξ64甑g〃os宏 Similar to Pκ205ゴαin general character but has on the large outer whorl frequent major ribs which are sigmoidal or arcuate and stronger on the sides than the numerous external minor ones．

Ambigious points in NowAK’s proposal of Pα夕αヵ％20s’o（1913， p．363）were pointed out by SpATH（1922， p．120）， who gave no clear generic diagnosis but liSted the species to be included and designated a Santonian form as type species．

Of the species hitherto assigned to Pα夕αカ〃20sゴαby SPATH and subsequent authors there are more than two groups of forms ranging through a number of stages of Neo〔retaceous． Taking into consideration the rich material from the Upper Cre・ taceous of Hokkaido and Saghalien as well as the hitherto known foreign species， I am obliged to take notice of the diversities in the ornamentation of Puzosiids． ’‘ Pαプα勿zosゴα（s．1）”seems to have been distinguished from Pκ205らchie且y by the relatively well developed costation． However there is more than one mode of development ill the ornamentation and here Mθ5ψ〃205Zαand IV泌ρ〃20sゴα（de6ned below）are separated from P〃ψ協osゴαand its allies． The examples of Pαγα吻zosらin my de丘nition are， besides the type species，五 〇〇γbαグゴcα （GRossouvRE）， P．沈κκθ〃6θ㎎1％s‘s （FRITscH ＆ Sc肌oENBAcH） and P． 1ψZψ吻砺（SHARPE）． Probably several species from America（MILLER＆YouNGQulsT， 1946；ScoTT＆MooRE，1928）and possibly“Pα6吻4ゴs6％s”鋤ρθ〃π4θ〃sゴs LANDols苦 may be the gigantic examples of this genus． Development of the major ribs in addition to the external costae is found also on the outer whorl of Aκ5励Z6〃αs and that genus may be intimately related to Pαグαヵ〃zo5ら． One criterion for distinguishing the type species of the two gellera is that∠1μsだ痂c〃αsα〃s’θ〃ゴ（SHARpE）has a convergent whorl section while Pαプαρ〃20sゴα 4磁6グρρゴ（de GRossouvRE）has a semiovaI or rather elliptical one． However there can be a certain range of variability in the breadth of venter and shape of whorl． section within the genus， as in the case of P％20s化and」晩sψ〃20s化． SpATII（1922， P．127）proposed the genus／1％s彦‘κZcθκs‘‘for one of the true puzosids still persisting

＊ Its suture is of the Pμ20siα・type（LANDoIS，1895， pls． i， ii）．『 Family Puzosiidae from Hokkaido and Saghalien 81 in the Turonian， specializing in size，”selecting A〃2〃2． oκs∫ε励SHARPE as type species． The statement is not de丘nitive but seems to suggest that∠4％sZ吻‘o〃αs is nearer to

P〃20sξαthan Pαγ4カ〃20s『α． Indeed one of the characteristic features of／1．砺sZθ〃『is the unmistakable sigmoidal curvature of the costae especia11y on the lateral sides of the outer whor1， apart from the forward projection of ventral ribs． However certain species of ‘‘ 〆1〃5だ砺o〃αs，”such as、4．4必1CyZ SpATH and ／L 〃20bぴgξ（de GRossouvRE）， have gently arcuate rather than sigmoidal ribs on the lateral sides， while in‘‘仇夕ψ〃20s’〆’ there is also some variability in the course of ribs． Thus the two genera approach each other in some species and specimens in which the outer whorls are missing are hardly distinguishable． In these circumstonces it seems me di伍cult to decide now whether the distinc． tion of∠4κsZ吻『c〃αs and Poγψ〃20sらis generic or subgeneric． Someone who is more acquainted with the European material may settle the status． Here I treat them quite provisionally as separate genera， fo110wing the current opinioll in recent publications． At any rate Pα夕ψ鵬os飢and／1％sZ吻ゴ¢〃αs are closely allied to each other and the former is probably a direct descendant from the Iatter． Our Mθ5ψ〃zos化is allied to∠飽s物‘τ〃αs but does not show much difference in strength between Ionger and shorter ribs and tends to be smooth on the last whor1． Probably the two genera developed in parallel from P〃20s『α． In some inner whorls and also in some weathered outer whorls Mθsψκ20s『αis often hardly distinguishable from∠4〃s》『励6ρ夕αs． Furthermore there are forms，1ike ／1〃s’沈£c〃αs〃20b〃gZ（de GRossouvRE） （＝ニノ1〃2〃2．α〃sZθ〃ゴin ScHLもTER，1872， p．38，

pl． xi，丘g．11）， in which differention into major and minor ribs is less distinct than

in the type species and thus A〃s彦ゴ〃ゴ6εγαs actually apProaches MεsOク〃zosゴα． Among the Japanese ammonites hitherto obtained， I have not yet identified any specimens referable to Pα7α』う〃20siαor to∠4〃sZゴ厄c〃αs here defined． Those which have been preliminarily identi丘ed with Poπ功〃20s’αare to be transferred to Mθso． カ％20s化or」Vεψ〃20s『o． Although SHIMIzu（1935）1isted a species of／1〃s〃〃£o〃αs，ノ1． 励κ物κ勿SHIMIzu MS．（〃0〃2．〃〃4．）， from the Cretaceous of the Naibuchi Valley， South Saghalien， the full description was not published． （It is doubtful if such a small specimen as is suggested by his speci丘c name could be precisely identi6ed．） From the character of the differentiation of ribs and the rectiradiate， coarse， 1ateral ornament Pαグψ〃20s『αhas been often misidenti丘ed or even regarded as

genetically related to Pαo雇y4『soκs （s．s．） （i．e． the go〃θ2ノ；〃θ〃sゴs一κθz4bθ㎎εo〃s group）．

As I have stated（1947，1951）， Pαo吻4£s6κs has nothing with the Puzosiidae， the two being an example of small scale homoeomorphy within the Desmocerataceae． One of the evidences， which are baseユupon continuous series of forms obtained by a good deal of field works， is the character of suture－1ines． Even in the compressed forms of Pμc吻4『s6〃s（s．s．）the suture is essentially similar to that in depressed 82 T．Matsumoto

Pachydiscids， as for instance∠1郷ρα6勿4ゴsτ〃s． Similarly tlle strongly constricted Pachydiscids， Cα〃α406〃α5 and closely allied Pα∫αg∫osi’θs， can be distinguished from P〃αμ20sξαby the suture as well as the umbilical tubercles（which however disap・ pear in the outer whorl of those genera）． Examining the original specimens I have noticed that‘‘Poグψ〃20sω”9夕砺彦乃ゴ（SHARPE） is a Pα’αgZos『Zθs and ‘‘Pαプ幼〃20s化”

づ6θ勿iτα（SHARpE）is an inner whorl of Poτ吻4どsoκs or 1元（∧后04θs勿oo〃αs）． Similarly

“ Pαグ幼〃20吻”s励oθ『（NILssoN）（MoBERG，1885）， which was regarded as a transi・ tional form from Pαγψ〃20s’αto仇o吻4‘s6％s， is nothing but a Pα’αg£os’『θs， a smo・ othed out derivative from Cακα4ρc〃αs． Poプαρ〃20sらthus revised occurs in Santonian and just above and below but never ranges up to UpPer Campanian or Maestrichtian， whereas∠4κs吻£o〃αs comes from Cenomanian and Turonian．

MρSoカ〃205『α1りαc萌τα， sp． nov．

P1．14， fig．1a， b；PI．15， figs．1a， b，2a， b；

Pl．16，6gs．1a， b，2a， b，3a， b；Text fig．2．

Mα》〃どα1：Holotype， GK．且1257 from Iocality Y 216 pl in the Shiyubari Valley， Ishikari Province， Hokkaido（T． MATsuMoTo Co11．）． Besides the holotype there are anumber of specimens． Examples from the same valley（locality number with prefix Y）（T．M． Coll．）and adjacent Oyubari area（10c． no． with Oy）（S． NAGAo＆ A．OsANAI Co11．）are：GK． H．1256a， b from Ioc． Y206 p1；GK． H 1265，10c． Y216 p1； GK． H1571， loc． Oy104；GK． H1244， Ioc． Y115 p1；GH． H1245，10c． Y216 p1；GK． H1246， 10c． Y216 P1；GK． H1231，10c． Y130 d；GK． H 1232， Ioc． Y137；GK． H1572，10c． Oy107A；

GK． H1573，10c． Oy158；GK． H 1574， loc． Oy167 b；GK． H1249，10c． Y225． All these came from the Saku formation and its equivalent in the western part of the Yubari Mountain Range， Ishikari Province， Hokkaido． From the same area was obtained GT．1－364（MM7635）， pebble of the Yubari（H． YABE Coll．，1abeled as P〃20吻ゴ〃ゐ． 吻αφτの，another example of the present species． Fllrthermore in the collection from the Shimo・Kanayama area on the eastern side of the Yubari Mountain Range， the Ikushumbets and Ashibets Vallies in Ishikari Province and the Abeshinai． and Obirashibets Vallies in Teshio Province， Hokkaido and the Naibuchi Valley in South Saghalien thefe are a皿mber of specimens which are referable to the same species． Their Iist is omitted here， except the two whose dimensions are recorded below：GT． 1－3216from locality T345 P3， bed IId（Saku formation）and GT．1－3217 from locality T42p， Ild in the Abeshinai Va11ey（T．M． Col1．）．

M斑sμγε〃2ε〃∫s： Specimen Diameter Height Breadth（B／H） Umbilicus（％） GK． H 1257 101．8 40．4 33．6（0．83） 33．2（32．6％） 32．3 25．9 （0．80）

21．5 18．3 （0．81） Famny Puzosiidae from Hokkaido and Saghalien 83

GK．正11571（outer ・112．5 45．2 37．8 （0．83） 38．5 （34．2％） whorl excluded） GKH1573 45．3 17．0 14．8 （0．87） 16．0 （35．3％） 12．5 11．0（0．88） GK． H 1244 17．9 7．8 Ca 6．0（0．89） 6．25 （34ら多）

GK． H 1245 69．25 27．4 22．0 （0．80） 23．1 （33g・6）

GK． H 1246 31．25 24ユ （0．77） 21．2 16．9 （0．79）

GT．1－364 Ca 120 44．8 34．7 （0．77） 45．5（38％？） 41．8 32．5 （0．78） 35．8 28．1 （0．785）

GT．1－3216 79．2 31．0 25．2 （0、81） 28．4（3696） 20．0 16．5 （0．825）

GT．1－3217 72．7 28．8 23．0 （0．8）

刀『㎎〃os『s：Shell large in the fu11・grown stage， similar to P％20sゴαin general aspect of shell form， increasing rather slowly in size with growth， and periodically con・ stricted， generaUy with 6 constrictions in one volution． Whorls fairly compressed with gently inflated Hanks， rnoderately arched venter， subrounded umbilical shoulder and perpendicular umbilical wal1． The whorls in early middle age are provided with alternately long and short Hexuous ribs． The ribs in later middle age are of moderate strength and coarseness， separated by interspaces nearly as wide as the ribs themselves， gently Hexuous on the lateral sides， regular in size and distance， showing a rnoderately forward projec・ tion on the external half． The Iong ribs begin at the umbilical margin． The shorter ribs，1ess numerous than the longer ones， rnostly begin a little below the middle of the flanks． Constrictions are only slightly flexuous on the lateral sides and gradual－ 1y pass to the moderate projection on the venter． In the large adult stage the ribs are fairly strong but narrow， separated by a Iittle wider interspaces． They show a gentle Hexuosity on the lateral sides and a considerable forward projection on the ventral area． The very large outermost part is nearly smooth． ’ Suture・lines are of typicaLPκ20W・type， characterized after early middle－age by aIarge， asymmetricaly tri6d，1ateral Iobe and strongly descending auxiliaries， and deeply and finely incised in later stages． R¢勿〃〃s：There are a number of specimens of this species in the Cretaceous of Hokkaido and Saghalien． As they resemble」膨sψ2420s飢吻4ψα02φoo（KossMAT）， I once referred them to that species in my previous stratigraphical papers（1938， 1942－43）．However most of them have gently inHated且anks， while the Indian form is said by KossMAT to have flattened， parallel flanks． The proportion between breadth and height of the whorl is variable to some extent with age and individua1．

It ranges from O．77 to O．84 in the middle or adult stage of Mμoがoαand， thus， on the average most of the Japanese specimens have always somewhat broader whorl than the type specimen of J肱沈4ψαo砺cα（KossMAT）from India， although there is 84 T．Matsumoto

apparently a form intermediate in this character． There is furtherrnore a difference in the curvature of ribs． The ilhlstration and description of the Indian original spe・ cimen show ribs which are straight and somewhat oblique on the inner half of the flanks and bent rather abruptly forward at the ventrolateral part， while the typicaI example of the Japanese form shows rather gently flexuous curvature with a moderate ventral projection． Only a few specimens have somewhat stronger for・ ward bend than the normal ones， but the character is not so remarkable as in the Indian form． Thus in spite of the resemblance to M吻ゐμ¢萌cαthe distinction is still fairly clear and the Japanese specimens in question constitute a solid group， so that I have decided to treat them as a separate species for which the speci丘c nameμα励α is here introduced． This conclusion should be confirmed by further examination of the variation in the Indian species． There is some variatlon in the frequency or coarseness or ribs． However a complete gradation is found and sometimes the rib density varies from one to an・ other and in the same individua1． There is rarely an abnormal form（GK． H1256b， P1．16， fig．3a， b）in which a long rib on one side is continued as a short one on the other and the short one on the former is divided at the periphery into Iong and

short ones on the latter． The present species has intimate relation to Pκ20s飢04ゴεκs『s KossMAT and may be a derivative from that species， as has been remarked on above． Oo6〃ググε〃τθ： Typica11y in the Saku formation and its equivalent（the so・called S6ψ励εs Bed）in the Shiyubari・Oyubari area and Shimokanayama area on both sides of the Yubari Mountain Range， Ishlkari Province， Hokkaido． Specimens have also been found in and near the zonule of Rθ¢s£4μθs 〃2勿『〃2〃〃2（HAYAsAKA＆ FuKADへ）in the Ikushumbets Va11ey， Ishikari Province， Hokkaido；‘‘5τ4ρ〃Zεs Beds” of the Obirashibets area， Teshio Province；Commonly in Bed Ild（Saku formatio1D and less frequently IIc（α，β）of the Abeshinai・Saku area， Teshio Province， Hokkaido and zone Mh3（and doubtfully zones Mh2 and Mh4）of the Naibuchi Valley， South Saghalien． Summarizing the above the species occurs most commonly in the Neogyliakian （Turonian）and occaionally in the Paleourakawan（approximately Coniacian）of 】日【okkaido and Saghalien．

MεSρμ20s劫吻4ρ吻0碗α（KOSSMAT）

1898．P〃gosiαi〃40餌6φco KossMAT， p．117， pl． xvii， fig．2a， b；p1． xviii， fig．3． 1932．1】嬬osゴα（P在夕ψμ20sゴα）ゴ励ψαoφεαKossMAT， CoLLIGNoN， P．18， P1． vi，毎s．1，1a，1b．

ル勧’〃∫αZ：（Examples in our materia1）GK． H1248a， b（adults）from locality Y207p2； GK． H1247（immature）from loc． Y207p1；GK． H1250（middle・aged）from Ioc． Y133； GK． H 1251（middle．aged）from Y466， a11 these came from the Saku formation in the Family Puzosiidae from Hokkaido and Saghalien 85

Shiyubari Valley， Ishikari Province， Hokkaido（T．M． Col1．）． GK． H 1572 from locality Oy158， equivalent of Saku formation in the Oyubari area， just adjacent to the Shiyubari area（S． NAGAo＆A． OsANAI Co11．）．

Mεαsκグε〃2θκ∫s：

Specimen Diameter Height Breadth（B／H） Umbilicus（％） I（oSSMAT，s type ｛115 44．5 33 （0．74） 41 （3696） （After KOSSMAT） 21 17 （0．81） GK．1248a Ca 100 36．5 26．5 （0．73） 32．5 （十） （32．5％） 48．2 22．4 17．0 （0．76） 15．2 （31．5％ GIく．Hl250 64．0 26．1 21．1 （0．81） 21．5（？） （33－34％） 20．0 16．0 （0．80） GKH 1247 383285 15．2 11．2 （0．73） 10．8（32％） GKH 1572 34．0 24．0 （0．71） 26．4 （3296） 12．5 11．0 （0．71） CoLLIGNoN，1932 184．0 80、0 60．0 （0、75） 50．0 （27％）

1）ゴ㎎i〃os‘s：Shell・form 1）〃20s『α・1ike， with a moderate growth of whorl・height， umbili・ cus of moderate width and about 1／2 involution． Whorls compressed withθattened and nearly parallel Hanks， rather narrowly arched venter， subangular umbiliCal shoulder and low but perpendicular umbilical wal1． Whorls in the middle growth．age provided with numerous gently Hexuous ribs， consisting genera11y of alternately Ionger and shorter ones． The Iong ribs start at or very llear the umbilical margin， while the short ribs begin at the middle of the 且anks or a little below． They are of equal strength and are arranged very regularly， separated by interspaces as wide as themselves． In the adult whorl ribs become coarser and run subradia11y（i．e． straight but slightly oblique to the strict radial direction）on the inner half of flanks and show a conspicuous forward projection on the external half of the whor1． Constrictions fairly frequent，6in one volution， running rather obliquely forward on flanks and show a distinct forward projection on the ventral area． Rθ勿αグ〃s： Specimens which are certainly identical with the KossMAT’s original Indian species have also been furnished from the Japanese Cretaceous， though not so abundantly as’ those referable to」協θsψ〃20sゴoραεがoαMATsuMoTo． The available rnaterial suggests， however， that the Japanese form is a little more narrowly umbili・ cate than the Indian type specimen． ‘ζP〃20s飢（Pαグαρ〃20s『∋吻吻抑oぽoαKossMAT”from the UpPer Cretaceous of Madagascar（CoLLIGNoN，1932， p．18， pL vi，丘g．1，1a，1b）is probably another example of this species， although its ribs look somewhat weaker than the ordinary one， being perhaps affected by a condition of presservation． It is rather narrowly umbilk〕ate， but the size of umbilicus in proportion to a diameter generally decreases with growth irl this species． KossMAT（1898）regarded‘‘1）θ5〃20c〃αs g磁4α勿α（FoRBEs），’in YoKoYAMA（1890， 86 T．Matsumoto

p．184，pl． xv血， fig．4；p1． xix， fig．5）from Urakawa， Hokkaido as synonymous with his species． However this is not tenable and the specimens in question represent a quite different species，ハ形ψ〃20sゴα∫ψα煽60（SpATH）described below， and its strati・ graphic horizon is higher than that ofノ協εsψ〃205どσ初4∂カα6萌oα（KossMAT）in Japan． 060〃グπ〃oθ： Saku formation of Hokkaido， i．e． Neogyliakian （approximately Turonian）of the Japanese Cretaceous；UpPer Trichinopoly grouP（probably Conia・ cian）of India；‘Upper Cretaceous’of Madagascar．

Mεsρρ〃20sら夕〃6〃ε〃sθ（JIMBO）

P1．13， figs．3a， b，4；P】．14， figs．2，3a， b．

1894． Z）θs〃200θプθs夕〃bα夕θηsεJIMBo， P．28， pl． i（xvii），69．6，6a，6b． 1909．’Pμ20sω夕θ20θμsθYABE， MS．〃o勿．批∂．， P．443，1isted only．

五勿∫θ〃αZ：Holotype， JIMBo’s single original specimen（GT．1－97）， a small immature she11， came from a pebble of the Yubai River in Ishikari Province， Hokkaido． One of YABE’s specimens（GT．1－385）is labeled similarly． Two others in YABE’s collec・ tion（GT．1－365，1－366）are from the upper course of the Ikushumbets， Ishikari Pro・ vince， Hokkaido． They are of moderate size． Subsequent collections（T．M．）contain several additional specimens， including Iarger ones， from the Neogyliakian of the Yubari Valley and Shimo．Kanayama area on both sides of the Yubari Mountain Range and the Paleourakawan and Neoyliakian of the Ikushumbets and Ashibets VaUies in Ishikari Province， Hokkaido． In the collection of Hokkaido University I saw two other specimens referable to the present species． They came from pebbles in the Obirashibets and the Nio・zawa， a tributary of the Abeshinai， Teshio Province， Hokkaido．

M6αs〃グθ〃2θκ’s：

Specimen Diameter Height Breadth（B／H） Umbilicus（％） GT．1－97 42ユ 18．8 12．9 （0．68） 11．0 （26 ％） GT．ト365 ｛82・° 34．0 22．0 （0．65） 27．0（33 ％） 24．0 15．5（0．66） GT．1－385 95．0 37．3 22．5 （0．60） 34．0 （35 ％）

Dゴ㎎κos‘s：Attains a large size， although the holotype is a small， immature shel1． Whorls increasing rather rapidly， considerably compressed， with rather Hattened and convergent flanks and a relatively narrowly arched venter． The maximum breadth is somewhat or a little below the middle of the whorl． Umbilcus of moderate size in the middle age but fairly narrow in younger stages， with gently rounded umbilicaI shoulder in early stages and more angular one in later stages of growth and provided with Iow， perpendicular， umbilical wa11． Below a diameter of 30mm． the ornamentation is very weak， especia11y so in the inner half of the 6anks． Shell in the middle and adult ages is ornamenten with Family Puzosiidae from Hokkaido and Saghalien 87 numerous ribs， close．set and separated by jnterspaces as narrow as or somewhat narrower than the ribs． There are Ionger and shorter rjbs， the former predominant over the Iatter． The long ribs begin at the umbilical margin and the short ones somewhat below the middle of the flanks， Ribs show an abrupt and strong forward bend in the ventrolateral portion with a remarkable projection on the ventral area， while their sinuosity on the inner half of the flanks is very slight． Constrictions and associated elevations are shallow and Iow， running nearly paralled to the ribs and are frequent only in the later middle age．

Shell in the later stage， of large size， is still pro▽ided with ribs of equal size but the last whorl is nearly smooth． Rθ〃2α7〃s： This species was established by JIMBo （1894）on the basis of a single specimen． The specimen is an immature shell， the later part poorly preserved， and was co11ected in a p6bble from the Yubari River in Hokkaido． There are two specimens（GT．1・－365 and I－366）which were labeled and Iisted by H． YABE as P％20s『αyε20θ〃sθYABE MS． but unfortunately have not yet been described． These three specimens agree well with one another in essential characteristics and should be assigned to one and the same species， for which JIMBo’s name must be adopted． Some difference between JIMBo’s specimen and YABE’s ones is due to difference in growth・stage． Another specimen（GT．1－385）which was Iabeld by YABE as P〃205ら 吻ゐ加α坊oσKossMAT is also an example of the present species． In the shelLform and ribbing the present species is akin to 1）〃20s『αoヵ゜θκZole MATsuMoTo but is somewhat more compressed and provided with numerous longer ribs which are less Hexuous and bent more obliquely forward． It is at the same time somewhat sirnilar to M杉sψ〃205『o沈4ρμ6萌oα（KossMAT）but has distinctly finer and more numerous ribs． There seems to be some variation in the coarseness of ribs within J％θsψ〃20s『o劫40加α河oα（KossMAT）． As the material of M夕〃b〃θκsθ （JIMBo）is relatively scanty and is derived from the area where Mゴκ勿αiβoα （KossMAT）is found in Japan， there is a possibility that the former is an extreme variety of the Iatter． However， so far as the specimens at hand are concerned the former has such a compressed whorl and narrowly arched venter that specific dis・ tinction is warrantable． Ooτ〃γプ閲oε：Although the exact horizon of the original material is not recorded， subsequent collections indicate that the occurrence of the present species is the same as that of M初4ψαoがoα（KossMAT）and」肱ヵαo流αMATsuMoTo， mainly in Neo・ gyliakian and partly in Paleourakawan． However it must be decided more precisely in future．

Mρsρρ〃20s∫α4ε〃s£τos∫6z’σ， sp． nov．

P1．22， figs．1a， b，2．

1929．Pμ20s似勧漉微α5（JIMBo），1くAwADA， P．3， listed only． 88 T．Matsumoto

Mα’ρWZ：Holotype， GT．1－544（＝MM7694）from locality‘Santan・gawa’， zone Mh6 0f the Miho group， Naibuchi Va11ey， South Saghalien（M． KAwADA Coll．）． Paratype， GT．1－3438 from locality T 311P（the Wakkawembets）， bed IIId（upPer）， the Abeshinai Valley， Teshig Province， Hokkaido（T． M． co11．）． other comparable specimens， GT．1－2689 from Iocality N331b， zone Mh6α（lower）；GT．1－2690 from Iocality N331a， zone Mh6α， Naibuchi Valley， South Saghalien（T． M． Col1．）， etc．

Mθαs〃γθ勿θ〃∫s：

Diameter Height Breadth（B／H） Umbilicus（％） Inner whorl of GT．1－544 113．0 44．7 31．5（0．70） 40．5（35．8％）

Sρθα捗01万α㌘osゴ5：Moderately involute（憂）and moderately umbilicate， large， dis・ coidal she11． Whorls much compressed and Hattened with parallel Hanks and nar・ rowly arched venter． Numerous， gently flexuous，10ng ribs with some intercalated shorter ribs， very regular and rather close・set on the external half of the whor1， showing a moderate ventral projection． Constrictions rather shallow and similar in curvature to the Iong ribs． Nearly smooth last whorl． Rε初此〃sごIn its fine and close・set costae， compressed whorls and narrow venter this species is rather similar to Mεsψ〃20sゴoツ％6αグθ〃sθ（JIMBo）but its costae are n．ot so projected as in that species and flanks are且at and parallel， instead of con・ vergent． In the curvature of ribs it is fairly similar to M¢sψκ20s化με萌6αMATsu．

MoTo，but the costae are distinctly finer and more close－set than in that species． From 2ぬsψ〃20sZo吻4ρφαα湧cα（KossMAT）it is easily distinguished by the dif・ ference in the curvature and density of ribs． ‘P〃20s批’9ακ4θ〃刎γ£sZ RoMAN＆ MAzERAN（ユ920， P．69， pl． ii，6gs．1，1a，2，2a）from the Turonian of France is very similar to the present species and is probably an example of M杉sψκ20s似in Europe． Our species seems somewhat more compressed and evolute than that species． Immature specimens of this species might be misidenti丘ed with‘‘1）εsノηoo〃αs” ξs万輪〃oづJIMBo， but that species is now proved to belong to a different genus． When the she11s with diameters of 100－150 mm． are compared the difference is very distinct， as wi11 be understood by the description of that species（see below）’Even in the smaller specimens careful observation can separate the two species by the curvature and strength of constrictions and some di｛壬erence in whorl section． It should be noted that this species occurs in the Neourakawan which corres・ ponds in age to the Santonianゆψs earliest Campanian）， when in Europe and America P吻ψ〃20s似is common， but it does not show the strong（or broad）and straight， major， Iateral ribs of Poγ幼κ20W・type． It represents a species of 1膨sψ〃・ 20sらwhich presists up to Santonian． 0τo％ググθκoθ：Neourakawan（mainly Santonian and possibly inclusive of lowest Cam・ panian）． De丘nitely identi丘ed specimens are few， but I have observed occasionally large puzosiid shells in the Neourakawan． They seem to belong to the present species． Family Puzosiidae from Hokkaido and Saghalien 89

Gemls Neopuzosia， nov．

（ex MATsuMoTo，1954， MS．％o吻．批4．）

7ンZ）θsρθ6ゴ杉s： 1百∫6乃切ゴZθs元ψo〃ゴo〃sSPATH，1922．

Gε〃〃ゴc4らgκ05紘 Similar to P〃20sゴαin shell f（）rm and in suture－1ines and resemb1． ing Mρsψ〃20sゴαand Pαγαρ酩osZαin the characters of inner whorls． The adult living chamber is abruptly ornamented with strong and coarse ribs which start from or near the Umbilical margin， are almost rectiradiate or slightly arcuate on the flanks and are curved forward on the ventrolateral part and cross the venter with increasing breadth． Shell typically of moderate size and usually not so large as in MθSψ酩o吻or POグψ批OSゴα． Rε〃2αグ〃s： The genus includesハ花ψ％20sゴαノψo砺6α（SpATH）， the type species，凡 ゴs〃ム％ゴ（JIMBo）and doubtfully certain foreign forms． 」Vθρρκosξαclosely resembles MεsOヵ〃20s似before the adult body chamber and the generic identification of immature specimens is often dif五cult． Examined in detail， however， the ribs are seen to cover more distinctly the whole surface of the whorl than in Mθ5ρ勿20sづαand Pμ20s紐， the smooth young whorl being succeeded soon by wholly costate whorl；the ventrally subcostate and internally smooth inter・ vening stage being very short， if not absent． The tendency to decrease the且exuosity of ribs on the umbilical half of flanks is one of the characteristic features of this genus， although a similar tendency is also found in Iater whorls of some species of 1膨soρ〃zosω（e． g． M伽4ψαα励α（KossMAT）． From both the morphological characters and stratigraphical occurrence，1Vεψ〃－ 20sξαcan be regarded as a direct derivative of 」妬¢soρz4zosゴα． On the other hand飽ψ協os『αresembles」膨Zo12沈舵s SpATH，1922． In fact SpATH （1922）included Wψκzos飢元幼o厄oα（SpATH）within苗’6碗〃宛es， but the latter should be con丘ned to the group of the type species，苗τc万”’θsカo〃磁6乃〃ηα〃〃s（KossMAT） （1897，p．40（147）， p1． vi（xvii，），丘g．6a・c）． It is characterized by a rectiradiate or somewhat prorsiradiate costation even in the immature stage and very distinctly so in the body chamber． In∧尼ψ〃20sゴαthe ribs are often still gently flexuous or arcuate on the flanks even in later whorls and show mostly a prominent forward projection on the periphery， although the degree of且exuosity and projection varies in some ribs． In respect of the curvature or straightness of ribbing κ劾c乃ゴκ☆θs bグθtノ‘oos∫α’〃叉

（MARsHALL）（1926， p．183， pl．24，丘g．3， pl．43，丘g．2， pl．45，丘g．6）is somewhat inter・ mediate between typica1κ批乃『碗θs and N6ψ酩os祖． The suture・line of Wρρ〃zosゴαin its later stages of growth is of typical P〃zos『α・ pattern， being characterized by a large and asymmetrically tri丘d L and obliquely arranged descending auxiliaries． As the type species of 万’c乃ゴκカθs is based on a small shell（BM． C．47548）， the asymmetry of its L is not so distinctly exempli丘ed as in the larger Puzosiids， but its suture is rather that of Puzosiidae・than that of 90 T．Matsumoto typical j陥5s勿α舵〃αs in its Iarge development of L and strongly descending auxil・ iaries．磁励吻ZZθs b夕鋤oos彦αZμs（MARsllALL）is fairly similar to IVεψ〃zosゴo in suture， especially in that exhibited by a specimen， probably adult shell of that species， in Mr． WRIGHT’s collection， which he kindly showed me．苦

ハ形ψκ205Zo is fairly similar to苗Zo〃碗ρs also in shell－from， but the type species and other possible members of the Iatter， sucb as one from West Australia（SpATH， 1940，p．45， p1． ii，丘g．2）andκ伽ε眈o吻輪（MARsHAIJ，）， have a remarkable Hat・ tening of whorls， whileハ花ρρ〃20sゴαretains an elliptical or oval whorl section． Another feature which should be noted is the intersection of the ribs by the more or Iess oblique constrictions． This feature， which may be called a kossmaticeroid character， is occasionally found in the immature shell but scarcely discernible on the outer whorl ofハ尼o勿20sω， while it is more constant and noticeable inκカo万碗θs． In this respectκbグ鋤605劫〃s（MARsllALL）andκ（？）40グ励〃（PIIILIppl）（STEIN． MANN，1895 p．73， pl． v，6g．3a， b）are also good examples of」磁励ゴ〃ゴZθs． WRIGHT’s specimen mentioned above clearly shows the character in the body chamber， Summarizing the above， I regard IV¢ψ〃205らas a distinct genus， which is cha・ racterized by the coarse and ventrally broadened ribs， particular to its adult she11， but is closely a11ied toハ4θsψ〃20s∫αin many respects， still keeping normal Puzosiid characters and， at the same time， somewhat allied toκゴZc乃仇ゴ’εs in the appearance of new characters in common． The assignement of the age of磁彦ε碗砿θs to the Cam・ panian and Maestrichtian（SPATH，1922，1940，1953）is probably correct． If it is so， ．〈尼oρ％zos飢， of Santonian and lowest Campanian， can well lead to苗Zc腕〃㌘5． ∧花ρρ〃205らis somewhat a11ied to 1）〃ψ〃20s化especially in the immature shell． 勘塑ρ〃20s似has rectiradiate major ribs on the lateral sides of the outer whorl which form a strong contrast to the numerous，丘ne， ventral ribs． Some of the minor ribs diverge from the major ribs． Such a differentiation of ornament does not take place in IWψ〃20s伝． Another difference may be in the size of she11． We know a good many huge examples in P〃妙〃20s化，∠4〃5吻Z6〃αs and Mθsρρ％20sどα． Probably the large size is one of the characteristic features of these genera． In my experience ∧尼oρ〃－ 20sゴαdoes not reach such a large size． Its body chamber， which is presumed to be adult from its relatively strong ornamentation， is always reached at a moderate size． Probably a reduction in size is another tendency acquired by ハ1セψ〃20sゴα and pro・ bably also by苗Zo万砿θs． In short」Vρψ〃zos飢and nearly contemporary Pαプψ〃zos化 are parallel and not in direct relationship．

＊Owing to the kindness of Mr． WRIGHT and Dr． C． V． FLEMING of the Geological Survey of New Zealand， I fortunately had an opportunity to study also the holotype of that species． Family Puzosiidae from Hokkaido and Saghalien 91

舵oρ〃20sゴα元αカo〃ゴoα（SPATII）

P1．17， figs．1a， b，2a， b；p1．18， figs．1，2a， b，

3a， b，4；Pl．23， figs．1a， b， c，3；Text fig．4．

1890． 1）θs物oε〃αs9α〃吻沈αYoKoYAMA（non FoRBEs）， P．184， PL xix， fig．5a， b；pl・xviii， 69．14． 1909． P％20s如元ψo〃icαYABE， MS．κo別．微ば， p．433，1isted only． 1927． Pμ20s陥元砲oκloαYABE MS．κo吻．〃〃4．， p．45， pl． vi， fig．3a， b． 1922． 1G’6乃沈旋sノψo仇cμs SPATH， p．127． 1935． 苗Zo万κi’¢sψα’痂SHIMIzU， p．179．

Mα∫〃らz： Lectotype， here designated， is the larger of the specilnens illustrated by

YoKoYAMA（1890， pl． xix， fig．5a， b）from Urakawa， Hidaka Province， Hokkaido， pro・ bably co11ected by Benjamin Smith LYMAN ．Its precise horizon was not recorded， but‘ the subsequent survey of the same area suggests its probable occurrence in beds Ur1βor Ur2， Neourakawan （Santonian）． This specimen is not preserved in Japan and is not at my disposa1． The Institution in which YoKoYAMA’s（1890）specimens have been preserved was not clearly described in his paper but is presumed to be in Berlin or in M置nchen， so that the lectotype may have been lost during World War

II．

In the subsequent collections there are a Iarge number of specimens which are specifically identical with YoKoYAMA’s type． The following is a list of selected ex・ amples：GT．1－368（＝MM7637）from the right branch of the Saushisanushibe， Popets （Hobetsu）， Iburi Province，‘‘Pαc勿4Zsc％s”（＝、4〃αρατ吻4Zs6％s）Bed（YABE Coll．）． GT． 1－2703（loc． N371， zone Mh6）， GT．1－2709（N189a， Mh6）， GT．1－2710（N184p2， Mh6）， GT．1－2711（N189b， Mh6β）， GT．1－2712（N400m1， Mh6β）（T． M． Co11．）and GT．1－2714， GT．1－2671（Miho）（M． KAwADA Col1．）from the Naibuchi Valley， South Saghalien； GK． H 5143（purchased， S． NAGAoKA’s Col1． from South Saghalien）；GT．1－3421（loc． T277c， bed IIId）， GT．1－3424（T277， IIId）， GT．1－3426（T277a， IIId）， GT．1－3428（T277，

IIId）， GT．1－3429（T739r， IIId）， GT．1－3431（T308， IIId）， GT．1－3433（T705P， IIId）， GT． 1－3434（T472p2， IIId（top？））and GT．1－3435（T947p， IIId）in the Abeshinai Va11ey， Teshio Province， Hokkaido（T． M． Coll．）；GK． H 3360（loc． U141p5， bed Ur1β）and GK． H 3350（U600b， Ur2β，）from the Urakawa area， Hidaka Province， Hokkaido （T．M． ColL）；BM． C．47735 presumably from zone Mh6， Naibuchi Valley， South Saghalien（T． M． Co11．， presented to the British Museum（Natural History））and？ BM． C．22418，“Hokkaido”， probably Neourakawan from the associated fossils（乃2・ oo〃α〃2μsκ微〃2α〃〃ゴYoKoYAMA and Po砂ρ砂o加6〃αs sp．）（purchased， Dr． KRANTz’s

Co11．）．

1レ名eαs〃7e〃2672Zs：

Specimen Diameter Height Breadth（B／H） Umbilicus（％） Lectotype（From YoKOYAMA’s五gure） 94．5｛ 39．5 ？ 24．5 （0．62） 31．0（32．8％） GK．H 5143 125．0 51．8 ？29．7 37．5 （30 ％） 79．0 31．5 21．1 （0．67） 37．2 （34 ％） 92 T．Matsumoto

GK．H 3350 52．5 20．5 16．9（0．82） 17．7（33．7％） BMC 47735 ｛Caき｝。 墾5 i；2㈱ ；1：㍊4㌘

1）ρs6吻Zゴo必 Shell of moderate size， attaining a little more than 12 cm． in diameter jn the adult， puzosiid in general aspect of shell・form， fairly narrowly umbilicate for the family and frequently constricted in the phragmocone and less so in the body chamber． After middle age the whorls are compressed， broadest in the Iower part， with slightly inflated flanks， narrowly arched venter， subangular umbilical shoulder and low but perpendicular umbilical wall． The immature she11， except for the very early smooth whorls， is ornamented with numerous sma11 ribs， of which some are gently flexuous and others are subradial on the main part of the flanks． Shorter ribs， which begill somewhat below the midst of flanks， are intercalated with or branch from Iong ones starting at the umbilical margin． All the ribs show a more or Iess strong forward projection on the ventraI area． The ribs become rather suddenly strong and coarse in the adult she11， espe・ cially on the venter；they run subradially on Hanks， with or without slight flexuosity， and show a forward inclination on the ventrolateral part． Spiral striae are discerni－ ble on the inner Iayer of test in the adult she11． The aperture with a pair of short inner lateral Iappets and shallow outer lateraI sinus and moderately projected rostrum；marginal part only weakly ornamented and strongly constricted behind． Suture・1ine of P〃20sゴα．type， with a large and asymmetrically trifid L， recurved U2 and strol191y descending auxiliaries（subdivided elements of U3（＝S））at least in the later stages of growth． Rε物αグ〃s：YoKoYAMA（1890）assigned the illustrated specimens from Urakawa to 1）θs勿oc〃αs g微4物α（FoRBEs）， but he certainly misidenti丘ed them． When SpATH （1922，P．127）propgsed 1爺》o乃ゴ〃∂ε5 for the group of ‘‘1701004ゴ56〃s” ρoκ4‘6乃θグタツακ〃s KossMAT， he gave the new specific name苦苗Zo厄κ舵s元ψo〃Z6〃s SPATH to YoKoYAMA’s speclmens． Meanwhile YABE（1909，1927）listed a number of undescribed MS names， including P〃20s級元幼o〃づcαYABE MS． Under that name a specimen was illustrated （YABE，1927， pl． vi，lfig．3a， b）， but YABE did not remark on its relation to YoKo・ YAMA’s described specimens and to SPATH’s nomenclature． SHIMIzu（1935， P．179） remarked thatκ仇万砿θsノ砂oκZc％s SpATH must be renamedκψα砺SHIMIzu as ‘‘ P微os化”元ψo痂oαYABE may be another species of濁τ6乃吻舵s． However， fo110wing the Rule of Nomenclature， SHIMIzu’s proposal is invalid， because “P％os『α” ノψo批oYABE MS was never described． Much of YABE’s collection（i．．e． the material of YABE，1909）was fortunately deposited in the Geological Institute， University of Tokyo． There are two specimens Iabeled as PκosZαノψo砺cαYabe． One of them，

＊ The specific name is valid since 1921， for it was proposed in his 1921 paper（p．45）． Family Puzosiidae from Hokkaido and Saghalien 93

GT．1－368， illustrated in this paper（PI．18， fig．3a， b）， is an adult shell which is speci6cally identical with YoKoYAMA’s specimel1． Accordingly‘‘P〃zos化ノψo〃’cα YABE MS”is， quite accidentally， conspeci6c with“」昭o〃Z〃’θs元ψoκ勧s SpAT｝1．” The immature shell of this species resembles quite well that of Mεsoρ〃205彪 ρα¢砺oαMATsuMoTo， both being provided with gently且exiradiate ribs． The oblitera・ tion of 6exuosity of ribs in the adult shell is found also in 1％θsρρμzos『αどη∂ψαc萌cα （KossMAT）． Moreover the suture－lines in the Iater growth stages of the present species are of unmistakable puzosiid pattern and somewhat different from the illustrated suture of五ゴ’ε〃〃Z杉sρoκ4ゴc乃〃γッα％s（KossMAT）， although the immature ones are fairly similar． The rectiradiate costation is found even in the immature shell ofκ．ρo〃4£612θγηα〃％s， while the present species is provided with gently Hexuous subcostae in its immature stage， as was illustrated by YoKoYAMA（1890， pl． xviii， fig．14）， YABE （1927， p1． vi， fig．3a， b）and also in this paper （PL 17， fig．2a， b；PL］8， fig．2a， b）． KossMAT noticed that the ribs of κカoκ4づc乃θプκソακκs are weakened on the siphonal line． Asimilar tendency can be detected in the early immature stage of the present species but is never found in the later stages， where， on the contrary， the ribs are strengthened on the ventral area． From the above I am led to the conclusion that it is better to remove the present species from lm6〃κ舵s． As there was no proper position in the hitherto established classi6cation， the new genus／Vεψ〃20sどαhas been established above． Apart from苗∫c万砿θsカo〃4ゴε乃〃η鋤〃s（KossMAT）there are a few forms provisionally or doubtfu11y referred to 1（カ6乃ゴκπθs， such as 1ζ． sp． （SPATH， 1940） from Western Australia and 1⊆bグωゴco吻∫〃s（MARsllALL，1926）， but they are not identical with the present species， because of their too much flattened whorls and different ornament． As has already been remarked the present species is fairly similar to五4θ5ρρ〃zos飢 μαφ6αMATsuMoTo orハ4．吻4ψαo功oα（KossMAT）especia11y in the immature stage． The strengthening of ribs in the adult of∧汐ψo〃ゴco is very remarkable and abrupt while in M．沈4ψαo萌6αof corresponding size it is very gradual， illconspicuous and， furthermore， obscured by the teDdency to smoothness on the large outer whor1． The forward projection of ribs on the ventral part of Mξ〃4ψα6炉oαof corre・ sponding size is more noticeable than in∧たノψo〃ゴ6α， although the extent of difference varies in some individuals． The stratigraphical occurrence of the three species is successive， and partly overlapping． Thus the derivation of∧乙∫ψo励oα from〃．μαWαis highly possible if not convincing and Mゴ〃4ρ勿α励σmay be a sbort lateral offshoot in the intervening stage． I have never seen specimens of 2V． ノαρo痂αzas large as full grown M．加α漬cαandルf．仇4ψααiβco， while the strongly ribbed body chamber of constant size（with a diameter of about 12 cm．）suggests the adult stage． Therefore the reduction in size may be one of the tendencies in the evolution from 1吻sψ〃20s化to／Vθψ〃zos化． 94 T．Matsumoto

06c％γグθ〃6θ：Zone Mh6 in the Naibuchi Valley and adjacent areas in South Saghalien；bed IIId in the Abeshinai Valley， Teshio Province；Beds Urlβand Ur2 in the Urakawa area， Hidaka Province；the corresponding horizons in other places of Hokkaido． Neourakawan（mainly Santonian）．

1Vθoρ批o吻ゴ5〃んα〃αZ（JIMBO）

Pl．19， figs．1a， b，2a， b，3a， b，4；

PI．23，6g．2a－d；Text fig．3．

1894．Dεs勿06〃α5ゴ∫万々α鋤ゴJIMBo， p．28， pl． i（xvii），6g．5，5a，5b． 1909．1動∬初αz‘c〃αsis万んαωα∫（JIMBo）YABE， P．44（18）． 1922．1mo疏痂zθs is万加z〃αi（JIMBo）SPATH， P．127． 1935．1動o碗η舵sis万ん鋼oi（JIMBo）SHIMIzu， P．174， etc．， listed． 1942－3．只αγψ〃205iα（ル化sρ餌20siα）ゴs嬬αωα↓（JIMBo）MATsuMoTo， P．161（1942）and elsewhere， listed． 1942－3．P〃砂据o‘os（漉so吻20siのco％εα♂zαMATsuMoTo MS．κo御．κ砿， P．161（1942） and elesewhere， li5ted．

ルfα∫〃妬：Lectotype， GT． L95a（JIMBo’s illustrated specimen）and another JIMBo’s syntype， GT． L95b， both from the Obirashibets River， about 52 km． frorn the mouth， Teshio Province， Hokkaido（K． JIMBo Co11．）． Among a number of specimens in subsequent collections the fo110wirlg is a Iist of selected examples：GT．1－2706 from locality N202b2， zone Mh6α・β， GT．1－2705（N167P， Mh6β）， GT．1－2687（N400m3， Mh6β）， GT． L2688 （N204b， Mh6α・β）， GT．1－2713（N400m4， Mh6β）and GK． H 2458 （N22z， Mh6β） from the Naibuchi Valley， South Saghalien（T． M． Coll，）． From the same valley （probably from zone Mh6）GT．1－547（“the Miho”）， GT．1－548（“the Santan”）， GT．1－550（“Naibuchi Va11ey”）（M． KAwADA Col1．）and BM． C．47736

（T．M． Co11．， presented to the British Museum CNatural History））；GT．1－3432 from

Iocality T212p， bed IIId， Abeshinai Valley， Teshio Province（T． M． Co1L）；GK． H 3366 from locality U512r4． bed Ur2β， Urakawa area， Hidaka Provillce， Hokkaido（T． M．

Co1L）．

ハ4θαs〃グε吻e〃∫s：

Specimen Diameter Ileight Breadth（B／H） Umbilicus（％） GT．1－95a（JIMBo’s desc．） 38 17 14 14（36．8％） 〃 （Reexamined） 38．5 16．5 13．8 （0．83） 12．0（31％） GT．1－2706 maximum Ca 140 Ca 126．O 50．4 ？47 GK．H 3366 49．5 19．0 14．5 （0．76） 16．5 （33．3％） BM． C．47736 63．4 25．4 19．8 （0．78） 20．9（32．9％）

Aspecies ofハ尼ψ〃205κcharacterized by fine and rather denseSρθ6痴〃㎎〃05ゴs： costae in the phragmocone；the costae and constrictions show a slight flexuosity on the flanks and a remarkable forward projection on the periphery． Adult body chamber ornamented with ribs which are distinctly coarser and stronger than those in the imma・ ture stages， gently arcuate on the flanks and show a prominent ventral projection． Whorls compressed with the maximum breadth nearly between the middle of且anks． Family Puzosiidae from Hokkaido and Saghalien 95

R醐α夕ゐs：This species di任ers from the closely allied and almost contemporary」V． ノψoη『εα（SpATH）mainly in the finer and denser costae． There may be slight difference in shell・form， which however varies to some extent in both species． There is also some variation in the frequency of ribs． Generally speaking舵ρρ％20sゴαZs碗ム％αゴ（JIMBo）might be interpreted as a descendant of ．ルfθsψ〃20sどαッz必απ〃cθ （JIMBo）just as IV．元αρo励oα（SPATII）can be assumed to be related to M勿6痴αMATsuMoTo or to 1吃ゴη4ψαε萌6α（KossMAT）． As JIMBo’s specimells were immature， there is some obscurity in the de丘nition of the species． There are among subsequent collections a number of specimens which are quite similar to， but often somewhat Iarger than， the type． In my stratigraphical paper（1942－43）11isted Pαγα勿zos’o（Mεso吻20sゴのoo勿θ6α〃αMS． ％o〃2．κκ4．，which is so far we know at present nothing but the later whorls of IVθψ鵬osらZs〃たα沈αゴ（JIMBo）． Thlls a revised diagnosis has been given above． ‘‘P〃20sどαgα〃4αηzα（FoRBEs）”of SIMIoNEscu（1899， p．19， pl． i，丘g．4）from the UpPer Cretaceous of Rumania seems to me very similar to the immature（deformed shell）of the present species． In the present species the constrictions occasionally cut a few of the ribs behind them． That character appears more frequently in the inner whorls， so that some autbors referred the species to砲ss〃2励ゴo〃αs or 1百’6乃鋤漉s． In the outer whorls， however， the character generally disappears and typical features ofハ花ψ〃20sゴαare shown． ‘‘P〃zosm”4αグ％吻Z PmLIPPI（STEINMANN，1895， p．73， p1． v，6g．3a， b）from the Quiriquina group of Chile is somewhat similar to the present species， but it has frequent constrictions which cut constantly ventral ribs even in the Iarge outer whorL It may be a special member of磁’ε万砿εs on which smoothing of costae takes place on the umbilical half of the Iateral side． 0εc〃グγθκcθ： Neourakawan of Hokkaido and South Saghalien， approximately Santonian．

Genus 1沈zboゴc〃αs SHIMIzu，1935

乃φθψθεi¢s： Z）θs〃20cε夕αs♪1α〃〃∂荻〃〃2θJIMBo，1894．

Gθ〃θ7Zc 4似gκosぽ Similar to P〃zosZαin lateral view but with whorls more rounded or eUiptical in cross－section， somewhat inHated flanks and rounded umbilical shoulder as compared with typical P〃205伝and its direct derivatives． The whole surface of the whorls after middle age is ornamented with costae， some of which in the middle age are bifurcating． The constrictions are very broad and deep and associated with ahigh elevation． The periodic ribs in the adult shell are very strong’and nearly rectiradiate． The shell usually attains a moderate or fairly Iarge size． Suture－lines in Iater growth stages are puzosiid with long and asymmetrically trifid L， recurved U2 and strongly descending elementsδf subdivided U3（＝S）． 96 T．Matsumoto

Rθ勿α夕〃5：SHIMIzu（1935， p．180）introduced the new generic name designating as type species the well defined Dθs〃200θグαsρ1砺％Zα1ガbγ〃2e JIMBo，1894， and remarked very brieHy that‘‘the holotype of this genus resembles P〃o吻205ゴα， but has a different type of ornamentation．” The de丘nition is so brief and incomplete that the validity of his proposal is questionable under the Rule of Nomenclature． The generic name is adopted here and a clearer diagnosis given． In its shel1・form and in the development of well marked constrictions and associated high elevations， which are replaced by strong ribs in the adult， the genus is allied to P〃20sZσ（・肋ψ〃20吻） defined above， but has better developed costation even on the inner whorls． From Mθsoρ〃20s似and舵0ρ〃zo5ゴαit is distinguished by the roundness of whor1（i． e． relatively inflated且anks and more rounded umbilical shoulder）as well as by the periodic， rectiradiate， strong ribs in the outer whorl． Similarlyノ吻δoゴcθγαs is parallel to and not directly connected with Pαγψ〃zosZσ． On the outer whorl of PoグO〃205κnearly straight， strong ribs do exist， but are confined to the sides with splitting into minor ventral ribs， which show forward projection and then obsoletioD， while in those of 1物boZcεγos the ventral projection of costae decreases with growth and the periodic， strong ribs cross the venter nearly radially． Thus 1物δo‘6〃αs may have evolved from P〃20sゴα（・4〃砂嬬osゴの， just as∧砲o吻一 20sらis possibly derived throughハ4θ5ρρ％20sZαfrom P〃zos’α（s． s．） Although the stratigraphic occurrence does not contradict this assumption，1inking species between Albian and（？）Lower Cenomanian species of P．（A微ρ〃20sどのand the Turonian species of／ゴ〃260i6杉れzs have still to be found． Apossible relation between 1物bo㌘グαs andκOss勿碗ゴo〃αs wi11 be mentioned in my paper of the Kossmaticeratidae（now in preparation）． Lastly the homoeomorphy between the Cretaceous Puzosiidae and the Jurassic Perisphinctidae should be pointed out here． In the mode of coiling and shel1－form the two are somewhat analogous． Even ill the suture4ine there is some analogy in the descending auxiliaries and Iong lateral Iobe． ノゴ〃260Zoθグos has diverging ribs at acertain stage and very coarse ribs in the adult． This feature appears in certain

Periphinctids （e． g．1）ρグ∫ψ〃沈cZθs （s． s．） or 1）．（／1γiψ乃吻c彦ρs））， although the Peri・ sphinctids include forms which are characterized by multipartite ribs and less projection of ribs on the venter・ Z）ゐ〃ゴb励ゴoκ：From the two species described below the genus ranges from the Neogyliakian（Turonian）to Lower Neourakawan（Lower Santonian）．

ノ物60Z6％sカ1α〃〃1α》豹夕〃¢θ（JIMBO）

PI．20， figs．1，2，3a， b， c，4．

1894．Dθs勿06〃αsカ1伽〃oτゲoγ吻召JIMBo， P．27， pL i， fig．4，4a・ 1927． P銘20sゴα」り1砺μ／α彦ゲ07勿θ（JIMBo）， YABE， P．45（19），？pl． ix（vii）， fig・2a， b・ Family Puzosiidae from Hokkaido and Saghalien 97

1935．ノi勿δo輌6〃αsρ1伽〃藺／ρ朋θ（JIMBo）， SHIMIzu， p．180． 1938．Aκψ〃20sm（ノ物boi62γαs）ヵ1砺μ～αz泊働θ（JIMBo）， MATsuMoTo， p．193．

ル1αZ〃Zo1：Holotype， GT．1－94 from a nodule of shale on the Obirashibets， Teshio Province（K． JIMBo Coll．）（＝JIMBo，1894， P1． i， fig．4．4a）． The examples in subse・ quent collections are：GT．1－2651 from locality I－236p． zone Mh 20r Mh 3， Aikawa Valley， South Saghalien（T． M． Coll．）；GT．1－2648 from loc． N126b， zone Mh3 and GT．1－2654 from loc． N124b， Mh2－3， Naibuchi Va11ey， South Saghalien（T．M． Coll．）； GT．’1－3219（loc． T7bp， bed Ilc）， GT．1－3230（T7bp， Ilc）， GT．1－3231（T42， Ild）， GT．

1－3224（T344p3， Ild）， GT． L3226（T735p， Ild）， etc from the Abeshinai Va11ey， Teshio Province， Hokkaido（T． M． ColL）． GK． H1257（loc． Y216p1）， GK． H1258（Y216p1）， GK． H1259（Y129p2）， GK． H．1260（Y115p）， GK． H1261（Y464p2）， GK． H1262（Y467p）and GK． H1266（Y214a）from the Saku formation， Shiyubari Valley， Ishikari Province， Hokkaido（T．M． Coll．）；GT．1－2719，0birashibets， Teshio Province（H． YABE Coll．）．

ル【杉αs〃グε勿θη’s：

Specimen Diameter Height Breadth（B／H） UmbiliCus（％） GTJ－94（JIMBo’s desc．） 118 45 33＊ 45（38％） （Reexamined） 116 41 39 （0．95） 44．7 （38％） GT．1－3221 133．2 53．5 48．8 （0．91） 47．1 （35％）

D‘㎎〃os応Whorls in immature ages rounded in cross section with moderately in・ Hated Hanks， rounded umbilical border and moderately arched venter；and ornament． ed with distinct costae which run subradially or with slight flexuosity on the inner half of the Hank and show a forward projection on the external part；in the middle age rather elliptical in section， with somewhat narrowly arched venter in the later substage and ornamented with we11・marked， broad， periodic constrictions， which are bordered and then replaced by thick ribs， becoming more frequent in the late sub・ stage， and numerous， rather closely・set， distinct costae consisting of longer and shorter ones． The longer ribs start from the umbilical margin while the shorter ribs are inserted or branch near the middle of the Hanks． The costae are mostly recti・ radiate and sometimes gently flexuous on the inner half of the flank and show a strong forward bend at the ventrolateral edge with a projection on crossing the venter． The ventral projection gradually decreases with growth． The constrictions fo110w a similar course but are laterally more straight than most of the intervening

ribs． In the fairly Iarge adult shell the ornament consists of strong and broadly rounded ribs separated by Hat interspaces as wide as or somewhat wider than the ribs． The ribs cross the venter without or with a slight ventral bend． Suture－lines after the early middle age are of typical P〃20sゴα・pattern， with

＊ This may be a misprint for 38． 98 T．Matsumoto

extremely asymmetrically trifid（and thus apparently bi丘d）Land strongly descend・ ing auxiliaries． Rε勿αψs：As the character changes fairly remarkably in the course of growth， specimens of this species must be carefully identified． JIMBo’s original specimen and YABE’s illustrated specimen are still middle・aged shells． The adult shell is repre－ sented by several specimens in subsequent collections and the original description is here revised． Ooτκグプ聞τε：The species is characteristic to the Neogyliakian（approximately Turo’ nian）of Hokkaido and Saghalien， although the exact horizon of the holotype was not recorded．

1ど〃2カo£6θグαs〃万乃oθ〃sε，sp． nov．

Pl．21，6gs．1，2a， b，3．

1938．Aψ〃20siσ（ノ吻boioθ斑s）幼加伽s∫s MATsuMoTo， MS．κo勿．κ〃4． P．193，1isted only．

Mα∫〃∫01：Holotype， GT．1－2641 from locality N131m1， zone Mh5， Naibuchi Valley， South Saghalien（T． MATsuMoTo Coll．）． Paratypes， GT．1－2642 from Ioc． N163a3， toP of zone Mh5；GT．1－2650 from loc． N136， top of zone Mh5；GT．1－2647 from loc． N133h， the Iowest pユrt of zone Mh6α；GT． L2643 from Ioc． N136， Mh5；GK． H 2455from loc． N136a4， top of zone Mh5；GK． H 2457 and H 2460 from loc． N311b， Mh50r Mh6 and four other comparable specimens from zone Mh5 in the Miho area， Naibuchi Valley， South Saghalien（T． M． Coll．）． Comparable specimens have also been obtained from the corresponding zone in the Ashibets Valley， Ishikari Province， Hokkaido（N． KANBE＆T． MATsuMoTo Co11． in the Geological Survey of Japan）． 、0／og〃osどs・：Whorls relatively compressed and with subrounded umbilical shoulder． The shell in most of immatllre stages is ornamented with relatively coarse costae which are nearly rectiradiate on the main part of the flank but show a gentle for－ ward projection on the periphery；strong constrictions follow a similar curvature． In the adult she11 there apPear abruptly strong ribs which are widely separated and rectiradiate． Most of them are much elevated and long but some are weak and somewhat shorter． The Iatter are inserted between or sometimes branch from the former more or less near the umbilical margin． Suture－lines after middle age are

of P〃20s『α・pattern． Rε〃2αプ〃s： This species and 1『〃260ゴτ〃αsカ1α〃〃αZ豹グ〃2ρ（JIMBo）have a noticeable common tendency in shell・from and ornamentation as well as suture・lines． The specific distinction is in that 1．励加ε〃sθhas a more compressed whorl， low umbilical wall and a wider umbilicus thanノ．1り1ακ〃1αZ豹グ勿θand that its ribs and constrictions are not so strongly projected as in 1．カ1α〃〃α苛b夕勿θ． In the former coarse ribs apPear earlier than in the latter and the branching of the ribs takes place at a different position． At the salne time the present species apParently resernbles ∧をρρ〃20s『α元ψo〃ゴoα Family Puzosiidae from Hokkaido and Sユghalien 99

（SpATH）in general aspects， but∧乙元ψo励oσhas a more compressed whorl with less inflated flanks and more angular umbilical shoulder． In the immature shellノ． 〃2仇o杉κsθis ornarnented with coarse costation than 1仏元αρoκτα and in the adult shell the ribs are distinctly different． Thus the resemblance of the two species is aparallelism between two different genera within the same family． On the other Iland the she11 0f 1・ 〃2ど乃oθηsθ before the strongly ribbed living ・h・mb・r has s・m・p。int・in・・mm・・with砲∬吻∫ゴ…α・吻・66・1〃微勿，9，。up），

which has oblique constrictions， slight elevation at the umbilical edge of the long ribs and a different type of suture． 066〃獺〃6θこCommon in zone Mh5 and the Iower part of Mh6αin South Saghalien and sometimes found in the corresponding horizon in Hokkaido． Lower half of the Neourakawan， apProximately Lower Sant⑳ian． The possibility of its occurrence in the Paleourakawan should be examined in future．

Genus 1）αo勿4εs〃206εγα5 SpATII，1922．

7ンカθ句ウεoゴθs： ／1〃2〃20〃どZθs4εヵ’soκ飢κ〃s SToLlczKA，1865．

Gθ〃εη’04飢g〃os紘 Fairly sirnilar to P磁osどαespecially in the immature shell， but characterized in Iater whorls by more or Iess rounded section with somewhat inflated flanks and rounded umbilical border and by gently arcuate， rather than sigmoida1， ribs which become very coarse in the adult． Suture・1ines of typicaI P〃205『α・type with large and somewhat asymlnetrically tri6d L， recurved U2 and strongly descending auxiliaries． Shell reaches to a large size and is sometimes smooth in the last part． Rθ勿σグ〃s：Superficially the adult shell of this genus is analogous to some inHated Pachydiscids and unlike P〃20s似． However its ontogenetic development， as was welI illustrated by KossMAT（1898）， clearly indicates its intirnate relation to the Puzosiids．

It is distinguishable from Lθz〃θ5ゴcθ夕αs or／1〃αραo〃y4£so〃s by its suture・1ine， absence of umbilical tubercles at any growth stage and the compressed inner whorls． The genus is one of the specialized Puzosiids． The coarse ribbing in the adult is somewhat similar to that of certain Iater Puzosiids． 1吻60£o〃αs however， which has coarser ribs in the outer whorl and is more round・whorled than jP〃205『α， does not show a pachydiscoid inflation of whorI in the adult and the ornamentation is different from．Pαo吻4εs吻06〃α5． Pα夕ψ〃20s化 has also coarse ribs in its Iarge outer whorl， but is generally compressed as in typical P磁osZαand has rninor external ribs some of which diverge from the major

ones． In connection with Pατ吻4θs勿06〃αs reference should be made to L夕’04’soo£4θs SPATH，1922 and／10乃〃θ06〃αs van HoEPEN，1951 from the UpPer Albian of Africa． They are probably specialized Puzosiids rather than early Pachydiscids， because 100 T．Matsumoto before the peculiarly ornamented adult body chamber their whorls are very similar to those of 1）αo吻4θs〃200ρプαs and， accordingly， in some respects to P批osゴα． Unfortu・ nately their suture was not clearly described， but that shown by CIIoFFAT suggests Puzosidae in the strongly descending auxiliaries． 1）£s〃ど6〃∫20〃： Two species referable to Po6吻4εs勿06〃αs are known from the Japanese province：Pα¢吻4θs勿oo〃αs 4θ〃ゴso厄α〃〃勿（SToLlczKA）， with a comparable form， and a new species described below． The first species and its a11ies are dis・ tributed fairly widely in the Indo・Paci丘c， Tethys and Malgash regions in the Upper Albian and Cenolnanian． The second species occurs in the Neogyliakian， that is ap・ proximately Turonian． Possible Turonian forms are also known in Europe（e． g．

‘‘ 1〕％20sゴα 4θ厄so励 （STol、IczKA）” ZIMMERMANN，1912， P．542， P1．26）and Africa

（Dθs〃700εγαs 〃α〃2θグ〃κθκs召 v． KoENEN， 1898， P．55， P1． vii， figs．1，2，3； P〃20s’α 6『伊

ヵ£∫o〃『oκα （SToLlczK A） SoLGER， 1904， P．103， pl． iii，69．1a， b and text figs・ 5，6）・ Therefore the genus has a vertical range from Upper Albian through Cenomanian up to Turonian．

Poo吻4εs”20τθグαs cf・46κ£soκ『α〃〃〃2（SToLlczKA）

Cf．1865． ノ1〃2〃20η∬¢s∂θ仇∫o仇αη祝sSToLlczKA， P．133， P1．1xvia：pl． lxvi， fig．2． 1898． Pμ20sZα庇泌o勿α妬（SToLlczKA）KossMAT， p．121（186）， pl． xiv（xx），6gs．5a， b，6； pl． xv（xxi）， fig．5a， b．

1914． P〃20sm鹿痂soη如獺（STol」czKA）YABE， p．72（2）， pl． xii（i）．

Z）θsτグZρZゴo〃：The following 6ve specimens before me are comparable to the desig’ nated species：GT． L3195 and GT．1－3194 from the upPer part of bed IIb and GT． 1－3196from the lowest part of bed Ilb of the Abeshinai Valley， Teshio Province， Hokkaido；GT．1－3765 from Iocality N305d， horizon Ky of Naibuchi Valley， South Saghalien；GK． H1226 from locality Y610， middle part of bed IIf in the Shiyubari Valley， Ishikari Province， Hokkaido（all T．M． Coll．）． Besides them I have seen a huge specimen collected from the zone of 1）εs勿oo〃αs／4ρo砺o％勿（Cenomanian）at Ashibets（Ashibets Park）by Mr． TANAKA and Mr． Y． MAEDA． It is now preserved in the Geological Survey of Japan． The 6rst specimell is a Iarge shell in which two outer whorls are visible and other inner whorls are not preserved． The outer whorl has only distant coarse ribs and resembles the outer whorl of SToLlczKA’s specimen（1865， pl． Ixvia）． The inner whorl has longer and larger ribs and shorter and smaller ones， both of which are coarsely arranged as in the outer whorl of KossMAT’s large specimen

（1898，p1． xv， fig．5a， b）．

The second specimen is Iarger than the丘rst one and sti11 has very coarse and distant ribs in its outer whorl and its inner whorls are similar to the 6rst one． The third one is smaller and resembles the middle aged whorl of the Indian species． The fourth one is not in a favourable state of preservation． Family Puzosiidae from Hokkaido and Saghalien 101

0τ6〃グプ杉κ6e： The specimens from Hokkaido indicate the vertical range from In・ fragyliakian to the whole Paleogyliakiらn， i．e． the approximate equivalent of the Uppermost Albian and Cenomaian．築 Outside Hokkaido within Japan the species was reported by YABE （1914）from ablock of丘ne grained sandstone from Oidaira in the Monobegewa Valley， Kochi Prefecture， Shikoku． In spite of the uncertainty of the exact horizon，‘‘P〃20sら・ shale”（＝Pα6吻4θs吻ooε夕αs bearing shale）was introduced in subsquent literature， and I have failed to ascertain the evidence about this change of recording． The fossiliferous fine’grained sandstone occurs at two or three horizons in the Cretaceous succession of Kochi Prefecture， one at the top of the Monobegawa group as is represented by Miyanohara sandstone， another in the Iower part of the upper sub・ group and another in the middle part of the lower subgroup of the same group． The first or the second horizon or the intervening part may be the possible source of the fossil． At any rate YABE’s dating of this fossil in Upper Albian and Ceno・ manian seems to be co面rmed by the material from Hokkaido． po6吻4θs勿oo〃αs 4ε砿o〃ε鋤％勿（STol．lczKA）is known from the Utatur group of India， Upper Albian of Persia and Madagascar and a closely allied（possibly identical）species．Pαo勿4θs〃206εグo1sα〃〃201ηθsだα〃％ゴ（PoPovlcl・HATzEG）（1899， P．14， pl． i，fig．1）from the Cenomanian of Rumania and also（？）from the Uppermost Albian of Southeast France（BRE【sTRoFFER，1936， p．65）． These facts are quite in harmony with the occurrence in Japan．

Poo雇y4ε5〃206εγαsカα6勿6だSooど4θ5， sp． nov．

Pl．9， fig．2a， b．

五4α’〃泌：Holotype， GT．1－2805 from the“Miho group”， Naibuchi Valley， South Saghalien（M． KAwADA ColL）． Paratypes， GT．1－2716 from Iocality N123c， zone Mh3 and GT．1－2717 and GT．1－2718 from locality N320b， zone Mh2， Naibuchi Valley， South Saghalien（T． MATsuMoTo ColL）；GT．1－2721 and GT．1－2720 from a left tributary of the Obirashibets， about l km above the mouth of the Sankeshomap（H． YABE Col1．）． Comparable specimens are GT．1－3207 from locality T72a， Saku forma・ tion（IId）， Abeshinai Valley（T．M． Co11．）and a large specilnen from the zone of 1〃ooεγα勿κs乃06θ彦sε％s『s NAGAo＆MATsuMoTo（1arge form）in the Ikushumbets Valley， Hokkaido and another from the same zone in the Odasam Valley， South Saghalien．

＊ P⑳紗4is6〃sδε痂50κωκμs（SToLlczKA）in JIMBo （1894， p．29， p1． ii， fig．1．1a． lb）is not referable to the designated species nor to IV∂醐虎iτεs（？）ガ働60i（KossMAT）but is an immature shell of C鋤αゴoε〃αsんo∬物励（YABE MS）MATsuMoTo， which was discribed in my recent paper （T．M．輌κT． M．（Editor）1954．） 102 T．Matsumoto

Mραs〃夕ε〃2θ〃’s：

Specimen Diameter Height Breadth（B／H） Umbilicus（％） GT．1－2805 215 98 84 （0．86） 65 （30 ％）

Sρθα湧04ゴ㎎κos紘 A species of Pα6吻4ρs〃20τ〃αs characterized by the development of stronger costae from much earlier stage of growth and somewhat more rapid growth of whorls than in Poo吻4ρ5〃oo〃〃s 4ε厄so〃α〃〃〃2（STo∫、lczKA）． Last whorI is almost smooth and attains a huge size． Rθ〃2αプ〃s：The species is very similar to．Pα6卵4εs吻ooθκs 4ε〃so〃α物勿（SToLlczKA） in suture・1ines and general shel1－form and ornamentation． In P．勿o吻磁sooゴ凌s however the increase of whorls is somewhat more rapid and， when the whorls of the same stage of growth are compared， the section is much higher than broad with its maximum inflation a little below the mid・height． Below 30cm． diameter the immature shell is constricted and almost smooth apart from丘ne subcostae on the ventral part of its latest stage． This stage is just com－ parable to the somewhat later inner whorl（40－55mm． in diameter）of R 4θη丞o厄α・ ％物，as illustrated by KossMAT（1898， p1． xiv， Hg．5a， b）． When the shell of且 釦6勿4£s60‘4εs attains a similar size， there appear distinct ribs which are still small， ro皿d， numerous and fairly close．set， being separated by interspaces nearly as wide as ribs， and gently arcuate or slightly flexuous as in certain ／1κsが厄τ〃αs． They consist of longer and shorter ones， alternating somewhat irregularly． Some of the shorter ribs reach below the middle of the flanks， being usully intercalated between the longer ones and rarely branching from a Iong one． Constrictions and the as・ sociated elevations are 50r 6 in one volution in this stage． This P〃20sら・1ike orna・ mentation prevails throughollt the middle age， alth皿gh in the Iater middle stage ribs are more widely separaいd and curve obliquely forward with a ventral projec－ tion and without curvature on the inner half of the flanks． In the adult stage when diameters ranges from 16cm． to about 30cm．， the ribs become rather abruptly strong and coarsely distributed and the shell is inHated， resulting in the pachydiscoid aspect． There are， however， no urnbilical nodes， but constrictions and the associated thick elevations continue to apPear though less frequently than before． Increase of whorl in this stage is very rapid． In the丘nal or gerontic（？）stage the ornamentation becomes obsolete， with low and distant ventral ribs in the earlier half and without notable ornament in the inner half． This smooth stage is represented by at least a half volution． The present species is also allied to Pクo吻4εs〃20cεγαs（？）輪勿〃〃〃杉〃sθ（voN KoENEN）from the Lower Turonian of Kamerun苦（1898， P．55， pl． vii，丘gs・1，2，3）

＊Itake this offortunity to express my thanks to Mr． R．A． REYMENT of the Geological Survey of Nigeria who has given me the recent information about the stratigraphical occurrence of the Nigerian species． Family Puzosiidae from Hokkaido and Saghalien 103

（＝？P〃20s伝4ρ〃Zso〃『o〃α（SToLlczKA）（SoLGER），1904）but has higher whorl and more arcuate， ventrally more projected and somewhat more widely spaced ribs・ 06ε〃タグθ〃6θ： The species is characteristic to the Neogyliakian of Hokkaido and South Saghalien， approxirnately equivalent to Turonian．

Concluding Remarks

‘Puzosinae’was proposed by Dr． SpATH（1922， p．120）as one of the subfamilies of Desmoceratidae， ZITTEI、． Under that name he put， besides P〃20s化， a number of Upper Cretaceous genera， mostly created by himself， such as∠4％s励ど6θグo∫， Pα夕αρ〃・ 20s化，2ッogo鹿s吻oc〃os， Poτ吻4θ5勿oc〃αs and苗Z6乃勿ゴZθs， and furthermore Sτ〃況〃化 （now 1）εs勿oρ勿1〃’θs）and正桓μεグ£o〃αs． Some of them were regarded as‘true Puzosiids’connected with ancestral P〃20sψbut in the same paper（P．120）he assumed that the Puzosiinae was‘‘a convenient but polyphyletic assemblage of successive waves of modi丘ed Phylloceratids”． He ranked the group as a family in his recent paper（1940，1953）without mentioning a reason， but his idea of it seems fundamenta11y unchanged． In the same 1922 paper Pachydiscinae and Kossmaticeratinae were established as other subfamilies of the Upper Cretaceous Desmoceratidae． While the two are now generally ranked as families， C． W． WRIGHT（1952）in his comprehensive scheme of classi丘cation of the Cretaceous Ammonites sti11 kept Puzosiinae and Desmoceratinae as subfamilies of Deslnoceratidae， the main stock of Desmocerataceae． It is often very di伍cult to prove precisely a true lineage or phylogenetic series． The evolution of many ammonoids may have proceeded in various lines， sometimes diverging， sometimes running nearly parallel and sometimes apparently entangled． If some of these lines have been derived from a common stock and have a similar general tendency of morphological change， they can be grouped together in one family， in spite of some diversities in the details of phylogenetic series of species． It seems preferable to try to find a natural group of such a kind and approach step by step nearer to a natural classification． This apPlies particularly in the case of the Desrnocerataceae， because it is one of the relatively Iess specialized and probably fundamental groups of the Cretaceous Ammonidea． Now there are a number of forms referable to the Desmocerataceae in the Cretaceous province of Japan and adjacent areas． The main purpose of a series of my papers is to describe what sort of forms are found in this province． Fortunately we have a nearly perfect and continuous succesion of ammonite－bearing strata from Albian to Maestricntian in Hokkaido and Saghalien and we can recognize fairly we11 relatively natural groups from carefully collected specimens． Without similarly continuous material of the Lower Cretaceous forms I cannot discuss fully the whole system of Desmocerataceae． Therefore the ranking of Puzosi一 104 T．Matsumoto ids as family or subfamily is quite provisional in this paper． What I want to do in this concluding chapter is to summariz3 characteristic features and history of the Puzosiids（Puzosiidae or Puzosiinae）in the present state of our knowledge． In the family Puzosiidae the foUowing genera are to be included： P〃20sωBayle（Type species， P． s〃δ♪1ακ〃oZα（ScHI．ゼTER））

Subgenus P〃20s『α（s．s．）

Subgenus A％ψ％20s；α（Type species， P．（ノL）δ〃θκα〃θ〃ψグαANDERsoN）

1ば杉sOρκ20s化， gen． nov．（Type species，ノMρα6がoα， sp． nov．）

ハをψ〃20sら， gen． nov．（Type speciesハ乙元幼o泌6α（SPATH）） 苗Zc乃吻∫9θs SPATH（Type species，κ1りo勿∂ゴ6乃〃グyακ〃s（KossMAT））

ノ1〃sτ仇『τ〃αsSPATH（Type species，ノLα〃5∫¢〃ゴ（S正IARPE）） P〃ψ〃205ψNowAK（Type species，」R 4ακ6πε『（GRossouvRE）） ノ初2bo‘ε〃αs， SHIMIzu（Type species，1．カ1α〃〃1α’ぴ∂グ勿θ（JIMBo））

1）ατ友y4ρs〃200θプαs SPATH（Type species，1）．4θ〃『soκゴακ〃〃z（SToLlczKA））

1汐∫04ゐω鋤sSPATH（Type sp3cies， L． oo〃4％oゴθ〃s云s（CHoFFAT）） Aτ乃〃～εoo〃αs van HoEpEN（Type species，ノLεグαs勿〃sゴv． HoEpEN） These have been mostly de6ned in the main chapter． They are intimately con・ nected with one another in morphological characters and stratigraphic occurrences， forming a relatively natural and solid group． The diagnostic features of the family common to all of the above genera may be described aS fo110ws． Discoidal shell consisting of many whorls（i． e． polygyral）， more or less evolute， in general moderately umbilicate and mostly very large when fuIl grown． Whorls usually compressed wlth an arched venter and flattened nanks， but in some case somewhat in且ated， although never depressed as in certain Pachydiscids． She11 periodically constricted and ornamented with numerous subcostae or ribs， which are essentially且exiradiate at Ieast on the imer whorls， more distinct on the external half of whorls but sometimes modified， especially on the outer whorls． The ribs and constrictions show a forward curvature on the ventraI area in most growth stages， except in the adult body chamber of certain genera． Suture．lines of［E L U2 U3（＝S）UI Iコ type；L well developed and the largest of a11， being much larger than E， asymmetrica11y tri6d in later growth・ stages；U2 recurved or oblique；UI reduced in size；subdivided elements of U3， together with U2（externally）or U1（interna11y）， strongly descend towards the umbilical suture；saddles mostly bi丘d and all the elements are行nely and deeply incised in later growth stages as in usually the case in Desmocerataceae． As a general tendency in this family the diagnostic characters of each genus are exhibited more distinctly in late than in early stages of growth． Consequently most of the genera listed above are fairly similar， especially between the closely related ones， in their immature shell but differ considerably in the adult． In Family Puzosiidae from Hokkaido and Saghalien 105 too many cases only immature shells of Puzosiids have been described and it is often hard to understand the actual feature of the genera from such material． It goes without saying that the exclusive dependence for description on adult shells is also undesirable． I have paid attention to the characters in every stage of growth． The continuous material from the successive strata is also helpfuユfor sound inter・ pretation． The conclusion through this study is that the Puzosiidae is a fairly com・ pact group， consisting of a series of forms which have evolved from a single stem， that is to say a monophyletic rather than polyphyletic family．

So far as the Albian and Upper Cretaceous forms are concerned， the Puzosiidae is generally quite distinct from the Desmoceratidae． The typical representatives of the Iatter are．Z）θs〃206ρ夕αs （s． s．），1）．（Psθ〃40〃〃1留¢〃α），1）． C乙％〃α∫04bグs6〃o）， Tグα1仔04θs頃

〃20c〃リゴ4θs，1）θ5〃zρρ吻1〃∫θ5 and 1）伽2es舵s． In the very young stage the two groups are， of course， very similar but at fairly early in immature stage the distinction begins to appear． In most of the growth stages the shell of Puzosiidae is more evolute and more widely umbilicate than that of Desmoceratidae． The proportion of umbilicus to diameter is generally 30－40％in the former as compared with about 20％or Iess in the Iatter． We should adrnit a few exceptions for these丘gures， since the outer whorl of some Puzosiids is more involute than the inner whorls． The dif・ ference in the suture is quite distinct． AII the above Iisted genera of Desmoceratidae are essentially constant in their sutures， which I have ca11ed the 1）杉5〃206εれ7s・type． It consists of numerous， regularly arranged，丘nely and deeply incised elements， in which saddles are bifid and lateral lobes are trifid． Lis not so Iarge nor so asym・ metric as in Puzosiids and all the numerous elements are arranged in a nearly straight row or quite gradually descending towards the ulnbilicus． The test of Desmoceratidae is genera11y thin and is nearly smooth or weakly ribbed（keeled in」Dα勿εsゴZθs）． P砿osωin Puzosiidae is rather weak in ornamentation， but broadly speaking， other genera in the same family have stronger ornament than most Desmoceratidae． Desmoceratids are genera11y small or moderate in size， while Puzosiids mostly reach a very Iarge size when full grown， although in a few genera of the latter，

such asハ花ρρκ205Zαand 1（批〃椛Zθs， a very large shell has not yet been known． More or less sigmoida1， periodic constrictions apPears in both groups and their curvature varies with species． Similarly the perpendicular umbilical wall with angular shoulders is not necessary rare in Desmoceratidae， though more frequently found in Puzosiidae． Shortly， so far as the above listed forms are concerned， Puzosiidae is well dis・ tinguishable from Desmoceratidae． Generally speaking the former is somewhat more specialized than the latter in the ornamentation， sutures and in size． They may be asingle， but flexible， stock with two branches of unequal specialization． 106 T．Matsumoto

To clarify the natural systematic position of Puzosiidae we must study the Lower Cretaceous“Desmoceratids”（s．1．）． However I am obliged to suspend the final decision of the problem since we have not enough material of them in our

provlnce． From a preliminary study on some foreign speclmens as well as literature follow・ ings are my preliminary views． Puzosiidae has its origin perhaps in Aptian Mρ1c万o・ ガZ6s． Although the type species， M〃2θ1ε乃『oグ£s（TIETzE）， has a rather convergent

whorl section， the genus incllldes species， such as Mε〃2¢グゴcゴ（RAspAIL）， of rounded or elliptical whorl section． It has frequellt constrictions and weak subcostae both of which show a prominent ventral projectioD， foreshadowing well the characters of ／1〃4ρ〃205らand P〃205『σ（s． s．）． The suture of」％¢1c〃oγゴZεs（Text fig．1）has a sub・ symmetric L， which is not so large as in the outer whorls of P〃20sゴα（s．s．）but nearly as large as in the immature shell of P批osゴαand P．（∠肋ψ〃20sω）， and its descending of the auxiliaries， if present， is not so remarkable as in Pκosゴα（s．1．）．

き L E u2 、 u4？ 1 UI ー l 勾 ∬ l

u5． ’

Fig．1． A septal suture ofル⑫1c万oγi’θsθ舵γiεi（RAspAIL）（immature）at a diameter of 33．5mm，8M．437426 from Barreme（Basses Alpes）， France．（T．M． del．， by kind permission of Keeper of Geology， British Museum（Natural History））．

Between 1吻10ωoグ舵s and‘‘evohlte Phylloceratids”（e． g． FALLoT，1920b）no one has discovered an intermediate from in the strict sense of the word， while M¢膓o厄o・ グ漉sis closely related， through some intermediate form（1ike‘1）ε5勿06〃αs’ρo〃旋％勿 KARAKAscH，1907妬）， to a nearly srnooth and straightly constricted Desmoceratid group， perhaps a new genus， represented by‘Z）65〃20cεグαs’rグαss‘40夕5αψ〃2 KARAKAscl1苦， 1907and‘1）θ5物oc〃αs’10ηi PAQulER，1900（Barremian・Hauterivian）and their allies． That group may have its ultimate origin in Eb4¢s勿oc〃os． These Neocomian genera ／ should not be included in the Puzosiidae （s． s．） since they have not acquired the diagnostic characters of the‘‘family”defined above． On the other hand there are a few Aptian species， like Z）εs〃20cεグαs〃ρyゴANDER・ soN，1902 and／1〃2〃20η批sαZ乃os CoQuAND，1865， which are referable or at least closely

allied to Dθs，κoo〃αs（s． s．）（i． e． the 1α’ゴ4ρグsα勧〃z・group of Albian・Cenomanian）・

＊Mr． R． A． REYMENT has kindly helped me in translating the Russian description of KARAKASα1． Family Puzosiidae from Hokkaido and Sagha！ien 107

旺 UlU3 U2 L E

3；．4タ・・一・ v∨r）～～／ 1 Ul U3（＝S）U2 L E

ε 1◆ ．．．‥・●． U2 L 20e’”・… し 3°6… 一

〆 〃 us． 2mρ1． L ε11“

4° Q＼、 し 1 ∪‘ U3（＝S） u2 E

、

ハ

11 E

ーー ー 1

u3（＝s〕

Fig．2． Very early growth・stages of磁sψμ20siαヵαcφoα， sp． nov．， showing whorl sections， lateral views and suture・lines． 1°1，2°e，＿＿＿late substage of the first whorl， early substage of the second whorl， etc． The suture at the bottom is at a whorl・ height of 6mm． Specimen GK． H．1246 from locality Y 216p 1， Saku formation， Shiyu・ bari VaUey， Ishikari Province， Hokkaido．（T．M． Coll．＆DeL）

Apart from the quite doubtful and inde丘nite genus P吻〃ρ4θ5勿ooε7α5， this kind of Aptian Dθ5勿oo〃α5 can be connected with the above mentioned‘‘c夕αssゼ407sα拓勿・ group”through su、ch intermediate forms as A勿勿o砺∫θs幼εαFoRBEs，1845苦 and レ毎Z4！θ40γsε11α（？）9ε∫κ1吻e（CoQuAND），1880．

Thus the branching of Desmoceratidae（s． s．）and Puzosiidae（s． s．）may have

＊ Ifortunately had an opportunity to study the holotype of A勿． iκ6αFoRBEs（BM．13096） from Bogota， which has a good Dεs形ooθグαs．type suture， gently sigmoidal constrictions and the fairly naTrow urnbilicus． 108 T．Matsumoto

⊆）pr＠ 1°e i°t、

ユ゜e

ユ゜t ・一・・一・ 3●

2°e ＼ ！ ！ 、 ’

3° 2． 卜一・ 2°1 o

、 ！！ 、 L ’ 、 、 3° o o

3mm．

l ／o’ O mm 5mm

Fig．3． Very young growth・stages ofハ彰ψ％20siαisω輪％αi（JIMBo）， showing enlarged protoconch， suture・lines， lateral views and sections of whorls up to a diameter of 10mm． pr．：protoconch，1°e：early substage of the 6rst whorl，2°1：1ate substage of the second whorl． Specimen， GK H2435 from locality N182f， zone Mh6β， Naibuchi Valley， South Saghalien．（T．M． Coll．＆De1．） taken place in late Neocomian． At that date the distinction of the branches was not clear enough for separation of families， but conventionally most of the Neocomian forms concerned could be grouped together in one‘family’or‘subfamily’with Eo4θ鋤oo〃αs as its representative． PSθ％4ρ％ρZo¢〃αs is one of the member of this Neocomian group， but does not seem to me the direct ancestor of P〃20s化or ∠肋α吻20sκ， because of too much development of costae and considerable difference in the curvature of costae and constrictions． FamHy Puzosiidae from Hokkaido and Saghalien 109

U3（＝S）

、

Fig．4． External suture of 2Vθo力偏os辺元ψo痂6α（SPATH）， enlarged， at a whor1・height of about 23mm．， BM． C．47735 from zone Mh6， Naibuchi VaUey， South Saghalien． （T．M． Col1．＆Del．）

In short I am inclined to group together Pz420siα， ノ1κα♪％zosゴα and the later members listed above in Puzosiidae（s s．）． It may have derived from the nexible Neocomian‘Desmoceratids’， which， on the other hand， may also have glven rise Desmoceratidae（s．s．）above de丘ned． Probably each of the four families of the Upper Cretaceous Desmocerataceae is well stabilized to form a distinct group res． pectively， while the main stock of the Lower Cretaceous Desmocerataceae is still very Hexible and not stabilized enough to form such distinct groups， apart from the lateral offshoots such as Holcodiscidae， Silesitidae and other derivatives． Now I will turn to a short summary of the history of Puzosiidae within itself． The evolutional change of characters in Puzosiidae is rather slow and unremarkable， as is also the case in Desmoceratidae（s．s．）． However there are a large number of forms so that the classi6cation into the ten genera listed above is， I think， necessary and quite useful， although morphological criteria between the allied genera may not always be so remarkable as in many examples of the we110rnamented Ammonitina． The geological range of each genus or species is generally rather long．

In the early epoch in the history of Puzosiidae， mainly in Albian， several genera have differentiated． They are， besides the simply ornamented and persistent P％20s〆α

（s．s．）， the more or less strongly ornamented P．（∠4〃αρ〃zos似），1汐》04ゴ∫ooゴ4θs and

Ac乃ゴ〃θoεθグαs aτ1d the rather inHated and coarsely ribbed 」仇c吻4θs〃zocθグαs． Their particular characters are， however， manifested mainly in the adult body chamber or later whorls and do not affect the irnmature she11， so that the specialization is by no means advanced． While A幼ψ〃20s∫αis known from Lower．Middle Albian， the other three genera apPear near the top of Albian． In the Upper Cretaceous， from Cenomanian to Maestrichtian， a very slow evolu’ tional change proceeded in three parallel lines． The丘rst is from Pκ05ゴαthrough 巳O Table I． Evolution of Puzosiidae and Desmoceratidae

K4 ρζ 馨（ 6 cぐ K2 K3 〆 K3β K3γ K4 β K5 〆 K5ρ K 5γ K 6 ／ 」 Nε0－ ）～FRA－ NEO＿ NEO－ ］NFRA＿1 ρALεO＿ ARITAN PALEO－ PALEO－ PALEO－ H訂。NA・］HET。。A閑 Nεo－ GYしlAK． HεTC；↓Al終「 MIYAKOAN 「》11YAKOAN GYUAKIAN GYUAK｛AN URAKAV》AN URAKAWAN 「111，ーFFー 』 ，ー，，ーー 一 、、ー層111 唱ー．‘t±ーi－」 PARAPUZOSIA しく ．，、’ AUSTINIC直RAS

メ「 MESOPUZOSIA ーーー 〔． ス ρ メ o口宝8男bω、．o力〉切⑩60力⑩b↓cヨー；o毛〕 PUZ° …IA！ ㌦］ NEOPUZOSIA ｝ 一 一 ，、 斗L＿1些型哩竺E R A T I D A E 」 1 1 l I△ MELCHIORITES〕 ？「㍉㍉一一か∴吟 C l l十 ㌶ 例 ↓＼ S S M A T l 「▲： P．｛ANAPUZOSIA） fK O 門 ｝N

＼＼∴V♪ LYTODISCαOES JIMBOICERAS 司二≦9ωロ日08

一一一一一 l三 ｝ ．」 「一 PACHYDεSMOCERAS

ACHiLLEOCERAS

＿＿‡＝＝L＿．～ 、一 VAしDEDORSEしLA〕 Dメ（LUNATODORSELLA） ’ ｝ ⌒ ・－L（ P A C H Y D 1 S C 1 D A E … 一一一 〕

… DESMOCERAS U ＜O一↑＜匡UOOΣのUO 、ギ 、 li°トーーー ー、、 TRAG°DεS竺゜CERαDES

、 L－一 ↓．一一一 D．｛PSEUDOUHLIGELLA） ？： DESMOPHYLLITES → ●■■ 一 マ

▼ DAMESITES 〒RAG◎DESMOCERAS

q． ド ？ぷ ー？： BHIMAITES HAUERICERAS 」 一 一 竺 H．・－8． APTIAN AL81AN CENOMANIAN TUR㎝IAN CONIACIAN SANT°NIA CAMPANIAN MAEST圃CHT． O A N． Those in［ ］are to be excluded from Puzosiidae（s．s．）and Desmoceratidae（s．s．）． Family Puzosiidae from Hokkaido and Saghalien 111

Mθsψμ20s’α（mainly Turonian・Coniacian， rarely Santonian）to∧花ψ〃zosゴα（Santonian ヵ1〃s～earliest Calnpanian）， in which gradual development of long ribs and streng－ thening of ribs took place， retaining quite well the fundalnental characters of P〃20s泌． The second is from Pκ20sゴαthroughんイs励Zcθγαs（Cenomanian．Turonian）to Pαグα・ μ20sゴα（Coniacian・Santonian－earliest Campanian）， in which differentiation of ribs into nlajor（broad and long）and minor（narrow and short or branched out）ones and also some strengthening of ribs took place． The third one， still somewhat obscure in tracing precisely its history， is Pzzzosゴσ（ノ1〃ψ〃20sゴα）（Albian and？Cello・ manian）」物60Zoθグαs（Turonian・early Salltonian）series， in which extremely strong， sometimes Hared， periodic ribs were specially developed on the outer whorl， besides some roundness of whorls， broadness of constrictions and increase of other ribs on the inner whorls． Broadly speaking in all these series the straightening of ribs on the lateral sides is revealed as time goes on and that character affects even the inner whorls in κ漉乃沈∬εs，which is probably a descendant of∧吻ρ〃20sω， acquiring at the same time sorne kossmaticeroid character（see remarks in IVεψ〃205ゴの． Pαo吻4θs勿06〃αs ranges up to Turonian with very slow change and does not seem to produce later derivatives． There are a few forms， probably lateral o任shoots， which are rather di缶cult to place in either of Puzosiidae or Desmoceratidae， for example石rα〃〃ゴc〃α5，αψ紗〃ゴ’θ5 and 1ケαgo4θs〃ωc〃αs． As we have a number of specimens of正1α％〃‘6〃αs ranging from Santonian to Maestrichtian， I sha11 not discuss that genus until I describe the叫苦altbough it might be included in Puzosiidae． 7物～卯4ρs沈oc〃αs has been included in Puzosiidae and I myself regarded its resemblance to 1＞αgo4召s勿oc〃oZ∂θs （of Desmoceratidae）as super丘cial（T．M．吻T．M．（Editor），1954）． However， examin・ ing some specimens of that genus as well as literature， I am now inclined to change my previous view． I would like to restrict the genus to∠4吻勿o碗θs c砂ρθα10Z4θs LEoNIIARDT， the type species，／1〃2〃zo〃∬εs o砂』うθα1ゴs ScHLUTER and their allies （e．9． two species reported from Turonian of North America（MoRRow，1935；MoREMAN， 1942））and remove‘‘7＞αgo4εs勿oc〃αs”沈髭〃〃ゴ（GRossouvRE）and‘‘τ”乃〃〃ρ〃sZs （ScHLUTER，1868， non 1872）to 1〕％20sZαof oγZε〃ZαZ¢group and ∧めz〃α〃∬θs （？）respec・ tively． The genus thus revised is fairly narrowly umbilicate， involute and has a sutures of Dεs〃zocθγαs・type・ It is closely a11ied to Tケα8り4εs〃zooθγo∫4θs especially in the inner whorls but has a fastigate venter in the outer whorls where ribs form angular chevrons and the sharp mid－venter has a crenulation by the intersection of the ribs． Thus the genus is better removed from Puzosiidae to Desmoceratidae and is probably derived directly from Tグαgo∂εs勿06〃oi4εs or from 1）θ5勿oc〃αs（Psθκ4・ o〃〃ゴgθ〃のin parallel with 2ツ確04θs勿oo〃o∫46s． At any rate its character is fairly

＊ αψ吻〃∫θswill be mentioned when I treat with仇μ〃iσ〃αs． 112 T．Matsumoto peculiar and the suture tends to be reduced， with minute fringing and broadening of elements， so that the genus can be regarded as a lateral offshoot， which， in turn， perhaps gives rise a particular form called Mz‘砺〃Z6〃αs．

＼ ＼ 1＼ 1パ ｛／

’！「ン ー 亥

5a 5b

／ 5c 巳～ 一

碗 シ

へ

Fig．5． Psεε吻ρz‘20s辺物γ10ル幽∫θ（NoBLE）， holotype， Geol． Surv．＆Museum， Great Britain，25456，γ醐ssiα微％subzone， UpPer Turonian， Blounts Farm， Buckinghamshire， England． Lateral（a）and ventral（b）views， natural size， and suture・line（c），×2． A posterior quater of the outer whorl is too much artificially treated， so that the umbili・ cal nodes are not preserved．（T．M． de1， by kind permission of the Director G． S． M．）

Fig．6．．Pse〃40μ20siα吻γ10ωθηsθ（NoBLE）， another comparable specimen， BM．48764， 1τ01αs’〃ρ1α励szone， Middle Chalk， UpPer Turonian， Iocality unrecorded， Toulmin SMITH Co且lection（1869）． Lateral（a）and frontal（b）views， natural size．（T．M． deL， by kind permission of the Keeper of Geo】ogy， Britlsh Museum（Natural History））． Family Puzosiidae from Hokkaido and Saghalien 113

Another doubtful genus which has been assigned to Puzosiidae is PSθ〃4ψ〃20sゴα SpATH，1926． Examining the type species，1）θs沈oo〃αs勿o〃oz〃ε〃sθNoBI．E，1911 （holotype， Geol Survey＆Museurn of Greユt Britain，25456 and another referable specimen Brit． Museum（Nat． Hist．）48764）（Text figs．5，6）， I have recognized that the genus is a Pachydiscid provided with weak umbilical bullae at the edge of sha1． 10w constrictions of a slight curvature and sometimes with faint ribs on the lateral sides， never showing P〃20srα一1ike ventral projection of the ornarnent． The sub・ rounded and rather broad whorl and the pattern of suture， which are similar to those of∠4〃ψαc吻4Zso〃s， YABE＆SHIMIzu， also supPort the assignement to Pachy・ discidae． And indeed this Turonian gemls may be a possible ancestor of Senonian

／1ク2αクα6吻4£sτ〃sand 2Vbz〃α〃∬θs．

Lastly here is another doubtful group of species that have heen assigned to P〃20s仇but distinct enough to require a new generic name．

Genus BLimaites， nov．

7ンカεsカθoπs： ノ1〃2〃20ηゴ∫¢s6乃i〃2αSToLlczKA，1865． Gε〃〃ゴ04飢g椥s’s：Shell involute， fairly narrowly umbilicate and compressed at Ieast in relatively late growth stages；umbilical wall steep；umbilical shoulder subangular to subrounded；flanks rather flattened；venter narrowly arched in typical forms． Constrictions frequent， rather prorsiradiate and only slightly flexuous on the flanks and projected forward on the venter． Surface nearly smooth， only with striae and sometimes with faint peripheral subcostae or weak Iateral costae in the outer whor1． Suture・lines are deeply and finely incised， with large and asymmetrically tri負d L as in P〃20siαbut consist of numerous elements as in 1）εs勿oc〃os， the auxiliaries being gradually or moderately descending to． wards the umbilical suture and UI erect and distinct． Sometimes she11 attains aIarge size． Rθ〃2α夕〃s： The new genus is typically represented by A〃2〃20励Zθs 6万〃2αSToLI・ czKA and Pz‘zos泌s∫01£02肋Z KossMAT（＝＝〆1〃2〃20κゴ’εs bε〃4α〃Zξ STOLICZKA）from the Iower part of the Utatur group of India and probably P〃20s『α♪沈g〃‘s CRIcK， 1907（＝＝？P．b乃ぼ〃2α）， P． s％bZ〃£s CRIcK，1907 and R s1う励万VENzo，1936 from the Cenomanian of Zululand（Africa）． The last species occurs also in the Albian of Angola（HAAs，1942）． A勿〃20〃鋤s o1『θ〃αSToLIczKA， another Utatur species， and P〃20s祖∫μグ〃鋤妬PERvlNQuIERE，1907 from the Upper Albian of Tunis may be immature of this genus． The second species（sτoZ£02肋のwas reported also from the Cenomanian of Zululand（CRIcK，1907， SpATH，1921）． Fortunately I have been able to study the original specimens of CRIcK’sが〃g〃ゴs（BM． C．18243， C．18244）， s∫o〃c2輪ゴ（BM． C．18241）and s〃b励s（BM． C．18242）． Although I have not had access to the Indian specimens， their description and illustration are so clear that the distinctness of the new genus is fully justified． 114 T．Matsumoto

The genus is interesting in that almost all its characters indicate an ap． parently intermediate state between 1）ε5zη06θグα5 and P〃20sゴσ． In shell－from it is rather nearer to Des〃206εγαs and very sirnilar to the subgenus Psεμ40％ゐZづ9θ〃α． B〃勿α舵shas however somewhat wider umbilicus than 1）6s勿oo〃os， especially in the inner whorls． In this respect and in the character of its adult suture it is allied to but not identical with P〃20吻． Although it is more involute than typical P〃20s化， some of the Puzosiids do show relatively stronger involution and narrower umbilicus in their outer whorl． For instance， P〃20s化吻s6〃砂ωKos・ sMAT， a rare species from the Utatur group， and Pκzos『αα〃〃o伽ρρ〃sどs BREIsT’ RoFFER吻BEsAIRIE，1936）from the Middle Albian of Madagascar seems to approach to B万〃2励θs in their relatively narrow umbilicus， considerable involu－ tion， frequent and rather prorsiradiate constrictions and very丘ne subcostation． Between these two intimately related families we can expect an apparently intermediate form， which， however， is not necessarily a passage form in the phylogenetic sense． In such a case its assignement to either of the two families may be arbitrary， although it could be decided on the basis of phylogeny． Whether B〃ヵη励杉s is a puzosioid derivative from D杉s物o〃αs（」巳θ〃40励〃8杉〃の or desmoceroid offshoot frorn P〃20s㌘or otherwise is rather difncult to tell at present． Although I am rather inclined to the latter view， I suspend a final conclusion until I obtain the su伍cient material to discuss the problem．

Acknowledgements

The many kind friends who have helped me in various ways have all incurred my gratitude． Most of their names were mentioned in my previous number of the serial papers（1954吻T． M．（Editor））， but， in particular， I should like to mention here Mr． C． W． WRIGHT of London who gave me frequent opportunities for fruitful discus・ sion， allowed me the use of his private collections， and kindly read through the manuscript；Professor Emeritus H． YABE and Professor T． KoBAYAs田， through whom Ihave had access to the collections in the University of Tokyo；Mr． W． N． EDwARDs， Keeper of Geology， British Museum（Natural History）， who has rendered facilities in that Museum where I have been able to work through a British Council Scholar－ ship；Dr． L． F． SpATII of the same Museum， who has given me valuable advice from his rich and deep experience；Dr． W．ANDERsoN， Dr． R． V． MERvlLLE and Mr． R． CAsEY， of the Geological Survey and Museurn of Great Britain， who， while enabling me to study the necessary specimens of that Museum， made mally excellent sugges・

tions． The photographs at the University of Tokyo have been taken by Mr． C， UEKI； at Kyushu University by myself with the kind assistance of Messrs． K． KANMERA and K． FuJII， and those at the British Museum（Natural History）by MrJ． V． BRowN， Family Puzosiidae from Hokkaido and Saghalien 115

Fina11y， my thanks are due to Professor T． ToMITA and Professor R． ToRIYAMA for their help in arranging for the publication of this paper by the Faculty of Science， Kyushu University．

Works cited

ANDERsoN， F． M．1902． Cretaceous Deposits of the Paci丘c Coast． P7ηε． Cα1σ． Acα4．8εi．，［3コ2， 1，1－154，pls． i－xii． 1938．Lower Cretaceous Deposits in California and Oregon． G¢01． So6．．4吻．， Sφ86iα1 P4ρ〃s， 16，339pp．，84 pls． BAYLE， E．1878． Fossiles prhlcipaux des Terrains． E功〃ε． Cαγzβgε01． Fグ醐τθ，4， pt．1 （Atlas）， 158pls． BEsAIRIE， H．1936． Recherches G6010giques a Madagascar． Premiere Suite．］二a G6010gie du Nord・ Ouest． M鍋．》，．40α∂． Mα1gαc舵，21， Text（259 pp．，3tables，1map，16 text五gs．）＆Pates （24pls．）． BouLE， M．， P． LEMolNE＆A． TH丘vENIN 1906． Pa160ntologie de Madagascar 3－C6phalopodes cr6tac6s des environs de Diego Suarez． ノ1κη． Po1εoκ’．，1，173－192（L20）， pls． xiv－xx（i－vii）． BREIsTRoFFER， M．1936． Les subdivisions du Vraconien dans le Sud・Est de la France． B〃〃． Soε． 9ε01．F〆α労oθ，［5］ 6，63－68． 1947．Sur Ies zones d’Ammonifes dans 1’Albien de France et d’Angletere． τグ勧． L功． g501．， 1♪α6．Soi・，～’～ゾηら． Gヵμob1θ （1946－47），26，17－104． CHAPuT， E．1920． Les Desmoc6ratid6s du Pal60cretac6（Revision du genre Z）θs〃200〃αs）仇W． KILIAN（Editor）： Contribution含r6tude des c6phalopodes pa160cr6tac6s du Sud・Est de la France． ルZθ〃2． Cαγ’¢gε01．碗力i1． F〆ακ6β（1920），167－188，1p1． CHoFFAT， P．1898． Recueil d’Etudes pal60ntologiques sur la faune cr6taciqlle du Portugal，1，［2］ 41－86，pls． iiトxxii． 1903．Contribution a la connaiss． g601． des Colonies Portugaises d’Afrique，1－Le cr6tacique de Conducia． Co〃2〃2i∬ioκS¢グ〃ioε9ε01． Po〃〃8α～，32 PP．，9pls． CHoFFAT， P．＆P． de LoRlol、1888． Mat6riaux pour l’6tude stratigraphique et pal60ntologique de la province d’Angola．ル㌘沈．800．劫夕s．θ’∂’万s’獺Z． Gεκら6，30，2，116 pp．，8pls． CoLUGNoN， M．1932． Pal60ntologie de Madagascar，17－Fossiles du Cr6tac6 Superieur du M6nabe． ノ1κη．Pα1．21，35－87， pls． iv－xii（i－ix）． CoQuAND， H．1865－66． Monographie pal6mtologique de retage aptien de l’Espagne．ハ4ε勿． So6． ♂E〃2〃1dθ1αPグo〃εηoθ，1レ『αγs杉∫〃θ，3，191－433 （1865）， pls． i－xxviii（1866）．

一一一 1880．Etude suppl6mentaires sur la pal60ntologie algerienne． Bμ1～．」’、46砿♂11物o％θ，15，1－449． CRIcK， G． C．1907． Cretaceous Fossils of Natal， Part 3． 7ソ2〃4θκ4 F肋α1 Rψoγ’Gω1． S〃〃．」Vατα～

＆Z％1z〃ακ4，163－262， pls． x－xv． DEsIo， A．1920． La creta nel bacino di Firenze． P31εoη彦．∫’α1．，26，189－243， Pls． xii－xix（i－viii）． DouvlLL面， H．1879． Note accompagnant la pr6sentation de 1’Atlas du tコv de rExplication de la Carte g601． de France de E． BAYLE et R． ZEILIER． Bμ～1． Soo．9き01． F夕α〃6ε，［3コ7，91－92， FABRE， S．1940． Le cr6tac6 sup6rieur de la Basse・Provence occidentale： 1． C6nomanien et Turonien．ノ1ημ． Fα6．86i．ルZαγ磁11ε， L2］14，355 PP．，10 Pls． FALLoT， P．1920a． Observations sur diverses espさces du Gargasien bathyal alpin et en particulier sur la faune de Blieus碗W． KIuAN：Contributionえ1’6tude des c6phalopodes pal60cr6tac6s du Sud・Est de la France． ルπ〃2． Cαグ∫θ、9ε01．4εω〃． F7ακ6ε（1920），229－266， pls． i－iii． ・1920b． Faune marnes Aptien et Albien de la Region d’Andraitx（Malorque）． Tプαb．1％〃s．

∧佐6ioη． Ciθκε，ハアα’．， sεγ． Gθ01．，26，5－68， pls． Liii． FoRBEs， E．1845． Report on the Cretaceotls Fossils from Santa Fe de Bogota， etc． QμαγZ・ノoμ夕・

G¢01．So6．」乙oκ40κ， 1，174－179． 1846．Report on the Fossil Invertebrata from Southern India， collected by Mr・KAYE and Mr． CuNLIFFE．τ燗s． Gε01． Soo． Loκ40κ，［2］7，97－174， pls． vii－xix． 116 T．Matsumoto

FRITscH， A． J．＆U． SαILoENBAcH 1872． Cephalopoden der b6hmischen Kreideformation，52 pp，， 19pls． Prague． GRossouvRE， A． de 1894． Recherches sur la Craie Sup6rieure II Pal60ntologie． Les Ammonites de la Craie Sup6rieure． ルπ〃2． Cαγ彦θgε01．4θ’o〃． Fγακc¢（1893），264 pp．，39 pls．

HAAs，0，1942． The VERNAY Collection of Cretaceous（Albian）Ammonites from Angola． B〃〃． ノ1η2．ルZ〃s．Nα彦．1五s∫．，81，1－224， pls． i－xlvii，2tables． vAN HoEPEN，1． E． C． N．1951． A remarkable Desmoceratid from the South African Albian． Pα1． 茄α〃oクs∫π∠7／V凌sξoκα16 1レZ〃s¢〃〃2Blo2〃2ノ⑳κ’¢『％，1，10，345－349，3 6 gs． JAcgB， C．1907． Etudes pal60ntologiques et stratigraphiques sur la partie moyenne des terrains cr6tac6s dans les Alpes frangaises． 丁傾〃． Zαb． gε01．σκ初． G7¢ηob1ε，8，2，280－590， pls． i－vi． 1908．Etudes sur quelques Ammonites du Cr6tac6 moyen．ルf鋤． So6． gε01． Fγ伽τε， Pα吻η’．， 15，ル〃〃2．38（1907），64pp．，9p！s． JIMBo， K．1894． Beitrage zur Kenntniss der Fauna der Kreideformation von Hokkaido．仇吻oκ∫． ノ1b乃功z∂～，，6 （2V．F．，2），149－194， Pls． xvi卜xxv． KARAKAscll， N．1907． Le Cr6tac6 inf6rieur de la Crirn6e et sa Faune． 7ンθ〃．800．吻φ．ハ励． S’． P〃εγsb％瑠．， s¢τ’． Gε01．ノレ露κ．，32，5（1905），1．・482， pls． i－xxviii． KAwADA， M．1929． On some new species of Ammonites from the Naibuchi District， South Saghalien． ∫α〃． Gθ01． Soc．7b〃夕o，36，（1）〈6）， pl． xiv． KILIAN， W．1907－1913． Unterkreide（Palaeocretacicum）仇FREcH：Letllaea Geognostica， II． Mesozoicum， Vol． III， Kreide， Lief．1，1907，1－168；Lief．2．1910，169－287， pls．1－7：Lief．3， 1913，289－398，pls．8－14． KoENEN， A． von 1897． Uber Fossilien der unteren Kreide am Ufer des Mungo in Kamerun．∠4b乃． ゐ．Gθs．η｝㌃∬． Gδ”m9杉η，〃20’カ．勿α’．、κ～．，∧た1亘，1，1．－48， pls． i－iv． KossMAT， F．1897－98． Untersuchungen Uber die SUdindische Kreideformation． II． B2〃． Pα1． Gθ01． OsZ．・σ〃g．0れ，11， pt．1（1897），1－46， pls． i－viii；III．1bi4．，11，pt．3（1898），89－152， pls． xiv－xix． LANDoIs， H．1895． Die Riesenammoniten von Seppenrade， Pαo勿∂∫s6μ∫sε妙ε〃α∂θηsis LANDols． ノα乃γθsδ¢γ」 πθsφ1．p7㊨〃∫κ2びθア」／ 1肪∬θκ∫εん．」尼z¢ηsτ． M諺κs’6γ，23，99－108， pls． i， ii．

LEoNHARDT， R．1897． Die Fauna der Iζreideformation in Oberschlesien． Pα1αθo％’09γ幼乃ゴτo，44， 11－70，pls． iii－vi． MARsHALL， P．1926． The Upper Cretaceous Ammonites of New Zealand．τ〆鋤s．1V． Z．1％s’．，56， 129－210，pls．19－47． MATsuMoTo， T．［MATuMoTo］1938． A Biostratigraphic Study on the Cretaceous Deposits of the Naibuchi Valley， South Karahuto， Pγ06．1勿ヵ． Aoα4．1ψ朗，14，190－194． 1942．ANote on the Japanese Cretaceous Ammonites Belonging to the Subfamily Desmo・ ceratinae． 16∫4．，18，24－29． 1942－43． Fundamentals in the Cretaceous Stratigraphy of Japan． Part I． ～晩〃2． Fα6． S砿， 1ζ〉μ訪μ1〃ψ．σμ初．，［D］1，129－280，pls． v－xx（1942）；Parts II＆III． Ibid．，2，97－237（1943）． 1951．ANote on the Pachydiscinae， a Cretaceous Amrnonite Group．丁傾ηs． Pγoo． Pα1αθoη彦． Soo．ノo』うακ，ノV． S．， 1， 19－26， MATsuMoTo， T．（Editor）1954． The Cretaceous System in the Japanese Islands．324 pp，36 pls．， Tokyo． MATsuMoTo， T．＆R． SAITo 1954． A nearly smooth Pachydiscid from Hokkaido， Japan．ノψακ． ノoμ夕．Gβ01． Cε09れ，24，87…92， pls． ix－xi． MILLER， A． K．＆w． YouNGQulsT 1946． A giant ammonite from the Cretaceous of Montana． ノoμ夕．Po1，，20，479－484， pls．73－75．

MoBERG， J． C．1885． Cephalopoderna I． Sveriges kritsystem． II． Artbeskrifning．5卿igεs Gε01． σκ4θ7soゐηiκg，［c］ 73，1－64， pls． i－vi． MoREMAN， W． L．1942． Paleontology of the Eagle Ford Group of North and Central Texas． ∫oμ夕．Pα1．，16，192－220， pls．31－34． MoRRow， A． L．1938． Cephalopods from the Upper Cretaceous of Kansas．ノo％7． Pα1．，9，463－473， pls．49－53． NoBLE， A． H．1911． On a new species of Dεs豹06εγαs from the Chalk Rock of Buckinghamshire， Family Puzosiidae from Hokkaido and Saghalien 117

Gθ01．／↓Zog．， ［5］ 8，398． NowAK・J・1913’Untersuchungen Uber die Cephalopoden der oberen Kreide in Polen， III． Bμ〃． ノ10α4．Soゴ， C夕ooωゴ2， C1．〃ω’乃．καプ．（1913），335－415， pls． xi－xiv． ORBIGNY・A・d’1840－42・ Pal60ntoIogie Francaise， Terrains Cr6tac6s，662 PP．，143 Pls．（PP．1－120． 1840；121－430，1841；431－662，1842），Paris． PAQulER・V・1901・Recherches g6010giques dans le Diois et la Baromies orientales． ApPendice Pal60ntologique． 7γα〃． Lαb． g201．， Fαε． S6↓．，～’σ％i〃． G〃ηob1θ（1899－1900），5，549－556， pls． viii， ix． PARoNA， C・F・＆ E・G． BoNARELLI 1896． Fossili Albiani d’Escragnolles del Nizzardo e della Liguria occidentale． Pα1．1’α1．，2，53－112， pls． x－xiv（i－v）． PERvlNQu工亘RE， L 1907． Etudes de Pal60ntologie Tunisienne，1． C6phalopodes des Terrains S6condaires． CαγZ2 gεo～．71zイηゴsθ，428 pp．，27 pls． 1910・Sコrquelques ammonites du cretace Algerien． ルf勧． So6．9ε01．蹄鋤6θ， P凌～θo〃τ．，17，， M6m．42，86 pp．，7pls． PoPovIcI・HATzEG・V・1899・ Contributions a 1’6tude de la Faune du Cr6tac6 sup6rieur de Roumanie． Environs de Campulung et de Sinaia．膨吻．806． g601． F勉雄， Po1診o〃．，8， M6m． 20（21？），1－20，pls． xiv， xv． RoMAN， E＆P． MAzERAN 1920． Monographie pa160ntologique de la faune du Turonien du Bassin d’Uchaux et de ses dependences・ ノ1γ㌦． M％sε¢碗5r．ヵαZ． L夕oκ，12，1－137， pls．トxi． SARAslN， C．1897． Quelques considerations sur les genres 肋少1ゴZθs， Soκηθγα，m， Dθs〃200θγα5 et 2Dzイ20sゴα．βμ〃．30ε．9201． Fプακ6σ，［3コ 25，760－799， figs． ロScHLuTE恥C・1871－76・Die Cephalopoden der oberen deutschen Kreide． Pα1α勿η彦09γψ万oα，21＆ 24・264 PP・ 55 pls・ （21， 1－24， pls・トviii，1871；25－120， P｜s． ix－xxxv，1872；24，121－264， pls． xxvi－lv，1876）． ScoTT， G．＆M． MooRE 1928． Ammonites of enormoコs size from the Texヨs Cretaceous．∫oμ夕． PαZ．，2，273－278，pls．36，37． SHARPE， D．1853－57． Description of the Fossil Remains of Mollusca found in the Chalk of England．1． Cephalopoda． Pα1αεo砺ogグ． So6．（1853－55），68 pp，27 pls．（pp．ト26， pls． i－x，1853； 27－36，pls． x仁xvi，1855；37－68， pls． xvi仁xxvii，1857；Index，1909） S田Mlzu S・1935． The UpPer Cretaceous Cephalopode of Japan， Part I．∫o〃γ． S加η9加2 S6↓．1％s∫．． ［IIコ 2，159－226． SIMIoNEscu， J．1899・Fauna Cretacica S叩eriora de la Urln63（Tramilvania）．、46α4θ励α、Ro・η⑳a， 4，239－274（1－38），pls． i－iii． SoLGER， F・1904・Die Fossnien der Mungokreide in Kamerun u． ihre geologische Bedeutung沈 Beitrage z． Geologie v． Kamerun，85－242， pls．3－5， Stuttgart． SowERBY， J・＆J・de C． SowERBY 1812－46． The Mineral Conchology of Great Britain，7vols． pls． 1－383（1812－22）by J． Sowerby；pls．38生648（1823－46）by J． de C． Sowerby， London． SpATH L．F．192L On the Upper Cretaceous Ammonoidea from Pondoland．∠飽，2． Z）μγb顕ルf〃sθ％勿， 3，39－57，pls． vトvii．

一一 1922．On the Senonian Ammonite Faurla of Pondoland．万ακs． Roy．506、 So％仇∠4／τ’6α，10， 3，113－147，pls． v－ix、 1923．AMonograph of the Ammonidea of the Gault，1， Pt．1． Pα1碗o鋤9γ．80c．（1921），1－72，

pls． i－iv．

－ 1925．Sur Quelques Ammonites du Gault nommees p3r P． REYNEs．・飽η． Mμs．万s彦．％砿， ル須αγsεi〃θ，20．97－105，pl． iv． 1940．On UpPer Cretaceous（Maestrichtian）Ammoidea from Western Australia．ノo〃．1～の1． 一一 so6． pγ、ノ1z4s〃α1ゴα，26，41－57， pls． i， i｛．

－ 1953．The UpPer Cretaceous Cephalopod Fauna of Graham Land． Fα1ゐ～ακ∂1s1α励s Dψθ％鹿η・ ciθs Sμγガ．， S6． Rθ1）．，3，60 pp．，13 pls． SroLIczKA， F．1863－65． Ammonoidea， with revision of the Nautilidae，＆c．沈BLANFoRD aコd SToLlczKA（1861－65）： The Fossil Cephalopoda of the Cretaceous Rocks of Southern Ind三a． ノ砿θ〃2．Gβ01． S〃γz）．∫カ4iα （Pα1．1％4∫（「α），216 pp．，94 p！s．

STEINMANN， G．1895． Die Cephalopoden der Quiriquina・Schichten． Nθ〃θ5∫α〃b．ル伽． Gθ01． Po》．， 」3ρ〃．．B4．10，64－94， pls． jv－vi． 118 T．Matsumoto

TIETzE E．1872． Geologische u． Palaeontologische Mitteilungen aus dem sUdlichen Theil des Banater Gebirgstockes． ノα〃b、ゐ．〃．、9ε01． R万6ゐsακs∫α～Z，ヤ防〃，22，35－142， Pls． ii－ix． WRIGHT， C．W．1952． A CIassi6cation of the Cretaceous Ammonites，∫oμγ． Pα～．，26，213－222． WRIGHT， C．W．＆E．V． WRIGHT，1951． A Survey of the Fossil Cephalopoda of the Chalk of Great Britain． Primarily a nomeaclatorial revision of Deniel SHARPE’s“Description of the Fossil Remains of Mollusca found in the Chalk of England． Part I， Cephalopoda”（1853－1857）． Pα10θo”’09γ．Soτ．（1950），40 PP． YABE・H1909． Zur Stratigraphie u． Palaontologie der oberen Kreide von Hokkaido u． Sachalin． 2rθ〃s6乃．4εμ’so乃．9ε01． G2s．，61，402－444． 1914・Ein neuer Ammonitenfund aus derτ夕igoκ辺Sandastein GrupPe von Provinz Tosa． S6i． 1～4）．7ro乃oゐ％1〃21ρ．σ％勿．，［2コ 1，5，71－74（1－4）， P1． xii（i）． YoKoYAMA， M．1890． Versteinerung aus der japanischen Kreide．．P吻εo吻9γψ〃cα，36，159－202， pls． xviii－xxv． ZIMMERMANN， E．1912． P批osiα7α〃がn． sp． und P〃205iα4θκisoμ拍καStol． in der oberen Kreide Norddeutschlands und die Lobenlinien der bisher bekannten P碗os抱・arten．ノα〃b．ん． Pγθμ∬． Gθ01．Lα％磁s．，33，1．533－556， pls．25，26． T．MATSUMOTO

Family Puzosiidae from Hokkaido and Saghalien

Explanation of Plates Plate 9

Fig・1． P協osiαs功60γ肋γicα（YABE MS．）sp． nov．＿．．．．．．＿．．＿．．．．＿．．．＿．．．．．．．．．＿．．．．．．．．．．．．＿Page 73 Lateral view（a）and whorl sections（b），×3／5． Holotype， GT．1－370， a Iittle above the Ikushumbets gorge， the Midd1e Yezo group（Lower Ammonite Bed in YABE，1927）， Ishikari Province， Hokkaido（H． YABE Coll．）．

Fig．2． 勘ε吻鹿s幼06θグαs Z）αo勧ωsεoi4θs， sp． nov．＿．．．＿．＿．．．．．．．．．．．．．．．．．．．．．．＿．．．．．．．．．＿＿＿＿．Page 101 Latera1（a）and fronta1（b）views，×4、 Holotype， GT．1－2805， Miho group of the Naibuchi Valley， South Saghalien（M． KAwADA ColL）．

Photos by C． UEKL Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 9

菖攣熟 ；潅』

狂

’鯵．・

惑㌍ぎ∴ 灘 ア 壱亨メ ・講’

禦．

1b

～’」・ごL

驚繊 レもW 肇・き一

へ式〆」、

甫中

妻 霧

鍵 羅 ‘ 絃幾，、 鑑 z 筏～ 雀 Plate 10

Fig．1． Pz420s紐κφρo％i6α， sp． nov．＿，．＿＿＿．＿．＿．．＿＿＿＿＿＿．．．．＿＿＿＿＿．＿．＿＿＿＿＿Page 77 Lateral view，×1／2． Ho1otype， GT．ト3191， locality T547p， bed Ilb， Abeshinai Valley， Teshio Province， Hokkaido（T． MATsuMoTo CoU．）．

Figs．2，3． Pμ20siα（？）o〃2bigz6α， sp． nov．＿．．＿＿＿＿．＿＿＿＿＿．．．＿＿＿＿．＿．＿．＿＿．．．．＿＿Page 78 Lateral view of inner whorls（2）and lateral view （3a）and cross・section（3b）of the incomplete outer whor1，×1／2． Holotype， GT・1－2639， locality N309d， zone Mho， Naibuchi VaUey， South Saghalien（T． MATsuMoTo Col1．）．

Photos by C． UEKI． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， VoL V， No．2 Plate 10

、

2 3a Plate ll

Fig．1． P〃20s彪％φ♪o痂60， sp． nov．．＿＿．．．．．．．．．＿．＿．．．．．．．．．．．．．、．．＿．．．．．．＿．．．．．．．．．．．．．．＿．．．．＿＿＿Page 77 Lateral view （a）， whorl・section （b） and ventral view （c）of an adult shell，×2／3． Paratype， GK． H 1221，10cality Y141， bed llk， Shiyubari Valley， lshikari Province・ Hokkaido（T． MATsuMoTo ColL）．

Photos by T． MATsuMoTo． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vo1． V， No．2 Plate 11

瞥（． ぱ ．・ ぷ・ 与穰 〆㌧’ 〜 ．〆三1 ダ．、、Wぷパ

一垣’ ／、己． 穰 づ・ 匙

ノr」7 ’ 戚 ⑱竃．‘

も「 、・、．噺 ￥豪 、 ’ 二φ ・栖 、 斎 べ ㌔⊃．▲’

オ 羅∵ 草ノ r 鶉 喝

蛋 ㍉ぷ 1娠ぽノ

W 告 Plate 12

Fig．1． Pμ20s’αs〃b60グb〃i6α（YABE MS．）sp． nov．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．一．．．．．．．．＿．．．．．＿．．．Page 73

Whorl・section，×1／2． Paratype， GT．1－671， a little above the Ikushumbets gorge， Middle Yezo group， Ishikari Province， Hokkaido（T． MATsuMoTo ColL）．

Figs．2’3． Pμ20siαoγiθκ’α1θ伽’θγ別θ∂iαKoSsMAT．＿．．．．．．．．．．．．．．．．＿．．．．．．．．．．．．．．．．．＿．．＿．．．．◆．．＿Page 76 Lateral view（2）， x 2／3；Apart of the same specimen showing suture・line（3）， x 1． An example from Japan， GK． H 1223，10cality Y137， Shiyubari Valley， Ishikari Province（T． MATsuMoTo Co1L）．

De1．＆photos by T． MATsuMoTo． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 12

泊 蚕・． 翼 当● 亀 夢

1 譲灘

蔭．yき罐 パ∨プ∠ ’パi 、 纏’

鷺∵ノ簿ぷ鞠

聯 Plate 13

Figs．1，2． Pμ205iα07花川α1θsp． nov．＿．．．＿．．．＿．．．．．．．．．．．．＿．＿．．．＿．．．．．．．．．．．．＿．．．，．．．＿．．．．＿．．．．．．．Page 74 Lateral view of a part of the outer whorl（1），×2／3；Lateral view（2a）and whorl・ section（2b）of the inner whorls of the same individual， x 2／3． Holotype， GK． H 1225， 10cality Y420c， bed IIn， Shiyubari Valley， Ishikari Province， Hokkaido（T． MATsuMoTo

Coll．），

Photos by T． MATsuMoTo．

Figs．3，4．ルZθ5ρμ20siα夕〃δαγθηs2（JIMBo）．．、＿．＿．＿．．．．．．．．．．．＿＿．．＿＿．．．＿．．．．．＿．＿＿．＿．．．＿．Page 86 3．Lateral（a）and ventral（b）views，×1． Reillustration of holotype（＝JIMBo，1894， pL i， fig．6）， immature， GT．1－97， Yubari Valley， Ishikari Province， Hokkaido（K． JIMBo

Coll．）． 4．Ventral view，×1． Middle・aged example， GT．1－366， Ikushumbets Valley， Ishikari Province， Hokkaido（H． YABE Coll．）．（See its lateral view， PL 14， fig．2．）

Photos by C． UEKI、 Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate l3

1

ぷ領㌔ 丙冴議灘預』

当 2b ・

2a

全 、、’〕ヨ且

タ

3a 3b Plate 14

Fig．1． ル彪501りzz205iα2り06φ6α， sp． nov．＿．．．．．．＿．＿．．．．．．．．．．．＿．．．．．＿＿．＿．．＿．．＿．．．．．．．．．．．．．．．＿．．．．．．＿Page 82 Lateral（a）and ventral（b）views，×2／3． Paratype， GT．1－364， pebble of the Yubari， Ishikari Province（H． YABE Coll．）．

Figs．2，3．ルrθso勿20s抱夕功〃吻sε（JIMBo）．．．．．．．．．．．．．．．．＿＿．．．．．．．．＿．．．＿．．．＿＿．．．．．．．．．．．．．．．．．．．．．．Page 86

2．Lateral view，×1． A middle aged example， GT．1－366， Ikushumbets Valley， Ishikari Province， Hokkaido（H． YABE ColL）． 3。Lateral（a）and periphera1（b）views and a whorl section（c），×1． Another middle・ aged example， GT．1－365， Upper course of the Ikushumbets River， Ishikari Province， Hokkaido（H． YABE Co1L）．

Photos by C． UEKI． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 14

⌒

噸百，．°≠、 ペ ロ 鷺 ノ 璽

覇

““

、竺・砧 、・“溺

2 Plate 15

Figs．1，2， ル〃sψ〃20s宛ヵαεφ6α， sp． nov．．＿．＿＿．．＿．＿＿．．．．．．．．．＿．．．．＿．．．．．．．．．．．．＿．．．．．．．．＿．．．．Page 82 1．Latera1（a）and ventra1（b）views，×1． Holotype， middle・aged， GH． H 1257， locality Y216P， Saku formation， Shiyubari Valley， Ishikari Province， Hokkaido（T． MATsuMoTo．

Coll．）． 2．Latera1（a）and ventral views，×2／3． Paratype， middle・aged， GH． H 1571，10cality「 104，0yubari area， Ishikari Province， Hokkaido（S． NAGAo＆A． OsANAI Coll．）．

Photos by T． MATsuMoTo． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 15

垣食、

躍

1♂鬼畠’忍．9

眠ボ鹸．． ぜ灘 濠 2b

ξ螢

1b Plate 16

Figs．1－3． ルZθsoρμ205辺♪αεφ6α， sp． nov．．．．．．，．、．．．．．＿．＿．．．．．＿＿．＿．．．．．．．．．＿．．．．．．＿．＿．．、．＿＿．Page 82 1．Laternal（a） and ventral（b）views，×1． Aform which is approaching ルf． 勿40ρααカ02in some respects． GK． H 1245， locality Y216P， Saku formation， Shiyubari Valley， Ishikari Province， Hokkaido（T． MATsuMoTo Coll．）． 2．Lヨteral（a）and ventral（b）views，×1． A relatively compressed form， middle・aged， GK。 H 1244， locality Y115P， Saku formation， Shiyubari Valley， Ishikari Province， Hok・ kaido（T． MATsuMoTo Co1L）． 3．Lateral（a）and ventral（b）views，×1． A form with the abnormal ribbing， GK． H 1256b，10cality Y216P， Saku formation， Shiyubari Valley， Ishikari Province， Hokkaido（T． MATsuMoTo ColL）．

Photos by K． KANMERA＆K． FuJII． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 16

3b

1b Plate 17

Figs．1，2． ∧rεψ％20siα」ψo痂oα（SPATH）．．＿．．．．＿．、．．．．．．．．．．＿＿＿．．．．．＿．．．．．．＿．．．．．．＿．．．．．．．，．．＿Page 91

1． Latera1（a）and vetral（b）views， x 4／5． An example of the adult shell， G K． H 5143，Iocality unrecorded in South Saghalin， purchased， S． NAGAoKA Col1． 2．Two lateral views（a， b），×1． Midd！e・aged shell of the same individua1．

Photos by T． MATsuMoTo． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 17

雀翻、

‘ 甲冬〉 ぷ’三

享、

・ ぷ・・ ←』／． 互．竃ylプ・ ダ’ 弔遍鷹， 、、、姶 、鴇鯵 垂 苓 ←～⊆～ ：エ 滝 纂∵』

・4㌧司・・

2b Plate 18

Figs． 1－4． 2V2ρρ〃20s～α元4ρo痂oα（SPATH）．＿．＿．．．．．．．．．．．＿．．．．．．．．．．．＿．＿．．．．．．．．．．．．．．＿．．．＿．．．．．．．Page 91

1．Lateral view， x 4／5． An example of the adult shel1， GK． H 5143，10cality unrecorded in South Saghalien， purchased， S． NAGAoKA Col1．（The same specimen as illustrated in P1．17 figs．1，2．） 2．Latera1（a）and frontal（b）views，×1． Immature shell， GK． H 3350， locality U600b， bed Ur2B’， Urakawa area， Hidaka Province， Hokkaido（T． MATsuMoTo Co1L）． 3．Lateral（a）and ventral（b）views， x 2／3． Adult shel1， GT．1－363， the right branch of the Sanushibe， Popets（Hobetsu）， Iburi Province， Hokkaido（H． YABE Coh．）． 4．1．ateral view，×1． GK H 3360，10cality U141p5， bed Ur1β， Urakawa area， Hidaka Province， Hokkaido（T． MATsuMoTo Coll．）．

Photos by C． UEKI（6g．3）and T． MATsuMoTo（丘gs．1，2and 4）． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 18

”〔1轍ご特

ゾ

仁’

1

3b Plate 19

Figs．1－4．1Vθo吻20s似is万輪ωαi（JIMBo）．．．．．．．＿．、＿．．．．＿．．．．．．．．．．．．．．＿＿．＿．．．＿．．．．．．．．．．．．．＿＿．Page 94 1．Lateral（a） and frontal（b）views，×1． Lectotype， immature， reillustration of JIMBo’s original specimen（＝JIMBo，1894， P1． i， fig．5）， GT．1－95， the Obirashibets， about 52 km． from its mouth， Teshio Province， Hokkaido（K． J IMBo Co1L）． 2．Two lateral views（a， b），×2／3． An example of the adult sheU， GT．1－2706，10cality N202b2， zone Mh6α・β， Naibuchi Valley， South Saghalien（T． MATsuMoTo ColL）． 3．Lateral（a）and ventral（b）views，×1． Immature， GK． H 3366， locality U512r4， bed Ur2β， Urakawa area， Hidaka Province， Hokkaido（T． MATsu MoTo ColL）． 4．Lateral view，×1． A middle・aged example， GK． H 2458， locality N22z， zone Mh6， Naibuchi VaUey， South Saghalien（T． MATsuMoTo Coll．）．

Photos（1，2）by C． UEKI and（3，4）T． MATsuMoTo． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 19

、元’・ 〆へ

1a 1b

3a 3b

．：恥 ρ馳r創b バぷ彪 議 鑓

灘嫁漫．

4 2b Plate 2①

Figs．1－4．ノゴ勿boτ6eγαsカ1α批履ぴoγ勿¢（JIMBo）．＿．．．＿．＿．、＿．．．＿．．＿＿．．．＿．．．．＿．．＿＿．＿＿・．Page 96 1、Lateral view，×2／3． Holotype， reillustration of JIMBo，s original specimen（＝JIMBo， 1894，pl． i， fig．4）， middle・aged， GT．1－94， from a nodule of the Obirashibets， Teshio Province， Hokkaido． 2．Latral view，×1． An immature example， GT．1－354a， pebble of the Iku5humbets， Ishikari Province， Hokkaido（H． YABE ColL）． 3．Lateral view（a）and whorl・sections（b， c），×2／3． An example of the adult， with its body chamber mostly destroyed away． GT，1－3221， locality T42、 Saku formatlon， Abeshinal－Saku area， Teshio Province， Hokkaido（T． MATsuMoTo ColL）． 4．A｛ragment of the body chamber，×2／3． GT．1－2951，10cality L236P， zone〕Mh20r Mh3， the Aikawa Valley， South Saghalien（T． MATsuMoTo Coll．）．

Photos by C． UEKI． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vo1． V， No．2 Plate 20

4

産 ，

ピ ∀ξ・、・

、

・ご ’

、

．言・

3c Plate 21

Figs．1－3． ノi加boi6θγos〃2偽02ηs召， sp． nov．＿．．．．．．．．．．．．＿．．．．．．．．．．＿．．．．．．．．．．＿．＿＿．．．．＿．．．．．．．、．．．．Page 98

1．Lateral view，×2／3． Holotype， adult， GT．1－－2641，10cality N131m， zone Mh5， Naibuchi Valley， South Saghalien（T． MATsuMoTo Coll．）． 2．Lateral view of fragmentary whorls（a， b），×2／3． Paratype， adult， GT．1－2642， locality N136a3， zone Mh5， Naibuchi Valley， South Saghalien（T． MATsuMoTo Coll．）． 3．Lateral view，×1． Paratype， middle・aged， GT．1－2650， locality N136， zone Mh5． Naibuchi Valley， South Saghalien（T． MATsuMoTo Co1L）．

Photos by C． UEKI． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vo1． V， No．2 Plate 21

藷

．篭畿， ．癒、

・S バ 〔 ㍉、

気

．ノ ．存

メ

’ぴ4

、ぼ 諺麹

幣 ぷム 3 Plate 22

Figs．1，2’ ノレZθsψ〃20s加4εκs元60s加ら， sp． nov．，．．．．．，．．．．．，、．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．．＿．Page．87

1．Lateral（a）and frontal（b）views， Ca×2／3． Holotype， GT．1－544， the Santan・gawa， atributary of the Naibuchi， upPer pユrt of the Miho group（zone Mh6）， South Saghalien （M．KAWADA ColL）． 2．Lateral view， Ca×2／3， Paratype， GT．1－3438， locality T311P， Wakkawembets， bed IIId or IIIe， Abeshinai area， Teshio Province， Hokkaido（T． MATsuMoTo Co11．）．

Photos by C． UEKI． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 Plate 22

攣ユ・・運鎌

、欝廿 湾・ Plate 23

Fig．1． 2Vθ01り〃20siαプψo痢εα（SP ATH）．．．．．．．．．．．．．．＿．．．．．＿＿＿．＿＿．．＿．．，＿．．．．．．＿．．＿＿．＿＿．．．Page 91 Two lateral（a， b）and fronta1（c）views，×1． An example of the adult shell， BM．C． 47735，apebble probably derived from zone Mh6， Naibuchi Valley， South Saghalien（T． MATsuMoTo Coll．）．

Fig，2．∧セ0ρμ20siαis万加ωoi（JIMBo）．．．．＿．．＿．＿＿＿＿＿＿．．．＿＿＿＿＿＿．．．＿．．．．．．＿＿＿．．Page 94． Latera1（a）and ventral（b）views， whorl section （c）and suture・1ine（d），×1． An example of the immature she11， BM．C．47736， a pebble probably derived from zone Mh6， Naibuchi Va11ey， South Saghali臼（T． MATsuMoTo Co1L）．

Fig．3． ハをρρμ20sjαaff．ブoρo功6α（SPATH）．．．．＿＿．．．．．．．．．＿．．．＿．．．．．．＿．．．．．．＿＿．．＿＿＿．．．．＿＿Page 91 Lateral view showing the last suture，×1． An example without the complete body cham・ ber， BM．C．22418， locality unrecorded， Hokkaido， probably Neourakawan from the assem・ blage of fossils（F． KRANTz’Coll．）．

Photos by J． V． BRowNs． Mem． Fac． Sci．， Kyushu Univ．， Ser． D， Vol． V， No．2 P1．23

1c

2c 鰺蓉

2d 2b 2a