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Transactions and Proceedings
of the Palaeontological Society of Japan
New Series No. 59
Palaeontological Society of japan Sept. 30th, 1965 CONTENTS
TRANSACTIONS Page 490. Carboniferous Conodonts from Yobara. Akiyoshi Limestone. japan (Studies of Asiatic Conodonts, Part II) ...... 1-1 isayoshi IGo and Toshio KOIKE 83 491. Some Fossil Anadara from Southwest japan ...... Hiroshi NooA 92 492. A Gigantic Scallop from the Sea Bottom off the Danjo Islands. Nagasaki Prefecture, japan ...... joji NAGASAWA 110 493. On a Lower Cretaceous Pelecypod ... Cvrena" naumanni. from japan ...... ltaru HAY Al\1! and !sao NAKAI 114 494. Cretaceous Echinoids from the Sanchu Graben. Central japan ...... Keisaku TAN AKA 126 PROCEEDINGS ...... 143
President : Kiyoshi AsANo Councillors: Kiyoshi ASA!\0 (Editor of "Fossils"), llaruyoshi FuJI~IOTO, Tetsuro HANAI (Editor of Transactions and Proceedings), Wataru HASIIIMOTO (Trea surer), Kotora IIATAI, lchiro HAYASAKA. Koichiro ICHIKAWA, Taro KANAYA, Teiichi KonAYASIII, Tatsuro :MATSUMOTO (Editor for Special Papers), l\lasao MINATO, Hiroshi OzAKI (Planning), Tokio SHIKAMA (Membership), Fuyuji TAKAI (Chairman of Executive Councillors' Committee), Ryuzo TORIYAMA Secretaries: Takashi HAJ\IADA. Hisayoshi IGO, Yokichi TAKAYANAGI Assistant Secretary: Takeo l<.:HIKAlVA
All Communications relating to this Journal should be addressed to the PALAEONTOLOGICAL SOCIETY OF JAPAN Geological Institute, Faculty of Science, University of Tokyo, japan Trans. Proc. Palaeont. Soc. Japan. K S., No. 59. pp. 83-91, pis. 8. 9, Sept. 20, 1965
490. CARBONIFEROUS CONODONTS FROM YOBARA. AKIYOSHI LIMESTONE. JAPAN (STUDIES OF ASIATIC CONODONTS. PART II)*
HISAYOSHI IGO and TOSHIO KOIKE
Institute of Geology and Mineralogy, Tokyo University- of Education
~~~~w~-~~~~~~~: •m•-~~~L~~@m~•b~~~~~uw~~ :rif$5~ ~ J F"' 1- ~~-"'. -t~llil'fi;:~~~H.. t..:, ~A':Z~I(:f'l*~ ~n~:9l;i(:f.fH!r lA..:'Wif#:tJJ;l(¥i ,i!lQ) i ~ l: mtrJ.i" 7.>iJ:. .t I)"":/:/ Jl.o<.::. -\"*Q)~*n: iW <. Chesterian .!: Q)mktJ
Introduction and Acknowledgements Iv1asamichi OT A of the Akiyoshidai Sci ence Museum for his valuable suggestion The Akiyoshi Limestone is the classi· in the field. \Ve also thank Mr. Tada· cal field of the Upper Paleozoic strati· hiko OGAWA for his help to our labora graphy and paleontology in Japan and tory work. A part of the expenses of has been repeatedly studied by many the field survey \vas defrayed from the workers. Recently YANAGIDA (l962i has Scientific Research Fund, :\1inistry of reported an interesting brachiopod fauna Education. japanese Government. from the Uzura quarry, Yobara. The stratigraphic position of this quarry is thought to be lower part of the Akiyoshi Conodont Fauna and its Geologic Age Limestone Group and to be equivalent The material was collected from the to the Millerella sp. a Zone (TORIY AMA, abandoned quarry named Uzura at Yo· 1958). Also YA:VIAGIWA and OTA (1963) bar a, Ofuku, Yamaguchi Prefecture, south· have described several corals from the western Japan (Text-fig. 1). Limestone same locality. V{e have succeeded to cropped out in this quarry is highly separate well-preserved rich conodonts fossiliferous, pale gray and massive to from the limestone collected from the bedded. It abundantly yields brachia· mentioned fossil locality. This paper is pods. corals. smaller foraminifera and dealt with these conodonts and discussion many other fossils. We have found the of their geologic age. following conodonts, namely :-Hindea· Acknowledgements are due to tvir. della sakagamii IGO and KOIKE. Synprio· niodina sp .. Ligonodina hanaii lGO and * Received Jan. 5, 1965: read April 5, 1964. KOIKE, Lonchodus sp .. Lonchodina aki· at Urawa. yoshiensis IGO and KOIKE, n. sp.. Lon· 83 84 Hisayoshi !Go and Toshio KOIKE
common species in both faunas. Gnatlzo dus opimus and Gnathodus commutatus nagatoensis are very abundant and char acteristic species in the Akiyoshi fauna, but they are rare in the Omi. Lonchodus sp., J.onchodina ? sp. A, Lonchodina sp., Lonchodina akiyoshiensis and Spatho gnathodus minutus are not so common in this fauna, but they have never been found in the Omi fauna. The genera Streptognathodzts and Idiognathodus are characteristic in the Omi fauna, parti cularly the former, but both genera have never been obtained from the Akiyoshi fauna. The species of Hindeodella and Synprioniodina are rather common in the Omi fauna, but they are rare in Akiyoshi. The geologic age of the representing fauna is an important problem. YANA GIDA (op. cit.) described many brachio pods from the same locality, although the brachiopod-bearing horizon is slightly below the conodont rich horizon. Accord ing to his extensive paleontological work, these brachiopods are similar to those of European and Asian upper Lower Carbon iferous (Visean), such as, Phricodothvris insolita GEROGE, Brachythyris a/ziyoshi Text-lig. 1. Maps showing the locality. ensis YANAGIDA, Spirifer aff. liangehow ensis CHAO, Spirijer sp., Cleiothyridina chodina ? sp. A, Lonchodina sp., Hinde expansa (PHILLIPS), Cleiothyhdina royssii odus imperjectus (REXROAD). Ozarkodina (L'EVEILE), .-l.ctinoconchus planosulcata orientale lGO and KOIKE, Spathognathodus (PHILLIPS), Composita aff. argentea (SHE minutus (ELLrso~). Gnathodus opimus PARD), Dielasma cfr. kingi DE KONINCK, [GO and KOIKE, Gnathodus commutatus Dielasma sp., Yanishewskiella japonica tBRA~SON and MEIIL) nagatoensis [GO YANAGIDA, Pugnax aff. sulcatus (Sow and KOIKE, n. subsp., and other frag ERBY) and Schizophoria aff. resupinata mentary indeterminable genera. (MARTIN). This conodont fauna is very similar YA:I\IAGIWA and OTA (1964) described to the Omi conodont fauna which was the following corals, namely :-Siylido described by !GO and KOIKE (1964) but Phyllum ozawae Y Al\IAGIWA and OTA, as will be discussed below there can be Clisiophyllum awa (1\hNATO), Clisiophyl recognized some differences between both lum sp., Lonsdaleoides toriyamai MINATO faunas. Hindeodella sakagamii, Loncho and Lophophyllidium uzurensis Y AMA dina hanaii and Ozarkodina orientale are GIWA and 0TA. Although they did not 4.90. Ca;·bo·nife·rous Conodont.~ from Akiyoshi
"discuss the geologic age of the coral of G. commutatus described from the fauna, it has close similarities to those lVIississippian ancl Namurian in North from the lower part of the !\•Iiddle Car America and Europe. boniferous (the Millerella to Profusuli As mentioned above the present fauna nella Zones) in southwestern japan. is consisting of both Upper Mississipian As already discussed by the writers, (Chesterian) and Pennsylvanian species the Omi conodont fauna \vas thought to or allied ones. On the other hand. be Early Pennsylvanian or Late Namurian entire lacking of Slreptognalhodus and in age, and not younger than l\Iiddle Jdiog11athodus is never overlooked to Pennsylvanian. The Omi conodont fauna consider the geologic age of this fauna. are lacking the typical Mississippian The mentioned genera are very charac genera and species. The Akiyoshi fauna teristic and prominent in the Omi Lime is also avoided the characteristic iVlissis stone. From these faunal characters we sippian conodont genera. but some of became to conclude that the Akiyoshi the species are related to the highest conodont fauna is slightly older than the Mississippian (Chesterian) species of Omi fauna and considered to be the North America. Hindeodus imPerfectus earliest Pennsylvanian or latest Missis is not so many in this fauna but it has sippian in age. There is. however. been repeatedly described from the stronger possibility of the earliest Penn Chesterian of the upper l\lississippi sylvanian age of this fauna rather than Valley region. According to COLLI.SS01\, of the Mississippian. ScoTT and REXROAD (1962) this species ranges up to the top of the Kinkaid Limestone. Spathognathodus minutus is Description of Species a long ranging species in the Pennsyl vanian (ELLISON, 19·11. SnmGEN and Genus llindeodella BASSLER, 1925 YouNGQUIST, 1949 etc.). Ozarkodina Hindeodella sakagamii leo and KOIKE orientale is similar to the Chesterian species of 0. compressa REXIWAD. Lo11· Pl. 8, figs. 1. 2 chodina akiyoshiensis resembles L. jur Hindeodella sakagamii !Go and KoiKE, 1961. nishi REXROAD \Vhich was described Pal. Soc. japan, Trails. Proc., 11. s., no. 53, from the Glen Dean Formation of the p. 18<1. pI. 27. figs. 1, 2. type Chesterian in the upper Mississippi Valley region. Gnathodus opimus is Comparison :-All specimens at hand related to G. roundyi \vhich has been are quite identical to the Omi specimens known from the various localities of and we could not find any remarkable the Desmoinesian in North America. It difference. Further description seems to also has some similarities to Gnathodus be unnecessary. girtyi which was described from the Reg. nos. 23090. 23091. Mississippian Barnet Formation in Texas (HAss. 1953). The Mississippian species Genus Synprioniodina ULRICH of Gnathodus texanus ROUNDY and the and BASSLER, 1926 cosmopolitan species of G. mosquensis PANDER are also allied species to our Synprioniodina sp. specimens. Gnathodus commutatus naga .toensis resembles the several subspecies Pl. 8. fig. 9 86 Hisayosll'i !GO and Toshio KoiKE
Two bars meet forming an angle of scribed from the Early Pennsylvanian. about 40 degrees in common plane. shale, Knoxville. Iowa. Posterior bar thin, laterally compressed, Reg. no. 23093. rather high and having sharply edged aboral side. Denticles subequal in size Genus Lonchodus PANI>EI<, 1856 throughout, sharply pointed, almost erect or slightly angled anteriorly. fused at Lonclwdus sp. base and deeply penetrated into bar. Anticusp short, having coalesced and PI 8. fig. 11 anteriorly inclined denticles. 1\lain cusp Imperfect bar straight, laterally com thin, sharply pointed. directed anteriorly. pressed, slightly curved inward and Aboral side of bar distinctly grooved. having very thin posterior end. Aboral Pulp cavity beneath main cusp deep, side distinctly grooved. Denticles long .. conical and with moderately elevated discrete, laterally compressed, almost flare. erect or slightly directed posteriorly,. Comparisou :-This indeterminable spe having sharp edges antcro-posteriorly cies resembles Synprioniodina microdenta and sharply pointed tip. ELLISON, but the former has higher pos Comparison :-.Many similar fragmen terior bar and subequal posterior denti tary bars have been described and illu cles. Synprioniodina collinsoni IGO and strated from the various Lower Pennsyl KOIKE is also allied species, but the vanian and Upper Mississippian rocks. denticles of the posterior bar and anti Lonc/wdus ? sp. came from Knoxville,. cusp are dissimilar in shape. The Iowa (YouNGQUIST and IIEEZEt\, 19,18) American Chesterian species of Syn and ELLISON's (1941) indeterminable prioniodina denticamura REXROAD and specimen (Pl. 20, fig. 28) are similar to LIEBE is very similar to our S. sp .. but our specimens. owing to the incomplete Akiyoshi mate Reg. no. 23094. rial detailed comparison is diflicult. Reg. no. 23092. Genus Lonchodina BASSLER, 1925
Genus Ligonodina BASSLER, 1925 Lonchodina ? sp. A
Ligonodina lwnaii lGO and KOIKE PI 8. fig. 15 Pl. 8. fig. 13 Cnit consisting of two bars forming about right angle. Anterior bar rather Ligonodina harwii !GO and KoiKE, 1964. Pal. long, thin, and \vith five denticles. An Soc. }af>arr. Trans. Proc., 11. s.. no. 53, p. 186, pl. 28. figs. 21, 22. terior dent ides discrete, sharply pointed, rounded in cross section, almost erect or Comparison:-The Akiyoshi specimens curved posteriorly and inward. .lvlain are quite identical to the Omi specimens cusp not so large, circular in transverse and no further description is necessary. section. Posterior denticles large, slight As already pointed out by IGO and KOIKE ly curved posteriorly, flattened and with this species resembles Ligonodina typa sharp edges antcro·posteriorly. Number (GU:\1\ELL). It also resembles Ugonodina of posterior denticles may be one or two. abbrelliala YOUNGQUIST and I IEEZEl' de· Pulp cavity large, located beneath main 490. Cw;·boniferoHs Conodonts from AJciyoshi 87
·cusp. conical and rather shan·ow, sur cusp than our form. rounded by slightly expanded flare. Reg. nos. 23096 (holotype), 23097-23099. Aboral side of bar distinctly grooved. Comparison :-Lonchodina ? sp. A is Genus Hindeodus REXROAD :similar to Lonchodina ? nipponica !GO and FURNISH, 1964 .and KOIKE described from the Omi Limestone, but the present indetermina Hindeodus imperfectus (REXROAD) ble species has different main cusp and Pl. 8. figs. 3-5, 7 posterior denticles. It also closely re sembles Lonchodina ? panderosa ELLISO.'i, Trichonode/la imperfeclcz REXROAD, 1957, 11- but our specimens have different shape /inois Geo/. Sun•. Rep. inv .. 199, p. -H. ·of the denticles. This species seems to pl. 4. figs. 4, 5: REXROAD, 1958, Ibid., be new to science but denomination is 209. p. 26, pl. 4. fig. 6. reserved until more numerous materials Elsonel/a ? imperfecla REXROAD and COLLJ;>; so~. 1961, Illi11ois Geol. Sun:., Circ., 319 . .are accumulated. p. 6: REXROAD and BUR TO:-.:, 1961. jour. Reg. no. 23095. Pal., vol. 35. p. 1152. pl. 141. fig. 1. lli11deodus imperfectus REXROAD and FuR Lonchodina a!?tyoshiensis IGO :"ISil, 1964. Ibid., vol. 38, p. 672. pl. 111. and KOIKE, n. sp. figs. 13, 14.
Pl. 8, figs. 8, 10. 12, 14 Lateral bars in one plane or very slightly twisted, thin and blade-like, Bar thin, blade-like, consisting of an meet at approximately 120 degrees terior and posterior bars meeting at an beneath main cusp. Aboral side of bars angle of 120 degrees. Anterior bar long slightly concave downward, sharply and rather high and with sharp anterior edged and not grooved. Denticles in ·end. Anterior denticles six to seven in both bars eight to nine in number and number, laterally compressed, somewhat more or less variable in size and number, ·curved posteriorly and most of them and generally smaller adjacent to main ·equal in size, with sharp edges fore and cusp and distal end. circular in cross aft and coalesced at base. Main cusp section and sharply pointed. whose an parallel to anterior denticles and having terior surface flat and posterior surface ·elevated median ridge continuing to ex convex posteriorly. Pulp cavity small, panded triangular flare. Posterior bar conical and shallow with faint elevation shorter than anterior bar. Posterior of flare on posterior side of main cusp ·denticles variable in size and shape, but depressed on opposite side. three or four in number. thin, sharply Comparison:-The Akiyoshi specimens pointed and almost erect to base of bar. are quite similar to the American Ches· Pulp bavity large and sharrow. Aboral terian specimens and no remarkable dif· side of bars with deep groove extended ference can be recognized. from pulp cavity. Reg. nos. 23100-23103. Comparison :-Lonchodina akiyoshiensis resembles Lonchodina furnishi REXROAD Genus Ozarkodina BRAJ\SON ·described from the Glen Dean Formation and :\IEHL, 1933 (Chesterian) of Illinois and others. but the American species has larger main Ozarkodina orientale leo and KOIKE 88 Hisa.yos/l'i ]GO and Tu:;hio KOIKR
Pl. 9. figs. 14. 15 Spathognathodus minulus ELLISO:>: and GRA· VES, 1g,11. Missouri Univ. Sch. Mines, Ozarkodina orientale leo and KOIKE. 1964. Metal/ .. Bull .. Tech. Ser .. vol. 14. no. 3. Pal. Soc. ]apa11. Trails. Proc .. 11. s .. no. 53. p. 3-4, pl. 2. figs. I, 3, 5: YouNt;QutsT p. 187. pl. 27. figs. 21-23. and Dow;-.;s, HJ49, four. Pal .. vol. 23. p. Comparison :-The Akiyoshi material ]69-170. pl. 30, fig. 4: STURGEON and YouNGQl:rsT. 1919. Ibid .. vol. 23, p. 385, is similar to the Omi specimens which pl. 74, figs. 9-ll : pl. 75. fig. 19. \vere illustrated in Text-fig. 3 on plate 2 (lGO and KOIKE, 1964). but it differs Blade short. thin. laterally straight and from the latter in weaker elevation of with arched aboral side and sharply flaring lip and larger main cusp. The edged anterior and posterior ends. Dcnti· mentioned biocharacter is closely related des coalesced. laterally compressed. with to Ozarkodina compressa REXROAD de sharply pointed tips, variable in size scribed from the Kinkaid Limestone. and shape, and become smaller toward uppermost Chesterian in Illinois. both anterior and posterior ends. Pos l~eg. nos. 23105, 23106. terior denticles chevron-like. nine to ten in number. Anterior denticles three in Genus Spathognathodus BRA!\SON number. small in size. 1\hin cusp large, and MEIIL. 1941 erect to slightly directed anteriorly. Pulp cavity near posterior end of blade, Spathognathodus minutus (ELLISON) large. expanded with the deepest point at slightly posterior of main cusp. Pl. 9, ligs. 16-18 Aboral side of anterior part of blade Spalhodus minutus Er.t.rso:-~. 1941. jour. Pal .. grooved. vol. 15. p. 120. pl. 20. figs. 50-52. Comparison :-Our specimens are iden·
------
Explanation of Plate 8
(All figures x 75 except for fig. 6)
Figs. l. 2. Jlindeodella sakagamii lGo and KoJKE 1. inner lateral view; 2. outer lateral view. Fig:;. 3-5, 7. Hindeodus imperjectus (REXROAD) 3, 4. outer lateral views; 5. inner lateral view; 7. outer lateral view. Fig. 6. Lonchodina sp. 6. inner lateral view. x 37. Figs. 8. 10. 12, 14. Lonchodina akiyoshiensis leo and KoiKE. n. sp. 8, 10. outer lateral Yiews: 12, inner lateral view: 14. inner lateral dew of the hololype. Fig. 9. Synprioniodina sp. inner lateral view. Fig. 11. Lonchod11s sp. outer lateral view. Fig. 13. Ligonodina hanaii leo and KotKE inner lateral view. Fig. 15. Lonchodina ? sp. A outer lateral view. leo and KOI KE: Carboniferous Conodonts from Akiyoshi Plate 8 490. Cm·boniferous Conodonts from Aki11oshi 89 tical to the ELLISON's specimens and Height of cup gradually decrease pos also to other American specimens. Com teriorly. Oral surface of cup smooth in pared with the ELI.Jso:-;'s holotype, the some specimens or ornamented by two Japanese specimens have slightly fewer low nodes adjacent to carina anteriorly number of the posterior denticles. in other specimens. Blade thin. laterally Reg. nos. 23107-23109. compressed, slightly longer than carina. Denticles of blade fused. increase in size Genus Gnathodus PANDER. 1856 to ncar anterior end. Each denticles has sharp-edged tip. Aboral side of blade Gnathodus opimus lGO and KOIKE sharply edged with fine groove merged into expanded pulp cavity. Apex of Pl. 9. figs. 1-8 pulp cavity located at same point of Gnathodus O/Jimus !Go and KotKE. 1964. Pal. widest part of cup. Soc. japan, Trans. Proc .. 11. s .. no. 53. p. Comparison :-This new subspecies of 189. pl. 28. figs. 15-18. Gnathodus commutatus differs from other subspecies of commutatus in the lateral Comparison:-The Akiyoshi specimens view of the cup. Summit line of Gna· slightly differ from the holotype of Omi. lhodus commutatus (s.l.) in l:ltcral view Species of Gnathodus arc very variable is usually straight or substraight, but our in the ornamentation and shape of cup. Some of the Akiyoshi specimens have subspecies has arched summit line and three parallel node-like ridges including shows narrow node-like carina on cup. carina continued from blade. The de Reg. nos. 23120 (holotype) 23118. 23ll9. velopment of these ridges along carina are very variable as illustrated in the References Cited plate. Therefore we treated these bio characters as an intraspeci fie variability. BAKER. R. C. (1942) : The age and fossils Gnathodus girtyi HAss has three parallel of the Olentang~· Shale of central Ohio. ilmer. jour. Sci .. v. 240. no. 2, p. 137-143. ridges but our species is lacking trans pis. 1-3. versely developed nodes. Gnathodus BRA<"so;-.;, E. B. and MEHL. M.G. (1941) : roundyi GUN:'\ELL is also similar to our New and litlle known Carboniferous species. conodont genera. jour. Pal .. v. 15. no. 2, Reg. nos. 23110-23117. p. 97-106. pl. 19. Cot.t.INSON. C., ScoTT. A. and REXROAD. Gnathodus commutatus (BRA~SON and C. B. (1962) : Six charts showing bio startigraphic zones and correlations 1VIEHL) nagatoensis lGO and based on conodonts from the Deveonian KOIKE, n. subsp. and Mississippian rocks of the upper Mississippi valley. Illinois Ceo/. Sun• .. Pl. 9, figs. 9-13 Circ .. 328. p. 1-32. Axis straight to slightly curved in Coop~:R. C. L. (1935): Conodonts from the upper and middle Arkansas no\·aculite, ward. Denticles of carina fused, node Mississippian, at Caddo Gap. Arkansas. like with obtuse tip or subtriangular Jour. Pal .. v. 9, no. 4. p. 307-315. pl. 27. shape in lateral view. Cup widest in Et.Ltso:>:. S. (1941): Revision of Pennsrl almost middle, asymmetrical its and vanian conodonts. Ibid .. \'. 15. no. 2. p. outerside slightly wider than inner side. 107-143. pis. 20-23. '90 Hisayoshi leo and To8hio KOIKE
and GrlAVES, R. W. (1941): Lower Niigata Prefecture. Central ].1pan Pennsylvanian (Dimple Limestone) cono (Studies of Asiatic conodonts, part 1). donts of the Marathon region, Texas. Trans. Proc. Pal. Soc. japan, 11. s .. no. 53, Univ. Missouri Sc/1., Min., and Met. Bull., p. 179-193, pis. 27, 28. Tech. Ser., v. 14. no. 3, p. 1-13, pis. 1-3. REXROAD, C. B. (1957) : Conodonts from the FAY, R. 0. (1952): Catalogue of conodonts. Chester Series in the type area of Kansas Univ. Pal. Contr., art 3, p. 1-206. southwestern Illinois. Illinois Geol. figs. 1-109. Surv. Rept. lnv .• 199, p. 1-43, pis. 1-·1. GuN:-;EL. F. II. (1931): Conodonts from the -- (1958) : Conodonts from the Glen Dean Fort Scott Limestone of Missouri. jour. Formation (Chester) of the Illinois Basin. Pal .. v. 5, no. 3. p. 2-14-252. pl. 29. Ibid .. 209, p. 1-27. pis. 1-6. -- (1933) : Conodonls and fish remains -- and Bt.:RTo:-:. R. C. (1961) : Conodonts from the Cherokee. Kansas City, and from the Kinkaid Formation (Chester) \Vabaunsee groups of Missouri and in Illinois. jour. Pal.. v. 35, no. 6, p. Kansas. Ibid .. v. 7. no. 3, p. 261-297. pis. 1143-1158. pis. 138-141. 31-33. -- and CLARK, C. E. (1960): Conodonts HArwrs. R. W. and Hol.l.ll'>GS\\'ORTII, R. V. from the Glen Dean Formation of Ken (1933) : New Pennsylvanian conodonts tucky and equivalent formations of Vir from Oklahoma. Amer. jour. Sci .. v. 25. ginia and West Virginia. Ibid., v. 34, p. no. 147, p. 193-20·1. pl. 1.. 1201-1206. !lAss. W. II. (1953): Conodonts of the Barnett -- and CoLLINsoN, C. W. (1961) : Prelimi Formation of Texas. U.S. Ceo/. Surv .. nary range chart of conodonts from the Prof. Paper. 243-F. p. 69-94, pis. 1-1-16. Chester Series (Mississippian) in the -- (1959) : Conodonts from the Chappel Illinois Basin. llli11ois Ceo/. Sur11. Circ., Limestone of Texas. Ibid., 29'1-J, p. 365- 319. p. 1-ll. pl. 1. 399, pis. ·16-50. -- and -- (1963) : Conodonts from the --. RuoDES. F. H. T. and MOLLER, K. J. St Louis Formation (Valmeyeran) of (1962) : Conodonts in Moore's Treatise Illinois, Indiana and Missouri. Ibid .. 355, on Invertebrate Paleontology. Pt. W, p. p. 1-28. pis. 1-2. Wl-W97: W216-W259. -- and Ftm~1s11, W. M. (196·1): Conodonts IliGGI:":S. A. C. (1961) : Some Namurian from the Pella Formation (Mississippian). conodonts from North Staffordshire. south-central Iowa. jour. Pal .• v. 38, no. Geol. Mag., v. 98, p. 210-224, pis. 10-12. 4, p. 667-676, pl. 111. !Go. H. and KOIKE. T. (1964) : Carbonifer -- and ]ARRELL. M. K. (1961) : Correlation ous conodonts from the Omi Limestone, by conodonts of Golconda Group (Ches-
Explanation of Plate 9
(All figures x 75)
Figs. 1-8. G11athodus opimus IGO and KoiKE 1-8, oral views. Figs. 9-13. Gnathodus commutatus (BRA;.!SON and MEIIL) 1zagatoe11sis lGo and KotKE, n. subsp. Figs. J.l. 15. Ozarkodi11a orie11ta/e leo and KOIKE 14. outer lateral view; 15, inner lateral view. Figs. 16-18. Spathognathodus minutus (ELLISON) 16-18. outer lateral views. l eo and KOIKE: Carboniferous Conodonts from Akiyoshi Plate 9
2 3
4 5
7
9
12
15 4uo. Ccu·bonife·rons Conodonts fnnn A.kiyoshi Hl
terian) in Illinois Basin. Amer. Assoc. v. 7, p. 1-264, pis. 1-·18. Pctr. Ceo[ .. Bull., v. •15, p. 2012-203-1. YA:>.tAGIWA, X. and 0TA, l\1. (1963): Faunas --- and LIEBE, R. M. (1962) : Conodonts and correlations of" Uzura" quarry, Aki· from the Paoli and equivalent formations yoshi, southwest Japan. Part 1. Akiyoshi in the Illinois Basin. Micropaleontology, dai Sci. Mus., Bull., no. 2. p. 87-93, pls. v. 8. p. 509-5H. 1-2. RHODES. F. H. T. (1963) : Conodonts from YA:-;AGILJA, ]. (1962) : Carboniferous Brachi the topmost Tensleep sandstone of the opods from Akiyoshi, southwest Japan, eastern Big Horn Mountains, Wyoming. Part 1. Kyushu U11iv., Fac. Sci., Mem., jour. Pal .. v. 37, p. 401-408. ser. D. v. 12, p. 87-127, pls. 14-21. ScoTT. II. W. (19,12): Conodonts assemblages You:w;QulsT, W. L. and DowNs. R. H. (19·19) : from the Heath Formation. Montana. Additional conodonts from the PennsyJ. Ibid .. v. 16. p. 293-301, pis. 37-40. vanian of lowa. jour. Pal .. v. 23. p. 161- STA:--:I.EY. E. A. (1958): Some Mississippian 171, pis. 30-31. conodonts from the High Resistivity Shale -- and HEEZE~. B. C. (1948) : Some Penn of the Nancy \Vas ton no. 1 well in north· sylvanian conodonts from Iowa. Ibid .. v. eastern .Mississippi. Ibid .. v. 32. p. 459- 22. p. 767-773, pl. 118. ,176. pis. 63-68. -- and M11.1.ER, A. K. (19,19) : Conodonts STAUFFER, C. and PLu~l~tER, H.]. (1932): from the Late Mississippian Pella beds Texas Pennsylvanian conodonts and their of south-central Iowa. Ibid., \'. 23. p. 617- stratigraphic relations. Univ. Texas Bull., 622, pl. 101. 3201. p. 13-50. pis. 1-4. --, -- and Dow1'is, R H. (1950): Burling STl1RGEO:'>l, M. T. and YoUNGQUt:>T. W. (19•19): ton conodonts from Iowa. Ibid .. v. 2·1. p. Allegheny conodonts from eastern Ohio. 525-530. pl. 67. jour. Pal .. v. 23, p. 380-386. pis. 7•1-75. --and PATTERSO~. S.ll. (1949): Conodonts THmiPSO:"'. T. L. and GoEBEL, E. D. (1963) : from the Lower Mississippian Prospect Preliminary report on conodonts of the Hill sandstone of Iowa. Ibid., v. 23. p. Meramecian Stage (Upper Mississippian) 57-73. pls. 15-17. from the subsurface of western Kansas. VoGEs, A. (1959) : Conodonten aus dem Kansas Ceo/. Surv. Bull .. 165, p. 1-16. Unterkarbon I und II (Gattendortia- und ToinYA:-tA, R. (1958): Geology of Akiyoshi. Pericyclus-Stufe) des Sauerlandes. Pal. Part III. Fusulinids of Akiyoshi. Kyu Zeitschr., Bd. 33, no. 4. p. 266-314, Tafs. sltu Univ., Fac. Sci .. Mem .. Ser. D. Ceo/., 33-35.
Yobara 7I Ofuku }~ Trans. Proc. Palaeonl. Soc. Japan. N. S .. 1\o. 59. pp. 92-109. pis. lO.ll. Sepl. 30. 1965
491. SOME FOSSIL ANAIJARA FROM SOUTHWEST JAPAN*
HIROSHI NODA
Institute of Geology and Paleontology, Faculty of Science. Tohoku University, Sendai, japan
l!§'iWB;4·:d)it.:W.f!l! Anadara 1(."?~·-c: Anadara takaoensis. Anadara tricenicosla. A11adara suzukii -a-1!;->'>-c Anadara suzukii group l: L,.:t~·VctLd)~\:lqll0:711ii'U::q)~~;J ~L,JH:o::> group r::f•n 7 Ni~;lef(L,f.::o 7 f;i!d) 5 ~... ~i!Etli I. ~if!J!3 a-13tr. 'If EE t'& l"l
Introduction ments on their characters. Ilowever. since some problems concerning them The younger Neogene deposits of japan seem to exist, the writer made an attempt are characterized by two marine faunas: to interpret the stratigraphic ranges the Oyashio type or Onma-Manganzi of those species and to correlate the Fauna of OTUKA (1936) and the Kuro Anadara (Scapharca) suzukii group with shio-type or Kakegawa Fauna of MAKI· other related species which are associat YAMA (1927). These two types of fauna ed with above group of Arcids from are also w·en shown in the species or the Formosa, Okinawa and japan. Based Genus Anadara. The Anadara (Scaph upon the abundant specimens of the arca) suzukii group is restricted to and group now stored in the Institute of Ge is characteristic of the latter type of ology and Paleontology. Tohoku Univer fauna whereas the Anadara (Anadara) sit v, Sendai from the various localities amicula and Anadara (ilnadara) talllllO· di;tributed in Formosa, Okinawa Island kutiensis group are significant to the and japan, the present study was under former type of fauna. The present arti taken. This article is the outgrowth of cle treats the Jlnadara (Scapharca) su part of the study on the japanese Arci zukii group. dae, fossil and Recent. The other group In 1926, YOKOY A~fA (1926a. p. 368) de or groups of Anadara will be reserved scribed Area suzukii from the Tonohama for another opportunity. Formation in Kochi Prefecture and in 1928 YoKOY A~! A (1928, p. 103) recorded and illustrated Area philippiana from the Acknowledgement upper part of the Byoritsu Formation in The writer takes this opportunity to Formosa. express his deep gratitude to Professor Recently. those two species of YoKO Kotora HATAI of the Institute of Geolo YAMA were included into the synonymy gy and Paleontology. Tohoku University of Anadara (Scaplwrca) tricenicosla by who first introduced him to the study of MAKIY AMA {1958, pl. 54) without com- this interesting group of marine pele * Received Jan. 2·1. 1965: read jan. 2•1. 1965 cypods, for his untiring and sincere en at the annual meeting of the society. at Tokyo. couragement throughout the course of
92 491. .4. nctda,ra .(TMn Southwest Japan 93 this study. Deep appreciation is due to dara (Scapharca\ tricenicosta occurred Dr. Shozo HAYASAKA of the same insti abundantly from the Tokazan Formation tute for his contiguous guidance and dis in Formosa and Naganuma Formation in cussions on the chronology of the Pacific Kanagawa Prefecture. As living, this side of japan based upon the molluscan species is distributed in the southwestern fossils. Acknowledgements are due to Dr. Sea of Japan, around the Ryukyu Islands. Koichiro MASUDA of the Department of Formosa. the Chinese Sea and in the Geology, Faculty of Education, Tohoku Indo-Pacific Ocean. University, for his kind suggestions. Mr. Anadara (Scapharca) suzukii is known Tunyow HUANG of the Chinese Petroleum to occur from the Takanabe Formation Corporation, Formosa for his kind infor in !\·tiyazaki Prefecture. Ananai Forma mation concerning the biostratigraphy tion in Kochi Prefecture. Dainichi For and details of the fossil localities of mation in Shizuoka Prefecture and from Arcids in Formosa, l\ir. Hiroo NATORJ of the Nakoshi Sandstone in Okinawa Island. Geology and Paleontology, Tohoku Uni Anadara (Scap/wrca) takaoensis is origi versity for his kind offer of the speci nally from the Kaizan Bed in Formosa mens which he collected from the Miya and is also recorded from the 1\akoshi zaki Basin, 1vlr. Yasuhide Iw ASAKJ of Sandstone in Okinawa Island. the Institute of Geology, Tokyo Univer The Tokazan Formation in the north· sity for his kind discussions on the ern part of Formosa is underlain with stratigraphy and taxonomy of the Genus the Takuran Formation which yielded Anadara in japan and to Dr. Tamotsu Pecten (Notovola)javanus MARTIN. Pecten MATSU:'\AGA, Chief of the Ariake Fish (Notovola) 11aganumanus YOKOY A?.! A, Con ery Research Laboratory, Yanagawa City. clwcele nipponica (Y ABE and NoMURA) Fukuoka Prefecture for his kind donation and consists mainly of sandstone and of Arcid specimens displaying a growth conglomerate. It is distinguished into the series from the Ariake Sea. Kozan and Kaenzan facies according to the prevalence of sandstone or conglom erate. The Kozan facies is chiefly of Remarks on the Anadara (Scaplwrca) loose silty sandstone with intercalated suzukii group clayey sbale, conglomerate, pyrite nodules. carbonized drift woods. ree~ limestones The Anadara (ScajJ/wrca) suzukii group and has yielded mammals. mollusks, echi in this article includes Anadara (Scaph noids and foraminifers. Most of the arca) tricenicosta (=Scapharca philippi species of the molluscan fossils from the ana) and Anadara (Scapharca) suzukii Kozan facies have been described by both of which were reported by YOKO YOKOYAMA (1928) and NOMURA (1933) YAMA (1926a. 1928) from the Tonohama as representing the Byoritsu Bed. Among Formation in Kochi Prefecture and Ana them. some interesting Arcids such as dara (Scapharca) takaoensis of Y ABE and Anadara (Scapharca) tricenicosta, Ana HATAI (1942) from the Nakoshi Sandstone clara (Tosarca) sedanensis, Tricidos lliyo of Okinawa Island, a stratigraphic unit noi, Hawaiarca uwaensis and Striarca defined by MAcNEIL (1960). These three interplicata (=Striarca yokoyamai) are species resemble one another very close· known from this facies. Recently, SHUTO ly morphologically and are thus consider (1961) from the results of his palaeonto ed to be related with each other. Ana- logical studies of the Miyazaki Group in Hiroshi NOD.-1
Kyushu. southwestern Japan, correlated NOMURA (1933), NO:I.IURA (1937). S!IUTO the Byoritsu Bed (=Kozan facies of (1961) and Tsuc111 (1961), but on the ·CHAKG. 1958) to his Amussiopecten prae other hand most of the fossil mammals signis-Granulifusus dualis Zonule (=his indicate the Pleistocene age, and it is 4th to 6th horizon of the Miyazaki Group) interesting that they are from the upper based upon the characteristic molluscan part of the Tokazan Formation. In 1958, fossils. CHANG summarized the stratigraphy of Furthermore, SHUTO (1961) extended Formosa and he stated that the Tokazan his study on the molluscan fossils to Formation can be divided into two facies .correlate the formations of Pliocene age of the Kozan and Kaenzan based on the distributed along the Pacific borderland characteristic lithology and he pointed -of southwestern japan listing the species out that the former facies occupies a in common from the isolated area as position somewhat lower than of the Indonesia, Formosa, Okinawa . .Miyazaki, latter stratigraphically. He also stated Kochi, Kakegawa and the Kwanto that the former is superposed \Vith dis regions. continuity or merges into the facies of In 1961. TsucHI from his studies on the upper part of the Kaenzan. l'vlore the fossil molluscs independently arrived over, CHANG considered that the lower to the same conclusion as SHUTO. The Tokazan Formation may be Pliocene results of their works have been accept whereas the upper is Pleistocene based ed in general by many paleontologist in upon the paleontological evidence. This Japan. view was previously held by OTUKA in Considering the mammal fossils. Ste 1935 even though he did not express a godun sinensis, Stegodon orienlalis. f'ar strong opinion at that time. This pro elephas trogontherii, Elephas sp .. Rhinco blem on the boundary between the Plio ceros sp., Cenms (Sika) taiouanus. Cervus cene and Pleistocene is reserved for an (Deperetia) kazuseusis and Bibos geron other opportunity. Without solving this have been reported by RIN (1935) and problem, one cannot expect to undertake ·CHANG (1958) from the facies transitional correlation of strata on a widespread to the Kaenzan from the Kazan. The scale as along the southwestern border same facies has yielded abundant marine land of the Pacific Ocean. fossils as above mentioned, and the The Nakoshi Sandstone \vhich yielded mammal yielding horizon is associated Anadara (Scapharca) takaoensis, .4nadara with Anadara (Tegillarca) granosa (LIN (Scapharca) suzul?ii and Anadara (Tos NAEUS). Those mammal fossils arc ac arca) sedanensis in the northwestern part -cording to TAKA! (1963). commonly of the Okinawa Island was well described known from the Pleistocene sediments by ~1ACNEIL (1960). This stratigraphic in japan. unit overlies the Shimajiri group with To make a comprehensive study on unconformity and is covered with Naha the fossil molluscs, another problem Limestone. a unit that was once consid arises as to whether Tokazan Formation ered to be equivalent with the Ryukyu is Pliocene or PleisLOcene. ?.·lany of the Limestone by 1-IANZAW A (1935). This mo\lusc::n fossils, particularly the im sandstone yielded abundant marine mol portant ones from the so-called Byoritsu luscan fossils as already reported by Bed arc characteristic Pliocene forms as NOMURA and ZINBO (1936), Y ABE and already pointed out by YOKOYAi\IA (1928), HAT At (1942) whom believed it to be the 491. A.nadam front Southwest Japa·n 95
Shimajiri Bed of IIANZAW A (1935) and of I\liocene Tsuma Formation. OTUK A (1930) l'viAcNEJL (1960) Anadara (Scapharca) considered the relation between his Taka· talwoensis from the Nakoshi Sandstone nabe Formation and Tsuma Formation is associated with Anadara (Scapharca) to be an unconformity that is indicated suzukii. These two species closely re· by the lithofacies and general geostruc sembles Anadara (Scapharca) tricenicosta ture which had been influenced by an in surface sculpture except for the num epeirogenetic movement, probably con ber of radial ribs and size. as will be cerned with the movement of the 1'vledian discussed later. Line. Such stratigraphic relationship is The younger Neogene formations dis also observed in Kochi Prefecture where tributed along the Pacific borderland of the Ananai Formation lies upon the ~o southwest Japan are developed in the bori or Nahari Formations with clino Miyazaki Basin of eastern Kyushu, the unconformity. and where the Kakegawa southwestern part of Kochi Prefecture Group overlies on the Sagara Group with and from the Kakegawa district in Shi unconformity. Generally, the Japanese zuoka Prefecture northwards to the l\liocene can be distinguished from the Kwanto region. These Neogene deposits early Pliocene by several important fea are represented by the Takanabe, Ananai tures as already pointed by HAT AI (1960). and Dainichi Formations respectively. and "Almost everywhere as known at pre· have yielded some extinct Anadara spe sent, there exsists a stratigraphical break cies which are only restricted to this between the two (Miocene and Pliocene) area. These younger strata (Pliocene) or evidence for diastrophism when the are aligned parallel to the lvledian Line relation is conformable. Frequently, vol already mentioned by OTUKA (1931). canic activity accompanies the sediments The molluscan fossils from the Taka superposed upon the unconformity or as nabe Formalion were studied by YoKO· sociated with eustatic movement. whether YAJI.IA (1928a). 0TUKA (1930), ITOIGAWA the sediments are terrestrial, brackish or (1953) and SmmJ (1952-1964). In addi marine, while immediately below it or tion to the molluscan fossils. OTUKA the uppermost limit of the late tvliocene (1932) reported Stegodon from the Taka evidences for regression can be often re nabe Formation: This mammal is gener cognized but without intense volcanism". ally accepted as an index fossil of the The same relation from faunal consider Pliocene age and its name is Stegodon ation was attained by SIIUTO (1961) and bombifrons according to TAKA! (1963). TsliCHI (1961). Further significant works 0TUKA \ 1931) and SHUTO (1958! expressed on the problem are the Umbonidae by the ,·iew that this elephant horizon is of SUZUKI (193-l), SUGIYA~IA (1935. 1935a) Pliocene age. SHUTO (1961) summarized and 1\·lAKJYAMA (192·1). on the phylogeny the biostratigraphy of the ~liyazaki Basin and evolution of the Turritella by Ko and established faunal zonules. and among TAKA (1969), on the Pectinidae by l\IASUDA them his 4th to 6th were stated to be (1962). Siphon alia by l'viAKIY MIA (1941} Pliocene in age. Lithologically, the thick and on the Veneridae by SIIUTO (1957). medium grained sandstone of the lower The results of studies on those fossils part of the Takanabe Formation grades clarified their geological ranges and re downwards inlO a tuff bed which is lationship with the different strata in superposed on a homogenous massive which they occur. The examined Ana· mudstone which is correlated with the dara species show chronological ranges '96 Hiroshi NODA. given in the Table 1 in comparison with oz other groups. til t'" ~---e-II) II) ll) II) An examination was made on the 0> fQ 0 0 <( - ..... z z 3 ell 0~ ..I <( <( Arcid specimens of the Anadara group <( 6 zo: (ij Ill II) <( ..... <(ILJ collected from the Tokazan. Nakoshi, (!) ~ 0 Ill I- Ul
<( 0 ILl 0 L <0 z Ill 0> 0 ::::> Fig. l. Key to symbols used in descrip - 1- ..I ~ _j - Ill ..I tions of Anadara species based on Anadara <( :r 0 ILl- Ill 0 (Scapharca) tricanicosta (1\YsT). Recent. z z 0 z :E - X:
21 r20
Cl) ...J
a:; w (J) ~ ;:) 5 z
(B) 25 NUMBER OF. RADIAL RIBS
Fig. 2. The relation between the number of radial ribs in the different species: (A). Anadm·a (Scapharca) lricenicosla (~YsT), (B). Anadara (Scapharca) sllzukii (YoKOYA1\IA), (C). Anadara (Scapharca) takaoensis (No~ll'RA). ~l8 Hiroshi ..ll.lODA
~ 10 0 ~ 311. 10 20 30 40 60 110
LENOTt-4 in mm. ------il> (Anodora tokooensis}
HEIGHT OF LIGAME~T' &HELL HEIGHT 60 . 40
1. 30 • . .E• 20 ,_ ::':-..r:i..:: .../ :J: ,:l" ~ 10 :J:"' ~t5 201I& 10 20 30 40 60 so 70 80 ; 10 ,-n ll..-n LENGTH In mm. ---~ ~ & ~-l~ ~--~~~~~~~~~-- (An odor a t r icenicost a} ~~~~~~~~;~~~ HEIGHT, LENGTH 40 Fig. 4. Figures showing the different statistical relations observed in Anadara 30 r (Scapharca) tricenicosta (Ni'ST). li 20 .E• ,_ 10 from Japan shows a maximum length of :J: ·.·/ 0 49 mm. and height 35 mm. This seems ~ 20 30 40 50 60 to be an example of size increase with
LENGTH In"'"'·----+ the lapse of time. SCHENCK and REIN· (Anodora suzuki! ) HART (1938) mentioned that the increase Fig. 3. The size \·ariation in each spe in size of the adult specimens is doubt· cies and the angle between the height and less too indefinite to have exact time length of the shells. value, but a trend from small to large is nevertheless an hypothesis worth test· the name of Anadara tricenicosta suzukii ing. Besides the difference in size of for the specimens yielded from the Taka· the shells, as noticed from Fig. 2, the nabe Formation and his I~echienjian stage. number of radial ribs are different. This Both names may be safely considered as is a very important specific character homonyms. Difference between them is and generally employed in the distinction size; Anadara (Scaphm·ca) tricenicosta of the species of the genus Anadara. from the Toi As above mentioned, the number of Subfamily Anadarinae REINHART. 1935 radial ribs is nearly constant from the Genus Anadara GRAY, 1847 juvenile stage to the adult. Anadara (Scapharca) takaoensi.~. an- Subgenus Scaphm·ca GRAY, 1847 100 Hiroshi NO!Jil .4 nadaaa (Scaplwrca) suzukii pages was included into the synonymy of the Recent Anadara (Scaphaaca) tri (YOKOYA~!A), 1926 cenicosta (NYST) by !VIAKIYAMA in 1958. Pl. 10. Figs. 3-7. 10-13; Pl. 11, Figs. 9-10 Three years later SrrUTO (1961) recorded Anadara (Scaplwrca) suzukii (Yor Pliocene; IGPS coil. cat. no. 29244, Tom This species is characterized by its radial be, Kitaogasa-mura, Ogasa-gun, Shizuoka ribs which are largely elevated. rather Prefecture. Dainichi Formation, Pliocene; wide and granulated on their back. Nakoshi Sandstone. Okinawa Island, Plio NOMURA (1933) ·stated that there are no cene; Takanabe Formation, !vliyazaki species of fossil as well as Recent Area Prefecture, Pliocene: Nango sandstone in Japan that are closely related to this and mudstone alternation, Shizuoka Pre species but Anadara (Scapharca) suzukii fecture, Pliocene. (YoKOYAMA) is closely allied to Anadara (ScajJharca) takaoe11.~is (NOMURA) in its Anadara (Scaplwrca) takaoensis shell surface sculptures. (NOMURA), 1933 Locality and Formation :-IGPS coli. cat. no. 37428. 3HH, type locality. NNW Pl. 10, Fig. 14 ; Pl. 11. Figs. 3-6 of Shinsui Police Box, Shinsui. Enshusho. Takao-shu, Formosa, Kaizan Beds. Mio 1933. Area (Area) takaoensis No:-.II.JRA. Sci. Rep., Tohoku Imp. Univ., 2nd Ser., Vol. cene: lGPS coli. cat. no. 61387. Yard of 16. No. 1, p. 39, pl. 4, figs. 2-5. the Nakoshi Primary School, Haneji 19-12. Anadara (Scapharca) takaoensis. YABE mura, Kunigami-gun. Okinawa Island. and l-IATAI. japan. jour. Geol. Geogr .. Nakoshi Sandstone, Pliocene; IGPS coli. Vol. 18. Nos. 1-2, p. 73-74, pl. 7, figs. cat. no. 51306. Gabesoga. Kunigami-gun, 2. 3, 6. Okinawa Island, Nakoshi Sandstone. Plio cene. The present species was originally de scribed by NoMURA in 1933 based upon the specimens from the Kaizan Beds in Anadara (Scapharca ?) sp. Formosa. He gave the following de Pl. 10. Figs. 8-9 .scription: "Shell small. longly-ovate, moderately inflated with rather low beak Shell moderate in size, inflated. test .at the anterior third of shell-length; an rather thick. stout. roundly quadrate . terior end rounded, the posterior sub Inequilateral, longer than high, posterior truncated and somewhat produced; valve end produced subtrapezoidal with pos with about twenty five distinct radial terior ridge. Anterior dorsal margin ribs which are separated by much nar shorter than posterior one, and both row interspaces; anterior ribs narrowQr nearly straight. Posterior end truncated, than the posterior, finely granulated. forming about 122-120' with hinge line. Hinge line rather short ; cardinal area Anterior end smoothly rounded. Ventral narrow. Teeth and other internal char margin widely arcuated. Umbo some acters not exposed. Five isolated left what swollen. beak small, low, turned valves were examined. A specimen anteriorly, situated at about one third of -chosen as the type is 23.5 mm. long, 16.0 shell-length from anterior. Ligamenta! mm. high and about 7 mm. deep." area with 1 to 1 1/2 imperfect v-shaped Remarks: The present species was chevrons; narrow hinge line straight, ·originally described based on the speci with numerous perpendicular teeth but mens from the Kaizan Beds above men details unknown. Inner surface rather tioned and subsequently YABE and HAT AI smooth but \vith crenulations on ventral (1942) \veil illustrated this species from margin corresponding to outer surface .the Nakoshi Sandstone in Okinawa Island. with radial ribs. Shell surface with 20- 102 Hiroshi 1\lODA 21 radial ribs. Radial ribs rather sub· 1954. Anadara (Di/uvarca) tricenicosla, KIRA. quadrate in cross section. flat-topped, Illust. Shells faPa11, Hoikusha, p. 87. pl. somewhat wider than interspaces. Inter· 43, fig. It. spaces sculptured with faint concentric (1932) growth lines. Posterior depressed area Remarks: PRASHAD pointed out runs from beak to posterior ventral end. that in view of the name Area radiata having been used by SoWERBY in 1840· sculptured there with 5-6 radial ribs. for a fossil species. NYST changed the Remarks: The present species is not name of REEVE's species to Area triceni· well preserved and therefore its precise costa in 1848. DUNKER proposed the details could not be studied. However, name of Scapharca philippiana for the it may represent a new species. It is same species. KOBEL T (1891) described characteristic in its few number and this species in detail and published a shape of radial ribs with a depressed figure of one of DUNKER's original Scaph area along the posterior border. This arca philipjJiana. In 1844. REEVE de unnamed species resembles Anadara scribed Area radiata as follows: .. Shell (Tegillarca) granosa (LINNAEUS) in hav ovately oblong, equivalve, side rounded, ing 16-20 characteristic radial ribs but whitish. stained with light brown about differs therefrom in the depressed area the umbones. sparingly covered with and surface sculptures. epiderms. radiating ribbed, ribs about Locality and Formation: IGPS coli. thirty in number. very narrow, obsolete· cat. no. 90033, Tonohama, Yasuda-mura, Aki-gun, Kochi Prefecture, Ananai For ly rounded, interspaces between the ribs mation, Pliocene. latticed, area of ligament middling."' KoBEL T (1891) gave a supplementary description to REEVE's one. According Anadara (Scapharca) tricenicosta to KOBEL T (1891), this species is charac (NYST), 1848 terized by the shell being inequilateral, inequivalve with 30 radial ribs: radial Pl. 10, Figs. 1-2. 16-17 ribs rather narrower than inlerspaces and fine lamellae form growth lines. 1844. llrca radiata REEVE (non SOWERBY), Conch. Icon., Vol. 2. Area, pl. 6, fig. 40. Ligamenta) area elongated, rhomboidal 1848. Area tricenicosta NYST, Mem. Acad. Ro1'. and measures 72 in length, 50 in height Belg.. l'ol. 22, p. 74. - and 43 in width in mm. As pointed out 1882. Scapha rca Philippiana DU!'KER. b1d. by KOBEL T (1891). REEVE's description Moll. Mar. japan., p. 235. was based only upon the shell surface. 1891. Area- (Scapharca) philippiana, Ko1JEL T ·while KoBEI.T's description included the in MARTI=" und CHEMI"ITZ, Conch. Cab., surface and inner shell. It is important Vol. 8, p. 90-91. pl. 25, figs. 1-2. that KOBEL T mentioned that the shell of 1928. Area (Scap/wrca) phi/ippimw, YoKO· this species is inequivalve and that there is YAMA, Imp. Ceo/. Sun•. japan, Rep. No. 101, p. 103. pl. 17. ligs. 4-5. discrepance in surface sculpture between 1932. Anadara (Scapharca) tricenicosta, PR.\· the right and left valves. REEVE on the SHAD, Lamellibranchia of the Siboga other hand said this species is equivalve Expedition, Part 2, p. 39-40. and he did not mention discrepancy be 1933. Area (.4rca) phi/ippiana, NoMURA, Sci. tween the valves. Concerning the .form Rep., Tohoku Imp. Uni11., 2nd Ser., Vol. of the muscle scars, this species as well 16, No. 1, p. 36-37. as Anadara (Scapharca) takaoensis (No- 4.91. A nada1·a j1·ont Southwest .Japan 103 MURA) and A nadara (Scapharca) suzukii dorsal margins. Hinge line straight. have L-formed posterior muscle scar Teeth rather large and decrease in size though the anterior one is rounded (Fig. near boundary of anterior and posterior 1, Pl. 10, fig. 2). The ligamenta! area is sides, and ventrally convergent at both depressed trigonal in form. turned an extremities. Anterior muscle scar ovate· teriorly, being shorter in the anterior ly rounded under the dorsal end, pos· half and, longer and narrower in the terior one larger and roundly quadrate. posterior half, with the irregular chevrons Pallial line smooth hardly incurved at rather few in number. Although No posterior muscle scar. rather deep vent· ~IURA (1933), NmtuRA and ZINBO (1936) ral margin of inner shell strongly cren· and iviAKIY A:\IA (1958) considered Ana· ulated. Dimension (in mm.) of holotype; dara (Scapharca) suzukii (YOKOYAMA) to Length 80.2, height 62.1, width 31.2. be a synonym of Anadara (Scapharca) height of ligament 8.6. length of ligament tricenicosta (NYST). this species differs 55.8, length of teeth 53.1. radial ribs 37 from Anadara (Scap/wrca) suzukii (YOKO· in number. YAMA) statistically, but coincides with Holotype: IGPS coli. cat. no. 78919. .Scapharca phi/ippiana DUNKER. Collector T. SATO . Geologic Ocwrrence: Tokazan Forma Type Locality : Hosoya, 1\itaogasa tion in Formosa, Pliocene; Naganuma mura, Ogasa-gun. Shizuoka Prefecture. Formation, Kanagawa Prefecture, Pleisto .Nango Sandstone and Mudstone Alter- cene (in part) and Recent. nation, Pliocene. Remarks: The Pliocene form of Ana· dara from the Kakegawa district, Shizu Anadara (Scapharca ?) shizuokaensis oka Prefecture had been known under NonA, n. sp. the name of Anadara castella/a (YoKO· Pl. 11, Figs 7-8 YA:\IA) and Anadara suzukii (YoKOYA~IA). The former one was described by YoKO· Shell large, much swollen. thick. stout, YA:\fA as a subspecies of sa/owi. YoKO· rounded ovate except for beak, longer y A:\! A stated that this species is charac than high. inequilateral. anterior side terized by the shell being very inequi short and posterior produced, ventral lateral, the anterior side rounded, the margin bro:tdly convex. Dorsal margin posterior more or less truncated, the straight, anterior dorsal margin shorter surface with a blunt edge running from than posterior one. Shell surface sculp the beak to the posterior ventral corner. tured with strong rather narrow, flat There are 36 radial ribs or there-about topped radial ribs which are strong, and they are broad, usually flattened, sharply squarish in cross section and separated by narrower interspaces and narrower than their interspaces. Inter the area is yery narrow. spaces sculptured with concentric lines Accordingly the present new species of growth, some lamellae cross backs of differs from .rlnadara caste/lata (YOKO· radial ribs. Umbo swollen, beak small. YA~IA) in having no edge along the pos· incurved strongly directed and situated terior border and by the narrow, sharp anteriorly. Ligamenta! area trigonal in ly squarish radial ribs and by the liga profile, flat, rather wide, with low angled. menta! area being rather broad. ilnadara chevron grooved. Ligamenta! are a bound· (Scapharca) taiwanica NonA (!'viS) from -ed by narrow and deep furrows along Formosa is another allied species but it 101 Hiroshi NODA differs from the present new species in having a depre.ssed area along the pos- its more swollen shell and rather wide. terior margin differs from the present low, flatly topped radial ribs. A.nadara new species though number of radial nmmaensis OTUKA is characterized by ribs is similar. its narrower umbonal area and fiat shell compared with the present new species. Subgenus Tosarca NonA, n. subgen. Anadara (Scapharca ?) iwaslzibaraensis Type species: Anadara (Tosarca) tosa NouA, n. sp. ensis NODA, n. sp., Ananai Formation, Kochi Prefecture. Pliocene. Pl. 10. Fig. 15 Diagnosis :-Shell very incquilateral, Shell medium in size. rather thick, trapezoidal in form. anterior very nar swollen, inequilateral in form. very pro· row, posterior produced and obliquely soclinal, anterior side narrowly rounded truncated behind. Surface sculptured and posterior side broad, somewhat trun with strong, numerous. dichotomous or cated, although somewhat poorly pre partly dichotomous radial ribs, some served. Dorsal margin slightly arcutated, twice dichotomous at both extremities ventral margin runs obliquely from nar with wide depressed area extending from rower anterior to broader posterior end. beak to posterior margin. Umbo swollen. Surface sculptured with strong radial Ligamenta! area rather narrow, more or ribs which arc rather wide, low, smooth, less depressed from beak to hinge line. fiat-topped with their interspaces rather Inner margin crenulated at ventral mar· smooth but having concentric growth gin. Teeth a continuous series. lines transversing the radial ribs. Radial Remarks: This new subgenus is pro· ribs 31 in number, and with no depressed posed for the species of :lnadara com area along posterior margin. Umbo swol· monly known as /lnadara sedanensis len, flat, lower. Beak small, pointed. (tvlARTI:'\), Area llellica/a REEVE and situated at one third shell length from Anadara tosaensis Nou,\, n. sp., the anterior side. Ligamenta! area narrow. latter of which is selected as the type bounded with rather strong furrows of species of the new subgenus. Anadara small teeth perpendicular to hinge line. s. s. and Scaplzarca are distinguishable Pallial line rather deep and smooth. An· from the present new subgenus by their terior muscle. scar smaller than posterior unique inequilateral shell with trapezoidal one. subrounded. Inner Yentral margin form, more S\vollen, slightly medially crenulated shallowly. impressed umbonal area. and narrow Holotype: IGPS coli. cat. no. 29050, ligamenta! area which is depressed in Collector S. NoMURA. profile. Although these features are Type Locality: Iwashibara, Kami· found in Anadara or Scapharca, Tosarca tareki-mura, Ogasa-gun, Shizuoka Pre· is characterized in having the above fecture, Dainichi Formation, Pliocene. mentioned shell form and shape of Remar!?s: The present new species dichotomous radial ribs. These charac· resembles the Recent Anadara (Scaph· ten; are easily grouped up from other area) broughtnii (SCHRENCK) but the Anadara species. l'vloreover this new former has fewer radial ribs. il.nadara subgenus is characteristic of the Indo (Scajllwrca) subcrenata (LJSCHKE) in Pacific Province. 491. A.nada1·a from Soutlm•est Japan 105 A.nadara (To.~arca) tosaen5is this new species in form but the former NODA, n. sp. is sculptured with only dichotomous radial ribs while the latter does not carry Pl. 11, Figs. 11-13 them in the middle part of the shell surface though their shell form and shape Shell medium in size, test very thick, of the radial ribs are similar with one stout, subtrapezoidal. inequilateral, longer another. than high, slightly concave with wide posterior depressed area. Dorsal margin Reference cited slightly arcuated, passing into angulated posterior and anterior sides. Anterior CHA:>~G. L. S. (1958): Stratigraphy of Taiwan ventral margin smoothly rounded, pos· and its correlation with adjacent Areas. terior ventral margin nearly straight. Formosau Scieuce, Vol. 12. No.1. p. 13- Posterior side truncated. Beak small, 28. I table, 1 geol. map. lo\v, situated anteriorly, umbonal area DUNKER. vV. (1882): Index l\'iolluscorum flat, slightly depressed medially. Liga Maris Japonice. p. J-301. pl. 1-16. HATAI. K. (19.U) : Sundry Notes on the mental area very narrow, depressed Japanese Pliocene (1). japan. jour. Ceo/. from beak to hinge line and with two Geogr .. Vol. 18. Nos. 1-2. p. 69-86. chevron grooves, covered with longitudi -- (1960) : Japanese Miocene Reconsidered. nal striations. Hinge line straight with Sci. Rep., Tohoku Unil' .. 2nd Ser .. Spec. perpendicular small teeth, ventrally con Vol., !•io. 4. p. 127-153. vergent at both extremities. Surface - (1962) : Mizuho To. ibid.. 2ud Ser .. sculptured with rather strong wide, low. Spec. Vol .. No . .5. p. 329-348. flat-topped radial ribs, 43 in number. lLo\NZAWA. S. (1935): Topography and Geo· lnterspaces of radial ribs very narrow. logy of the Riukiu Islands. Sci. Rep .. Anterior 10-11 ribs dichotomous, backs Tohoku Imp. Univ .. 2nd Ser., Vol 17. p. of radial ribs and posterior 14-15 radial 1-59. pis. 1-15, 5 maps. ribs sculptured \Vith two or three very hoiGAWA, J, (1953) : A new species of fos sil Siphonalia from the Miyazaki Group. fine longitudinal furrows on their backs, Venus. Vol. 17, No. 4. p. 213-218, text middle part of shell without furrows on figs. 1-4. their backs of radial ribs. Dimension (in IwASAKI, Y. (196<1) : Notes on the Historical mm.) of holotype; Length 52.'1. height Changes of the japanese Tertiary Ana 52.0. length of ligament 37.8. angle of umbo dara (in Japanese with English abstract). 106", angle of hinge line and posterior l'enus. Vol. 22. No. 4. p. 379 .. 389, text end 103'. and radial ribs 43 in number. figs. 1-2. Holotype: IGPS coil. cat. no. 51609, KATTO, J., NAKAMURA, J. and TAKAYA:>IAGI, Collector S. NOMURA. Y. (1953) : Stratigraphical and Paleont Type Locality : Oono. Yasuda-mura. ological Studies of the Tonohama Group, Aki -gun, Kochi Prefecture. Ananai For· Kochi Prefecture. Japan. (in Japanese with English abstract). Res. Rep., Kochi mation, Pliocene. Unit~., Vol. 2, No. 32. p. 1-15, pis. 1-2, Remarks: The present new species tables 1-3. text-figs. 1-2. resembles ilnadara iu.wtonoensis NooA - and OzAKI, II. (1955) : Miocene Nobori (~IS) from Yamanashi Prefecture in type Formation of Kochi Prefecture, Japan. (in of furrows on backs of the radial ribs Japanese with English abstract). ibid .. but differs in their form. Anadara (Tos· Vol. 4, No. 1, p. 1-7, tables 1-3. text area) sedanensis (lVIARTIN) is allied to figs. 1-4. 10() Hiroshi NOJJA KIRA, T. (1954) : Coloured Illustrations of Part of the Kakegawa Series in the Pro the Shells of Japan. l/oikusha, p. 1-204, vince of Totomi, Japan. Mem. Col/. Sci., pis. 1-67. Kyoto Imp. Univ., Ser. B. Vol. 3, p. 1- KoBELT, ',V. (1891) : Conchylien-Cabinet in 147, pls. 1-6. MARTIN und CHEJ>I:XITZ. Gattung Area -- (1931): Stratigraphy of the Kakegawa L., p. 1-238, pis. 1-49. Pliocene in Totomi. Ibid., Ser. B. Vol. -KOTAKA, T. (1959) : The Cenozoic Turritel 7, p. 1-53, pis. 1-2, 1 geol. map. lidae of japan. Sci. Rep., Tohoku Univ., -- (1941) : Evolution of the Gastropod 2nd Ser, Vol. 31, No. 2. p. 1-135, pls. 1- Genus Siphonalia with accounts on the 15, text-figs. 1-10, text-fig. A. charts 1-8. Pliocene Species of Totomi and other MACNEIL, F. S. (1960) : Tertiary and Qua Examples. Ibid., Ser. B, Vol. 16, No. 2, ternary Gastropoda of Okinawa. U.S. p. 75-93. pis. 3-6, text-figs. 1-4. Geol. Surv. Prof. Pap., JVo. 339. p. 1-I.JS, -- (1958) : Tertiary Fossils from the vari pls. 1-19. ous localities in japan. Palaeont. Soc. MAKJYAl\IA, ]. (1924): The Evolution of japan, Spec. Papers, No. 4, Part 2, pls. Umbonium. japan. jour. Geol. Geogr., 25-57. Vol. 3. i\ios. 3-4, p. 119-130, pl. 20. -- and SAKA~IOTO, T. (1955) : Explanatory --- (1927) .: :\lolluscan Fauna of the Lower Text of the Geological Map of Japan, Explanation of Plate 10 (All figures in natural size) Figs. 1-2. Anadara (Scapharca) tricenicosta (Nvs-r), p. 102-103 1. Left valve. 2. Inner surface of right valve. IGPS coli. cat. no. 37591. Locality; 300m. East of Hakushaton, Chikunan-gun. Shinchiku-shu. Formosa, Tokazan Formation, Pliocene. Figs. 3-7. Anadara (Scapharca) suzukii (YoKOYA:-IA), p. 100-101 3. Right valve. 4. Inner surface of right valve, 5. Showing the ligamenta! area, 6. Inner surface of fig. 7, 7. Left valve. IGPS coil. cat. no. 54606, Locality: Tonohama, Yasu(la mura, Aki-gun, Kochi Prefecture. Ananai Formation. Pliocene. Figs. 8-9. Anadara (Scapharca ?) sp., p. 101-102 IGPS coli. cat. no. 90033, Locality; Tonohama, Yasuda-mura. Aki-gun, Kochi Prefecture, Ananai Formation, Pliocene. Figs. 10-13. AllC!dara (Scapharca) suzukii (YoKOYAMA), p. 100-101 10. Right valve. 11. Inner surface of fig. 10, 12. Right valve, 13. Inner surface of fig. 12. IGPS coil. cat. no. 29244. Locality: Tombe, Kamitareki-mura, Ogasa-gun, Shizuoka Prefec ture, Dainichi Formation, Pliocene. Fig. 14. .ilnadara (Scapharca) takaoensis (NoMURA), p. 101 Left valve, IGPS coil. cat. no. 51306, Locality; Gabesoga, Kunigami-gun, Okinawa Island, Nakoshi Sandstone, Pliocene. Fig. 15. Anadara (Scapharca ?) iwashibaraensis NooA, n. sp., p. lO Abbreviation: IGPS=lnstitute of Geology and Paleontology, Tohoku University. Sendai. Japan. Plate 10 NODA: Anadara from South'West Japan K u~ l i\Gi\ 1 Photo. 491. Anadara. fton~ Southwest Japan 107 Scale I : 50.000. Mitsuke and Kakezuka. races in Southeastern Kyushu. (in Japa (in Japanese with English abstract). nese with English abstract). Geol. Re11. Geol. Surv. ]a/Jail, p. 1--n. japan. Vol. 8. p. 81-95. text-figs. 1-5. I MARTI:-1, K. (1909-1922): Die Fossilien von table. java. Samml. Ceo/. R-,\lus., Leiden N.F. -- (1932a) : Post Pliocene Crustal Move Bd. 1. p. 333-538, pis. •10-63. ment in the Outer Zone of Southwest MASUDA. K. (1962): Tertiary Pectinidae of Japan and in .. Fossa Magna". Bull. japan. Sci. Rep .. Tohoku Univ., 2nd Ser., Earthq. Res. Ins/., Imp. Univ. Tokyo. No. Vol. 33, No.2. p. 117-238. pis. 1-10. text 10, p. 701-722. figs. 1-7. -- (1935) : The Earthquake of Central XoML'RA, S. (1933) : Catalogue of the Ter Taiwan (Formosa). April 21. 1935. and tiary and Quaternary Mollusca from the Earthquake Faults. (in japanese with Island of Taiwan (Formosa) in toe In English abstract). 1bid .. No. 3. p. 22-27, stitute of Geology and Paleontology. pis. 35. 36. 46. 56-63. 65-66, 90. 101. 10-L Tohoku Imperial University, Japan. Sci. 122. 123. 126. 128. 130-132. text-figs. 1-26. Rep .. Tohoku Imp. Univ., 2nd Ser .. Vol. -- (1936) : Pliocene :\·Iollusca from Man 16. No. 1. p. 1-106. pis. 1-4. ganzi in Kotomo-mura. Akita Prefecture. -- (1937) : The Molluscan Fauna from the Japan. jour. Ceo/. Soc. Japan. Vol. -13. Pliocene of Tosa. japan. jour. Ceol. No. 516. p. 726-736. pis. 41--12. Geogr .. Vol. 14. Nos. 1-2. p. 66-90. pl. 6. PRASHAD. B. (1932) : The Lamellibranchia --and IIAT,\1, K. (H)36): On some species of the Siboga Expedition. Part 2. Pelecy of the Genus Area from the Neogene of poda. Result. Exp/or. Siboga. Monogr. :'lfortheast llonshu. Japan. Ibid., Vol. 13, 53. p. 1-353. pls. I -9. Nos. 1-2. p. 6:~-70. pis. 12-13. REEVE. L.A. (184-1) : Monograph of the -- and ZINBo. N. (1934) : Marine Mollusca Genus Area. Conch. Jconica. Vol. 2. from the Hyukyu Limestone of 1-i.ikai Area. pis. 1-17. Zima, Ryukyu Group. Sci. Rep .. Tohoku REJ:-11.\RT. P. W. (1935) : Classification of Imp. Univ., 2nd Ser .. Vol. 16. No. 2. p. the Pelecypod Family Arcidae. Bull. 109-164. pl. 5. .\Ius. Roy. His/. Nat. /Jelg .. Vol. 11. p. -- and -- (1936) : Molluscan Fossil from 1-68. pi 1. the Shimaziri Beds of Okinawa-zima. H1:-<. T. (1935) : Stratigraphical Studies on Ryukyu Islands. Ibid., 2nd Ser .. Vol. 18. the Younger Tertiary and Pleistocene /llo. 2. p. 229-266. pl. 9. Formations of the Toyohara District. NYST. P. H. (18-18) : Tableau Synoptique et Taityu Prefecture. Taiwan (Formosa). Synonymique des Especes Vivantes et .\lem. Fac. Sci ..-lgricull .. Taihoku Imp. Fossiles de Ia Famille des Arcacees. Univ .. Vol. 13. p. 13-30, pis. 1-7. 1 geol. Part 1. Genera Area. .-lead. Roy. Sci .. map. Letters Beaux .-Iris Be/g., Mem., Vol. 22 .. ScnE> p. 101-110, pis. 16-17. text-figs. l-4. -- (1960): On some Pectinids and Veneri ds -- (1956) : Urnboniinae from the Miyazaki from the Miyazaki Group. Mem. Fac. Group. japan. jour. Geol. Geogr.. Vol. Sci .. ](yushu Univ .. Ser. D. Vol. 9. No. 3. 27. No. J, p. 47-6G. pl. 4. text-figs. 1-7. p. 119-14!), pis. 12-U. text-figs. 1-14. tables 1-4. tables 1-2. -- (1957) : Crassatellites and lfenericardia -- (1960a) : Carditids from the Miyazaki from the Miyazaki Group. A/em. Fac. Group. Trans. Proc. Palaeont. Soc. japan. Sci., ](yushu Univ .. Ser. D. Vol. 6, No. 2. N. S.. No. 37, p. 209-222, pl. 25, text-figs. p. 69-8!l, pl. 22. text-figs. 1-7, tables 1-3. 1-2. -- (l957a): Fossil Paphia from the l'vliya -- (1961) : Palaeontological Study of the zaki Group. japan. jou1·. Geol. Geogr .. l'vliyazaki Group. Mem. Fac. Sci .. J(yusllll Vol. 28. Nos. 1-3, p. 139-160, pl. 12. text Univ .. Ser. D. l'ol. 10. No. 2, p. 73-206, figs. 1-9. tables 1-6. pls. 11-13. text-figs. 1-23. tables 1-15. -- (1958): A Preliminary Note on the -- (1964) : Naticid Gastropods from the Medial and Late Cenozoic History in Miyazaki Group. Trans. Proc. Palaeont. Kyushu. (in japanese). Shinseidai no Soc. japan. N. S .. No. 55. p. 281-293, pls. ](enkyu. No. 28, p. 634-653, text-figs. 1-4 42-43, text-figs. 1-3. -- (1958a) : Cranulifusus from the Miya SuGIYAMA, T. (1935): On the Variation of zaki Group. Trans. Proc. Pa/aeonl. Soc. the shell of Li,·ing and Fossil Umbonium Japan, N. S .. No. J /, p. 253-204, pl. 38. from japan and its Evolution. (in Japa text-figs. 1-3. tables l-3. nese). jour. Ceo/. Soc. japan. Vol. "12. -- (l!l59): Olivid Gastropods from the No. 502, p. 40cl-430. pl. 11. figs. 1-6. Miyazaki Group. japan. jour. Ceo/. -- (1935a) : On the Variation of the shell Ceogr., Vol. 30, p. 169-182. pl. II. text of Living and Fossil Umbonium from figs. J ... l, Japan and its Evolution. (in Japanese). Explanation of Plate 11 (All ligures in natural size) Figs. 1-2. Anadara (Tosarca) sedanensis (1·1ARTI:o\). 1. Showing the teeth and the narrow ligamenta[ area, 2. Left valve. !GPS coli. cat. no. 61388. Locality: Yard of Nakoshi Primary School. Nakoshi, Haneji-rnura. Kunigami-gun. Okinawa Island, Nnkoshi Sandstone, Pliocene. Figs. 3-6. Anada1·a (Scap/za1·ca) takaoensis (NOl\IURA), p. 101 3-4. Umbonal view. 5. Right valve, 6. Left valve. IGPS coiL cat. no. 51306. Locality: Gabesoga. Kunigarni-gun, Okinawa Island. Nakoshi Sandstone. Pliocene. Figs. 7-8. Anadara (Scafl/rarca ?) shizuo/wensis NniJA, n. sp .. p. 10:~-104 7. Right valve. 8. Inner surface of fig. 7. Holntype, IGPS coiL cat. no. 29180. Locality; Hosoya, Kitaogasa-mura. Ogasa-gun, Shizuoka Prefecture. Nango Formation. Pliocene. Figs. 9-10. Anadara (Scapharca) suzukii (YoKOL-\~IA). p. 100-101 9. Right valve. 10. Urnbonal view. IGPS coli. cat. no. 61387. Locality: Yard of Nakoshi Primary School. Nakoshi. Ilaneji-mura, Okinawa Island. Nakoshi Sandstone. Pliocene. Figs. 11-13. Anadara (Tosarca) tosaensis NooA, n. sp .. p. 105 11. Showing the depressed area along the posterior side with fine furrows on radial ribs, 12. Umbonal view and showing the depressed narrow ligamenta! area. 13. Left valve. Holotype. IGPS coli. cat. no. 54609. Locality: Oono. Yasuda-mura. Aki-gun. Kochi Prefec ture. Ananai Formation. Pliocene. Plate 11 NODA: Anadara from Southwest Japan K uMAGA I Photo. 491. Anada.ra. from Southwest Japan 10~} Ibid., Vol. 42. No. 503. p. 4~9-482, text Fossil from the Shimajiri Beds of Oki figs. 1-30. nawa-zima. Ryukyu Islands. japan. japan. SUZl'l Enshusho !?.~ .u~ .1± Nakoshi frl• I'd ~ Haneji-mura ;JjJ .11!! t! Oono };, ~tf Hosoya ~II .ft Shinsui i;fi I washibara !!1l !Iii Takao-shu t:j !11l *HI Kaenzan !k ~ ill Tokazan !!ft. ¥,~ ill Kozan iff LlJ Tom be 'Iii t'l!S Kunigami-gun ~ !fi'i lif> Tonohama f.'.t IJf 1ft lVIiaoli fti ~ Trans. Proc. Palaeont. Soc. Japan, :>1. S., No. 59, pp. 110-113, pl. 12. Sept. 20, 1965 492. A GIGANTIC SCALLOP FRO~l THE SEA BOTTO)! OFF THE DANJO ISLANDS, NAGASAKI PREFECTURE, JAPAN* JO]l NAGASAWA Institute of Earth Science, Tokyo Gakugei University N:~~ljl. Yl:tctf~i lH~(1)~i:::.n ·n··:r-c ~l...tJf ~~'l.t.:;k1~(1) Mizultopecten W1&) ft;fil:::. -?I. ·'"C, .c..:: l::.tlH~--t ~o .c..;/1.!1J'~i~l:::.;k~(1) Q -ck~ ~ ·c:t * J 7 ~(1)(tfl!IH"C:I:t~l? Introduction and Acknowledgements result of abnormal growth of the shell. The external surface of this shell is The specimen described in this article bluish gray and partly covered with cal was dredged by a coral net from the sea careous organic remains. The shell is bottom off the Danjo Islands near the more or less water worn and damaged Goto Islands, Nagasaki Prefecture. few slightly, but the specific characteristics years ago. of the specimen are clear and show it to In the spring of 1964, the writer at be an undescribed form. the suggestion of Professor N. SAKAZD:\IE The writer is greatly indebted to Pro of the Doshisha University in Kyoto, fessor Nakao SAKAZUME for his kind visited Fukue Islet, one of the Goto help and encouragement during the course Islands, and was fortunate in being able of this study. to study a fossil specimen which is now The writer wishes to express his deep preserved in the collections of l'vlr. I. gratitude to 1vlr. !taro KAMAGA of Fukue KAMAGA, a resident of Fukue Islet. This Islet, for kind permission to study the fossil A1izuhopecten is interesting because specimen, to Professor Kotara HATAI of it is the largest one hitherto known from the Tohoku University for his kindness japan. The comparatively thin test and in reading this manuscript and for his the morphological characters of this speci advice, to Dr. Koichiro MASUDA of the men indicate that its unusually large size same university for the permission to is a specific character, rather than the study his collection, and to Dr. Shozo * Received Jan. 29. 1965; read jan. 2-1, 1965 I-lA y AS AKA of the same university for at Tokyo. his kind help. 110 G1'ga.nhc Species of lllizuhopecten 111 ones were observed, that is, 4""'6 radial Description ribs which form a group are more ele Family Pectinidae vated than the rather low I ""'2 radial ribs which are situated between the Subfamily Pectininae groups of elevated radial ribs. Altogether five such groups, counted from the right Genus Alizuhopecten l\IASUDA. 1963 margin of shell could be recognized. but Mizuhopecten kamagai this feature is obscure at the left sub margin of the shell as seen often near NAGASAWA, n. sp. the beak of Alizuhopecten tolzyoensis (To Pl. 12, figs. 1-7 KU:- threads, or divided into riblets, and But. as the extraordinary arrangement the other group has more numerous of the radial ribs on the upper half of radial ribs which are not so broad, but this specimen is considered to be only equal or sometimes subequal in their an indication or the remnant of the breadth and often furnished with one or character which the AI. kimurai group two radial furrows. or in parts of the and its ancestor possessed, the present disc, divided into two parts. one may be incorporated into the latter MizulwjJeclen kimurai (YoKOY Al\IA) and group mentioned above or treated as a 1U. tokyoensis and their allies belong to new form. the former group, and the latter group Though the mode of biufrcations of includes M. nakatombetuensis (AKIY A:'.! A), the radial ribs of the present new species M. yamasallii (YoKOYAMA). M. tryblium is the same in M. yamasakii and its (YOKOY A~! A) and their allies. allies, this one is distinguishable from The characteristics mentioned above them by its larger auricles and by the -of the radial ribs of the two groups are left auricle being not truncated behind recognized in the present single speci· and in the shell shape having the length men, namely. the characteristics of the exceeding the height. former group, especially near the beak, Especially, M. yamasakii is distinguish· and that of the latter group on the ed from this species by its conspicuous lower half of the shell, as already de· stout lateral ridges on both margins of scribed. the resilial pit. Therefore, the arrangement of the The present species resembles those of radial ribs on the upper half of the disc the l1·yblium group, but it can be distin· in this specimen is similar to the radial guishcd from M. tryblittm lryblium (YO· ribs of i\1. kimurai whereas the features KOYAMA), M. t. shinshuensis (AKIYA:\lA) <>f M. lokyoensis may be seen on the and AI. t. ibaragiensis (MASUDA) by having disc as a whole. larger number of trifurcate radial ribs This characteristic seems to be im· and its large right auricle, and also from portant from the phylogenetic point of M. t. kintaichiensis (MASUDA) by the view. large number of radial ribs and by the Explanation of Plate 12 Figs. 1-7. Mizuhopecten kamagai, n. sp. 1. Right valve, Holotype, x lf3.6, from the bottom off the Danjo Islands, Nagasaki Pre- fecture, now kept by Mr. I. KAMAGA. 2. Interior view of Fig. 1. ca. x 1/3.5. 3. Posterior profile of Fig. 1. ca. x 1/3.5. 4. Left auricle stripped of covering substances, and the ·1 groups of elevated radial ribs showing the special arrangement; a part of the plaster model of Fig. 1. 5. Right auricle stripped, partially, of covering substances, its concentric striations and the 6 groups of elevated radial ribs; a part of the plaster model of Fig. 1. 6. The half part of the hinge area of Fig. 2 showing a cardinal crura; a part of the plaster model of Fig. 2. 7. Surface sculptures of several radial ribs which are trifurcate or bifurcate at the middle part of the left ventral margin: a part of the plaster model of Fig. l. NACAS.4 WA: Gigantic species of Mizuhopecten Plate 12 5 7 Giynnhc Species of Miznhopecten 113 left auricle being not truncated. I-VIII. It is noticed that in AI. tryblium try HATAI. K. (1963) : New species of Gadus blium, the outline of both lateral ridges from Lhe Pliocene of Japan. l'a/aeonl. around its resilial pit is roundish in shape, Soc. japan, Trans. !'roc .. N. S .. 110. •19. pp. 25-28. pl. 5. whereas it is triangular in the present lToiGAWA, ]. (1958): 1\lolluscan Fossils from one like M. yessoensis and AI. tokyoensis. the Niitsu. Higashiyama and Takezawa M. nakatombetuensis (AKIYA~!A) differs Oil-Field. Niigata Prefecture. Japan. from this new species by the elevated Univ. Kyoto. Colt. Sci., Mem .. Ser. B. vo/. flat-topped. squarish radial ribs. .\'XIV. no. 4. pp. 249-263. pl. 1. figs. 8-9. In short, this species can not be identi l\IASCDA. K. (1960) : On the Miocene Pecti fied with any known species of ,\fizuho nidae from the Environs of Sendai: Part pecten (=Patinopecten of authors) in 16, Pecten kimurai YoKoYA~IA and Pal Japan. or with forms of Patinopecten of Iiolum cf. Peckami (GADB). l'a/aeont. Northwest America. therefore the writer Soc. japan, Trans. Proc., N. S .. no. 38. pp. proposes the new species name ... kama 2-19-262. pls. 29-30. -- (1962): Tertiary Pectinidae of ,Japan. gai" after the name of the collector. Tohoku Unir .. Sci. Rep., 2nd Ser. (Geol.). Geological .-lge :-Probably Pliocene. vol. 3 3. no. 2, pp. 1-238. pis. 18-27. inferred from the reasons: Among the -- (1963): The So-called Palinopec/en of numerous species of fossil Mizulwpecten Japan. Palaerm/. Soc. japan. Trans. Proc., (recorded as l'atinopecten), the species N. S., no. 52. pp. U5-153. pis. 22-23. having more than 20 radial ribs and To~IIZAWA. T. (1958): Studies on Fossil morphological characters related to this from the Kami-Minochi District. Nagano new species are known only from the Prefecture, in T. and K. YAel. Geology Pliocene of japan and, abundant Pliocene oj Kami-Minochi-gzm (in Japanese). pp. fossils have been dredged from the sea 317-347. pl. IV. lig. 10. bottom of the japan Sea, as off lhe coast YoKOYA~IA. lVl. (1925): Tertiary Mollusca of Yamaguchi, Shimanc. Niigata, Yama from Shinano and Echigo. Imp. Univ. Tokyo, Fac. Sci., four .. Sec. 2. 11ol. I, pt. gata, and Akita Prefectures. and from I, p. 17, pl. 5. tigs. 1-2. pl. 6, figs. 1-2. the Korea and Tsushima Straits. -- (1926): Fossil i\'lollusca from the Oil Fields of Akita. Ibid .. vol. 1. pt. 9. p. Ht>ference Cited 388. pl. ·15, fig. 3. -- (1926) : Tertiary l\lollusca from the Oil AKIYA:\IA. M. (1962) : Studies on the Ph~·Io Field of Embets and Etaibets. Ibid., vol. geny of Patirwpecten in Japan. Tokyo 1' pt. 7. p. 2-15. pl. 32. fig. 1. Kyoiku Daigaku, Sci. Rep., Sec. C (Geol.. -- (1927): Fossil Mollusca from Kaga . .\lin .. Geogr.). mi. 8. no. 74. pp. 1-63. pis. Ibid .. mi. 11. pt . .J.p. 180. pl. 49, fig. 1. Akita t.k E!:J Shimane !lh .!U Danjo Islands 9.l:tc9!JW; Tomie-machi '1& 1t IIIJ Fukue Islet :ffii ):[ li:; Tushima Straits ;{:(',tlj~tild: Goto Islands li,fi!;Jlj!If; Yamagata 111 JrJ. Niigata 'lfr if.J Yamaguchi LlJ II Onmma A. ~ Trans. Proc. Palaeont. Soc. Japan, N. S .. No. 59, pp. 114-125, pis. 13. 14. Sept. 20, 1965 493. ON A LOWER CRETACEOQS PELECYPOD ... CYRENA" NAUJ.liANNI. FR0:\1 JAPAN* ITARU HAY AMI and !SAO NAKAI Department of Geology, Kyushu University ~fm~j!ft*i:J'*Ji!~ "Cyrena" naumanni t::.\, ·--=>"'C: "Cyrena" naumanni NEU~tAYR, 1890 f1 t1 <11, I? ;;f.:~~ s~* ~~fi\ICI)tJi:tl /fll~r:.~j.ii· Q::. C. tJ:~ !?it., tl1li'\f!1t:ti'I:..:~tt-t.. · (i:ij fii$f.qJr\Jf(f'f.!ll}J!Iml!¥0)t:p '"C'J:l: 13 ~;ft. "'C ~t-:N\-c·t, QIJ·.. -t:'CI)f.f~~ ..tCI){.ir.[i1tf1;;pB]Jff'ti-ct,--:>t-:, ~lll•~~ft/.ji;f!i!CI)m:t~:;lll!-c·t, Q :ft(Ch~Jmi!iilll~l.1!!CI)W!Ji:ti:.:tu~r, -c~~CI)t'\'i*~f*~ ~..-. mt:t ~.bn;;t.t..:~.*. i:.CI)N\fi VoKEs (1946) tJ~ Lebanon Cl) Aptian ~ii'G~~L-t-: Proto· cyprina Cl).j~!;i'i;~I:.Jll{J'):t" Q::. C. iJ'biJ•--=>t..:o ::. .:.1:. Prolocyprina ~~ j!}}E~ L. -c, N\CI) ~i:'.l\t\t~11--=>t-:o ;;f.:.ifl::t. Y, 7~t:.~*L- f,: Eomiodon Cox. 1935 ~:.rk'.lti' J.) C.~;;{_ I? ;ft., -'C Cl)~~.m.i1!ft Corbiculidae CI)~M.fiq C. ft.1N*t'!'~jl:.~ IJ. CASEY (1955) Cl):;g~L. t..:: Neomio don ti dae 1:. -35'£-t .Q o J2f Jj( m- · ~' .15 r}] Introduction from the Ryoseki group and its compar able strata at various localities of the "Cyrena" naumanni NEU:>.IAYR is a Outer Zone of Southwest Japan and also celebrated pelecypod which occurs com· of Northeast Japan. Since index fossils monly in the brackish-water deposits of are scarce in the Ryoseki fauna, the oc the Ryoseki group of Japan. It was currence of this species has been parti · first described by NEUMAYI{ in NAU· cularly noticed by a number of strati· MANN and NEUMAYR (1890) from Yanagi graphers. (Text-fig. 1) dani of the Katsuuragawa basin of east· ern Shikoku. NAUJ\IANN and NEUMA YR interpreted it to be a Jurassic species. but the actual locality is situated in the outcrop area of the Tatsukawa forma tion. which is a representative of the Ryoseki group in this area and is pre· sumed to be Neocomian (probably lower Neocomian) in age. At the same time NEUMAYR described also Cyrena gravida and Cyrena lithocardiurn from the same locality. but, as interpreted by many authors, the two must be synonyms of C)rena naumanni. Subsequently the present species was o-;....~~....;;.;300Km reported to occur by many stratigraphers Do * Received Feb. 29. 1965: read june 20. 1965. Text-fig. l. Map indicating the localities of aL Kanazawa. Protocyprina naumamzi. 114 493. On a Lowe1· C1·etaceous Pelec1J1Jod. "Cyrena." 1ta1wwnni 115. Y ABE, NAGAO and SHIMIZU (1926) re· narmranni from the type locality, i.e. described many specimens from Yanagi the Tatsukawa formation of Yanagidani, dani and referred several ones from the and also from a few other localities in Shiroi formation of the Sanchu area of cooperation of Prof. T. MATSUMOTO, the Kwanto mountains to Cyrena nau Prof. Y. OTA and Mr. K. NU!\IANO. One manni. Besides, this species has been of us (1. H.) examined also many speci reported to occur from the Kawaguchi mens of this species which had been formation of the Yatsushiro area (MA· described by YARE, NAGAO and SH!i\IIZU TSUMOTO and KAN!I.IEI~A. 1952: MATSU (1926) and are now kept in the Tohoku MOTO, 1954), the Ryoseki formation of University. A few specimens from the the Monobegawa basin and in the vici Kawaguchi, Yuasa, Shiroi and Ayukawa nity of Kochi City, the Yuasa formation formations are also available for study. of the Yuasa-Aritagawa area (MATSU The result of our observation on these MOTO, 1947; MATSUMOTO, 1954). and specimens is reported in this paper. the Ayukawa formation of the Ojika area One of us (1. H.) is responsible for the (0:->uKI, 1955). further note on the taxonomic position Little has been done, however, about of "Cyrena" nazwzanni. the palaeontological reexamination of Before going into description, we ex this pelecypod. jurasso-Cretaceous non press our sincere thanks to Prof. Tatsuro marine pelecypods were investigated by !viATSUMOTO of the Kyushu University KOBAYASHI and SUZUKI (1936, 1937, 1939). for his kind guidance and supervision They assigned some other Lower Creta of this manuscript. Acknowledgements ceous cyrenoids to Polymesoda RAFINES are also due to Prof. Yoshihisa OTA of QUE, 1820. Since then, Cyrena naumanni the Fukuoka Gakugei University and has been conventionally referred to Poly Mr. K6ichir6 NUMAi\O of the Tanabe mesoda and especially to its "section " High School for their kind assistanc;; in Jsodome/la KOBAYASHI and SUZUKI, 1939, the laboratory and field works. without any solid foundation (SUZUKI. 1949, etc.). IIAYAMI in MATSUMOTO Systematic description (1963. ed.), in which NAUMA!' lkuna akaizu \ .. _/. ' ~u1don1 Text-fig. 2. Map .showing the localities of Prolocyprina naumanni in the Katsuuragawa area of eastern Shikoku. nearly smooth except· for somewhat synonym of Eomiodon Cox, 1935. In rugose growth-lines in the adult stage; fact, Prolocyprina is similar to Eomiodon radial ornament and marginal crenula in many characters. The type species lions absent; umbo very prosogyrous; of l'rotocyprina, i.e . .-lstarte liban'otica hinge essentially similar to that of Eo FRAAS, 1878, occurs from the Aptian miodon. as formulated: beds at .. Olive locality" of Lebanon. . . -~ . . Alii AI 3a 3b 5b PI The immature specimens of Protocyprina libanolica are especially similar to some All 2 ·lb PI! species of Eomiodon, such as E. fim <:ardinal tooth 3b especially thick ; 5b bria/us (LYCETT) from the Bathonian of distinctly separated from nymph; lateral Europe, not only in the internal struc teeth comparatively short in the adult ture but also in the external features. stage; transverse crenulations on the The concentri.c sculpture on the surface lateral teeth, if present,. very weak; of immature shells (VOKES, 1946, pl. 5, pallial line simple but bent somewhat figs. •1. 5, 9) and also on the umbonal abruptly beneath the posterior adductor area of mature shells (VOKES, 1946, pl. s·car; umbonal cavity comparatively 5, figs. 2, 3, 6) reminds ~s that of many shallow. species of Eomiodon. As to. the denti Remarks.-ln a study of the Neomio tion no marked difference is recognized dontidae CASEY (1955) regarded Proto between Eomiodon and Protocyprina, al cyprina VoKES, 1946, as a subjective though the cardinal tooth 5b may be 4rn. On a Lowe·r Cretaceou.H f'elecypod. ··Cyrena., naumanni 117 ·slightly stronger and the posterior lateral VoKES, 19,16. from the Aptian of Leba· teeth PI and PII may be proportionally non,. also to Eomiodon. The arrange ·shorter in the latter than in the former. ment of the cardinal teeth agree well We regard here, however, Protocyprina with that of Eomiodon and Protoc_V/>rina, as a distinct genus from Eomiodon in while the comparatively short· posterior vie\v of the following characters. lateral teeth are quite identical with 1) The maximum length of an adult those of Protocyprina libanotica. Since ·shell is only about 10-25 mm in Eomiodon the holotype of Amphiaraus seleniscus but frequently exceeds 70 mm in Proto (ca. 28 mm long) is larger than normal cyrina libanotica and "Cyrena" nau species of Eomiodon, it is better refera manni. ble Protocyprina than to Eomiodon. We 2) The lunule is less clearly demar treat here Amplziaraus VoKES .. 1946 (p. cated in Protocyprina than in Eomiodon. 175) as a subjective synonym of Proto 3) The concentric sculpture in the cyprina VOKES, 1916 (p. 170) by page adult stage is less prominent in Proto preference. cyprina than in Eomiodon. Eomiodon appeared already in the VOKES (1946. p. 170-172) described the Hettangian of japan (HAYA:\11, 1958) hinge structure of Protocyprina libanotica, and flourished in the Bathonian-Pur interpreting that the species belongs to beckian of N. 'N. Europe and Tethyan the Arcticidae. He compared the hinge province. A few· Cretaceous species with that of Cyprina ( =ArclicaJ islandica have been listed by CASEY (1955). but (LJ:>:NAEUS) from the north Atlantic and they are mostly not typical for the Venilicardia bifida (ZITTEL) from the genus. Astarte sakawana KoBAYASHI Upper Cretaceous Gosau beds of Alps. and SUZUKI, 1939, from the Lower Cre But the dentition of Arctica, Venilicardia taceous of Japan is probably a member and other genera of the advanced Arctic of Eomiodon. but so far as we are idae is characterized by the presence of aware, there is no other species of typi the nearly complete cardinal tooth 1, as cal Eomiodon in the Cretaceous. Proto· CASEY (1952) called such a state of den cyprina is known at present only from tition " cyj>rinoid ". VOKES suggested the Aptian of Lebanon and the Neo furthermore that Protocyprina might be comian of japan. Judging from the considered to be ancestral to, or very stratigraphic occurrence and also from near the ancestral line of, Cyprina itself, the resemblance between Eomiodon and but from the above mentioned evidences immature shells of ProtocJ•prina, the it is clear that Protocyprina is not directly latter was probably derived from the related to the Arcticidae of the present former in early Cretaceous times. sense. The ancestry of Arctica, we think, should be sought in such genera Protocyprina naumanni (NEU!'IIAYR) as Venilicardia STOLICZKA, 1871. in the Upper Cretaceous and Somarctica TA Pl. 13, figs. 1-3; Pl. H figs. 1-8; MURA, 1960. in the Upper jurassic. Text-fig. 3 Amphiaraus VOKES, 1946, was origi 1890. Cyrena naumanni NEt;~JAYR, in NAu nally referred to the Astartidae with :\!A:-iN and XEu:-.JAYH, !Jenkschr. Math. a query, but it is likewise referable Naturu:. Cl. Kaiser/. ilkad. Wiss .. Bd. 57, to the Neomiodontidae. CASEY assigned p. 33. pl. 4, figs. 3. 4. :its type-species, Amphiaraus seleniscus 1890. Cyrena gravida NF.I:MAYR, in N.-\U!\1.-\=":'-l' 118 ltaru HA.YA.MI and !sao NAKAI and NEt:~IAYR, ibid .. Bd. 57, p. 34, pl. not accessible to us. They were col 4, fig. 2. lected at Yanagidani. Kamikatsu town 1890. Cyrena /itlwcardium NEl!~1AYR. in NAU· ( ·. Menuki). Katsuura County, Tokushima MANN and NELJMAYR, Ibid., Bd. 57. p. Prefecture. 24 specimens (GK. H6726- :~4. pl. 1. lig. I. GK. H6749) from the Katsuuragawa area 1926. Cynma naltmarmi. YABE, NAGAO and including the type locality (tviATSUMOTO. SIIIJ\fi7.U, Sci. Rep. Tohoku Imp. Univ .. 0TA, NUl\IANO, HAY AMI and NAKAI coli.) Ser. 2. Vol. 9, No. 3, p. 49, pl. 12, figs. 23. 24' 26, 29, 30. 31. are preserved in the Kyushu University, 1926. Cyrena naumanni, YABE r.nd NAGAO. Seven other topotypes. which were illu· Chikyu, Vol. 5. p. 434. strated by Y ABE, NAGAO and SHIMIZU 1927. Cyrena naumanni, YABE, Sci. Rep. To (1926, pl. 12, figs. 6. 17, pl. 13. fig. 25, pl. hoku Imp. Univ., Ser. 2, Vol. 11. No. 1. 14, figs. 23, 26. 29, 31) and are now kept pl. 3, figs. Sa, b. in the Tohoku University, are also con 1947. Polymesoda (Jsodomella) naumanni, MA cerned with the description below. TSU~IOTO. Sci. Rep. Fac. Sci., Kyushu Descriptioii.-Shell very large, equi Univ .. Geol .. Vol. 2. No. 1, p. 3, t(sted. valve. inequilateral, usually exceeding 1949. Polymesoda (lsodomella) naumanni. Su 70 mm in length in the adult stage. tri ZUKI, japan. jour. Geol. Geogr .. Vol. 21. angular-ovate in outline. more or less Nos. 1-4, p. 119. listed. 1952. Polymesoda (lsodomella) naumanni, MA longer than high, moderately inflated; TsuMoTO and KANMERA, Guide book test fairly thick especially in the geron for the geological excursions. The tic stage; antero·dorsal margin relative lower valley of the Kuma, p. 38, listed. ly long, faintly concave in front of 1954 [for 1953]. Polymesoda (Isodomella) umbo. passing gradually inlo antero naumarwi. MATSU~IOTO, Cret. System. ventral margin; postero-dorsal margin Japan. Islands, pp. 63, 74. 81. 85, llO. strongly convex; siphonal margin not listed. clearly defined from postero-dorsal mar non 1955. Polymesoda (lsodomella) rwumamzi. gin ; ventral margin broadly arcuate but YAMA<;IWA, jour. Osaka Gakugei Univ .. sometimes a little concave in its posterior No. 3, p. 47, pl. 1, figs. 5-15. part; an indistinct carina extends from 1956. Polymesoda (lsodomella) naumanni. ONUKI, Explanatory text of the geo umbo to the postero-ventral extremity ; logic map of lwate Prefecture, p. 145, umbo very prosogyrous. placed at about listed. one-fourth or one-third of shell-length 1963. "Cyrena" naumanni, HAYA!'.Il in MA· from the anterior end; lunule moderate TSt.:!o.IOTO (ed.). A survey of the fossils in width, rather shallow. very weakly from Japan illustrated in classical defined ; escutcheon well demarcated by monographs. p. 34. pl. 52, figs. 1-4. (re an angular ridge ; ligament external, production of original figures of C. short but highly elevated above the naumarwi, C. gravida and C. lithocar dorsal margin; surface marked numerous dium) concentric lines of growth. which are somewhat rugose and quite irregular in Material.-The syntypes (NAUMA:-;N prominence: no prominent concentric ribs and NEUMAYR, 1890, pl. 4. figs. 3, 4: on the umbonal region : hinge plate broad HAYAMI in MATSUI\IOTO, 1963, pl. 52, especially in adult shells: dentition char figs. 3. 4). which are to be preserved acterized by much modified lucinoid at Gcologisch-Palaontologische Abteilung cardinal teeth and corbiculoid elongated. des Natur-historisch Museum, Wien, are lateral teeth, as formulated: 493. On a Lower Cret~ceous Pelecypod, "Cyrena" nau1nanni 119 Alii AI 3a 3b 5b PI interruption ; 3b especially brge, very Ail 2 4b PII ' stout and broad; 4b moderately thick, 3a c:>mparatively small, t ubercular, acline, obliquely elongated, very prosocline; 5b represented by a terminal thickening of narrow, short but distinctly separated AIII; 2 fairly stout, highly elevated, from nymph; anterior lateral teeth li ne prosocline, separated from Ail by a wide arly elongated along the antero-dorsal T ext-fig. 3. Protocyprina naumanni (NEU:VIA YR) l. Rubber cast taken from a right internal mould (GK. H6749) x 1.5. [See also Pl. 14, Fig. 5] 2. Rubber cast take n from a right internal mould (GK. H6747) x l. [See also Pl. 14, Fig. 8] 3. Rubber cast taken from a left internal mould (GK. H6745) x 1.5. [See also Pl. 14, Fig. 3] 4. Rubber cast taken f rom a right internal mould (GK. H6746) x l. [See also Pl. 14, Fig. 6] 5. Rubber cast taken from a left internal mould (GK. H6739) x l. [See also Pl. 14, Fig. 2] ·6. Rubber cast taken from a left internal mould (GK. H6737) x l. [See also Pl. 14, Fig. 7] 1211 ltnru If!I YAAfl und lsno NilK/tl margin, but AI and Alii ill-defined from verse crenulations on lateral teeth; ad margin of hinge plate ; posterior lateral ductor scars subovate, subequal in size; teeth PI and PI! remote from cardinal pallial line abruptly bent beneath the pos teeth. much weaker than anterior laterals, terior adductor scar, but never sinuate ;. comparatively short in the adult stage; pedal scar not clearly marked: umbonal Pill not defined: no prominent trans- cavity compar:ltively shallow. ·-:._ A1easurements in 111111.- Specimen Length Height Thickness L/H Both valves (G K. H6726) 85.5 68.0 31.0 1. 26 Both valves (GK. H6727) 78.0 73.5 24.5 l. 06 Left valve (GK. 1!6728.) : 61.0 112.0+ 13.0 1.45- Both valves (GK. H6729) 59.0+ 46.0+ 25.0 Right valve (GK. H6730) 56.5 53.5 13.0 1.06 Both valves (GK. H6731) 60.5 57.0 28.5 1. 06 Both valves (GK. H6732) 75.0 75.0 28.0+ 1. 00 Right valve (GK. H673·l) 30.0 22.5 6.5 l. 33 Left valve (GK. H6735) 36.0 33.5 8.5 1. 07 Left in. mould (GK. II6737) 69.5+ 78.0 13.5 0.89+ Right in mould (GK. H6738) 36.0 27.0 7.0 1.33 Left in. mould (GK. H6739) 50.0 39.5 8.5 1. 27 Both valves (GK. H6740) 56.0 48.0 23.5 1. 17 Right in. mould (GK. H6741) 21.0 17.0 5.0 l. 24 Right in. mould (GK. H6742) 41.0 29.0 8.0 l. 41 Left in. mould (GK. H6743) 37.0 32.0 7.0 1. 16 Left in. mould (GK. H6745) 28.0 24.5 5.5 1.14 Right in. mould (GK. H6746) 46.0 37.0 8.0 1.24 Right in. mould (GK. H6747) 4•1. 5 35.0 7.5 1. 27 Right in. mould (GK. H6748) 33.5 24.5 5.5 l. 37 Right in. mould (GK. II6749) 23.0 18.5 4.0 1. 24 Obseruations and co111parisons.---'-ln ad sidered his material from Yanagidani to· dition to the 31 specimens above de be separable into three species. In one scribed. many specimens from the type of the syntypes (NAU:\IA~N and NEu and other areas at hand .are referable MAYI<, 1890. pl. 4, fig. 3) and some of • 1 to the present species. Most of these the present topotypes (GK. H6728, GK. specimens are more or less secondarily H6729) the ventral margin is slightly ' deformed. and the ratio of length/height concave, while it is broadly arcuate in ·apparently varies to a great extent. other specimens. The prominence of the l\lost specimens with two valves, jn posterior carination and the position of juxtaposition are crushed and secondari the umbo are also somewhat variable, ly depressed, and the thickness is gen but it may be partly due to the differ· erally much decreased. On the grounds ent states of secondary deformation. of measurements of undeformed speci Beside the type area i.e. the Katsu mens. it is evident that the range of uragawa valley, the present species oc the intraspecific variation is fairly wide; curs also from the Yatsushiro. Yuasa, hence NEUMAYR (1890) previously con- Sancln1 and Ojika areas. So far as we 4.9:1. On a /,ower· Cretaceons l'elec]IJwd. ··Cyrena" nawnanni 121 observed the present m:1terial. no mark brackish-water sediments of japan. ed morphological difference is discernible It is probably a general tendency that between the groups of specimens from the ratio of length/height decreases with one area to another. Although they- are growth. In most of the young specimens variable in the state of preservation and the ratio is slightly larger than L20, generally more strongly deformed than while in many adult specimens it scare the specimens from the type area, two ly exceeds 1.10. The tendency is well specimens(GK. H6750. GK. 116751) from the recognizable also from the growth-lines Yuasa formation of the Yuasa area. one of one specimen. specimen (GK. H6752) from the Kawa The present species is closely related guchi formation of the Yatsushiro area. to Protocypri n a lib an otic a (FRAAS. 1878} one specimen (GK. H6753) and several from the Aptian of Lebanon (NOETLING, ones in the Tohoku University from the 1886: VOKES, 19•16; CASEY, 1955). because Shiroi formation of the Sanchu area, and they are similar in every essential char two ill-preserved moulds from the Ayu acter. The distinctly separated cardinal kawa formation of the Ojika area are tooth 5b and the much thickened 3b certainly referable to l'rotocyprina nau show that they are equally distinguisha manni in view of the similar external ble from Eomiodrm. The size of the and/or internal characters. adult specimens of P. liba11otica (ca. 80 The immature shells of this species. mm in maximum length) is just com which are represented by several speci parable with that of the present species. mens (GK 116734. GK. 116741, GK. 1167,15. The Lebanon species is. however, differ GK. J-16749). show an Eomiodon-like inter ent from the present one in the more nal structure. The disposition of the centrally placed umbo and the presence cardinal teeth is essentially similar to of conspicuous concentric sculpture on that of many Jurassic species of Eo the umbonal surface. miodon, although the anterior lateral We agree withY ABE. NAGAO and SHI· teeth are not so strongly curved inwards MIZU (1926) and other subsequent inves as in Eomiodon. In some gerontic speci tigators in considering that the three mens (GK. H6737, etc.), however, the nominate species of NEUMAYR (1890), hinge plate is extraordinarily thickened, Cyrena naumanni, C. gravida and C. the lateral teeth become somewhat ob Lithocardium, are actually conspecific; solete, and the cardinal tooth 5b is pro· the specific name of Cyre11a naumanni portionally much thickened. The hinge is applicable on account of its page structure in various ontogenetic stages priority. Y ABE, NAGAO and SHL\!IZU is well exhibited in the specimens GK. (1926, p. 50) noted the presence of three 116736, GK. 1-16737, GK. H6741. GK H67,12, cardinal teeth in each valve, regarding GK. H6746, GK. H6748, GK. H6749 (Text the dentition of this species as cyrenoid. fig. 3) and also in the specimen IGPS However. as described above, the left reg. no. 35153 (YABE, NAGAO and SHI valve has only two cardinals 2 2-nd 4b. MIZU, 1926. pl. 12, fig. 6) preserved in the cardinal 1 is absent. and the hinge the Tohoku University. In the speci structure is certainly a kind of Jucinoid mens GK. 1-16726, GK 116727. GK H6731, type. the opisthodetic external ligament is well Y A:'>! AGIW A (1955) interpreted .. Cyrena" preserved, as is usually so in other eyre shiroiensis Y ABE and NAGAO in YABE, ooids from the Jurassic and Cretaceous NAGAO and Sll!l\IIZU (1926) to be a 122 lta.1·u HAYAMJ and ]sao NAKAI synonym of "Cyrena " naumanni, con ximately upper Neocomian). Dark grey sidering that the two species are hardly shale of the Tatsukawa formation at separable as regards his material from Hy. 5010, south of Yanagidani (type the Lower Cretaceous of the Shima area. locality) and at Hy. 5041, south of Sho But the syntypes of "Cyrena " shiroi kuda, Kamikatsu town, Katsuura County, ensis (Y ABE, NAGAO and SHIMIZU, 1926, Tokushima Prefecture. Weathered sandy pl. 14, figs. 4-6, 19, 20, 22, 25), from the shale of the same formation at Hy. 5032, Shirai formation of the Sanchu area, are near Tatsukawa, Katsuura town, the clearly distinguishable from the typical same county, and at Nk. 5018, south of specimens of Protocyprina naumanni in Nishioka, the same town. Above noted the much smaller dimensions, the deeper localities are indicated in Text-fig. 2. umbonal cavity, the presence of trans Black shale of the Kawaguchi formation verse crenulations on the side slopes of at a road-cut between Kawaguchi and the cardinal teeth, and the different dis Shimofukami, Sakamoto town. Yatsu position of the cardinal teeth of C. shi shiro County, Kumamoto Prefecture roiensis, as is well exhibited in the ~KANl\IERA coli.). Dark grey sandy shale hypotypes from the Yoshimo formation of the Yuasa formation at Tataki cape, of the Shimonoseki area (KOBAY ASH! south of Suhara, Yuasa town, Arita and SuzuKI, 1939). These characters do County, Wakayama Prefecture (MATSU not agree with the diagnosis of any MOTO, 0TA and HAYAMI coli.). I3lack known genus of the Neomiodontidae. shale of the Shiroi formation at Bomc Although further studies are needed on kisawa, OhinaLa village, ivlinamisaku the taxonomic position of ··C." shiroi County, Nagano Prefecture (YABI~ et al. eusis, it is evidently distinct from Proio coli.). Grey sandy shale of the Ayukawa cyprina naumanni in a generic level. formation at Kukunari, Ojika town, Ojika Y A~IAGIWA's specimens are probably re County, Miyagi Prefecture (HAYAl\11 coli.). ferable to •· C." shiroiensis instead of P. Y ABE, NAGAO and SHIMIZU (1926) re nauinarzni in view of the deep umbonal ported this species also from .. cyrenoid cavity and small dimensions, although beds " at Shirai and Hachimanzawa of their hinge structure is unknown in the eastern part of the Sanchu area in detail. Gumma Prefecture, where Aritan and Occurrence.- Koch ian (approximately l'vliyakoan deposits are distributed HIRA· lower Neocomian) and (?) Aritan (appro- YMIA et al. (1956) and some others re· Explanation of Plate 13 Prolocyprina naumanni (NEe~IAYR) ...... p. 117 Fig. L Bivalved specimen (GK. H6727) x 1. Tatsukawa formation at Hy. 5010. Yanagi dani, Kamikatsu town, Katsuura County, Tokushima Pref. la: left valve, lb: right valve. Fig. 2. Right valve (GK. H6731) x 1. Loc. ditto. Fig. 3. Bivalved specimen (GK. H6726) x 1. Loc. ditto. 3a: left valve, 3b: right vah·e, 3c: upper view. All specimens illustrated are kept in the Department of Geology, Kyushu University. Photos by I-IAYA:\11 and NAKAI. H AYAM I and NAKAI: "Cyrena" naurnanni Plate 13 4.9;J. On a Luwer Cl'etaceous l)elecypod . .. Cyrena .. na:unanni l::~:J ported that "Cyrena" naumanni occur It is here sugge:;ted that the Neomio red also from certain brackish-water dontidae are sep:1rable into two phyla beds in the Hanoura formation of the genetical suites: one is the group of Katsuuragawa area. Those occurrences, Neomiodon FISCHER, 1887 (=.\liodon however, are doubtful, because the pele SANDBERGER. 1871. non DUMf~RIL, 1859, cypod specimens from those localities nee CARPENTER, 1865: ?=Protomiodon are certainly referable to the species Al\DERSON and Cox. 1948), including which are distinct from Protocyprina Myrene CASEY, 1955 and Crenolrapezium n azmzannr. HAY A:\11, 1958, and the other is the group of Eomiodon Cox, 1935 (non CIIAV A:'\, 1936), including Pseudasaphis MATSU· Further notes on the taxonomic position :\lOTO, 1938. Protocyprina VOKES, 1946, of ·• Cyrena " naunuwni and the and Coslocyrena MATSUMOTO and KAN classification of the :\IER:\, 1952 ~l'viS*J. ~eomiodontidae The group of Neomiodon is generally characterized by the thin test. the more By ltaru IIAYA:\11 or less conspicuously carin3te shell. the absence of a well defined lunule. the un As has been precisely described above. developed cardinal tooth 5b, the well de· .. Cvrena" IWUIIWI!Ili is clearly different veloped transverse crcnulations on the fr0;11 any species of the Corbiculidae in lateral teeth and the smoothly arcuate the hinge structure. All the species of pallial line. In many characters this the Corbiculidac. including Polymcsoda group is fairly similar to J~'otrapezium RAFII'\ESQUE, 1820. have in each valve DouviLLE, 1913, a primitive genus of three cardinal teeth. of which the cent the Arcticidae from the marine Lower ral cardinal tooth 1 is well developed. jurassic. The group of Eomiodon, on In "Cyrena" naumanni. however. this the contrary, shows thick test, a weak tooth is absent, the cardinal tooth 2 is postero-ventral carina, a clearly defined never differentiated into 2a and 2b. and lunule and a well developed cardinal the weak cardinal tooth 5b is clearly tooth 5b. The transverse crenulations demarcated from the nymph. In the on the lateral teeth are less distinctly disposition of the cardinal and lateral developed. The pallial line is generally teeth and also in external features, this abruptly bent beneath the posterior ad species is especially similar to .-lstarte ductor scar in the group of Eomiodon. tibanotica fi{AAS. 1878. from the Aptian The surface, especially the umbonal of Lebanon. which is the type-species of region, is commonly marked with con Protocyprina VoKES, 19·16. It is con centric ribs and rarely also with radial sidered here the two species are con riblets. In some characters the group of generic. In other words .. Cyrena" nau Eomiodon is more similar to the Astart manni is assigned to Prolocyprina. idae than to the Arcticidac. Although The dentition of Protocyprina is not the Neomiodontidae have been referred of cvrenoid but of lucinoid type. The to the Arcticacea, the two groups were elongated lateral teeth may remind me probably derived independently from those of corbiculids, but in the general hinge structure it is best referred to the * The diagnosis of this genu:; will be given Neomiodontidae defined by CASEY (1955). on another occasion. 124 !tarn 1-!A.J'AMI and !sao NA!Cll two m::!rine heterodont pelecypods which MATSUMOTO, Tatsuro (195-l): The Creta are unrelated with e:1ch other. If the ceous System in the japanese Islands. xiY Neomiodontidae had dual origin, they +32-l pp., 36 pis. Japan. Soc. Promotion could be separated into two subfamilies Sci. Res .. Tokyo. [for 1953] or even into two families. -- (1963. ed.): A survey of tire fossils from japan illustrated in cl!lSS.~~a/ monographs. 57 pp., 68 pis. Palaeont. Soc. japan. 25th References Anniv. Volume. MATSU\JOTO, Tatsuro and KA?':<.Il::RA, Kame CASEY. Raymond (1952): Some genera and toshi (1952) : Guide book for geological subgenera, mainly new, of Mesozoic excursions. The lou•er valley of lire Kuma. heterodont lamellibranchs. Proc. Ma/ac. 71 pp., 6 maps. Dept. Geol., Kyushu UniY. Soc. London, 29. 121-176. (in Japanese) -- (1955): The Neomiodontidae. a new NAUMANI". E. and NEUMAYR. M. (1890): Zur family of the Arcticacea (Pelecypoda). Geologie und Palaontologie von Japan. Ibid. 31. 208 -222. pl. 11. Denkschr. Kaiser/. Akad. IViss.. Mati!. HAYA:>.ll, Itaru (1958): A re,·iew of the Naturw. C/., 57. 1--41. pis. 1-5. so-called Liassic -- cyrenoids" in Japan. NoF.TLII"G, Fritz (1886): Entwurf einer japan. jour. Ceo/. Ceogr., 29. (1-3). 11-27. Gliederung der Kreide-formation in Sy pis. 2. 3. rien und PaHistina. Zeitschr. deut. geo/. HIRAYA\JA, Takeshi et al. (1956): Explana Gesell., 38. 824-875. pis. 2•1-27. tory text of the geologic map of Kenzan O~uKr. Yoshio (1956): Explanatory text of (I /75.000). 52pp. Tokushima Pref. (in the geologic map of !wale Prefecture japanese) (1 I 100.000). The geology of the Kita KEEN, A. Myra (1958): Sea shells of tropical kami mountains. 189 pp. Iwate Pref. west .·lmerica. 62-1 pp.. 10 pis. Stanford (in Japanese) Univ. SuzuKI, K6iti (1949): Development of the KOBAYASHI, Teiichi and SliZUKI, K6iti (1939): fossil non-marine molluscan faunas in The brackish Wealden fauna of the Yo eastern Asia. japa11. jour. Ceo/. Ceogr .• shirno beds in Prov. Nagato, Japan. 21' (1-4), 91-133. japan. jour. Ceo/. Ceogr .. 16. (3-'1). 213- VoKES, Ilarold Ernest (1946): Contributions 22,1. pis. 13. H. to the paleontology of the Lebanon Explanation of Plate 14 Prolocyprina lllll111la1111i (NEUJIIA YR) ...... p. 117 Fig. 1. Left valve (GK. H6728) x 1. Tatsukawa formation at Hy. 5010. Yanagidani. Kamikatsu town. Katsuura County. Tokushirna Pref. Fig. 2. Left internal mould (GK. I-16739) x 1. Loc. ditto. Fig. 3. Left internal mould (GK. H6745) x 1.5. Loc. ditto. Fig. 4. Right valve (GK. H6740) x l. Loc. ditto. Fig. 5. Right internal mould (GK. H6749) x 1.5. Tatsukawa formation at Nk. 5018, south of Nishioka. Katsuura town. Katsuura County. Tokushima Pref. Fig. 6. Right internal mouth (GK. 1-16746) x 1. Loc. same as Fig. 1. Fig. 7. Obliquely compressed left internal mould (GK. H6737) x 1. Loc. same as Fig. 1. Fig. 8. Right internal mould (GK. H6747) x 1. Loc. same as Fig. 5. All specimens illustrated are kept in the Department of Geology,_ Kyushu University. Photos by IIAYAMI and NAKAI. HAYAM I and NAKAI : "Cyrena" naumanni Plate 14 1 49.1. ( >11 a Lower Cretaceous Pelecypod. ··Cyrena.,. nanmcmni 125- mountains. Republic of Lebanon. Part Kwanto mountainland. Sci. Nep. Tohoku 3. The pelecypod fauna of the "Oli1·e Imp. Univ .. [2], 9. (2). 33-76. pis. 12-15. locality" (Aptian) at Abeih. Bull . .:tmer YA~!AGIW.'\, Nobuo (1955): Cretaceous Mol ican Museum Nat. His/ .. 87. (3). 143-215, lusca from the Shima peninsula, japan. pis. 1-10. jour. Osaka Gakugei Unit•.. (3). 43-56, YABE. Hisakatsu. NAGAo. Takumi and Slll pis. 1. 2. (in Japanese with English re· ~llzL·. Saburo (1926): Cretaceous l\lol· surue) lusca from the Sanchu graben in the ------ ± Jf< Ayukawa ~ Jll Shima •C.• ,. Bomekisawa :f.-;l~iR Shimofukami 'f i~ * Ilachi ma nsa wa /\ fl iR Shiroi t'l ;It- Kamikatsu town J:Jmii!J Sbokuda D.ft Ill Katsuura town Mi i!li II!J Suhara li§ )Jj( Kawaguchi Jll 0 Tataki 9liJ ~ Kukunari-hama i- :IL ~ Tatsukawa 'Sr. Jll Monobegawa ~J.I $ Jll Yanagidani ~p .fj- Nishioka jl_§ (ii\j Yatsushiro 1\ 1\:: Ohinata 1•illage :kBf,','Jf:t Yuasa /},} (~ Trans. Proc. Palaeont. Soc. Japan, N. S., No. 591 pp. 126-1-12. pis. 15-16, S.:pt. 20, 1965 -194. CRETACEOUS ECHINOIDS FROM THE SANCHU GRABEN, CENTRAL JAPAN* KEISAKU TANAKA Geological Survey of Japan Introduction and Acknowledgements criminated among them were six genera and eight species ; one of these species The Cretaceous deposits in the Sanchu was already described by the writer and graben. about 100 km northwest of Tokyo, his co-worker under the name of Aphel have been hitherto investigated by many aster serotinus TANAKA and SHIBATA, persons from the standpoint of strati· and two others are new to science. graphy and paleontology. Nevertheless, Some of the species here described are the detailed geological map published found also in the Lower Cretaceous of still covers only the eastern part of the several other areas in the Outer side of area ; and moreover the paleontological Southwest Japan. So, for the description works have been done chiefly on the of such species here complementally molluscan fossils alone. As to the echi dealt with are materials obtained from noids which are very subordinate consti the Barremian Arita formation in the tuents among the Cretaceous fauna in Yuasa area in the western pan of the this area, only a few species have been Kii Peninsula. reported by Y. Y ABE and others ll955), The writer expresses his cordial thanks F. ARAI and others (1958), and K. T AKEI to the following persons: Dr. Masahiro (1962) without paleontologic descriptions. OKUBO of the Geological Institute, Uni Such being the case. for the purpose of versity of Tokyo for his much help in a more complete collection of specimens the collecting of materials and photo together with examination of the strati graphing: .Mr. Yukio YABE of the Japa graphic occurrence, the writer visit~d nese Information Center of Science and the Sanchu graben in 1953, and agam m Technology and ~Jr. Kensaku T AKEI of 1958. !'vfeanwhile some other investi the Chichibu Natural Science !\luseum gators' collections from this area were for their kind offer of materials and in ·offered to the writer. Thus, many formation on the stratigraphy; Dr. No specimens from the Lower Cretaceous boru YAJ\IASHITA of the Geological Insti in the Sanchu graben were ready to hts tute, University of Tokyo and Mr. !v1an· hand. As the result of the study, di:;- kichi HOI{IGUCHI of the Department of • Received May 5, 1965; read Sept. 2:{, 1961. Earth Science, Saitama University for 12(i 494. C1·etaceous echinoids 127 their kind offer of materials; Mr. Yoshio Fossil Localities MASAI of the Geological Survey of Japan for the photographing. Most of the materials here dealt with were collected from the Ishido forma tion. and only a few of them from the Stratigraphical Note presumed Ishido formation. Their local ities are as follows (Fig. 1). The Cretaceous deposits in the Sanchu graben. 40 km long and 2-3.5 km broad. Loc. 1 :-About 1.1 km south of Hikage. Oga are in fault relation to the Paleozoic on no-cho. Chichibu-gun. Saitama Prefecture: both the northern and southern sides. dark gray, massive. sandy siltstone in the being in a direction subparallel to the lower part of the Ishido formation: echi general trend of the Paleozoic. They noids scarce. show a synclinorium structure compli Loc. 2 :-About 800 m northwest of Sebayashi. cated by numerous longitudinal and Nakazato-mura. Tano-gun, Gumma Pre fecture; dark gray. massive. sandy silt transversal faults. According to T AKEI stone in the lower part of the Ishido (1963), the stratigraphic succession in the formation : echinoids sporadic. eastern part of the area is as follows in Loc. 3 :-About 500 m north of Myoke. Naka descending order. zato-mura, Tano-gun, Gumma Prefecture: dark gray, massive. sandy siltstone in Sanyama formation (lower part of the Upper the lower part of the lshido formation: Cretaceous) : About 500 m thick. begin echinoids scarce. ing with basal conglomerate which. in Loc. 4 :-About 600 m north of Shiroi. Ueno turn. is succeeded by shale and subordi mura. Tano-gun. Gumma Prefecture: nate sandstone. Marine fossils are spo dark gray, massive, silty fine-grained radic. sandstone to sandy siltstone in the lower part of the Ishido formation: echinoids ~-- Unconformity sporadic. Sebayashi formation (Aptian-Albian): Less Loc. 5 :-About 2.5 km northwest of Shiroi. Ueoo-mura. Tano-gun, Gumma Prefec than 600 m thick. ~.:om posed of arkose sandstone in the lower and alternation ture: dark gray. massive, silty fine grained sandstone to sandy siltstone in of sandstone and shale in the upper. the lower part of the lshido formation~ Molluscan remains. chiefly of brackish echinoids common in some laminae. origin are sporadic and a plant bed is Loc. 6 :-Upper course of the Honya. Minami found in the lower. maki-cho. Shigaraki-gun. Gumma Prefec lshido formation (Neocomian): About 400 m ture; dark gray siltstone in the lower thick, begining with conglomerate and part of the Ishido formation : echinoids. composed mainly of sandy shale or silt scarce. stone. :\Iarine molluscan fossils such as Loc. 7 :-lshido. Saku-cho. Minamisaku-gun, ammonites, trigonians and other bivalves Nagano Prefecture; dark gray, rather occur in abundance. Brackish shells and massive siltstone in the lower parl of plant remains are also common in certain the Ishido formation: echinoids sporadic. horizons. Loc. 8 :-Lower course of the Onozawa. Saku cho, Minamisaku-gun, Nagano Prefecture: The Ishido formation is to be corre· bluish gray. massive. medium-grained lated to the Hauterivian and Barremian sandstone in the presumed Ishido forma from the ammonite assemblages. tion: echinoids scarce. 128 Keisaku TANAK.~l Fig. 1. Map showing the fossil localities. 1-8. fossil localities; 9. Kawarazawa; 10, Kanna river; 11, Kagahara; 12, Shiroi: 13, Jukkoku-toge. Inset .is a map of Kwanto, indi· eating the Cretaceous outcrop in the Sanchu graben. Echinoids occur scarcely also in the surface concave around the peristome, Sanyama formation. But they are not somewhat pulvinate, less strongly inflat .dealt with in this paper. ed in the antero-lateral interambulacra than in the others. Apical system some~ what in front, small, with four genital Description of Species pores and a large central madreporite. Ambulacra all similar, superficial, Order Cassiduloida DUNCAN petaloid ; petals lanceolate, closed api cally, slightly open distally, extending Suborder Cassidulina DELAGE almost to the ambitus; anterior petal and HEROUARD shorter, narrower than the others; an Family Clypeidae LA!\IBERT, 1898 terior paired petals widest. diverging at an angle of 120° to 130° ; posterior pair Genus Pygurus L. AGASSIZ, 1839 ed petals longest, diverging at an angle approximating 60°. Poriferous zones Subgenus Pygurus (s. s.) L. AGASSIZ narrower than the interporiferous; pores conjugate, outer pores long slit-like, inner Pygurus (Pygurus) complanatus n. sp. pores small, round to oval in the petaloid Pl. 15, figs. la-c, 2a-c part; pore pairs minute, rounded, ob liquely set near the ambitus. Ambulacra Type specimens :-Holotype, GSJ. 6090; on the adoral surface lodged in distinct paratype. GSJ. 6091. furrows. Description:-Test small, subovate. Peristome somewhat in front, directly low, slightly longer than wide, widest under the apical system; pentagonal, well behind the center, rounded in front. sunken ; phyllodes short, widened, de lacking the anterior notch, nearly straight pressed ; bourrelets conspicuous, elon in the postero-lateral margins, slightly gated. Periproct transversely oval. produced behind. Adapical surface broad· inframarginal. not visible from above. ly convex. highest somewhat behind the Tubercles small, perforate, crowded, center, steeper in front than behind. larger on adoral surface than on adapi rather acute at the ambitus; adoral cal surface. 494. Cretaceous eehinoids 129 Measurements (in mm.) :- Lower Cretaceous (GSJ. 6090, 6091, 6125, 6126. coli. by Y. Y ABE: GSJ. 6106, coli. ~ _\ Gs]~6ogo 1Gsj 6091 by K. TANAKA and Y. Y ABE). Length 21.2 19.7 Width Hl. 0 \6.6 Order Spatangoida L. AGASSIZ Height I 7. 5 6. 1 1 Distance of apex from 1 Suborder ~vleridosternata (Lovf;;N) the anterior end 8.9 8. 4 ~v[ORTENSE:\ Remarks:--The para type (Pl. 15, figs. Family Holasteridae ZITTEL, 1879 2a-c) shows a slightly more elongated emend. LA!\IBERT. 1917 outline than the holotype (Pl. 15, figs. la-c) which represents the general form Subfamily Holasterinae 1loRTEl'\SES. 1950 of the test. According to KIER's classi· Genus Pseudholasler PoMEL, 1833 fication of the genus Pygurus (1962), the present species is to be placed in the Pseudholaster n. sp. (?) subgenus Pygurus. This species is clearly Pl. 15. figs. 3a-d. 4a-c: Text.figs. 2a-b distinguished from the Japanese known species. Pygurus (Pygurus) asiaticus To Descriptioll :-Test medium-sized, cor· KUNAGA*. The latter has a tumid test, date. nearly as \vide as long, widest a a distinct anterior notch and a large little in front of the midpoint. contract· posterior rostrum. This new species re· ed behind; adapical surface rather fiat sembles to some extent Pygurus (Pygurus) topped, highest on the margin of the impar GAUTHIER from the Upper Neo· anterior sulcus somewhat in front of the comian of Algeria, although in the latter apical system. sloping abruptly in front, features of the posterior part of test is truncated bchined: posterior truncated unknown. However, Pygurus (Pygurus) surface slightly concave. thus the pos· complanatus differs from P. (P.) impar terior margin showing a shallow sinus; in having shorter. narrower and more adoral surface slightly convex. Apical tapering petals. The species hue de· system somewhat in front. elongated, scribed is furthermore easily distinguish· the length about three times the width ; able from Pygurus (Pygurus) monlmollini apical system. though its detailed struc (AGASSIZ) from the rvliddle Neocomian ture being not observable. probably of France and Switzerland. In /'. (P.) intercalary type because the anterior montmollini the test is higher, distinctly paired ambulacra and the posterior are notched in front and largely rostrated somewhat distant from each other at behind. Occurrence :-Loc. 8, presumed lshido - # formation. medium-grained sandstone, - - -- 2a • Although this species was collected from the presumed Cretaceous strata in the south· -- -- 2b ern part of Shikoku. it exact horizon is still Figs. 2a. b. Pseudholaster n. sp. ( ?). unknown. The horizon was misled lo be the Pore pairs in the left anterior paired Cenomanian in the Essai de nomenclature ambulacra (2a) and left posterior paired raison nee. ambulacra (2b). x6.· (GSJ. 60-16). 130 Keisaku TANAKA the apex. Anterior sulcus deep, rather sized, more closely spaced on plastron short, increasing in width and depth to· than elsewhere. No fascicles. ward the ambitus, forming a distinct anterior notch. bordered by sharp keel· Measurements (in mm.) :- like elevations on both sides. extending to the peristome as a less distinct groove GSJ. 6050 on the adoral surface. Anterior ambulacrum lodged in the Length 26.8 deep anterior sulcus, shortest, not peta· Width 26.8 loid ; poriferous zones much narrower Height 13.8 Distance of apex from than half the width of the interporifer· the anterior end 10.9 ous zones; pores similar, smaller. oval. closely set, transverse. Paired ambulacra open distally. superficial. subpetaloid; an Remarks:-The specimen registered terior ambulacra slightly flexuous, wider GS]. 6050 (Pl. 15, figs. 4a-c). though th:w the posterior ambulacra which are lacking about half of the anterior mar straight: pores opposite, not conjugate. ginal part of the test, is regarded as In the anterior paired ambulacra. anteri· showing the general form of the test in or poriferous zones much narrower than the present species. The specimens at the posterior, nearly half the width of hand are fairly close to Pseudholaster the latter; interporiferous zones some· baconicus SZORENYI from the Albian and what narrower than the posterior zones. Cenomanian of Hungary in general fea· Pores in the anterior zones elongated tures of the test. But there is a minor oval. opposite, rather near together. Pos· but distinct difference between the two. terior zones composed of longer slit·like In P. baconicus tubercles are larger on outer pores and shorter slit-like inner the margin of the adoral surface and on pores; pores of each pair opposite, wide· that of the plastron than elsewhere. The ly set. In the posterior paired ambula· present form is distinguished from Ps£'Ud· era, two poriferous zones less unequal in holaster bicarinatus (AGASSIZ) from the comparison with those of the anterior Cenomanian of France in many respects. paired ambulacra; anterior poriferous In the former, the test is not arcuate zones narrower than the posterior ; inter· but rounded at the ambitus and the api poriferous zones somewhat narrower cal system is somewhat fonvard, thus than the posterior poriferous zones. the anterior sulcus is shorter than in the Pores in the anterior zones elongated latter species. In P. bicarinatus, more oval, opposite, rather closely set; pores over. the posterior interambulacral area in the posterior zones slit-like, opposite. on the adapical surface is elevated in widely set, a little longer in the outer the form of carina. To sum up, the row than in the inner. species here described probably repre· Peristome semicircular. deep, situated sents a new species. The establishment at about one-fourth from anterior end, of this new species is, however, sus· lying in the recurved end of the anterior pended until more specimens are obtain sulcus; plastron meridosternous. Peri· ed. The occurrence of Pseudholaste1· proct high up on the posterior truncated from the Upper Neocomian of Japan surf::!ce which is concave, longitudinally requires correction of the stratigraphic elongated oval. Tubercles small, similar- distribution of this genus. 494. Cretaceous echinoids Occurrence :-Loc. 5, Ishida formation, silty fine-grained sandstone to sandy ~ ~~ siltstone, Neocomian (GSJ. 6044-6050, 3a 6129, coli. by K. TAN AKA and M. OKUBO). Suborder Amphisternata (LOYts) .iVIORTENSE:\ Family Toxasteridae LA~IBERT. 1920 Figs. 3a-c. Toxaster sa11chuensis n. sp. 3a. Anterior ambulacrum. x6. 3b. Left Genus Toxaster L. AGASSIZ, 1840 anterior paired ambulacra. x6. 3c. Left posterior paired am hulacra. x 6. (GSJ. .~anchuensis n. Toxaster sp. 6124). Pl. 15. figs 5a-b. 6a-b: Pl. 16, figs. Ia -c. 2a-c; Text-figs. 3a-c ly set. near the anterior outer corner of ambulacral plates; pores of each pair Type specimens :-Holotype, GSj. 6124: not separated by a granule. Paired am paratypes. GSj. 60,11, 6042, 6110. bulacra unequal. open distally, slightly Description:-Test medium-sized, cor sunken, subpetaloid; petaloid part longer date. widest somewhat in front of the in the anterior paired ambul::cra than in midpoint. not greatly contracted behind ; the posterior. Anterior paired ambulacra adapical surface inflated. rather flat slightly shorter. wider than the posterior topped. highest at the apical system. ambulacra. diverging at an angle appro truncated behind; adoral surface nearly ximating 110°. slightly flexuous; petaloid ftattish. Apical system some\vhat in part about two-thirds the way to the front of the midpoint. with four genital margin; poriferous zones somewhat un pores. ethmophract. Anterior sulcus equal, anterior zones narrower than the rather shallow. becoming wider. much posterior zones. Pores in the anterior shallower tow·ard the frontal margin. ex poriferous zones composed of short slit· tending to the pcristome: anterior notch like outer pores and elongated onll inner rather indistinct. pores. pores of each pair opposite, rather Anterior ambulacrum depressed through widely set; pores in the posterior zones out the way, somewhat shorter, wider slit-like. opposite. widely set, outer pores than the paired ambulacra; poriferous longer than inner pores, acuminated in zones much narrower than the interpori ward. Pores in the distal part diminish ferous zones. somewhat less than half ing in length, becoming closer together; the width of the latter in the middle pores near the ambitus minute. almost part. widest near the middle, tapering circular. near together. obliquely set. near toward the ambitus and apical system. the anterior outer corner of ambulacral Pores in the middle part oval to elon plates. lnterporiferous zones somewhat gated oval. near together; outer pores narrower than the posterior pori ferous nearly transverse or slightly oblique. zones. Posterior paired ambulacra near inner pores oblique; pores in the proxi ly straight. diverging at an angle appro mal and distal parts smaller, oval : pores ximating 60' ; petaloid part shorter .than near the ambitus minute. round. oblique- that of the anterior ambulacra. about ·~·) 1 ~_,_ Ke·isak1t 'TANAKtl half the way to the margin, somewhat of lVIorocco in the features of pore pairs ·closed at the end, composed of two equal in the anterior ambulacrum, the depressed poriferous zones. Poriferous zones near paired ambulacra and the anteriorly ec ly equal to the interporiferous zones in centric position of the apical system. width ; pores elongated, opposite, widely But in T. gibbus the test is more inflat set, outer pores longer than inner pores, ed and the petals are longer than in T. slit-like; features of the pores in the sanchuensis, and moreover the interpori distal part and near the ambitus similar ferous zones of the paired petals have to the case of the anterior paired am no tubercles. T. sanchuensis is distin bulacra. guished from T. peroni. which has tuber Peristome subpentagonal, somewhat cles in the interporiferous zones of the transverse, near the anterior fourth to paired petals like the former species, by fifth, shallowly sunl 1961. APhelaster serotinus TANAKA and SIII· BATA. Trans. Proc. Pal. Soc. japan, N. S.. No. 42, p. 68-72, pl. 10, figs. I -6. text-figs. 1. 2. Occurrence :-Loc. 7, Ishido formation. siltstone. Neocomian (GSJ. 6092. 6093. 6095, 6096, coli. by Y. Y ABE). %I~~::~:~:=::-=-=-~~ '-'------=_.1 4b Genus Heteraster D'OHBIGNY. 1853 .--·-(;; } -----....__ -~ ( =Ena/laster D'0RBIG:>lY, 1853) ~-~'>---~-~ -'--~-~)4c Heteraster macroholcus (NISIY :\\IAJ Figs. 4a-d. Heteraster macroholcus Pl. 16. figs. 3, Ja-b: Text-figs. 4a-d (NisiYA:\IA). 4a. Anterior ambulacrum. x 5.5. 4b, Right anterior paired ambu 1950. 1Vashitaster (?) macrolwlcus NisiYA~IA, lacra, x 5.5. •lc. Right posterior paired Short Papers IGPS. No. 1, p. 45. figs. ambulacra. x5.5. (GSJ. 6128. Arita forma 4-7. tion). 4d, Plastron, x 0.75. (GSJ. 6002. 1954. Washitasler macroholcus. T A:"AKA and Arita formation). 0Kt:Bo. jour. Geol. Soc. japan. Vol. 60. No. 705. p. 221, pl. 7, figs. 1. 2, text Anterior ambulacrum longest, lodged figs. 5. 7. in the deep anterior sulcus, widest mid 1954. lVashitaster barremicus, T.·\:->AKA and way between the apical system and the OKUBO, Ibid., Vol. 60, No. 705, p. 220. frontal margin: poriferous zones some pl. 7, fig. 3. text-fig. 7. what narrower than the interporiferous. Description:-Test large. ovate, rather Pores in the main part of the petali low, widest near the midpoint. not greatly ferous part very unequal, opposite, rather contracted behind: adapical surface gent· close together ; in the outer row pores ly arched. highest on the margin of the slit-like, acuminated inward, several 134 Keisa/m LL\'AKA longer pores irregularly alternating with fourth, lying in the recurved end of the one shorter pore; in the inner row pores anterior sulcus. Pbstron amphisternous. round to oval. pores opposite shorter labrum slightly emarginate. sternal plates outer ones slightly smaller. somewhat nearly symmetrical. equal in size and inward. thus pore pairs lining up in shape. Ptriprcct longitudinally oval, three (or better to say rather four) files. high up on the posterior truncated sur Pores in the proximal part becoming face. Tubucks small. perforate, crtnu less unequal. inner pores round. outer late, scrobiculate. rather wid€'ly scattered; pores oval to elongated oval. Paired tubercles smaller. more closely spaced on ambulacra very unequal in length. :::uper· both sides of the anterior sulcus and at ficial, flexuous. subpetaloid. Anterior the ambitus; interporiferous zones of the paired ambulacra much longer than the paired ambulacra dotted with tubercles; posterior. diverging at an angle appro· plastron con.'red with close-set tubercles; ximating 120• then turn forwards and numerous microscopic granules between laterally, angle between mid-line of each tubercles. No fasciolcs. petal about 70•. and then diverge laterally The largest of the specimens at hand and cross the ambitus far anteriorly; including those from the '{uasa area poriferous zones very unequal. anterior attains about 8 ern in length. zones much narrower than the posterior Remarks:-The above description is zones. Pores of the anterior zones oval based principally upon observations of in the outer row. round to oval in the a fairly large number of specimens from inner row. opposite. near together; pores the Arita formation. This species was of the posterior zones elongated oval in provisionally referred to Washitaster by the inner row, slit·like in the outer row, the original author. However, it was opposite. r the posterior end. No fascioles. ---, Measurements (in mm.) :- ~- GSJ. 6108 Length 23.0 Width 23.6 Height 8.8 The largest of all the specimens at hand including those from the Yuasa Figs. 6a-d. Heteraster yuasensis (TA area attains a little more than 4 em in length. XAKA and OKUBO). 6a. Anterior ambula crum, x 12. 6b. Right anterior paired Remarks:-The description of this ambulacra. x9. 6c. Right posterior paired species is based on observations of the ambulacra. x9 (GS]. 6108). 6d. Plastron. specimens from the Yuasa area in addi x0.9. (GSJ. 6007, Arita formation). tion to those from the Sanchu graben. The present species is clearly distin the posterior poriferous zones, dotted guished from the contemporary Heleraster with tubercles. Posterior paired ambula nexilis NISIY AMA in many respects. In cra shorter, less flexuous than the an the latter the anterior sulcus is rather terior ambulacra, very slightly sunken deep, the anterior notch is distinct, the or nearly flush, subpetaloid ; petaloid paired ambulacra are superficial and lhe part halfway, somewhat narrower than periproct is transversely oval. Heterasler that in the anterior paired ambulacra. yuasensis has more petaloid paired am somewhat closed at the end; anterior bulacra and less flexuous. more closed poriferous zones narrower than the pos posterior paired ambulacra than H. terior; pores slit-like. opposite. widely nexilis. The distinction is moreover re set, slightly longer in the outer row than cognized in the features of pore pairs in in the inner row; interporiferous zones all the ambulacra. 1!. yuasensis is also somewhat narrower than the poriferous, different from the contemporary H. dotted with tubercles. macroholcus and the comparisons with Peristome transversely oval. situated that species are as described above. at about one fourth the length from the This species resembles Heteraster ob frontal margin, shallowly sunken. Plas liquatus (CLARK) from the Albian of tron amphisternous; labrum slightly Texas in the slightly depressed paired emarginate; sternal plates nearly sym ambulacra and the mode of alternation metrical, equal in size and shape. Peri of pore pairs in the anterior ambubcrum. proct longitudinally oval, well up on the But it differs from that species in having posterior truncated surface. Tubercles a very indistinct anterior notch and a small, perforate, more closely spaced on longitudinally oval periproct. Further, both sides of the anterior sulcus and on H. yuasensis is distinguished from H. the plastron than elsewhere; tubercles obliqualus by the shape of pore pairs in on the plastron slightly larger, arranged all the ambulacra. The species here de in a concentric form with the center at scribed is similar also to H. _tiflolll· 138 Keisak1~ TA:V.4KA (DESOR) from the Aptian of Switzerland zones broader than half the width of and England in the slightly depressed the interporiferous zones. Pores slit-like paired ambulacra and the shape of pore in the outer row. while round to oval pairs in the anterior ambulacrum. How in the inner; pores of each pair opposite, ever, there are distinct differences with rather close together. Paired ambulacra regard to the shape of pore pairs in the very unequal, flexuous, open distally. paired ambulacra between the two spe Anterior paired ambulacra very long, cies. Furthermore, Heteras/er yuasensis considerably narrow almost throughout is easily distinguished from the foreign the way, but rapidly widening near the Neocomian species, H. couloni (AGASSIZ), ambitus, very slightly sunken or nearly H. oblongus (BIWNGNIART) and H. cesar ftush, diverging at a smaller angle than ensis CooKE, the second of which occurs the posterior paired ambulacra then turn -also in the Aptian, by its general fea forwards and laterally, becoming almost tures of the test. straight, and then diverge laterally and It draws one's attention that the spe cross the ambitus far anteriorly. An· cies here described shows almost sym terior poriferous zones very narrow; metrical disposition of the sternal plates. pores minute. round, near together. Pos which is regarded as being a much ad terior zones much wider than the an vanced character in the evolution of terior zones; pores oval in the inner plastron in toxasterids by DEVRIES (1960), although it is an earlier representative of the genus Heteraster. Occurrence :-Loc. 2, Ishida formation, sandy siltstone, Neocomian (GSJ. 6108, ·coli. by K. TANAKA, GSJ. 6123, coli. by M. HoRIGUCHI; loc. 3, Ishida formation, sandy siltstone, Neocomian (some speci mens deposited in the Department of Earth Science, Saitama University, coli. ~~--~ by K. WAN113UCI11). ~lc Figs. 7a-c. Washilaster (?) sp. 7a, Anterior ambulacrum. x 10. 7b. Right Genus W ashitaster LAJ'v!BERT, 1927 anterior paired ambulacra. x 10. 7c. Right posterior paired ambulacra, x 10. (GSJ. lVashitaster (?) sp. 6116). Pl. 16. figs. 8, 9: Text-figs. 7a-c row, while elongated oval in the outer Description:-The two specimens at row; pores of each pair opposite, rather hand are considerably deformed or frag widely set. Interporiferous zones nearly mentary. It. however. seems very likely equal to the poriferous zones in width that the horizontal outline of the test is near the midway between the apical longer than wide, the apical system is system and the ambitus. Posterior pair situated far backward and the anterior ed ambulacra shortest, wide, flush, di sulcus is long and deep. verging at a very large angle and then Anterior ambulacrum lodged in the converge laterally. Anterior poriferous anterior sulcus, long, wide; poriferous zones much narrower than the posterior 494. Cretar:eons cchinoids 139 zones, composed of minute round pores zones where pores are count about 40 closely spaced. Posterior poriferous zones pairs in the preserved middle and pro composed of oval inner pores and slit ximal parts respectively, the inner pores like outer ones; pores of each pair op aligned, while among the outer pores posite, rather widely set. lnterporiferous only one shorter pore is placed somewhat zones w·ider than the posterior pori ferous inward or quite inward beyond the zones. others, thus the pores therein lining up Peristome very eccentric in front, poor in three files as in Heteraster. Such ar ly preserved; periproct not preserved. rangement of pores in the anterior am Tubercles small, of varing sizes. per bulacrum is in this case regarded as forate. crenulate; the largest scattered being quite anomalous and exceptional in the anterior interambulacral areas, for this individual. To sum up, the pre widely scrobiculate; interporiferous zones sent form is here provisionally referred in the paired ambulacra dotted with to Washitaster on the general features tubercles: numerous microscopic granules of the test, although it is better to es between tubercles. Comparatively well tablish a new separated genus for the defined narrow peripetalous fasciole (or form when more specimens are obtained. better to say pseudo- fasciole) observable, This form closely resembles Washit crossing the anterior paired ambulacra aster japonicus TA:\AKA and OKUBO at about one-fourth Lhe way from the from the Albian Yatsushiro formation ambitus. in middle Kyushu in general features of Length attains about 5.8 em. the test, but is distinguished from that Remarks :-Although structure of the species especially by the course of the apical system and outline of the peri peripetalous fasciole. In the former the stome can not be ascertained due to ill peripetalous fasciole crosses the anterior preservation of the test, the presence of paired ambulacra much less distally than peri petalous fasciole and many other in the latter. The present form is to peculiar features mentioned above may some extent similar to the two Albian remined us of JVashitaster. However, in species of Texas, Washitaster longisulcus the specimens at hand the pores in the ':ADKINS and WINTON) and ll". riot:istae anterior ambulacrum are oval in the (ADKINS). But it is distinguished from inner row, while slit-like in the outer W. longisulcus by the much larger size row, the pores of each pair are not of the test, the larger number of pore separated by a granule and the peri pairs in the ambulacra and the greater petalous fasciole is not multiple but dissimilarity in shape of pore pairs in single. These features prevent us from the anterior ambulacrum. Comparison identification of the present form with with W. riovistae are given belo\v. ln Washitaster. On the other hand, differ the specimens here described the peri ing from Heteraster the pores in the petalous fasciole is not multiple but anterior ambulacrum are aligned in single, and the pores of each pair in the each of the outer and inner rows as in anterior ambulacrum are very unequal Washitaster. There are. however. re in shape and are not separated by a cognized abnormal disposition of the granule. Furthermore. it attracts one's outer pores in the anterior ambulacrum attention that the anterior paired am in one of the specimens (GSj. 6116). bulacra are considerably narrow in the That is. in each of the two poriferous present form as well as in 1-F. japonicus 140 KeisaJw TANAKA and TV. longisulcus. CooKE, C. W. (1955): Some Cretaceous echi Occurrence :-Loc. I. Ishido formation. noids from Americas. U.S. Ceo/. Surv., sandy siltstone, Neocomian la specimen Proj. Paper, 264-E. p. 87-l12. pis. 18-29. deposited in the Chichibu National Sci· text-figs. 1-1. CorrEAU, G. II., PEROK. A. and GAUTHIER. ence Museum, coli. by K. T AKEI) ; loc. 7. V. (1876-188-l): Echinides fossiles de Ishido formation. siltstone, Neocomian !'Algerie: Description des especes re (GS]. 6116, 6117, coli. by K. TAN AKA cueillies dans ce pays et considerations and Y. YABE). sur leur position stratigraphique. ;1nn. Soc. Ceo/. vol. 4. no. 6, p. 1-30, pis. l-2; References ibid., vol. 6, no. 4, p. 1-91, pis. l-8. Df:NrzoT. G. (1934): Description des Massif ADKI:-;s, W.S. (1928): Handbook of the de Marseilleverge et de Puget. Ann. Texas Cretaceous fossils. Texas Unill. Mus. d'hist. nat. Marseille, mern. 5, vol. Bull., no. 2838, 385 p., 37 pis. 26. p. 140-1·12, pl. 5. -- and Wr1'TON. W. M. (1920): Palaeonto Di,SOR, E. (1855-58): Synopsis des echinides logical correlation of the Fredericksburg fossiles. 490 p., 44 pis. and Washita formation in 1\orth Texas. DEVRIES. A. (1955) : Etudes sur Toxaster Ibid., no. 1945, 84 p., 21 pis. t•i/lei (GAUTIIIER sp.). Pub/. Serv. Carte ARAI, F .. TAKE!, K., I!OSOYA, s .. IIAYASHI, Ceo/. Algerie (nouv. serie), bull .. no. 5, p. S. and TAKAHASHI. K. (1958) : Descrip 127-155, pis. 1-2. tions and some considerations concern -- (1955) : Note sur le genre Helerasler. ing ripple marks discovered in the San Bull. Soc. Ceo/. France, 6 ser., vol. 5, p. chu graben. Chikyulwgaku, no. 40. p. 1- 315-323. text-figs. 1-2. 12 (in japanese with English abstract). -- (1960): Contribution a !'etude de quel CLARK, \V. B. (1893): The Mesozoic Echi ques groupes d'echinides fossiles !•Algerie. nodermata of the United States. Bull. Pub/. Serv. Carte Ceo/. Algerie (nouv. U.S. Ceo/. Surv.. no. 97. 207 p., 50 pis. serie). mem., no. 3. p. 1-278. pis. 1-39. Explanation of Plate 15 Figs. la-c. Pygurus (Pygurus) complanafus n. sp. 1a. 1\dapical side, x2. lb. Adoral side, x2. lc. Left lateral side. x2. Presumed Ishida formation. (Holotype. GSJ. 6090). Figs. 2a-c. Pygurus (l'ygurus) comp/analus n. sp. 2a, Adapical side, x2. 2b. Adoral side, x2. 2c. Left lateral side. x2. Presumed Ishido formation. (Paratype. GSJ. 6091). Figs. 3a-d. f'seudholastrr n. sp. ( ?) 3a, Adapical side. x 1.5. 3b. Adoral side. x 1.5. 3c. Left lateral side. x 1.5. 3d, Anterior side. x 1.5. Ishido formation. (GS,J. 60,16). Figs. 4a-c. Pseudholaster n. sp. ( ?) 4a, Adapical side, x 1.5. 4b. Adoral side. x 1.5. k, Posterior side. x 1.5. Ishida forma tion. (GSJ. 6050). Figs. 5a. b. Toxaster sanchuensis n. sp. 5a, 1\dapical side. x 1.2. 5b, Adoral side. x 1.2. Ishido formation. (Holotype, GSJ. 612,1). Figs. 6a, b. Toxasler sancfwensis n. sp. 6a, Adapical side, x 1.2. 6b. Adoral side, x 1.2. Ishido formation. (Paratype. GSJ. 6110). All specimens here illustrated are internal moulds. TANA.KA. : Cretaceous echinoids Plate 15 494. Ct·eta.ceous ech:inoids 141 DuNcA:x. P.M. (1889): A revision of the vertebres. Terrain cretace: Echinides. genera and great groups of the Echi Yo I. 6 ( 1853-60), p. 1-595. pis. 801-1006. JJOidea. }our. Linn. Soc. London. Zoology, SztiRE"lYI, E. (1955): Echinides cretaces de vol. 23, 311 p. Ia Bakony. Geo/. Hung .. Ser. Palaeont .. KIER, P.M. (1962): Re\·ision of the Cas. fasc. 27. p. 1-332. pis. 1-22. text-figs. 1-45. siduloid echinoids. Smithsmt. Misc. Col/., TAKEI. K. (1963) : Stratigraphy and geologi· vol. 1H. no. 3. publ. 4500. ?62 p .. 4-t pls .. cal structure of the Cretaceous System 184 text-figs. in the eastern part of the Sanchu graben, LA~tBERT, J. (1926): Considerations sur les Kwanto mountainland. foul'. Ceo/. Soc. echinides de Ia Commanche serie du japan. vol. 69, no. 810. p. 130-146 (in Texas. Br1ll. Soc. Ceo/. France. 4 ser.. japanese with English abstract). vol. 26. p. 263-278. text-figs. 1-2. TA:XAKA. K. and OKL'BO, M. (1954): On -- (1931) : Etudes sur echinides fossiles some echinoids from the Paleocretaceous du ~ord de !'Afrique. AUm. Soc. Ceo/. of the Yuasa district in the Kii Penin France. N. S., vol. 7. no. 16. p. 1-228. pis. sula and the Yatsushiro district in Kyu. 1-8. shu. Ibid., vol. 60, no. 705. p. 215-227, --and TII!EI~Y. P. (1924): Essai de nomen pl. 7. text-figs. 1-7. clature raisonnee des cchinides. fasc. 6-9, -- and SHIBATA. M. (1961): A new species p. 385-607, pis. 10-15. of Aphelaster from the Lower Cretaceou;, Lm~IOL, P. de (1873): Echinologie helveti of japan. Tra11s. Proc. Palaeont. Soc. que: Description des Oursins fossiles de japan. N. S .. no. 42. p. 68-72. pl. 10. text· Ia Suisse. Part 2, Echinides de Ia periode figs. 1-2. cretace. Mater. Pal. Suisse. 6 ser., p. 1- ToKUNAGA, S. (1903) : On Lhe fossil echi· 398. pis. 1-33. noids of japan. jour. Col/. Sci. Imp. MoRTE~SI·:N. Th. (1948): A monograph of Uniu. Tokyo, vol. 17, art. 12, p. 1-27. pis. the Echinoidea. IV-1. llolectypoida. Cas. 1-4. siduloida. WRIGHT. T. (1864-82): Monograph of the -- (1950): A monograph of the Echinoidea. British fossil Echinodermata from the V, Spatang11ida. Cretaceous formations. /'a/aeon/. Soc. N1s1Y A~IA, S. (1950) : Two new species of London, 371 p., 80 pis. the Toxasteridae from japan. Shm·t YABE. Y .. KAl"EKO, S. and AKAGI, S. (1955): Papers, Inst. Ceo/. Pal. Tohoku Univ .. no. On the Lower Cretaceous deposits in the 1. p. 42-47, figs. 1-6. northeastern border of the Sanchu graben. ORBIG:-.Y. A. d' (1853-56): Pali:ontologie jour. Ceo/. Soc. japan, vol. 61. no. 721. p. fran~aise: Description des animaux in. 503-505 (in Japanese). A rita tr rn Onozawa * !llf iR. Chichibu-gun ~ 5(1!1\ Saku-cho (1,: 9.. lllf I-Iikage 8 ~ Sanyama ~ Ill Ilonya ~ Sebayashi lfli .f+; Minamimaki-cho *Iff~ !!If Shigaraki-gun 11' ~ l!Y. Minamisaku-gun iYHt.:?..llh Shiroi r't tl' Myoke I!JJ Tano-gun ~ !llf Uti Nakazato.mura '-fl ![ *.f.f Ueno.mura 1.: !!lf H Ogano-cho tJ-1/'[!l!fiOJ Yuasa l'Ll t~ 142 Keisaku TANAKA ------ Explan::tion of Plate 16 Figs. la-c. Toxasler sanchuensis n. sp. Ia, Ada pica I side, x 1.5. l b, Adoral side. x 1.5. lc. Left lateral side. x 1.5. Ishido for mation. (Paratype, GSJ. 6042). Figs. 2a-c. Toxas/er sanchuensis n. sp. 2a, Ad apical side. x 1.5. 2b, Adorsal side, x 1.5. 2c, Left lateral side, x 1.5. Ishido for mation. (Paratype, GSJ. {i041). Fig. 3. 1/eleras/er macroholws (NtstYAMA) Adapical side. x 1. lshido formation. Figs. -la, b. Heleraster macroholcus (:\'ISIYAl.IA) 4a, Adapical side. xI. 41.>. Adoral side. xl. Arita formation. Fig. 5. Heleraster cf. nexilis NtsiYA~IA Adapical side, x 1.5. Ishido formation. (GS]. 6105). Figs. 6a-c. Heterasler yuasensis (T Al\AKA and OKUBO) G:~. Adapical side. x 1.5. 6b. Adoral side, x 1.5. 6c. Right lateral side, x 1.5. Ishido for mation. (GSJ. 6108). Fig. 7. Heleraster yuasensis (TA=":\KA and 0Kuno) Adapical side, xl.5. Ishido formation. (GSJ. 6123). Fig. 8. I.Vashitaster (?) sp. Ada pica] side, x 1.2. Ishido formation. (GSJ. 6116). Fig. 9. IVashitaster ( ?) sp. Adapical side, x 1.5. Ishido formation. (GSJ. 6117). All specimens here illustrated are internal moulds. TAN AKA : Cretaceous echinoids Plate 16 14:3 PROCEEDINGS OF THE PALAEONTOLOGICAL SOCIETY OF JAPAN El;f;i51=.!ft.r~~?g 9o rm~J~.i>J:.a r~t!li.lilrJJ~ ~) !1:-::>~'"'l ...... ;kJi¥. ~ c:fl·l.·c l..d.:JT1:.ttf&~O)i5.1tlJJ!l!c ti1:.!1mO)~i'lH:£ A new species of a whale tympanic tone c l"Ci5kti'lful!¥~ News <) ?f! 2 [ill['! l!!~$t:lilXO)Jffi 1) 0 Secretariat Working Committee. 2nd International Conference on Palynology. cfo Royal Netherlands Industries Fair. Vredenburg, Utrecht, Netherland <) i:i!J~r!"i1=.~~)l!!-8' (International Palaeontological Union) 0)~-3-li 1964 ~ 12 Jj 16 13-21 8 iC-1' './ f-'0)~ ~ -7•J --z:IU~iJ.n"f:ie!0$ll'i7'J::>iMtt-nL 1) ~ :!Jl:: M.R. Sahni (-1' './ r) aiU0~: 13. Boucek ( 'T"' 7 :::1 7. t1 ... '""-\") ; C. L. Arambourg ( 7 7 './ 7.) ; K. M. Sultanov ( '/ )!!!) ~ $: B.S. Tewari (-1' './ r) ~ ~·: A. L. McAlester (7 ;J 'J :h-2':!'/t~) tflfj~Jil. 9 ~0)? '!::> R;f;J:.IJ li, t~;f;~f$ · 'J;;ff;_R-iitiitl'iJ~~:bu l n'oc 144 2) tll:WJ/HI 4 7 7 1) ;tJ ~ft: H. Hollard ( 'E: a ._, :::1) : (¢$ lVI. S. Willefert ( -r o .7 :::1) 5 .:t -1:7"" 7 1.';=;{i; C. A. Fleming (:=.,-;; -7 :/ r) : (it$ G. I{. Stevens. (-"'~-:/-7:/!-') 3) ~O)t'Jl~ (JftJ':J:.;?~t;') )J.:::J'j,~_l;l_1',;~~lLld:o I Palaeontologia Universalis ;_;j'l,K R. Dehm ( !-' -f 'Y) 2 Directory of the Palaeontologists of the World ~f!ft: L. G. Love ( 1 ilf 1) .;;~.) 2 Palaeoecology ~~ft N.D. Newell (g.*ft;j) Sub·Committee-Reef Building Organisms 1 4 Palaeobiogeography ~J':l.R C. J. Stubblefield ( 1 ilf ) .;;~.) ;_;ft 1! ffi.i iJ!.i .li. @ ~HEHH~ · Jl'lii$R~O)filli;fi:t 7 B tft'EI.I.t !J *~ 1 7' F.1 r::t)f:.IJ ...- 71 $!i1.JO).lik~ · i 1 i1J11J•1:~1f..;E-:ff fJ:P 8 B 1!1'1ilffltlii!Lt.:. @) 4l;~fjifi~9HJI;!:'i!i~~~JVf~O)f.:;Jb7' ;/ ...-- ~ · .:t 7 :Y 1/' "'-JcJit 9 rJ J: 1lJilJ;£ Lt:.o @ 4l;ft~JIL.'.;!(tll!it/it~!h1Vf~0t.:~ 9 JH 1u*l~h(c]lttfl~ Lt.:. @) ~H~*~J-;1J0)~~1:tJ: t?atr~Hiii'f:05t'fl:::i'ilt 7.>it!!f:f~I'0M6;}J l::)f L E1-*+1!~1'~Jt1J<~lj. ~tJ.f.:o shall call a Special ~Ieeting at the wriLLen request of more than one-third of the members. The request shall be granted only if the written statement fully explains the reasons for assemhly and items for discussion. Article 19. Members unable to attend the General ~Ieeting may give an attending member a wrinen statement signed by himself tru!Hing the bearer with the decision of business matters. Only one attending member may represent one absentee. Article 20. The decison of the General Meeting shall be by majority vote. When the number of votes is equal. the President shall cast the deciding vote. Article 21. The President and Councillors shall compose the Council. The dicision of the General Meeting concerning administration shall be considered and implemented by the Council. Article 22. The Executive Council shall carry out the decisions of the Council. Article 23. The fiscal year of the Society shall begin on the first of January each year and end on the thirtylirst of December of the same year. Arlicle 24. The amendments to the Constitution of the Society shall be decided at the General M(~eting and must he approved by more than two-thirds of those mem bers who arc in attendance. Addendum l) Voting in the Council shall be by unsigned ballot. 1m 00 Jtt! 1m rut f:l ~iJll:$.i.Hii!WB _j - ---· -)..:_ ~"j: 1965 11 JJ G, 1 10 m 92 1m f~J ~---~ 'f· ~ {r n 1965 iflOfJ 13 1966tf~~ . ~·~:; * ~I: ').;, q: 1966 ~ 1 fJ 2·1. 25EJ 'l~ 1965 ij! 12 Jl 20 B ;g 92@1§11~ (-=f-~:7;:~) : 11 JJ 6 El ( ±.) !ftMY;; 1' &cJ'~'!ti:~fvJi 1 i'l=!f'IJ.J • .ff!ls!!0~ :.-' ,f!;; ~? .l· (lliil6A: m;;$:: II· DfJrn!'Y t![l). lfUii911!f30.HUIJ!IfL tr-uu.&u 1-fi~llil·W~: H:Jilli-0, lfi&i&~: Jl!m7:/7oJ·i!J~I#oitL'IftOJ.A7-1' ri~HliJ. 11 Jj 7 n ( 1:1) fi.IIA~~iWL lf·u(I91T'.f 30 01JIJIJf.lo -0-"J: =f~;I:"[;:;:FJ!·~::i$ (jllj-f·;il~lf(~I:Ul:J!t, -i;E~Iif:r)v {1·)~'1:/[igtit: t~IC3i.~.i!l!hlvJ.::.. ~ (iJiJLLI!'Yfll)~). 1ii· r'h :~ n ~~R JtHu .~;; @ JJ;j:·:{;(~jJ;:1J:h;)jltlUJ~::U G~ li~ · .11!!\."t·:;;: • -'iJl irr~i!lt~rf]E;:,> 1::1\9d;j.:!J!JJ~I.llt1i#0l'Vf1\!~~ ~l~7.ljj£~ l., t.: 0 @ lllH11 ·11 #'f!£fl.!Vfn~H~~~ff!l!:: ~:l:. l!f;1&L10rll~0f.~*~·~~~: L <:1'3~,:·.){!+! · ~.fi-;kM · WJ*!i (l\J!ii'l· w!I!F.J'm ·li'IHU!If!fj;; · WJ#It 1 9 6 5 1f. 9 J.j25~1 :Jlt);(:;k~~~iillJt!!'l'f~~~Pi 19651f.9J.l30EJ fl*~~:tt~~ iiij * ~· :Jt: ft a *~~:tb~~fil\f ·It?¥ 9] rr =If m m ~ m ilf .w m sg ~ (~ ~ p ~ Jt! J.l{ 8 4 7 8 0 ~) J:iJ JliU J.!i 'llil *"~.! .u~ 1:{ ~ ~t: 2 1 13 4 00 F3 =If * z ::f:f,l1~ 11r-r:illii1J t~:l:\': ~ tt 1:~ Ill 5t:; I I 'I J r CONSTITUTION of the PALAEONTOLOGICAL SOCIETY OF JAPAN Article I. The Society shall he known as the Palaeontological Society of Japan. Article 2. The object of the Society is to promote the study and popularization of palaeon· to logy and relal eel sciences. Article 3. The Society, to execute Article 2, shall undertake the following business: 1. Issue the Society journal and other publications. 2. Hold or sponsor scientific le6tures and meetings. 3. Popularize the science by field trips, scientific lectures and other projects. 4. Aid and encourage research work; award outstanding contributions to l he Society: carry out the objectives stated in Article 2. Article 4. To attain the object of the Society, the Society may, by decision of the General Meeting, establish within it research committees. Article 5. The society shall be composed of members who are active or interested in palaeontology or related sciences. Article G. The members shall be known as Regular .l'vlembers, Fellows. Pal ron and Honorary Members. Article 7. Persons desiring membership in the Society are requested to fill out the neces sary application forms and receive the approval of the Council. Article 8. Fellows are persons who have held Regular Membership in the Society for more that ten years. have contributed to the science of palaeontology. have been nominated by five Fellows and approved b~· the Council. Article 9. Patrons are organizations supporting Article 2 and recommended by the Council. Article 10. Honorary Members are persons of distinguished achie\•ernent in palaeontology. They shall be recommended by the Council and approved by the General Meeting. Article 11. The members of the Society shall be ohliged to pay the annual dues stated in Article 12. Members shall enjoy the privilege of receiving the Society journal and participating in the activities stated under Article 3. Article 12. The rates for annual dues shall be decided by the General Meeting. Rates for annual dues arc: Regular Members. Yen l,OOO; Fellows. Yen 1,500; and Foreign 1\·lernbers. $ 4.00. Patrons are organizations donating more than Yen 10.000 annually; Honorary Members are free from obligations. Article 13. The budget of the Society ;;hall be from membership dues, donations and be· stowals. Article H. The Society. hy decision of the Council, may expel from membership persons who have failed to pay the annual dues or those who have di~graced the Society. Article 15. The otlicers of the Society shall be cnmpos,,d of one President and fifteen Coun cillors. among whom several shall be Executive Councillors. The term of office is two years and thev may be eligible for re-election without limitation. The Presiden.t may appoi~t se\·eral persons who shall be Secretaries and Assistant Secretaries. An Executive Council shall be nominated and approved by the Council. Councillors shall be elected from Fellows by vote of returned mail unsigned ballot. Article Hi. The President shall br a Fellow nominated and approved by l he Council. The President shall represent the Society and supervise the business affairs. The President may appoint a Vice-President when he is unable to perform his duties. Article 17. The Societ}' may have the honarary President. The honorary President shall be recommended bv the council and approved by the General Meeting. The honor· ary President ~ay participate in the Council. Article 18. The Societ}' shall hold regularly one General Meeting a year. The President shall be Chairman and preside over the administrative affairs. The program for the General Meeting shall be decided by the Council. The President may call a special meeting when he deems il necessary. The General Meeting re· quires the attendance of more than onc·tcnlh of the members. The President