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(1)Note. fauna. the molluscan. on. its. amd. Sagami. of. Bay. waters. adjacent By. Masuoki. IIORIEOS耳Ⅰ. Ⅰ. Introduetion The the. of. the. of. object ecologlCal. rather. zoogeograpby in. neglected, the. attracted last. century.. On. bay. had. much. been. though. an. tribution. author. his. encouragement. for. reading. and. to offer. a. tentative. wishes for. to. express. has. which. the. since. the. conditions. explanation. the. of. Al-. surveys･. oceanograpbical be continued should. causal. has. taxonomists. recent. bay. bay. of the. biological. and. elucidation been. hitherto. fauna. rich. foreign. physical. of the. survey. Dr.. Kuroda, Dr.. valuable. N.. into. futnre,. the dis-. the molluscan. of. helps. and. advices,. General. Account. Bay main. land. of. Sho^nan. District. B6s6. Peninsula,. three. on. channel･. volcanic. submarine depth. since. on. The. rise,. the. which. Bay. Honsh^1. From. lies.. in the. the. Uraga. to. Izu. lzu. the. east,. Bay Paci丘c island. Islands. Channel. and. is much. Araka甲a, Oyama,. of the Dr･ T･ Dr･ S･. kindly.furnished. who. Waters. adjaceltt. part of of the central The bay is surrounded. coast. Tokyo. Wada. members Stuff. and. K･. for. the. facilities. Dr･. Peninsula. on. the. its. and. S･K･. other. Y･. Okutani,. Hondo･. 0r. the. Mr･. Sbikama. Mr･. and. the. Dr･ Is･ Taki. Paci丘c. the. on. T･. and. Sagami. of. carries. Dan. offering. indebted. the north, and between which bay into opens. 0-shima. water. for. Mr･. (Fig. 1): the. sides. island. Station. Takemura,. is situated island, namely. Dr･ K･. T･. Dr･. and also to Mr･ R･ Komukai Dr･ O氏ce to Ⅰ･Tomiyama and. and. Y.. to. thanks. to. work,. is also greatly Mr･ Ⅲ･ Noguchi,. Nasu,. the. uraga. present. hearty. he. Mr.. sagami. his. BiologlCal. K. Suzuki,. II.. Japanese. the. Hydrographic. Further,. institutions.. a. Japanese. through. clari丘ed. Marine. Misaki. of the. the. that. band,. other. the manuscript,. Japanese. the. suto^. the. fact. the. there.. The. of. of of both. extensive. is going. author. of. towards. Bay. Sagami. the. spite. attention. is to contribute. paper. present. the. on. the. on. the. southward, some banks. in丑uenced. by. coast. Peninsula. itself. empties Ocean. the. west,. Miura. the. and. throughthe south, there of. by. where runs. 100-200m. the. coastal. a.

(2) 3畠. M.玩()rikoshi. IiONA. BAY. TOKYO ama. ur. ::: I:I:･S. -1S. S?ganli.. I. uS. ･●･･･､r-. 二′. L＋. KA. Eno.shima ヽ●-■●. ---＼. IUR ENINSULA. tan. OSH. ＼ I. ∫. Z. ノ. ′. #'; l. No. ENINSUL. Jlma-Zaki. ■-■▲. ,.....･･=･･50'tl. l. 一. しし. ′_100 200＼-･ノ. /. 1. nator. ,090三 / ー. / /. ノ. /. hiraham. ＼ 1Sam. i /. -ー/. 一-●_ノ●●●. ､`■. 刀. Ir6-zaki _へ_. 50.A.I/''l …○ノ/. ′二ヽ. ｢ー ∫. ー■■. ｢＼. /. 100′ー ''Mikomo-to-jirha. {J. /. ▲. ヽノ. ー＼--J･･. ヽ_/. : e1.. 200. -shima. 1. 0m. da ski. ur5'＼. /-‥′/. C3. ,000. /. / / /. 1. ′ /. Text一点gure. l･. Topographical. map. of. Sagami. Bay. and. its. adjacent. i waters..

(3) Note. water. in. Tokyo. of. a. the. on. separate. the. of the the. except. On with. B6s6. the. width,. eastern. Odawara. of. the. bay,. 1,600m. side deep. the. at. is. of. 0-shima terrace. submarine. no. known. close ('37,'53), Kimura. to. northeasterly. into. east. and. Peninsula,. On. nermost. a. of At. usually. times,. the. a. sula,. The seen. body part. out且owing the. Channel) of the of. cape. east. wise. '37;. southward. coast. of. very. from. the 42. Tokyo. frequently. Peninsula. on. east,. the. lzu. off into. the. 2 &. 3).. the. in-. (Figs. towards. corner. Uda. north-. and. bay. the. to. Bows. runs. bay.. the. of. A dif-. oceanographically the. side,. velocity of north side, there is is induced by the branch the. below bay. 0.5kt. east. side. half. northern. Regardless. these,. of of the. coast. (0.3-1kt.).. the. along. in the. the. north-. According. south. is induced. along. along. runs. 0-shima. which is usually into the. and. slope has a. bay. lzu. of offshoots. the. '50).. steep. ocean且oor the. in. except. of the. Kuroshio. of the. circulation. current. of Kawana from Tokyo. the. lat. 350N.. while,. Marumo,. 5-8km. of. shelf,. Kurosbio,. (ト3.5kt), velocity. small. Bay. southeast demarcates on. with. '55).. the. circulation. '36; Uda,. Mogi,. sets. Kuroshio丑ows. the. (Suda, '43, tf.. outBow. it goes. of. main. and the half of. three. 2): i.e.,. current. clockwise. persistent the. along. Uraga. a. (Aikawa,. from. lkt. the. and branch. when. fairly. (see Fig.. is. which. headlands.. shelves. basin. between. sourthern. and Misaki. and. anticlock. from. sends corner. exceeds. persitent Kuroshio,. of 0-shima, the bay is. bay. the. of. current. the. branch. main. with. shelves. as. northeast. the. northwest between Kawana. parts. fairly. the. a. have. ('50),a branch. through. of. is bordered. few. is studded. current,. far. as. usually. to. the. part,. ferent. of Japan. then. Bay. proⅢ1inent. Sag･ami. ocean. ､Marumo. Sagami. and. '50;. Of. warm. bay. the. the. drawn. the. ('40)and. area. betⅥreen. The. (Tayama,. the. coast. sweeping. its way,. line. the. bending. ocean,. open. that. coast. (B∂sht^1District). such. The. ⅠⅠⅠ. ⅡydrograpIly lt is well. the. and the western here described,. into the opens and is connected vith. center,. 0-shima.. the. fringed. are. coasts. there. western,. Peninsula. extending is rocky,. coast. shingle. half of the. properly. Therefore. Zusb･i,. to. beach. the. more. water.. from sand. rest. Miura. 39. waters. adjacent treated. Bay.. Peninsula. Shimoda･ of Ito^ and 100-200m to 700m depth.. from ranging depth of about 500m. oceanic. be. from. Bo^so^. the. the. of. Tokyo. of the. its. and. can. excluded. of. coast,. in. neighbourhoods. by. are. Bay. channel of. coast. the. of. eastern. while,. eastern. part. or. of sand. In. that. Peninsura,. The. 1)I. beaches. the. the. e.,. its northern long stretches. (see Fig･. of the. concerning. southern in且uence. the. under. of Sagami. fauna. the. paper. channel,. coast. Bay,. i.. fauna. molluscan. lzu. of. there Penin-. southward.. Bay. Peninsula. in p. 224; Bay around. is of. which. Miura. Marumo,. extends the. de丘nitly. (the. coastal. western. side. '50). Although. southwest-ward Miura Peninsula. is. nature. the. into. the. as. far. of. the. main bay, nortll. a.

(4) 40. M.. -●･. >1kt. ---. <1kt. Horikoshi. i9i3 Jトヽ. /ン. r. ′. 1ミ /JH ≦'/. 乞. 鞘. t/i. 一. ∼. /}}. → ー■. ∼. ---ト. J. こさ: /. .. ポ. ヽヽヽー. ヽl. ヽ-. ､ヽ. ら?＼ニ. /. = ぢ I///)L=_ Text一色g.. 2.. Condition during. '{/Trycoastal. the. water. Mixed. current. Uda,. in. Sagami. Bay. '37). ”r. 匹争KubrrOaSnhcihOes づ￣. -. 1∼2kt. (from. winter. ing. Up-well. water. of. ､--. J. water. /;. ○. ノ) ノ / Text一丘g.. Distributions. 3.. the. as. the. interior. coastal and. also. 0-sbima. nautre occures. winter.. of the. bay. predominates in lt6 and. (see丘g.. 3-Uda,. of. the. (from. different. Uda,. waters. '37, slightly. (Fig. 4-Marumo,. in. '50).. during. '37). The. water. modi丘ed). '50; Uda,. Peninsula the Miura along on Shimoda vicinities and. '37; Marumo,. Bay. Sagami. and the. Sho^nan northeast′. of a District, side. of.

(5) -Note. the. on. fauna. molluscan. Sagami. of. Bay. its. and. 41. waters. adjacent. ￣ ′. _.i_Jj.I. 19_･や150. ′一一. /. 18.40. 17o. ､･. 18.60. 14.5⊂〉. 1SO. ---ヽ. 18.80. ■■一. ′一′. 15.5O. ′. / I. 19.10. 190. 1. l. 19.00. __一一二=. 一′■. ∫ ∫. 19.20. 1. 1. ∫. I. ∫. Q ′′■､ヽ. Texト丘gs.. 4.. peratnre. face 1948. Distribution. and. chlorinity Bay: Sagami. water. in. (from. Marumo. the. of. Text-丘gs.. tem-. of the. the. sur-. 5.. perature face. February,. diagram ヽ. cal strata Matsudaira. ′. ヽ. they. _′■. are. 24言･. water,. 250. 18.80. 100m. and ing. _∼. -ejx) l. t I I l. Text-丘g. perature face. water. told. roshio the. coastal of. the. water. shelf.. the. sur-. in. The. the. of the dominant is slope. and. connection. occupies. (A'). 300-1,000m. 2.6oC,. temperature. (A). is. with. of. the. the. whole. surface. during shelf, while area in the inshore shelf. and. the丑at. the. the. coastal in-. in. the. wa-. of the depth,. vater at. surr. 600m. (the Paci卑c. water. deepest. the. bay. the. Ku-. in the. bay. in. 34･5roo･ topography,. submarine of the. (A),. water to. β-Intermediate. submerged its center. of salinity. with. Kuroshio. by replaced low salinity. area;. (the. 160C,. uppermost. upward. 34.3roo; C-Bottom and of salinity from to the bottom 1,000m (the. ranging. this. 25-50m. face,. waterーof. July, 1948. ranging. the. of. 50-. at. A'-Dur-. the. summer,. from. ter. 5.5OC,. circumference water. tem-. of. the. shore. System),. m), of. Expressing. the. 300m. to. 0. 34.65roo;. salinity. of. layer. '50). water), 1,600. cblorinity Bay: Sagami. in. temperature. deep. of. the. Marumo,. Oyashio. of. and. Distribution. and. (from. ca.. 6.. A-Kurosbio. from. its main force with depth, of temperature. I. J. follows:. ranglng. depth,. ヽ. ′. as. above,. ヽ. 1. 18.80. '50;. From. alり'36).. et. 230. 廿＼. ′. water. in verti-. recognized (Uda, '37; Marumo,. ′. ヽ. three. be. can. ′. ′. 1948. salinity. bay,. the. of. masses. ”;i ;S,i. sur_. temperature. the. ′■￣ヽ ′. tem-. '50). From 230. the. of the May,. of. cblorinity Bay: Sagami. Marumo. (from. '50). Distribution the. and in. water. 19.20. offshore the. summer. covering below. just. area. Season. the. upper. it. the part. (ca･ 700m.

(6) 42. M.. depth) the. or the intermediate the water water soaked with submerged of 1,000m System. The basin deeper depth is than central about bottom or deep These the the Paci丘c water water. water with. are. Oyashio. 丘11ed. up. 血asses bear. their. environment,. to. greatest. the. the. nanlely,. VerticalZolteS. benthic. shoreline. faunas.. respective IV.. The. deeps,. shallow-sea. cluding one. while. the. latter. the. slope. of. with. FaurLa. depth. '42, p.. 275).. is subdivided the shelf with. into the. A.. in丑uence. of. dominated Ekman,. but. Position. two. Bay. '53, Utinomi, at. southern and. bou.ndary. (36oN,. east. minology, its. fauna. shelf. is also. Ekman,. '53,. ***. called 1:. the. See. nature. self-explanatory ** polytroba (-Nucella). SPisula. p.. as. &. later.. glVen. as. is zoogeographically. Hatai, two. the. of. '36;. freycineti hayseana. regions,. galea. (Pl. ll,丘g.. 19). MS and. in F.. the o.. south. lies. which. limit. southern with between the mollusgap one forms on hand, and of. the. term. a. makes. fauna,. neritic. as and, faunan ”shelf. demar-. for.the. ter-. becauseof. '57. Protothaca. (Sowerby),. euglyPta. Schrenck･. venulosa. (Lischke) (Pl. ll,丘g･ (also in Sagami Bay), and. oregonensis. Is., '38. a. (Dunker),. Tellina. Kuroda. or. author Hedgpeth,. sachalinensis (Schrenck) and Lischkeia argenteonitens argenteonitens. oregonensis & otuka. littoral. Taki,. coincides as. prefers. also. upper. the under subtropical region, the northern temperate region,. of Tokyo),. forms**,. see. shelf. the. zones,. water shallow well fauna some shelf of southern and､ endemic on forms the other (Fig. 7). The same northern latitude also line between some palrS cating Of closely allied mollusks.*** The. theo-. the. anther,. two. of Japan. (Nomura. current. '55). The. both. of. of Japan. coast. current,. Oyashio. Ch6shi. Paci丘c. the. Kuroshio cold. the. of each different. be. may. it is. Hence,. can. *. lower. the. and. in the zoogeograPhy. coast. i.eリ the. temperate. of. in-. Fauna. Shelf. of Sagami. that. warm. the. shelf. of them separately. further into subdivided detailed discussion will be. regions:. the. approximately. upper. fauna. be. can. established. by. shelf. zone. independently. To. of the Pacijic. into. '53, p. 226; contains. fauna,. differ. to treat. use. V.. lt is well. the. which. fauna.. abyssal. retical and practical fauna Bay of Sagami and lower shelf zones,. divided. system. zones,. archibenthal. of. Ekman,. '52;. the. systems,. main boundary. former. two. from. terrain two. the. (Oyama, The. can faunas zoogeography of the three i.e., at two different sites of surveying, fauna be common. the archibenthal may. while. into. systems,. The other. bottom. entire divided. be. deep-sea. 200m. at somewhat arbitrarily Sverdrup, & Fleming, Jonnson. the. can. the. and. Benthic. Of. including. is set. fauna,*. florikoshi. Redfield. in. the. north･. 18) L.. and a･. Fusitrion. hirasei. Taki.

(7) Note. the. on. fauna. molluscan. Sagami. of. Bay. its. and Cold. 24. 26. 23. 25. 28. 30. 27. 32. 29. 31. 35 33. 34. Water 37 36. Forms 41 40. 39 3g. 43. waters. adjacent. 43 42. 45 44. 47 46. 49 48. 50. I. 42o. 5Ⅰ 53 52. I. 420N. 410. 410. 吐oo. 40o. I. 89o. 89o. 38c). 38o. 87o. 870. 36o. 860. i. c'. 35. I. 84o. 83o. o､. 32. I. 350. 340. l. 33o. 82o. I. Blo. 810. 300. 800. 1234. 56789. 10. 12. 14. 11 Warm. Water. Forms. Text一色g.. the at. Enderrlic. 1-4. warm. of f'aci丘c coast. the. on. Phalium,. :. 5-9. NePtunea,. :. in. water gastropods and cold endemic a distributional the of existence (note. water,. Japan.. of. Semicassis,. :. 42-53. :. gap. areola. strigatum Kuroda. MS,. pilsbry,. ll.. 14.. casidariaeformis. Siph.. eve),. SiPh.. 17. SiPh.. Sibh.. de#eri A.. A.. damon. 23-28. Siphonalia,. :. (Reeve), (Reeve),. Pila. 12.. 18･. Adams,. Siph.. :. AncistrolePis】, 29133. Siph･. A･. juosa. bandatum. :. JaPelion,. A･. Siph･. Adams,. Melvill,. 10･. (Pilsbry),㌔ 13･. 19･ Siph･. 4･. (Perry), 7･ Sem･. (Watson),. Adams,. corrugata. micado. Ph･. 3･. u,yvillei inornata.. 9. Sem.. Siph.. 16･. Siph･. aestuosa. Siph･. vanattai. (Could), (Rep. signum. modijicata. (Reeve),. Siph･ fusoides (Reeve), (Reeve), 261 A･ unicus (Dall), 251 A･ fujitqi Kuroda, 28･. Dall,. A･. (Dall),. damon. 29･J･. latus. Ph･. Persimilis. 22･. sPadicea. trochoideus. Polygramma. 6･ Sem･. Siph･. 15.. (Reeve), 21.. (Linn6),. glaucum. Sowerby,. (Reeve), (Kuroda), 24. A.. 27.. Ph.. japonica. Sem.. grisea. 2.. trochulus. kinoshitai. bry),. 8.. 10-22. Buccinum.. (Linn6), (Gmelin), 5. Sem.. 1. 1%.. 20.. Forms. 36oN). ca.. 34-41. 18 20 22 17- 19 21. 16 15. 7･＼ Distribution. seas. open. 13. (Dall),. 23･. A･. (PilsSOT J･. (Dall), 31. I. Pericochlion parallelus (Dall), 32･ J･ hirasei (Pilsbry), 33, i peri36･ N･ con･ (Sowerby), (Schrenck), 34. N. minor (Hirase), 35･ N･ intersculPta 39･ N･ m'nosa N. arthritica 38･ N･ frater 37. (Bernardi), (Dall), (Pilsbry), (Dall), Dall, 43･ B･ je#reysii 41._ N. soluta 42･ B･ 1yrata suruganum (nermann), (Gmelin),. adelphicus cochlion stricta. 40. N. smith,. (Jay), B.. 44. 48.. inclytum. B.. B.. zelotes. Dall,. ochotense 52･ Pilsbry,. 45.. B.. leucostoma. (Middendorff), BI. Polare. mirandum. 49･. Lischke B･. 46･. rossicum. Smith,. 53･. Dall, B. nil･Ponense 47･ B･ perryi 50･ B･ limnoideum Dall, 51･ Dall, BI. Cnismata. Dall. var･.

(8) 44. M.. large. The tion. warm. shows. a. ature. Kitou,. rather. Bay. from. region. lS. the. Paci丘c. abrupt. in丑uenced. current.. At. during. the. change. shelト1ess. elements. § Tu)o found. the. northeastern Peninsula. the. Miura. by. Cho^shi. distribu-. the. the. temper･. water. &. (Marumo. season. winter. distributed ift the. (Could), Tegula found. fri). are. the. latter. the. species. RaPana. water. the. the. is. hitherto. south-western region･ iurbinata frequently,. In. the. the. south-western. water. Channel,. a. as. as. the. the. mollusks it is possible. of the. coast. B6sa the. the. and. east. of the. coast. delphinus. Pe血sdla,. west. e曙St. Of. A. Adams. by. a. For. is much in the. this. it is. x),. noctu7,na. is found､. species forms. water. siro (Kuroda) On the otherhand,. south-western dual in丑uence. nature.. last. the. are. which infrequent. by. Leptothyra. region,. warm. other. denoted. T. 1ischkei (Tapparone-Cane-. and only. iswidely. (Reeve). atrata 8,. Fig.. (see former. Crosse, is not. like. Cerato-. i丘t,he. mor与COmmOn a. muricid in. common. gastropod Tokyo Bay. northeastern. above. branch. of the. situation. the. of it is possible. reason,. but. region,. The. reglOn.. in. and. Kuroshio. the. to. call. north-. ”. in the. subdivisional hydrographical the. follows:. '49),. south-western. "Oceanicp Water Region, region ･the "Coastal Water Region respectively.. areas. well. shelf,. as. § SubdiL'isional. region. are. latter･. coastal. the. as. and. thomassiana. as. several. Purbura. in the. than. of. of. the. the触y祖d. of. Angaria. while. some. addition,. unrecorded brought about. and. distribution. west. lndo-West-. (Baba,. 0-shima,. coast. in. fact. the. shelf fauna. part of i.e., the. of the. shell-bearby. is rich. element. upper. the. region In the. arg.vrostoma. in the. is obviously. eastern. species. northeastern. Uraga. and. in the. Bay,. the. (Fig. 8).. region.. region. northern. bay. water. cold. upper. subtropICal. (particularly the. includes. part. southern. together. former. former. The. fournieri (Crosse). stoma. and in Sagami. southern. is also ascertained of. From the. water. warm. in. Bay.･. reglOnS. and the includes. a. fauna the. the. of. This. views･. distribution. Sagami. Peninsula. Although. absent. in. regions.. latter. of. con丘ne. biological. as. well. points. Molluscan. two. Izu. and. as. shallow. distinguish. the. within. opistbobrancbian is devoid and of. yegions. in. the. S,ituated. fauna). B･. Bay,. ocean. cold. geographical. molluscan. that. to. the. and. is undoubtedly. '54).. Sagami. in?. 7faunal. the. of. difference. Forikoshi. areas. two can. and. Within regions.･ be recognized the. each in. physiographical. region. relation. of to. the. conditions･. Sagami fauna They.

(9) Note. the. on. fauna. molluscan. Bay. of Sagami. its. and. 45. 甲aters. adjacent. TOKYO. HONA. BAY. (ヽl 一一与'..･_1. _SagamiRiver-. 1001. ”:. ノJ. ヽ. a... l＼l. frr. ENl. ､r5. s). nag. ヽ ;･,エ/:-. 穿::. =coastal= ＼､＼､ RegiorL. G.. IJ. a.･､. (n / Uraga l. (12. Water. ). J' ノ. nO. Northeastern. ＼､ご､､J､. a. B. G.. 200. ヽ. ＼. ゝご. /′. aW. C-Eno-ご ma. 宅. net. ､､-I--. usbina. South-We島ter払 ” Water. eプ. ･･醜e&r[-ic Regio血. Z ENI. Nojima-zaki. U. ､､､ーノー､50100. 200. fms). 節. A G.α. >15. blra. ScimO. J'(. ロ. ′ I. ). fms). fms). ㌔阜l. /. 100 ￣｢＼. 200. Text一丘g.. 8.. Upper. shelf. fauna. in. Sagami. Bay..

(10) 46. M.. ?. Horikosbi. conidae. 口cypra-e 冒. ∇日. 官日. of absence conid species. TEMPERATE. !;. tllC ZOOgCOgrapllical reglOnS. REGION. ?sS. 1zu & Miura. 壷野胃ゝ開閉硝捕醐 sWaki cJc I----I. between. boundary. R iktlZell. /. Sea. Inland. 0-shima. 句≒去モ. SUBTROPICAL REGION. Taiwan. Ryukyu. Group. 0 開閉 Text-丘g･. shallow indicate. 〟. 9･. Distribution the. water. on. the. species. Oceanic〃. i. Izu. Coastal=. Water. § Tropical-subtropical of the occupied. by. by. cally shown Paci丘c coast. Miura. (Fig. 9), their little. a. both pical number and tip. the. changes the. and. of the. at. regions.. towards Sea.. At. I(ii Peninsula,. the the. northeast,. cape. protruding. of the in close. the. Sagami. Bay). Miura. Peninsula). by. An. a. percentage. is graphi･ forms on the. water. and. cypraeid. species. species forms. though. conids. number. of the. of the. tropical,. subtropical. region,. exception which stream. extent. This. conformity,. main. Peninsula). tropical-subtropical. The. with. the. B6s8. fauna.. conid. of Shiono-misaki, into. numerals. Districts.･. warm. boundary. Within. the. Peninsula). of the. of. B∂shd. cypraeids. the. lzu. indicated. Taking. whole,. than. step-wise. temperate. decreases lnland. the. on. coast. some. representatives. stenotbermal. more. groups. are,. patterns. of. the. coast. in the. elements pattern. in. the. of. the. of. and be. can. lslands.. as. water. (west. water. oceanic. Japanese. coast. in 0-shima. elements. part. (northern. District. distribution. the. (east. District. tropical-subtropical. of the in the shallow. found. are. the. of. the. (southern. District. found. species lslands:. (0-shima). District. I. Region. in8uence. District. Sh6nan. (northeastern). cypraeid. of the Japanese in the localities.. Be･sha. Region. and. conid. 0-sbima. Water. REGION. coast. number. (south-vestern) =. of. Paci丘c. TROPICAL. of. the. the species Shiono-misaki. is situated of. subtro-. the. at. the. Kuroshio.

(11) Note. there. current,. as. up. the. the. lnland. both. District. can. the. rest. of. 58).. The. p.. character ing of the the. and. the. the. at. coast. the. the and fauna is not. the. fauna. of the forms,**. which. fact. the. (including. marked. and. the. (see. Figs.. assemblage. the. tropical. the. up-well･. show to. Marumo. on. system. ,50)as. to. as. well. in Bo^shG. District. from. the. in. the. although subtropical. occurence. detail. character warm. of somp Provinces.. Tosa. of Kii. to. relation. water. Despite Bay. an. in pp,. 8-1O,. 15).. of the. offshoot Bay Tokyo. Because,. the. branch. of the. turnes. Kuroshio. (Uda, '29),. Miura. the. around. there. water. found. is under Peninsula. found. assemblage. among. tropical-subtropical. some. above,. Besides. :. seau)eeds. the. forms. two. molluscan. found. are. in. an. feed on and take shelter the frond of among which mollusks are Since in the bay gelidiacean red algae wbicb abundant are in for District purposes, collected quantities economical detached from different localities the at algae collect mollusks. of. seaweeds. Sb6nan. it is easy. to. (Kanamaru,. '32).*** Water. "Oceanic‖. distinguishable *. 37;. in. 2-4).. mentioned. Tbe. infered. 4-7. of from. outflowing. families. except. 3-U<da,. 5. text-丘g.. south and is situated just at the mouth of Tokyo little coastal is frequently Channel), very water. '37, text-丘g.. § Molluscan. the. cold. than. water. District. in月.uence. the. Of. numbers 0-shima. in. Oyashio. and cypraeids, conids to the author. The. distributed. Uraga. the. (Uda,. there. is also. Bo^sh^1. that. not. be assigned. the. fauna. of the. aveilable. yet. are. in. '40,. Kimura,. low. 0-shima,. oceanic. does. could. (Fig.. warm. see. Ⅵ7ater. of. numbers. there. the. island. the. On. and fauna. the. respect,. of. water.. is found. aspect. similar. fauna. on. influence. coastal in species. by. cypraeids. decidedly. are. water.. temperature,. submerged island the of. coastal. this. Shiono-misaki. of. cape. In. and. stronger. richer. several. with. conids. a. the丘gures. the. in月.uenced. water. the. why. intermediate. by. both. 47. waters. fauna. troplCal. contrary,. appreciably. more. (for. areas. of. be. to. reason as. the. is doⅡ1inated. cypraeids Miura Districts.. species. of. its adjacent. and. of the. outpost. On. which. and be said. the血ixing the. Bay. Sagami. of. an. are. northeast A. found. current.. Sea,. conids in lzu. than. be. can. Kuroshio. warm. in. fauna. molluscan. on this locality, tbe丘gures species.串In high as in the tropICal indicating reglOn,. corallophile go. the. on. by. Magilus. their. molluscan. Monfort. antiqus. ‖Coastal〃. the. and. and. species.. several. species. Water In. the. of the. Regions former. of the region,. Coralliophila,. genera. bay the. are. mol-. Coralliobia. Leptoconchus.. and **. enode gia. Malleus. Hiras6. Cantharidus. (Could), misera. dant. or. Lamarck,. (Taki, lu'rasei. Colina. macrostoma. (Sowerby),. P.. common.. SPondylus. Laeuicardium. (Sowerby), elongata. ***. albus. C.. (Hinds), of. them. Pyrene. are. seldom. (Pl.. Polynices. and Horikoshi, hilaris japonicas. P･. subuitrea in the. and. with. 2) Vasticardium (Linn6) and Pteri-. unpublished). Phasianella (Lischke), tylerae. met. ll,丘g.. albumen. testudinaria. (Pilsbry),. ♪leurotomoides. Some. (Sowerby),. unpublished,. (Pilsbry),. Dunker,. sangineus. lyratum. modesta. (Gri丘th & Pidgeon), P. (Smith) are either abtlntidal. zone,.

(12) M.. ､4/B. luscan. found. assemblage. forms,. cal-subtropical not. from. the. Region,. the. only. Water. in. while,. the. algae. seinblage. of. the. to. into. several. However,. mollusks. in the district In. the. Kawana. before. (see. circulation the. south the. the. of the. southern. 3). In the the. of. cape current. southward. of. lines. pass. which By. bles. distinction. the. not. only boundary. between the. offOdawara, was. from. along implied. District. Favartia. munda. Kuroda,. Nassarius. (Smith). a一e. ber. found. dermestinus. Cantharidus. fig.. 17), DruPa. (Could),. frequently Pusia,. in. Lienardia. the. cape of different. district,. the. south. i.e.,. on. al., '36;. Fig.. of the. isothermal. and. '50). al., '55), but the. et. of Kawana, At. evident. of definitly. two. low. stations. transparancy. water of of the is further separated. District. which. line of. 19.10roo Kuroda. varia-. ll-Sasaki. cape. on. The. current,. hydrographical. some. the. while. (Figs. 4-6-Marumo,. cape. are. the two. persistent isobaline. the. pulcher. in. chlorinity &. Taki,. Turbo. a. Fig. 4.. excellens. ll,fig･. 8) APollon pusillus (Broderip), Conothais (Sowerby), ♪aucimaculata citrina (Pl･. Latilus. Smith,. nagusakiensis Water. Oceanic. and. of. factors. Philbertia. Region. are. well. The. and warm. represented. Clavus. humilis. water. genera. by. a. good. mum-. species.. of **. (Pl. ll,. (Reeve). Triphora,. Clanculus,. no. of. Districts. (Sowerby),. assemblage. is prevailing,. water. sides. coast of Sh6nan by an isopleth. lkebe, shimodense Ataxocerithium abnormale. further. different;. also. water. 港Calliostoma Sowerby,. two. Sh(3nan. and. the. nature. Izu. lzu. between. with. of the. of. et. bewhich divisible. the branch with the anticlockwise. area. area. with. 10-Matsudaira. as-. poor. physico-chemical. of yellowish colour and indicating the (see Fig. 10), prevalence. observed. coastal. (Fig.. District is. water. mixed. vicinity distribution patterns. the. at glance in the district. a. there.. of the. throughthe. a. brown. with. gelidiacean. are. sets. ln. only. C).**. the. oceanic. Kawana. of. water,. Bay. water mixed inshore area. northern. 2 &. more,. grow. from offshore Peninsula demarcates. Miura. the. to. or. laminariacean. Izu. zoogeography line drawn. a. water predominates north side coastal demarcation is indicated by of well. line. Ⅰn. the. Columbella C. hirasei dant. to refer. the. District,. the. and Fig.. coasts. north side,. tO. i. e.. areas,. Kuroshio,. point. ‖Oceanic”. fms. algae a. District:. of the. 13. as. gelidiacean. of Sagarpi. stand. golng. Misaki. bydrographical. Region. the. of lzu. o氏ng. of lzu. it is convenient. towards. of the. Water. from. deep. (Assemblage. mollusks. physiograPhy. "Oceanic”. the. In the. points.. as. is supplanted by in the deeper. which. Kjellman. Gal)a. view. range. Region,. different. and. areas. their. Water. 5 fms.,. slightly. 8oristic. also. extend. ”. than. § HydrograPhy longs. but. algae. Ecklonia. species. the. faunistic. "Ooastal. water. shallower. and. is rich in species in gelidiacean algae and in latter, it is destitute A),辛 while the tropト of many two are The different regions (Assemblage B).. (Assemblage. numbers. in. Horikoshi. in. Ecklonia. versicolor. Pilsbry the. and Geldiacean. assemblage, Duclos. atladona. Pyrene. Canthwidus are. testudinaria. assemblage.. very. japonicus jaPonicus (A. Adams), and instead of C.j. hilaris (Lischke),. frequent. tylerae. (GrifBth. &. Pidgeon),. which. are. abun-.

(13) Note. the. on. fauna. molluscan. Bay. Sagami. of. its adjacent. and. 49. waters. (33.0‰) (32.2c/oo). ●?v5 5{5<5 苛L. (32･6o/oo) 13･30. ●. (34.Oo/oo). 15 1V '12. (34.60‰) (34.69roo). (33.8o/oo). 1V ./17.5O. (34･74‰). 15.30. (34･74%｡) ●13. (33,9‰). III. ′ 16.3o. ●. (34.74roo) ●12 (33.9‰) ⅠⅠⅠ. ∫. 17.7｡. (34･82roo). ′ 17.9Q 83 roe). ′つ+. 10. Transparancy,. Texト丘g. colour. and. ter 1936. in. numerals. Forel. parentheses:. In. addition,. the. ture. Arabic. coast. line･. north. of. the. to. the at. the. In. a. shows. the. allowing development. (Sut∂,. the and. On. influenced shoot. red. on. other by. of the. and. hand,. the. of. north. t･he anticlock branch of the. C;. Salinity. :. coastal. a. direc-. and. Kawana. above the. more. water.. be. settled. sj･de of the. only. wise circulation Kuroshio from. isothermal. is ascribable. situation. Manazuru,. is. in the. from. the south. the. coast. current,. by. the. in lt(3 vicinioccurence. of. water. of Kawana in. suspended. quiet. area.. the. asscertained. are. of Manazuru in the bay. the. of since. sheltered. perticles. cape. of 15m. 14.5O. the. nap. oceanic. transparency. scintillans (Macartney)) is also indicated by the in the area between the capes. silt-clay. al., '55),. ct. physiograp血y. This. water. predominates. (Sasaki. 10, and. and. is. nature. the. note. The. the. of. comparatively. Fig.. 4).. area. distribution. and. I), since. the. in. current. Manazuru. of. in. coastal. shelf. can. Arabic. '55). al.. (Noctilluca. tide. they. water. cape. the. of the. (Chart water,. capes. information),. sediment. Manazuru. the. the. of and. hydrography. embayment,. et. Arrows:. a. 10, ll &4:. in Fig.. the. off 1955. in February,. in parenthesis. the. water. the. cape,. the. stagnation. personal. muddy. turbulant. of. water. temperature. roe;. in. of Kawana. off the. large. of. the. of 34.Oroo. between. area. is found. Manazuru. salinity. surface. tion.. (see Figs･. between. relation. the. line. cape. in. found. salinity the. latter. of. numerals:. in Too.. capes. Temerature. Sasaki. Numerals. colour. numerals. the. current. (from. in. Although. between. ll.. the lzu Peninsula. '36). al,. irregularity. an. and. June,. Water. Salinity. is frequently. and line. et. :. Scale;. in. the along in the area. in. transparency. :. Romannumerals. m;. ty. Peninsila. Matsudaira. (from. Arabic. in. Tzu. wa-. surface. ･. Texト丘g.. water. of. salinity. the. off. (34. (34120/oo). '21 11. ヽ. (ヽ′ヽA/. (Nasu,. the. '56).. is alternating】y as. (see. as well 2 Figs. a. an. 3).. off-.

(14) M.. 50. § subdiuisional. Izu. factors,. chemical. sides of the north divided into two Izu. the ment. the less. the. physiographical. area area. former. Conforming. two.. narrower. hitherto. some. of. or. unknown are. which know. to. esting. of the. amansii. Lamouroux. main. in big. abounds of 且at. be At. the. limit. ing. the. of. (pl.. flg･. (pl.. ll,. Bg.. ve). were. to. coastal. bottoIⅥ. open. 6 km. about. and. to. be. geology. steeply and. In. The. and. consists the. addition, inauenced. more. Ito^, belongs. or. offAtami. faunistically. of its geograis rich in species there assemblage ′and forms in common that of with characteristic beyond to the fact that the islet is frequently. due. nature. of. district). the. of. because. water. of the an. regardless. offshore of. offshoot. (Dunker), rare. noumeensis. marine. gently. sediments･. Conus. at. information)･ rather. it slopes. G･. latter･. the. co#ea. Okamura. Shirahama,. at. the. of. tends. it is inter-. Pacif7Cum. sandy sea. which in且equently,. connection,. Slopes. (Pilsbry), Latirus. 14) and 16), Latirus. collected. the sea. with. the. difference. Shira-. and. forms not. Gelidium. Sbirahama,. at. covered. of oceanic. borealis. DruPa ll,. be. may. the. water. to. the. while,. some. containing This. this. 0-shima,. on. and. part (the southern (off Area B). The. situation. In. a. more)･. found. are. and is. algae. Inatori. water. warm. several. gelidi-. second. the. or. localities,. the. the. of. (15 fms. two. 0-sbima.*. ascribable lnatori,. islet. an. A. range. at Shirahama. rare on. than. water. oceanic. numbers, lnatori.**. ･. and zoo-. gelidiacean. of. production in poorest. gelidiacean且ora, while, of the is dominant (see Fig. 8-Sut6,personal. rocks partly is exposed locality. Area. pbical. the. [A],. Inatori,. Inatori. boulders,. Hatsu-shima, the. At. bed. former. to. or. the. of. A], the. body. can situation two localities. the. the. by more. that. with. [Area. District. much. at. above. by. of. embay-. hydrographical. coincide. gradation,. common. also. that,. consists. of. such. part southern a little different･. are. are. to. of Izu. the. hama,. district. tip. of Manazuru,. The. 8)･. area, in the丘rst the richest bathymetrical in the last, where the area (13-14 fms) than in the丘rst. algae intermediate. In. Fig.. (see. sub-. the. predominated. cape. is the. acean. little. of the. of the. part. to. and. south be. B-the. oceanic Manazuru, and. the. of. the. of. Kawana. water;. north. water. further. part. cape. the. parts, can. the. th占physico-. peninsula southern in the embayis in species and numbers･ while of mollusks rich formstropical-subtropical [B], it is poor and is destitute of many between the [C] is an intermediate of the cape of Manazuru north. assemblage The. area. -the. oceanic. the. of. south by. two. latter. the. by. above,. into. Kavana. of. subdivision In. geography.. ment. C. and. by. in且uenced. capes. stated. divisible and. influenced. the. water;. coastal. is. A-the. much. As. District:. Kawana,. of. areas:. betⅥ7een. Izu. District. cape. Peninsula,. area. in. areas. Horikoshi. rhodostoma Gmelin are not. (Crosse) (Pl･. lnatori,. while. Conus. co#ea. the. ll, of. most. 9,. them. Pusia Bursa. ; and figs1. situation the branch. it, receiv-. of. the. Pusia. Kuro-. (Lamarck). microzonias. (Sowerby) (Ree-. rhodostoma. 10), are. of. porPhyletica. hitherto. unknown. from. Shirabama. ･*. DurPa. borealis. and. are. not. rare. and. Bursa. rhododtoma. is collected,.

(15) Note. The of beaches. some. At. can. near. water. 0-shima. on. is found. in. § Sh∂nan. [A]. southern by show-a. its. and. 51. waters. adjacent. situated. very. frequently,. [B,C] parts northern drifted on mollusks sandy in the Area A, there found are soⅢ`1e. Nii-jima (one. of the lzu of the district. part. northern. From. District:. Odawara. to. the. and. some. Shimoda,. pelecypods and. the. Bay. the be. also. Kisami. warm. also. between. District. Sagami. of. 3).. difference. lzu. fauna. molluscan. 2 &. Figs.. (see. shio. the. on. Of. lslands),*. abundant. none while denoted 8,. (see Fig.. Zushi,. are. which. long. some. of v-hich by □). beaches. sandy. the coast District. The stretched along sloplng of Sh6nan gently bottom the water harbours nature covered with of a coastal various a few common are Some cypods and gastropods.** members of which are. Tokyo. with Miura. Bay*柵and. District The. been. mentiond can be. land. water. Channel,. water of the Hydrography (see. from. quantities. Besides,. the. the. of. be responsible this can and Donax Dunker semigranosus 8, denoted by A). cribable. Sagami. '56;. shared to. spread. the. the. auther's. frequently. very. occurence. a. of. just. of Miura. District. the. in numbers,. fauna. than. species the. on. of the After. the. water. by. clear. Miura. of lzu. the. lacking. the. District. is. District.. former. surf,. of Ⅵ7edge shells line (see Fig.. Despite. :. of. that in the. of phy/Biography. the. of. etc.. and. has. observation).. is beaten. forms,. Rivers inflow. turbid. district. the. character the in且ow. Sakawa. is abudant. Physiography. and. in. the which its origin to. the. the. the. which. to. and. between. for. in species, if not to the intricacy. richer. water. oⅥ7eS. district. troplCal-subtroplCal. several. lzu),. the. (Nasu,. coast. § Hydrography. others. nature. coastal. of. boundary. the. is conspicuous. water. and. a. of. Coastal. ascribale.. in. some. pele-. coves.****. precipitation,. sea. Uraga. prevalence. fauna. much. in. the. Sandy. of little. a. This. district.. is. as-. Although. /. the. coast *. abounds. They. are. transmontana. locality. nica. is also *Anadara. Roemer,. son), Hastula 1”** ****. D･. die,erSa. The The. Mactra. (Smith). and. antiquata. (Martens),. ＋M.. Martens,. Siliqua. T. iridella. are. costatum. Kuroda. Donax. in. unlike ll,fig.. (Dunker)” (Pl. (Yokoyama) (also on. reeveana. imperialis. Reeve,. sulcatwia praetexta. Dunker,. U･. G.. not. 5). (also. Nii-jima),. The. Izu. common. DisO-. on. Thraとiopsis. occurence. kiusiuensis. of in. Pilsbry. the. *Glycymeris (Pilsbry), albolineata (Lischke), *＋Dosinia japo(Gray), Sunetta *Gomphina menstrualis (Menke), melanaegis. bilunulata. *Mactra. (Lamarck),. Myadora. District. remarkable.. ＋Macoma. nitidula. "concinna. neastartoides. and. nil'Ponensis. (Reeve),. (Jay),. Gomphina. in Miura. shares. Suuetta. (Yokoyama) vestita (Dunker),. Glycymeris. **. rocky. follows:. as. Nii-jima),. and. shima. in. pelecypods･. (Kiener), (Smith).. sectior. pulchella. Representative *'Neuerita. gastropods didyma. species. arc. indicated. by. species. are. indicated. by＋.. *in. Oyama. tile. Spengler, ＋. (Dunker), are. (R6ding),. Preceding. *Sanguinolaria. Tellinajedoensis and. Umbonium Terebra. footnote.. olivacea. Lischke,. *Aloidis. T,. erythrodon. (Les-. gigmteum. blfrons. *＋. Hinds. and.

(16) 52. M.白orikoshi. it is fringed. trict,. habitats. than. District,. the. a. in coast. assortment. good. easily. In. '55,. Miura. of Bay.. 2 &. to. Tokyo. Bay. the. ence. the. of. (Asakura,. offshoot. § Subdivisional of the. graphy in some. forming. district. interior. the. a. of off. minor. turns. clockwise. '40). The. (Kimura,. current. coast,. On. the. bay,. of the. circulation driving the. from. outflow hand, at. other. water. another the when Tokyo. times,. espe-. the. no. minor circulation, when Miura Peninsula bathing. depth Fusinus. common. 20-30. in. and. the. Turbo. cornutus. In. the. in water. Fasciolaria. "OceanicH. water. oceanic. m.. on. Solander,. the of. The. :. fauna. Cymatium. of. outflow interior. the. distribution. pattern. of. tide且owing. course. the. Region. of. in the. Kuroda. &. part. species, by. and. the. Murex widely. are. The of. other. two. which Bay.. Habe. (Crosse). replaced. Jonus. southern. to. some. 甲ith. former. Sagami. by. down. thomasiana. are. audoini. bottom. water. together. nature,. hydro-. is reflected. rocky. the. in且u-. the. District. the. ire-. Bay.. between. RaPana. part,. coastal. echo. set. Tokyo. the. the. of. dual. the. from. in. of. alternate. plankton indicating. of Miura from D) taken. southern. part. southern. distinction. part, northern are frequent. red. the. outflow. (v. Siebold). a. the. parts. trapezium Water. the. the. and. northern. the. ln. observation),. jaPonicus. while to. species. District. (A. Adams). perplexus. common. neritic. the. the. '37).. (Assemblage. Panulirus. (Kuroda). distributed. and. species. gastropods*, are. '51), and. '08ノ12-Uda,. in Miura. southern. of about. Marumo,. auther's the Kuroshio. of. by. ascertained. the. areas. gastropod for net. lobster. be. the. and. '54;. qu､ently. (Reeve).. Bay. sea.. the. can. '36;. oceanic. (Kawada,. *. Tokyo. approximately wcast-ward The current ,40). eastward. major. the. is. around. (Aikawa,. of Tokyo. the. the. there. summer,. situation. plankton. district,. of. by. prevails along into the open. turnes. above. asianus. outflow into. offshoot. from. Bay.. Tbe. which. an. and. of the. coast. the. straight. Sagami. of. i.e.,. water,. and. comes. Kimura,. corner. is induced. Bay. of Sagami. and. water. coastal. east-. ,37;. of the. systems. thecoastal edge of the shelf (Uda, '53), while inner part of the widely extended shelf. Uda Miura District, the part ('37),off southern of. southwestward the cially during. the. are. zones. sublittoral. the. Bay. a. the. bifurcates. 3-Uda,. current. southward. out. as. well. and. in the. circulation. the. three. Kuroshio. northern. along. predominates According. from. (Gislen, '31),as. of. of Miura. part. inlets, with several flat to rocky point. complicated from muddy. nitches. are. the. of. off the run. less. or. Kuroshio,. northeastern. circulation to. more. there. then. Fig.. the. minor. is. In. kinds. more. affording platform in the southern addition,. erosion. '56).. and. 6-iso (see. seems. line. offshoot. Bay,. around. latter.. of the. The. Sagami. the. District,. branch. the. thewider. of ecological in the intertidal. available. (Horikosbi,. by. influence district. Tritonalia. is. sauliae.

(17) Note. also. by. shown. sional. the. on. Miura. than. Ara-saki,. as. lzu. in the deep. District. the. faunistic. district. of the. part. (see Fig.. ashore. the. the. that. ground. Bay. C･. § Vertical. into two. 1uscan. Bay. also, are. species. In. the. semblage. to. the. that. the. minor. algae. is not. which. circulation bring may. clockwise fauna. on. distribution the. on. It is. shelf: zones,. vertical the two. in the a. general. regardless. zones. are. yet. the. available,. off the the. cape of be explained inauenced by. side. zone. divide. to. half. the. of. west. (Assemblage. of mollusks. terminology,**** as. far. **. In. Reeve. of. specimens. (Born). Drupa. ,. Latirus. ***. ****. citrina,. invertebrate In. Persimile. Clanculus■. Chlamys. Pusia. not. Station,. (Pilsbry). stearnsii. Fulvia. shelf.. freqtlent,. are. the. ,. author. ColumbeZla Mactra. (Kobelt),. schmeltzii. of the. and. collected Tectus. (Philippi),. margaritarius. umfasciata. microdon. (Wood). and. few. pyramis. z)arians Sowerby, Gray and. ornata. following. MS,. To-a. (Reeve), undatopicta. Hedgpeth,. See. are. species luteosto7na. Nassarius. Ataxocerithium. Pilsbry,. ater P.. 〟. 〟. of of. '57.. frequent. :. Strombus. japonicus. Ficus. and. Element. '54 al., '42-Clarke, '53 & Twenhfel, Principles. et. (Ktister), subintermedia Turris ▲(Lamarck), clathratus. (Pilsbry). abnormale,. (Sowerby).. subquadrata. &. addition, Kuroda. (Kira),. sagamiensis. rare.. Marine王∋iologlCal :. Coralliobia. palaeontologyn).. japonica. Reeve),. are. (Ekman, '35-Sverdrup sublittoral & infraneritic epineritic (Scott, '40-Shrock. Ecology”), *****. ,. japonica. marica. Sowerby. Clanculus. pulcher,. Eulittoral. mol-. Kuroda.. niAPonica. Cantharidus. Conothais. lonia. (Kiener) (Dunker),. musiDa. rhodostoma. Heteroglvpta. Chione. of the Misaki vicinity following the species. the. and, the. as. an asPeninsula, of the Miura Decatopecten striatus (Schumacher),. coast. E), with. (Gmelin) and C. fulgetrum and. scutulata. fulmen. the. concerned.. southern. Mitra. southern the. (Schr6ter), Callista chinensis (Holten) and Ploynices albicans Pilsbry,***** is dredged from bottom the sandy of the upper part *. water. mixed. Pecten. Conus. southern. off the. distinct. actually. their. extend,. practice their. of. common. Al-. south. lou'er shelf. cape of faunistic. information).. circulation the. (As-. narrower. of in. forms. the and Sut∂, personal. the. before,. case. the tip of the peninsula around may latter place tends to be more readily than the former.. Molluscan. dim'sion. fauna. shelf in Sagami. than the. of Tokyo. water. fact. the. a. stated. forms. water. is. area. occa-. as. is much algae Fig. (see 8). At the. of the. due. mentioned 3). Considering. 2 &. of the district, Arasaki is richer of the. hydrograpby be. warm. characteristic. '55;. is,. mollusks. District***,. (Kawana,. may. coast. on. part. fms. the. and. the. of. several. of lzu. of. more) (A'), which. assemblage contains. 12-13. detail of irregularity. though. or. 53. waters. I(Oyama, '56).. species**. range. (13 fms. forms,*. water. assemblage lacking many. and numbers bathymetrical. its adjacent. and. warm. gelidiacean. southern. as. Bay. Sagami. tropical-subtropical. the. molluscarl irregularity,. and丘oristic. range. some. the. and in. the. with. of. some. of. B),. that. occurence. in species. semblage. (5 fms). of. District,. poor. above,. fauna. the. appearence. In. molluscan. Crassatellites. japonicus. (Reeve),. Semicasis. (d'Orbigny), Baby& (Adams. leucotropis. (Dunker)..

(18) M.. 54 From. the. ent. (Yokoyama),. the. hydrographical. 41), the. as. considered in Sagami. above. (Assemblage. Bg.. 1), Dimya. from. the D,. (Assemblage to. be. It. p.. see. 52).. here. the. of. shrimp. Turcica are. coastal. water. MS -. (pl. ll,丘g･. Pease,. from. and. too) that. are. the. all. molluscan. distributed. of. south. is. zone. net. known. are. the. widely lower shelf. taken. lobster. a. alcyonarians since. and. Solander). those. by. water. shallower. Bay,. of Sagami. the. part. the. under. by. a. smll. from. the. Bate. is. trawl,. sized upper. no. other. the. of. shelf. is. (r), mollusks is collected. assemblage of foveolata Sowerby,***. Venus. and. lower. another. where. part. while of the. than. the. (Philippi). GuildjTordia triumPhans by. Pedicularia. and. DOIva. the. assem-. shelf. by. a. E. Assemblage. XenoPhora. and. Pallidula. Kuroda. Chlamys. uesiculosa,. stylasteris. Semicassis. (Linne)-, MS. Chlamys. Hedley. var･. (Pl･. (Gmelin),. squamata ll,figs･. ll-13),. Latiaxis. Pteria steno-. others･. some. 15), Granulifusus. schencki. and. musashiana. cochlear. I)･. accompani占d. (Dunker),. volva. (Yokoyama). uu,aensis. infrequent･. not are. Kuroda. frequent.. the. water. part. Chart. coreensis. They. ･**. Acila. &. the. it is clear. northeastern. 12. brevialata spina. appro-. coincides. β) is different. madreporerians factor,. taken ashore mollusks Peneus for net japonicas. (see Fig.. (Reeve). in. Since. muddy sediments, with Glycymeris (Dunker) with rotunda some demersal丘shes mingled with. ･*. uesiculosa. species madreporarian Cythelia axillaris (Ellis &. (Assemblage. covered. ･. neign-. at. and Chlamys. Anisopsamma. by. (see footnote. enumerated Tosa Provinces, Kii and in且uence of the Kurosbio. blage. with. a. (see p･ strati丘cation be has out, ('52) pointed distribution molluscan vertical. hydrographical. the. species. with. bottom. rocky. to. sensitive. In. species. Oya皿a. Picnodonta. a. accompanied. alcyonarians.. several. MS,. Habe. together. AIcock. amphihelioides. ashore. of. assemblage. summer. Hawaiaraca. β) containing. argentata. Reev-e**. fragum. and. of. fact･ A by the following corroborated Marine BiologlCal Station, Misaki glVeS mOl-. the. nearl. ”,. 〟. the. depth. be. to. seems. deep. species. chama. during. boundary. may, condition limitting factors of the. opinion. 30-40m. ll,. between. valves demarcation of the layer of. as. major. an. of. odd. depth. the. water. the. at. Bay.. The station 1uscan. 30m,. (Fig･ 12)I. drawn. found,. was. by. ashore. dominant. the. as. cochlear. taken. Schlegel) 30m,. than. sagamiensis. than. Kurosbio. underlying. be. jaPonicus. Since. of the. that. with. ximately. (pl.. deeper. can. shallower. Polynices. and. station slightly found in quantities･. were. and. striatus. &. zones. station. Crassatelites. containing. Decatopecten. the. one. at. two. is. (Reeve),*. (Temmink. di鮎r-. a. shelf,. Pycnodonta. (Dunker),. modesta. olivaceus. between. because,. mollusks bouring. Paralichthys. boundary. 30m,. about. for. net. aflounder The. of the. part. vesiculosa. Astraea. and. lower. the. Chlamys. (α),with. assemblage. musashiana. bottomof. gravelly. or. sandy. fioriko占hi. nil,Ponicus and. Tellina. (Reeve),. 7'aponica. (Smith),. Conus. vestalioides. Siphonalia. orbignyi. Yokoyama. modljicata C･. Audoin,. (Pl･. ll,丘g･. sieboldi. 7). are. (Reeve) Reeve, not. in-.

(19) Mote. on. the. molluscan. fauna. of. SagamiBay. and. its adjacent. waters. 55.

(20) 56. M.. About. the. delineate. to. northeastern. the. distribution, tween. the. the. sandy. may. the. and. '50),obtained. Hydrographic. O丘ce). of. between. boundary. I) (Tayama,. the. bay'althougb. the. two. as. data the. yet. terms. in. of demarcating. the. on. in the. from. as. well. fall. probably. bottom muddy from sounding. it is not. zones. marine. geological. (Smooth. (Chart. map. in the. sheets. mechanical. possible molluscan line be-. analyses. Japanese the. of. sedi-. (Nasu, '56).. ments. The. line. coincides. runs. with. bottom. the bend. approximately line the isobath. of 25. down. very. which. (Tayama,. current. slopes. '50; on. action. factors,. grapbical to. part. boundary. Ⅱorikosbi. Mogi,. parallel. lower. the. in the. roughly. this. depth,. the. pro丘1e. of. gently. from. the. shore in. line. shows. a. the. di#erence If it is. sides･ bottom. nature. the. wave. besides. so,. found in the two of the molluscan species Oyama an ('52)has divised elaborate system of zoning, threeりfasciasりon a The shelf with sharp edge･ Upper. and bydro-. the. be. may. distinction. the. and. At. '55),indicating. and difference. line,. coast. 30m･. or. its upper. the. with. respons.ible. zones.. discriminating zone. shelf. the. of. Oyama's Euneritic coincides with the depth fascia in both its The and molluscan Lower corassemblage･ author's shelf zone to Oyama's Mesoresponds Sub-neritic in depth, but and fascias the sandy bottom and the lower zone muddy assemblage of shelf that coincides with fascia･ The disposes of subneritic as an author of Oyama's mesoneritic Present. Paper. limit. in. ecotone.. § Lou,er. just. shelf. mentioned,. are. comparable bottom assemblage bottom (50 & 54m Chlamys. ”)ithin Sagami. zone. assemblages. to. the. vesiculosa, from the. interior. bay･. the. of. An. by. Glycymeris. current. assemblage. sourthern. ofa. tip. 12)･ From was. collected from 0-iso. extending. muddy. the sandy Peninsula,. Izu. the. of. zone. shelf. or. α. ridge. the. those. (Sakai, in the. Venus are and foveolata, which repredredged r, Such (unpublished). molluslargely to depend upon the sediments, in turn, which,. seems. the. the. Assemblage. (α). the. (see Fig･. near. than. rotunda. Assemblage. sentatives of the can distribution is governed land water.. top. muddy且at. from assemblage. offShimoda, indicator of the. other lower. area. Peninsula. deep). '35),while,. the. bottom. sandy. (㍗)of the Miura an. In. dredged. molluscan either. Bay:. of the. were. and. wave. actions,. dredged mollusks B6s∂ Peninsula. at. and. a. the. station. inaow. of the. turbid. in the. offTateyama. of (Fujita, '29) show･s overlapping Chlamys on one hand, containing Xenophola ♪allidula vesiculosus and Glycymeris Venus foueolata, Siphonalia spadicea rotunda, Conus and sieboldi part. an. feature, and, on. the. other･. Peninsula. Another. between. (offManazuru,. seems. to. Bolma. modesta. be. re一ated and. dredged. assemblage. to. the. Xenophora. and Assemblage. in. the. Ito" and α,. pallidula but. containing Chlamys. northern. part. Hatsushima). the. (Sakai,. Guildfordia uesiculosa. of. was. lzu. ･35),. triumphans, not. found..

(21) Note. § Lou'er from. the. on. zone. shelf. there southward, To-shima. Nii-jima and is covered of banks. ･55), and fo.t. the. into. slopes The from. is re且ected. which I)elt. running. the. rise. sity. sounding. the. of Tbe. Kurosbio. of the. lzu. of the bottom. ridge. There. (-ga)-shima,. Ryukyu. there. one. were. tained. the. of the. fact. that. fossils,. thinks. A. living. specimen. *. S. &. Kikai-zima, ･*. 42;. flabe, Kuroda,. Mollusca ***. of. Acar. (Reeve),. "Genera. 1951. Sci.. of T･. T･&Habe,. Spondylus. (6). that. and. characteroccurence. wide. ll,figs･. 3,. fossil. from. Kikai banks. ligament. ob-. p.. Marine Rep.,. Japanese. 1952. the. =Check. from Imp.. Shells, list. the. Univ.. Pelecypoda” and. that was. the. con-. ln. area. the. and. Osu皿i. information) personal on Kuroshio the of the. assemblage*** banks, since. Mollusca Tohoku. spite. flachijo^Island. Okinawa**. (Okutani,. in the on. near. influence. strong. AI-. 4)･*. the. on. collected. banks,. the. on. of the. the. pleistocene. from. also. species. 1934. Group:. T,. a. sediments. N.. Zinb∂, b･. congenitum. bank. tip. the gravelly difference of of. is still living. species. Kyt^1Sh^1. and. the. of. 5, f･3a･. Japan”,. a. the. and. (Pl･. specimens fresh odd. reported. of. of the. Ryukyu. Pl･. Zinbo. Shinkuro-s6. of. the. was. indication. coarseness. 152,. that. lsland. dominance. Nomura,. (2): p.. Tane. further. The. many. bank. the. author. the. upon. from. the. is. &. facing. from. results. and. inten-. '44)･. of the. of mollusks depth･ One. common. 2,000m. scarpes. them,. the. cover. enhanced. as. top. sandy. several valves vith and In Hyo"tan-s6 information)･ (Okutani, personal of & Kotaka Hatai, Niino (in Niino, '52) took it for granted. between. which banks.. among. the. '44),. wide. sediments depth of. extending. the. are. a. bank. obtained. cerned. channel. ridge. (Suzuki,. as. (Suzuki,. between. as. conjoined. from. specimens. Group,. to. rise. at. found. II). places. a. of. Nomura. orlglnaly. it. side,. understandable. area. great. sheltered. is the. hanzau'ai. was. species. the. assemblage zone in their. assemblage. Glycymeris. pelecypod the. the. of. by. trough sloping facing southwest. a. side,. ocean. island. sandy. unusually This is due. and. (Niino,. the. is. of the. The. accumulation. different entirely to the lower shelf. feature. though. gently. parts. exposed. belongs. a. a. sand. On the. banks. the. such. Zenトsu. of. the. in. and. at. mud. strength. is an. current. of. Peninsula,. at. which. bank. the. of. northwest. istic. of. sedimentation. map. interrupted. current. shallowness. is nearlyflat. (Chart. ocean且oor･. 2･216m)･. station. running. depth･. 200m. to. rise. 100-200m. of. 57. waters. submarine. banks. of the. geological. marine. muddy down ranglng. completely,. (the deepest. the. the. banks. on the materials bottom topography. the. across. a. and shell･ gravel on floor, and,. ocean. than. coarse. and in. the. more. of the. prevalence the hydrography. top. sand, to. On. several. The. coarse. with. continues depression of. a. are. its adjacent. and. Bay:. of Sagami. outside. Bay. Sagami. of. 0-shima. around. of. fauna. molluscan. a. different. slightly. Limestone=. ‖Ryukyu 2nd. Ser･,. No･1,publ･. bibliography. largely. depends. of. the. by. 16. (Gcol･), the. recent. author, marine. 21.. (Smith), anacanthus. 1m'catula Mawe,. and. muricata Lima. Sowerby,. fujitai Oyama. Chlam),s are. vesiculosa, common･. Ch. mollita.

(22) 58. M.. in assemblage, from the bank the. coarse. mollusks mixed.. still. islands,. because. the. of. than. of. more. mollusks. remains. § Subregions the of. lower. the. shelf stand. region. of. parts,. the Utinomi,. of. in. in. the. belonging. species in the. not. loⅥ7er. washed. by. the. since off the. trough. of. assemblage. reduction. of. region. to. Shelf. the. of. faunas. species can. Japan. of. (Fig.. west,. the subtroplCal divisible into two. numbers illustrated of the. 13;. see. &. with by. that. Bay,. Sagami. of. one. Nomura. and. and. be. zoogeo-. Hatai,. coast southeast of distribution molluscan. the. of. the. the. on. in the. zoogeography. From. '33;. is set. that. possible. the. Japap.. (Yokoya,. Fulgwaria,. genus. zone. in. role of. which. shelf. This. to be. seems. crustaceans, and cyrriped is bitberto known to be. of. lower. It. so血e. view points Kii and provinces identical.. between. former. the. zone*. fossils,. of be. can. many. shelf. exceptional. :. coast. the. Tosa. are. lies. of this. that. upper. islands. the. halves. eastern. boundary. From. difference. Kii. of Japan the. and. '55),**the. also, the faunas Bay in the east. from. subtropical. of decapod side. western. I(ii Peninsula.. nor. '35).. fact. remains. periostracum,. mentioned plays Paci丘c the coast. on. point. the. forms. zone. ocean. '36;. The. just. rise. the. the. of be. can. problem. the Japanese. on. graphical. The. is the. of. unsolved.. sand-covered. and. depth.. bottom. sandy. instead. predominate. (a). is found. muricata,. ; cf. Niino,. assemblage. isolated. are. Plicatula. sedi皿entS. neither. their. retain banks. 200m. a. forms. shallow. them. some. on. by. information. of the. dwellers. These. sandy. peI･SOnal. feature. ar-e. which. where. (Okutani,. confusing. is replaced. species. of Zenトsu. materials. Another. are. the. which. Ⅲorikoshi. the. and. Chart. Tosa. some. endemic distribution of. bestknown. also. of Sagami. II).. gastropods The Sea of. TosaKiiSEenashOufsuBrauygaSaBgaaymiPacoifBcB6CsohaGSt lIIIll. F.mentiens. 甲■■ll■. F.cancellata. 叫■. F.hamillei F.daviesi F.hirasei F.concinna. ●●●●●. F.clara F.prevostiana. Text-fig1. ●●●●. 13･. Distribution region. *. not and. Limopsis. infrequent, Solen **. forskalii and. roseomaculatus. subregions. Fulgolaria. Paci丘c. species coast. in. the. subtropical. of Japan... Adams,. Diplodonta. Kyusyu-Sikoku. EantoITokai. A･. of. the. of. Pilsbry. Dunker, Pecten Septlfer grayanus and japonica Pilsbry, Callista c/u'nesis; Venus were. and匡ii-Kwanto. (Utinomi).. albicans toreuma. are. Could. found. subregions. (Nomura. &. Hatai). ;. Nankai. and.

(23) Note. the. on. Ensha. and. Suruga. range. of F.. hirasei. that. with In. found. this. for. Sagami. In. by the. shima), separated. Island. by. mud. the. zoogeography. the. the. on. of the. edge. water. locality.. At. the. that. in. Peninsula. Bo^s6. from. of. the. in. settlement. of. survey. sea. of. of. which has never. dredging 237. depth. 3,4I2m. of. (see Chart. in the. the. abyssal. is点11ed. with. been. tried. (65km. II),*** abyssal. found. found. are. mollusks Although. SagamiBay. 42), the. those. by. companied. of by. off the. assemblage. of in the. zone. archibenthal. The. are. mations). An. in. article. to. bank. the. yellow. those. of. mimeograph. others, in. Fulgoraria. than Tosa. Kii. and. prints. the. or. other. re-. at. pre-. 12;. Chart. Sowerby,****. ac-. (Fig･. Sea. Perotrochus. and. taken. are. which. (Noguchi limited. with. the. (Okino-yama). (Sowerby). smithi. Ensha. of. and. Tsuchi,. and. circulation. hard. two,. is known,. Limagoliath. (Iiilgendorf).and. other. fauna. of Okino-s6 Peninsulas. B∂s6. mussel,. Fulgoraria. into. Atlantic. North. bottom. the. and. gastropods. fauna. related. bard. around. Miura large. beyrichii. molluscan. also. slopes. is divisble. in the. '53)一 The. the a. Bay. Sagami. is found. as. rocky. large. (-pleurotomaria). in. (Ekman,. the coast along It is I). represented. **. of. facies. and. Bay. for. barrier. a. ecologlCal. of deep number Bay･ Sagami of. bay). fauna. world from the. only. *. role. faunas. two. the. as. south. Fauna. Station. the. different. the. of. sent,. a. 41,. pp.. Challenger. archibenthal soft bottom. the. gions. far. are. dredged.. The and. Sea. basin. central. (see. outside. entirely. mollusks bay was. the. Deep. shelf, bottom. the. on. and. is expected Paci丘c deep. fauna. in. slope. areas. as. of. O-. and. two. extend. a. and. Peninsula. the. of. and. suggesting. topographically. the. an. coincide. required. V.. Beyond. faunas. not. are. forms. the. Preuos-. Suruga. lzu. characteristic belt might sandy play fauna. ⅢoⅥ7eVer, shelf. the. between. areas. the. of. do. in F.. of. is also. rise. zone shelf belt which. sandy. Since. study. are. concerned. the. extensive the lower. of detailed. a. question, area. an. lower. the. of. (Chart II)I. dwellers,. are. the. bottom. sedimentarily. Hacbij6. the. general of the fact that the two depth (between of 500m. spite. muddy. be. to. that. Kuroda**. that,. in. is in. 59. waters. included. are. distribution. molluscan fauna.. it is interesting. trough. a. Bay. the. crustacean. mollusks. Bays.. continuous. the. in the. by. Kii. and. Sagami. while. its adjacent. and. Tosa. with. (Sowerby),* boundary. Bay. Sagafni. of. together. connection,. boundary. a. Bay. This. (Cross).. tiana. fauna. molluscan. ashore in. Suruga infor-. personal. 2. (Yumehamaguri,. (22):300)･ ***. St･ 237. c,ahllenger. :. mus). japonica. (Smith),. and. Myonella. (-CusPidaria). ･***. Lima. is. a. genus. large mussel, yellow Norwegian fjords. 34o7'N,. Barbatia. of Lima. (Ekman,. Malletia. 138oO'E:. (Verill) (-Arca. Profundicola lischkei a. world. excauata, '53,. p･. (Smith) wide also. 289)I. dunkeri. were. Smith,. (Barbatia). Smith),. ptereossa. found･. distribution,. and. in. facies. the. (-Glo･. Pristigloma. same. it. is interesting. (Lophohelia. to. Zone). find in. a. the.

(24) SO. M.. by丘shing. nets. 236a),a and among. other At. 2. Albatross. Sts. 5087. MS. Bay,. &. a. fauna. is. &. 5088. (Chal･. Bay. and. Okino-s6. at. specimen. are. &. St. 232. not. Alb.. St.. Lima. of. 236-. (St.. goliath. notable form which. in. also. MS. The. &. soft. its. aeola engonia water. adjacent. Cho^shi. off Cadulus. Kuro-. summa. three So"y6. at. collected in. Sagami So^y6. at. collected. the. and. following. the. MS. Smith. Chart. 12;. Lischkeia. offOdawara. Okutani. niponensis. Verrill. from. also. of bottoln. Riuguhdrillia and. St.. 'part. (Fig.. of. of Kuroda. kawamurai. the. depth. and. occurence. is hithertoknown Halicardia. to. water. and. So^yo"-maru. northeastern. Bay. deep. Okutani. 2).. the. in Sagami. 1886)**. New. one. occurence wide So^yo^ st. 2) and. &. i,e･, Akebiconcha. :. in. Watson,. which of 700-1,000m. 5088). rare. much. 1885;. belong. muddy且at by the. characterized. offCh6shi; forms H･. 2,. a. (Dall, '25)*** and. soyoae abundance of Calyptogena da MS found S6y6 St. (both at. species St･ 2, the. Smith,. of mollusks. number from the. St･ 232. (both of which. are. 1895;. information)****. (Pl･ Ⅰ･丘g･ 20) (Chal･. (Watson) (Watson). getting. (Murray,. personal. good. hauled. were. I). The. dredged. facies. animals.. (Okutani,. fauna. Challenger. bottom. St. 232. Sagami. 冗.M.S.. hard. the. Challenger. two. at. lines.. and. hit. Eorikoshi. St.. New. Jiexuosa (from England allied waters) and H･ gouldi Dall, Bartsch & Rchder having been (off Hawaii) found in also deep Leptothyra transenna Baywater ; and the late Hira(Watson) (in Sagami se. the. late. of the. Sea. and. o丘ng. Hosoya. Collections). of EnshG. Considering. the. fact. of fauna. of the boreal bentbal fauna in. Oyashio. more. belonging. to. shitai. * **. such. Challenger. St. 236. Challenger. St･. ***. Albatross. ricula). hondoana. guhdrillia **** *****. tothyra were. (Watson). engonia. ll,. (Pl･ were. St. 5087:. Sely6-maru. Challenger. (-Homalopoma) collected.. St.2;. St. 235:. transenna. among. 41,. flg･. 139｡19'05〃. 35Qll'25H. N,. E. 138oO'E.. and. 1028m,. Orectospira. MS,. 1,118m,. (-Echinella). :. (-jYeuro-. green. 139o30.0'E.. mud.. (-Nu-. (-Pecten. Aj:oria. :. mud. 671-737m, N,. green. (Hirase). Habe. Riuguhdrillia. green E. A. kino-. Portlandia. mud;. and. 139o28'20”. cold. (see Ekman,. macrocheiricola. (Watson). shelf arcbi-. 764m.. green. 6), Delectopecten aeola. &. Sea. some. (Dall), N. minor. 1,410. II). Ancistrolepis,. Kuroda. galea. 627m,. the. However,. distribution. adelphicus 29'E:. in the. submerged. 42).. Fusitriton,. as. restricted. 139o28'E:. N,. the. the. is found. of the. existence to. pp.. sagamiana Dall). 139o33.3'E-35oO5,5' 35oO5.1'N,. 35o7'N,. commonly. related. 139o. 34o58'N,. (-Bembix). (Dall) ; St. (-Suavodrillia. which Bay,. of F. oregonensis. obtained. 35oO9'40= N, 5088:. engonia. New. 236a:. Lischkeia. a. in Suruga. the. genera. Dall, JaPelion. 35o11'. (Smith). (Chemnitz)),. toma). &. 232:. water. show. ranges. trochoideus. very. '52) (see. cold. Buccinum. A･. culan-1) likschkei vitreus. Oyama,. (Gmelin),. from. (see Chart. depth).*****. 720N,. regions. known. originally. Bay,. as. north. southern. and 290, 291); i･e,, the. Kuroda,. Sagami is found. far. as. '38;. JaPellion, Neptunea pp･. in. of Tosa,. region. (Taki,. water. species. fauna. arcbibenthal in the o氏ng and. EnshG,. '53,. that. the. among. was which St･ 235 of 1,028m Macoma calcarea. Chal･. at. (-Tur1. mud:. 700-750. Lischkeia. tectUormis. aeola,. Riu-. mud. Lep-. (Watson).

(25) Note. PI. and. N). the. on. Dall. Suruganum. coinciding In. the. (see Fig.. Sagami. Bay. underlying. fauna depth of. 300m. to. seems. (see in. archibenthal forms. '55;. (Niino,. the. lowest. the. separate. tical. and. the. present. in. Saganli. practical. archibenthal likely bears the found. and some. there. (note the. 100-200m. see. to. treat. shelf. zones.. to. the. sand frequently. Misaki. gravell. coarse. the. and. is clear. lt. both. 甲ords,. that. the by. nature. characteristics. the. pbysico-chemical bottom, the. the. of. The. four these. of. environmental the. fauna bottom. soft. the. of the. are. rise around *. lower. the. Species. tip. Nos.. the. 29,. of. for. be. 30,. in. that. claims. between. established its speci丘c. an. of. molluscan. bed. naked. ecotone. very. the. at. condition. edge. rock. of be. to. tend. Kuenen,. '50,. p.. 263). off the. edge. into to. &. zone. in the. archibenthal hard and. bay. it and. of the. moト. the. in. constancy as. assemblages. interior. wave and actions. in the complexities. the. two,. only. in other. the sedimentary determined by the. and turn,. data,. relative. molluscan. 43.. of. goverened. substratum;. water. is, in. lack. due. in the. and. the. the current and fauna can differ. the. are. animals. and. which. found. the. 34, 42. shelf. necessity establishing it would be of both theoreas an betⅥ7een ecotone the. the. the. arcbibenthal. fauna. and. of peninsulas 24,. of. benthic. may. in the. different,. 23,. nature. is divisible. This. zone,. shelf. entirely. Bay. water. medium. zone. Sagami. of. facies.. stagnancy. In. abyssal. lower. for. benthic. of the. latter. of the factors.. the. of. ConcltlSion. topography. zones. vertical. Omitting 1uscan. bottom. the. pbysiograpby,. that. member with. al., '42, p. 1021;. the. of. of. two. the. known. at the shelf and gravel Arasaki in Chart I).. of. distribution. the. a. appearence. and et. sand cape. been. Oyama be. sedimentary. (Sverdrup. between. It has. zone. The. special. and. of the. occurence. a. (Tayama,. that. this. the. at. of about boundary. the. see. shelf. inclination. should because. suggests. VI.. by. zone. lover found. gentle. shallowness, dwells together. zones. be. to. 100-200m. 57). Iiowever,. p.. and. the. water. a. shelf.. fails to. author Bay, he. lower. Kuroshio. band,. the. beyrichii,. banks. relation. more. between. coast. about. advantage the. because. shelf,. Of the. of. the. zone. (36O. temperate. the. bears. sense,. margln. Perotrochus. ヽ. a. Cho"shi. of. and. warm. other depth. the. at. slope. the. on. for. the. topographical. a. the. of. archibentbal feature･ Since. subtropical. 61. ∇aters. cape. each. On. tlle Shelf a separate the low･er shelf and. part. the. of the. of which is said respectively,. 41).. p.. of banks. fauna,. its adjacent. and. south the. water,. fauna. into. fall. top. the. on. the. between. intermediate. breakes. faunas even. on. Bay. between. boundary. the. shelf Mogi, '55),and,. '50;. boundary. archibenthal. of about. the. Sagami. 7)辛.. cold. the. and. of. terminate. the. with. fauna.. shelf. fauna. molluscan. is. with that are. bay.. the. nature. and. other found on also In. seas.. the. different the. upper.

(26) M.. 62. Bay. of Sagami shelf zone biotopes is also found. current. Japan, the. from. but. the. of. places. this. forms,. with. between It. a. differ. not. some. which. fauna. of the. shelf. forms. bay. is. a. little. a. coast. of. tha･n. those. substantial. re-. less. or. more. far. HoⅥ7eVer,. within if anything, in. in. as. bay･. the. found. are. fauna. Paci丘c. moreover,. the. making. range. subtropICal. Japan,. western. and. zoogeography. from that much. so. forms. little poorer,. a. the. the. on. molluscan. in. the. zone,. sheltered. in the. subtropical. which. Japan,. of. Bay. lS. directly. adjoins the. without. Hokkaido^,. tO. mingling forms in the cold water conin the geographical. the. and. endemic distribut-. elements,. Kyt^.sh^1. Sagami. region, side. from south. because. is interesting. ocean. the. Japanese. several. temperate. warm. Islands,. forms. found. also. are as. to. temperate. the. temperate. warm. in. region. them. seems. more. fanuas. far. a. of. on. a. the. oりapan,. place Sheltered the settlement tbougb. the. on. side. less. Bay,. study. that,. suggest. Paci丘c. the. or. sagami. to. possible. like. current to. is. there. Japanese. the. the. on. region. dose. this. role. the. of. sequence. water,. important. of the homogeneous. considered. water. This north. 丘ne of the. in. place, be. can. warm. the. half. western. a. In. land. situations of difference the. contains The lower. ocean,. bay.. sheltered. throughout the. the. localities. the. which. an. Bay. tropicaトsubtropical. within. In. even. region･ of. subtropical of the. plays. on. zoogeographically fauna of the bay. shelf. duction. ing. that. it is. upper. it. and. boreal. the. of. water,. reflected of Sagami. fauna. Japan,. as north different. a. are. archibenthal. of western. sea. the. entrance･. inflow. the. on. complicated. in the ecologlCal. zones. respective. The. the. of. more much difference. sltuation such the. depends. strength. to. Opens Widely whicll in a bay withnarrow. as. which. water,. coastal. Ⅲorikoshi. coast. by. predominated. the. is con丘ned in. as. water coastal be reached not. than. area. ocean. strong. fauna. can. problem. extensive. more. the. temperate. warm. of the. by. swept. Bay. Sagami. until is. made. Cited. Literature H. 1936. AIKAWA,. 0n. oceanogr. in. munities BABA,. K.. 1949. of EKMAN, & F口JITA,. &. T.. 3): 1931. notes. fIEDGPETE,. A. Sec. J.W.. on. 58-65,. pp.,. Bay,. PIs･, 161. 50. the. of. 60 29,. tfs.. of Sagami. the. 30. the. waters. (On. tabs･,. tabs･. 35-38,)･ by. collected. Eis. tfs･, 1wanami,. Rec･. Japan:. surrounding. tfs” 61. Ⅹiv＋417. sea”:. of. their 1V,. 1957. dredged. Pl･ 3,. 88-92,. survey. concerning. Tokyo,. 1-159,. diatom. the. Majesty. com-. Emperor. the. Tokyo-. pp･,. 121. Sidgwick. tfs･,49tabs･,. London. Report. 1929. (1): 80-89,. "Zoogeography. Jackson,. (2 GISLEN,. Bay:. 4＋1＋194＋7. 1953. T.. Jap.,. Sagami. in. comrr]unities. 8. 0pisthobra□chia. Japan:. S.. diatom. the. works. Zool.,. the. 3. shells tfs･,. marine. 2 (4). :. associations. 389-44=4, of. Tateyama. Bay,. (1 &. Venus,. 2):. (in Japanese)･. environIⅥental. Classi丘cation. of. marine. in. condition: 18,19, 4 pls･ environments. the. Misaki. Journ･. Fac･. District Sci･,. Imp･. with Univ･. tfs･, tabs･. (in. Treatise. on. Marirle. 1.

(27) Note. the. on. Ecology. Soc.. 1955. Jap.,. 1956. -,. Palaeoecology. and. M.. floRIKOSF_i,. Marine. T.. Inst.. 1932. Venus, KAWANA,. note. Res.. KANAMARU,. 1955. Damages. Aquiculture, KAWARADA,. Y.. KIMURA,. K.. 1940. Imp. MARUMO,. Exp.. The. 1954. of. Tokyo. Meteorl･. Obsリ3. MATSUDAIRA,. T.,. MoGI,. the. coastal. 7 (2):. 101-124,. A･. 1955. Sagami MuRRAY,. 10. &. 5. of. Cove.. Gelidium:. alga. algae:. gelildiacean. tfs･, 41. 3 tfs.. 2 tabs.. Bay:. Sagami. Joga-. the. at. Journ.. tabs･ Bay I. in. (2). May. February,. 92-103,. :. ll. tfs.. from. conditions 1952): Oceanogr.. the Rep.. en-. Cent.. tfs･, 2 tabs･. 2. lzu. ⅠⅠ.1936. 0n. the. oceanographical 1936: Suisan. in June. peninsula. conditions Gakkwai Ho,. (in Japanese)･. tfs･,. in. the. the. eastern. Special. Bull” of. in. yellowtail. (February. topography. summary. for the. ground. oceanograpbical. Kushiro. Hydrographic. A. the. with. conditions of Sagami Meteor. Centr. Obs., and. around. tabs･,. fishing. 31十(1). TANAIくA,. snbmarine. Bay:. J. 1895. 0. Ⅵ7ater. The. 38-230,. 188-190,. (3) :. TANAEA,. Miyata. of. tab.. together. 丘sheries. PlanktologlCal to. 1. tfs.,. the microplankton of variations Centr. Meteor. Obs., 3 (4) : 233-238,. and. Bay. t∫s,. Biogeogr.. (in Japanese).. oceanograpbical Oceanogr. Rep.. M.. trance. the. tfs,. Rep.. :. 3. 93-106, Bull.. :. communities. 2. 61-66,. :. caught. on. seasonal. Stリ(10). 1948:. July,. KITOU,. in. the Oceanogr.. Hydrography. 1950. and &. 0n. Fish. R.. -,. 1954 lsland:. shima. 2. (67) : Cove. (in Japanese).. tfs,. inflicted. 3 (3) :ト11,. benthic. marine. shells. 79. Mem.. tabs.. (41-42). on. : 27ト281,. 2. tis.,. Res.,. Nat.. Amr.. 63. waters. adjacent. in Moroiso-Aburatsubo. the. Remarks. 3 (5). T.. 3. its. and. Soc.. Geol.. :. vol.冒). on. Bay. Sagami. Of. communities. 410-418,. 1611g:. Preliminary. Journ.. fatlna. mollnscall. scienti丘c. the. and. Number. (17) : Pt.:. 2nd. results,. Ⅵ7eStern. 115-127,. parts. 8. Chall.. 0. tfs.. Rep,. ;. i-Ⅹix＋. 797-1608. NASU,. N･. Particle. 1956. 65-108,. (1): NIINO,. 1935. E.. Zassbi, -,. 1952. 0n tbe. -,. 0n. lzu. (562). the. bottom. a. S, & T.. OKUTANI,. MS. K.. 1952. 27-35 1955. Notes. SMITIi,. on. an. 3 list. A. Nリ. water. in. tfs.,. 2 tabs.. the. 1885. the. on. note. Soc.. Jap., 6 (21). Izu. Zeni･su,. of. dredged. Chigaku. in. deep. Reg･. tfs.. the. near. 1-2,. Pis.. and. 12. i. tis.. Japanese. the. 13.. pl.. fromthe. of. (2):. Island. banks. the. 1-5,. provinces. 207-214,. Tokai. Ⅲachijo (1) : 101-110,. from. Jap., 2. zoological :. islands:. (in Japanese)･. tabs･. distribution. waters. Fisher.. Res.. Mollusca:. marine. on. years. A.. of. Mollusca:. in Sagami. Bay. Lab.. (in Press). Venus, 17 (I):. Bull. Biogeogr.. of 1944. from. collected animals marine Mar, Biol. St., (1) :. S. &. Challenger Ocean”:. Tokyo. On. the. (p.. G.. Oceangr.. Lamellibranchiata. the the. OsHIBA, Rec.. current:. 1873-1876:. Kokinshoin,. SATO,. appearence. WATANABE,. "Science. tabs･,. the. Kuroshio. Report. the. 1943. &. A. vertical. of. OKAMI,. K. 1936. occasional. T.,. K･. mouth (The Tokyo,川. Soc.. Jap.,. tabs.. Shimoda. 11. SuzuEI,. the. Rep.,. during SuDA,. Rec.. species of Bivalvia Bull. : R.Ⅴ. S6y6-Maru. the. 80-83,. 1935. E.A.. bank. new. Biol. SASAEI,. 2 tfsリ2. and Protrochus Oceangr. Works. nodule. K.. 0n. S°i., Univ.. (in Japanese).. 16-79: T.. the. of. pl, 10,. Biogeogr.. by. sands). River. offSagami Fac.. Journ.. :. insular of the a･round shelf character Tokyo Univ. Fish., banks: 39 Journ.. Two. co11ected. nature. 32-37,. Japan:. Bull.. vicinity. tabs.. mang･anese. fIATAI,. seas:. SAEAI,. :. in the. dune. and. bottom. 47. Islands,. NoMURA,. -,. tfsり4. the. neighbouring. 1955. OyAMA,. beach. 14. 0n. distribution. size. forming. processes. the. 1955. Shimoda. 0ptical. Works. vicinities:. property. Jap., 2. (2). :. by H.M.S. collected 1-341, Rep‥ 13: pls. 1-25.. ed., revised tf, 42). 2＋5＋10＋770. pp.,. the. of. 133-140,. ll. Challenger. (1 pl.),181. tis.,. 224,. bottorrl担attlre. in the. waters. frpm. the. sotlther!1.

(28) M,日orikosbi. 64. extremity H.U., physics,. TAKI,. Is.. 1938. 0n. 〉. Report. Mutsu. Imp.. to. Bay. with. Univ.,. 4th. c｡mm｡nt. Oceano-. (in Japanese)･. tabs･. 1942. R･S･B･. biology=. Journ･. To-shima:. and. Oceans:. =The. =又＋1085 pp, J･ in Japanese. 265. 7 charts･. waters:. their. tfs･,. 121十v. Zool.. Mag･. (in Japanese)･. 12(3) : Japan,. Biol･, of. chitons. Bay･. Mutsu. of. survey. discussion. general. the. 〉on. tfs･,. Cliffs, N･. biologlCal. ser.,. 3. distribution. 176-177. the. Kbzu-shima. FLFJMING,. general. molluscan. (4) :. of. 7 &. Englewood. the. 50. (Tokyo), 1938. and. chemistry Prentice-Hull,. tabs.,. Peninsula. Japan,, 3 (4): 193-206, M.W･ JoHONSON,. soc.. gr.. SVERDRUP,. lzu. the. of. on. chitons. 323-423, II.. faunal. Rep･,. of. General 408-409. pp･. chitons,. of. T('hoku. (appendix･. 7tfs･,. areas. chitons. on. Sci･. Japan:. 14-34,. pls･. The. Studies. 31･. of. tf.7) TAYAMA,. R,. Submarine. 1950. eastern UDA,. part. 1929. M.. 0n. Hydrogr. of the. strati丘cation Umi to Sora,9. System:. shio. and. Bay:. Sagami. of. the. topography. (ll):. sea. of. Bull･,. 1-26,. (981):. tfs･, 6＋1. 10. in. layers. water. 1-8,. bottom. distribution. 12. the. ar･ea. Kuro-. the. of 7-8. (pp･. tabs･,. on. sediment tfs･. tfs･. 10)･ (in. Japanese). J. J. Results. 1937 with. the. "Buri”. Exp.. St.,. (8):. 0n. 1953 I,:. UTINOMI,. the. Journ. Ⅲ.. Bull.. 1955. Y.. Studies. nental. (1):. on. 0n. shelf. 1-126,. year. distribution. the. around during 71. the. the. Japan, the. tis.,. year 4. tabs･. S･)fishing:. ln. COnneCtion Imp. Fish･. Journ.. of. 113-123,. Scaphopoda 187311876‥ of. chie且y. decapod. based. 1923-1930:. prediction tfs” 2 tabs･. 2. 3. tfs･, and. (in Japanese)･. Gastropoda. the. 15･: 1-722, inhabiting. crustaceans. upon. collected. Rep･. Challenger. Journ.. distribution:. ⅠⅠ･Geographical. Japan,. Bay. Sagami. in the. its. and 15122,. 9 (1):. Cirripedia. Sらc. Jap., 16-19: Report. soyo-maru, 12. Jap.,. the. on. Bay. Sagami. tabsリ. ("Kyuty6”). Soc.. Oceanogr.. durirlg. 1933. 14. tfs･. &. T･. quinqueradiata,. cutrent. stormy. 1886. cha11enger. 19. in the. investigations. (Seriola 1-50,. Biogeogr.. R.B.. WATSON, yoKOYA,. bydrographical. of. materials. Coll.. Agri･. by. the. collected Tokyo. H･M･S･. pls･ト50･. Imp･. contiby S･S･ Univ･.