Trans. Proc. Palaeont, Soc. Japan N.S.. No. 5, pp. 179•\183, 1 text-fig. May 30. 1952. 215. A MIOCENE CRAB, HYAS TSUCHIDAI N. SP. FROM THE WAKKANAI FORMATION OF TESHIO PROVINCE, HOKKAIDO RIKIZO IMAIZUMI Ist college of Arts and Sciences, Tohoku University, Sendai 稚内層産ツチダノヒキガニ:北 海道天塩国豊富村沙流沙流別パンケエベ コロベツ川支流南岸, 豊 富 ロ ー タ リ ー2号 井 の 檐 下 の 稚 内 層 より 土 田 定 次 郎 に よ り探 集 され た ツ チ ダ ノ ヒ キ ガ ニ は 寒 流 系 の 現 生 種Hyas coarctatus LEACH等 に 近 縁 を 有 す る。 従 来Austria,PredingのHeiVetianよ り Hyas meridionalis5 GLAESSNER, 1928がAlgeriae, OranのSahelianよ りHyas oranensis VAN STRAELEN. 1936 が 報 告 され て い る。 今 泉 力 蔵 The fossil crab described herein was deposited in the same ecological condi- collected by Mr. T. Tsucmon of the tion as the Recent species of the genus Teikoku Oil Company from the upper are governed. The first described fossil Miocene Wakkanai formation at Saro, species Hyas meridionalis GLAESSNER Toyotomi-mura, Teshio Province, Hok- was found in the Helvetian stage of kaido. along the south bank of the Wenzeldort Preding, Austria. This fos- Sarubetsu. a tributary of the Panke- sil record from Austria seems to no to epekorobetsu and kindly submitted by indicate the influence of a cold current him to the writer for study. in that region during that period. The writer proposed a new specific The writer wishes to express his sincer name Hyas tsurkidai for this fossil form, thanks to Mr. T. TSUCHIDA for his kind the specific name was dedicated to the offer of the fossil crab, and also to Dr. collector of the specimens. H. YABE, Prefessors S. HANZAWA and K. All the recent species of the genus ASANO and Dr. K. HATAI of the Institute Hyas are the inhabitants of the Arctic of Geology and Paleontology, Tohoku circle, except for only one subspecies, University, for their encouragement. Hyas coarctatus ursineus RATHBUN, which is now known to be distributed from Family Majidae ALCOCK the Okhotsuk Sea to Amoy along the South China Sea via the Japan Sea, as Subfamily Hyastentinae BALSS stated below again. The exceptional Genus Hyas LEACH 1814 distribution just mentioned is evidently controlled by the cold Liman stream. Genotype, Hyas araneus (LINNAEUS). Therefore, the occurrence of the fossil RATHBUN, M. J., 1925, U. S. Nat. Mus. crab suggests that the Wakkanai forma- Bul, 129, Smith. Inst., p. 252. tion which has yield this species was Hyas tsuchidai IMAIZUMI n. sp. 1) Read June 30. 1951; received Feb. 5. Preservation:-one carapace and its 1952. impression preserved in a gray tufface- 179 180 ikizo IMAIZUMI - ous fine sandstone. It is compressed gin of carapace tuberculate behind towards the right frontal direction but hepatic rigion. Outer surface of rostrum exposes the left lateral side and the densely granulate. Granules on gastric , orbital cavity as a result of the left cardiac and intestinal region also dense- supra-orbital eave and the left post- ly arranged. Epi- and meta-branchial ocular cup being shoved towards the regions distinct. frontal region. Right branchial regions with numerous wrinkles extending from Dimensions:-carapace, length 16mm . width the posterior margin to the anterolateral , 13mm. due to subsequent pressure. rostrum, width 2.5mm. The color of the fossil is brownish proto- and meso-gastric region, sepia. Convex parts of the carapace and width 5mm. the tops of the tubercles are worn, but the concave surface of the impression is Holotype:-IGPS coll. cat. no. 74001. well preserved. Appendages lost. Locality and geological horizon:-IGPS Description:-carapace broad, sub- loc. no. Te-10. Under the derick of the triangular of lyrate in shape, but nar- boring "Toyotomi" Well no. 2 of the rower than the post frontal length. Teikoku Oil Co. at Saro on the bank of Rostrum triangular, flat, bifid, a narrow the Sarubetsu, a tributary of the Panke- cleft between rostral horns, the tips epekorobetsu-gawa, Sarobetsu, Saro, more or less separated; tips of horns Toyotomi-mura, Teshio Province, Hok- subacute. Cavity of orbit oblong-sphe- kaido, (Toyotomi sheet), Lat. 45•‹4' 43" roidal. Post-orbital and hepatic region N., Long. 141•‹50' 10."4 E., Wakkanai not dilated laterally, antero-lateral mar- formation, upper Miocene. T. TSUCHIDA gin of hepatic region sharp with a coll. 1950. rounded postero-lateral angle. Postero- Geographical distribution of the Recent lateral margin of carapace rounded. species of the genus Hyas:-According Cervical groove distinct, marginal line to RATHBUN (1925, pp. 252-281) and interrupted by a small and shallow SAKAI (1934, p. 295, 1935, p. 94), this sinus between hepatic and branchial genus is now living in Arctic Ocean regions. Surface uneven, ornamented with the exception of the Siberian coast with granules and granular tubercles. between Long. 147•‹E. and the Kara Sea, especially on median gastric area or south of Novaya Zemlya and of the proto- and meso-gastric regions and in American coast between Baffin Bay and an oblique row on branchial region. Langton Bay, North West Territories: Meso-gastric region with two large me- Bearing Seas in the Arctic circle, be- dian tubercles. Proto-gastric region with sides, North Pacific Ocean southward two inner and three outer tubercles ar- along the Asiatic side to Korea and ranged side by side: the inner two tu- perhaps Amoy, and on the American bercles in proto-gastric region continue side to the state of Washington; North with smaller ones to frontal region. Atlantic, Cape Hatteras, North Carolina, Pustules on inner side of outer surface and on the European side to the English of horns of rostrum decrease in size channel. anteriorly. Row of tubercles along The geographical distribution of the boundary between meso- and meta- species. branchial regions distinct. Lateral mar- 1. Hyas araneus (LINNAEUS), (RATH- R A Miocene Crab. Hyas tsuchidai n. sp, from the Wakkanai 181 1 Text-fig. 1. Hyas tsuchidai IMAIZUMI n. sp. Holotype, •~ 1. Text-fig. 2. Impression of holotype, •~ 1. 4 Text-fig. 3. The same speci- men as text-fig. 2, enlarged to show details, •~ 5. Text-fig. 4. Holotype rereored , 2 ×2. Text-fig. 5. A copy of Hays eridianalis mfrom GRAESSNFR'S fig.15, Taf. III. 3 5 A Miocene Crab. Hyas Tsuchidai n sp. from the Wakkanai formation of Teshio Province. Hokkaido. BUN, 1925, p. 258). type-locality, North Iceland, Arctic coast of Europe to Long. Sea. 49•‹30' N. Corst of Siberia and northward, as far west West coast of Greenland from tat. 69•‹15' to s Bennett Isl (about 147•‹E.) as north a as 64•‹11' N. Labrador at Hebron. about 60•‹E., 76•‹50' N. to East Cape. in Kara Sea.? Atka, Aleutian Isis. The species ranges from low water mark to The species ranges from tidal zone to 500 682 meters in depth with an exceptional record meters in depth with a temperature gradient of 1656 meters in depth (W. Atlantic). The of 29•‹7-64.•‹5 F.. (RATHBUN, 1925. pp. 255- temperature ranges from 29•‹8 52•‹9 F. (RATH- 257, 1925, p. 270). The bottom materials from UN, 1925, pp. 260-268). The bottom materialsB where the species has been collected comprises comprises silts, sands, pebbles, gravels and sands. pebbles and gravels and broken shells shells (RATHBUN, 1925, pp. 260-268). rarely silts (RATHBUN, 1925, pp. 255-252). T. SAKAI (1934, p. 295) reported two female specimens in the collection of the surveying 2. Hyas coarelatus LEACH, (RATHBUN, ship Oshioro-maru of the Fisheries Department 1925, pp. 259-268), type locality, North of the Hokkaido University from the East Sea. China Sea (loc. unknown), subspecies, altaceus BRANDT. T. SAKAI states that Hyas coarctatus From West (Lat. 70•‹25' N.) and East Green- has never been recorded from the Pacific side land (Lat. 60•‹N.) to Hudson Strait and Bay, of Honshu of Japan. thence southward via Kaintchatka and Sakha. 3. Hyas lyratus DANA, (RATHBUN, lin Isl. to Yeso Strait and through the Sea of 1925, p. 275), type locality, Oregon coast. Japan to Korea (Lat. 37•‹02' N.); subspecies, ursinus RATHBUN, Shanghai, Amoy (Lat. Bearing Sea, from a line connecting Bearing 24•‹30' N.) Isl., Commander Isis., Siberia, with Pribilof 182 Rikizo IMAIZUMI Isl. and Bristol Bay. Alaska (greatest Lat, 58•‹ with granules and pustules, the pustules 8' 30" N.), southward to Admiralty Inlet,3 on the cardiac region being very distinct. Washington (about Lat. 42•‹N.). Hyas tsuchidai is distinguished from This species ranges from 9 meters to 440 Hyas meridionalis by the ornamentation meters depth (RATHBUN, 1925, pp. 271-275). of the carapace. The hepatic region is The bottom materials comprises silts, sands, larger than the intestinal region in Hyas nobbles. gravels and broken shells (RATIHBUN, tsuchidai but the reverse in Hyas meri- 1925. pp. 271-275). dionalis and from Hyas oranensis by the Geological and geographical distribu- ornamentations of the gastric and cardiac tion of the fossil species of the genus regions. It is also distinguishable from Hyas ever recorded. the Recent species of the genus Hyas as 1. Hyas merdionalis M. F. GLAESSNER, stated below, the rostrum of Hyas ara- 1928,(text-fig.£), type locality, neus resembles Hyas tsuchidai but the Wenzeldorf of Preding, Austria, sandy silt, one of Hyas tsuchidai is broader and the Helvetian, and Gamlitz, torton Leithakalk, posterior angles of the hepatic projection Baden, Korallenkalk of Rauchstallbrun, coll.,J of the former species subacute but the oanneum Graz. later has broadly rounded posterior 2. Hyas oranensis V. VAN STRAELEN, angles of the hepatic region. The orna- 1936, type locality, Oran, mentation of the surfaces of the carapace Algerla, limy rock.