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(1)On. Mesosaurus. Some. Skeletons. kept. in Japan. By. Tokio. In May, two. by. the. en. Goiania.. de. The. those. them,. was. by. Miss. kindly. offering. to. to. and. Prof.. A.. Dr.. Mrs.. Mr.. H.. OzAKI. SEILACHER. specimens. University,. Mr.. generosity. braziliensis,. All a. OKUDA the. well. known. South. Mesosaurus. brasiliensis. for. this. American. the. for writer. are. due. also. B. PATTERSON. Zoology, kind. their. Harvard. guidance. belong. and. Mesosaurus. to. mesosaurid.*. brasiliensis. r869. McGREGOR,. Text丘gs･. McGREGOR.. Tokyo,. Geologisch-PalaontoProf.. article. GERVAIS,. (PIs･ 2-6, 1908.. of. in. Mesosaurus Mesosaurus. A. RoMER,. his. Crown. of the. Museun,. the. Comparative. and. expresses. writer. also helping Hearty thanks. Prof.. with Tokyo. Saopaulo. Chamberlain. Of. deals. de. and. study. MATSUOKA. treated. skeletons. chance. the. Estado The. a. Palace,. had. Museilm,. for. Museum. Miss. and. YAGI,. Prince's. Science. Science. Ttibingen,. Of the. City.. of this study. F. WESTPHAL. Prof.. Universitat. National. Nationaづ1. the. Of. course. and. SpRINKLE. Mr.. to. Socie-. the. the writer This article. them.. in K6be. Prince,. Crown. in Bastos,. OKUDA. occasion,. mesosaurid skeleton Brazilia, en Anapolis and. in the. study. that by. one. Prince,. in the. MATSUOKA. valuable during the. G.K.. to. able. en. kept. now. TAMIZO. the. Institut,. 1ogisches. are. of the Crown. Crown. the. ways. various. and. by. and. Japonesa. of Mesosaurus. NoRIKO to. thanks. Cultura. was. and. specimen. to. Saopaulo. en. skeletons. skeletons. cordial Prince,. Japonesa de. On visited Brazil. Prince the Crown. oりapan. presented. courtesy. collected. donated. in. three. the. another. which. were. Paulista. Through. see. Prince. Cultura. Sociedade. Tokyo.. Crown. the. skeletons. mesosaurid Pauliste. dade. to. 1967. SⅡIKAMA. Comm.. 1908. 1-5) est.. carv.. min.. pea.. Brasil,. 303-. pp.. 306. 1941. Mesosaurus. HuENE.. Palaeontographica,. 1952. Mesosaurus. RoMER.. Osteology. 1955. Mesosaurus. PIVETEAU.. 1956. Mesosaurus. brasiliensis. Traite. 92, pt.. pp. of Reptile, de Pa16ontologie,. McGREGOR,. HuENE.. A,. pp,. 45-58,. pls. 7-9.. 645-646. 5,. tom.. Pal.. phyl.. pp.. Nied.. 409-411. Tetrapod･,. p,. 245.. V. It. *. 1967. should. the. reported. hood NADOLNY. of. be. Sao from. Mateus a. here. mentioned occurrence. white. do. that. the. of Mesosaurus de Su上, estado compact. rock. of. Brazilian. newspaper. from. skeleton it. Parana; lrati. type.. was. a. "Estado”. colliery by found. in. Prof.. July. of the. 4tb,. neighbour-. JosE. RoMEU.

(2) 30. T.. Specimens. described. Skeleton. Paulista. h畠;d. de. Palace. :. an. adult. (no. 2942;. Bun 2;. no･. ; Bun. en. 3 ;. no･. adult. sale,. Paulo;. stored. Skeleton. black. shale,. etc.;. by. pres6nted in. stored. reglOn,. caudal. Sociedado. the. Crown. the. Pre-. Prince's. tuffaceous. shale,. Paulo;. Sao. limbs. with. but. presented. in the. stored. without skull, preserved de Paulista Socieda the. by. Prince's. Crown. Palace. (no.. skeleton. young. by. presented. collected. Prince's. Crown. caudal. and. region. by. T.. de. Saopaulo,. in hard. yellowish. Cultura. Japonesa. without skull, preserved de Paulista de the Socieda Palace. right. OKUDA;. (no. 2950-2; limb. aft. in the. Stored. Bun in. preserved. National. 663l.. Science. greyish. Museum,. (NSMT-P2-2780). IJOCality:. Estado. Formation:. much tion. of. caudal. of 4 which. are. pubis,. left丘fth. Left. largely. are. costae. from. brate. it.. column,. Dorsal. region. no.. radii,. 23. right. and. and. portion *. of Tbe. tibiae,. reglOn. writer. could. 1ogisch-Pa】aontologisches closely Grand. liked do. Sul. rock and. with. metatarsi, metatarsi. dorsal,. missing,. and. of limbs. also. but. its. gently. right. lateral. right and. ilium. Manus. in. its orlglnal. arrangement. Vertebrate. Ypojacまbei. Rio. wbicb specimens, Sa6paulo. Claro,. are. bent. collection. labelled. as. and. right and Skull is. bones.. of. few. 15. and. unpreserved. almost. are. verte-. right. pes.. of. colum. and. posteriorly.. ischium,. phalanges. right. partially. humeri,. and. 5. and. to. vertical. left scapulae,. and. unpreserved.. 1-3. of. unpreserved. ones. side upward. dorsal, 2 sacral. 23. in the HuENE's mesosaurid -that lnstitut, Ttibingen Universitat there mos.. but. Bbula. curved. know. the. por-. cervic-caudal. right axis. but. sacral humeri, left. left tibia,. their. with. 2 left. and. right. column. 3 cervic,. unpreserved.. also. 23. femur,. straight. right. a. and. partially, X-ray photo. an. largely. disturbed. much. caudal. of tarsi,. vertebrae. cervic pes. right. part. ulna,. left. preserved,. costae,. paired. 1 cervic,. vertebrate. almost. limb. aft damaged. took. is disturbed. no.3. bones.. and. vertebrate column 2, dorsal side, retains. femora,負bulae,. missing,. with humerl. runs. OzAKI. left costae,. sets. vertebrae,. caudal. Both. which of. Skeleton. left. jointed. or. pectoral girdle are Distal portion. and. unpreserved･. almost. detached. 14. right. Skull. of. retains. costae,. ilium,. right. metatarsus.. vertebrae. outline. side,. 22 right. H･. and. aright. is exposed. sediments･. detailed. i isnext,. no.. 4 comprlSeS. bones. of. by. 1, ventral. no.. No.. Surface. a. vertebrae, left. Permian.. in preservation,. coated. shows. Skeleton. and. lower. (?1 ;. of bones.. reglOn･. 4. no･. caudal. 2 is best. no.. arrangement. those. (?)*.. :. Skeleton in. Brazil.. Irati formation. Description. left. skeleton. in the. 4;. no･. shale. Tokyo. no.. a. tu庁aceous. Sao. Brazilia,. en. and. 663).. Skeleton grey. skull. 662). an. grey yellowish Cultura en Japonesa. 2950-1. without. tuffac占ous. grey. Japonesa. hard. de. skeleton. yellowish. Cultura. Skeleton in. l;. no･. in. served. SHIKAMA. Distal leftward,. at. Geo_. the. specimens. Saろ Gabriel,. of. the. Riv..

(3) On. Some. Mesosaurus. Skeletons. kept. in. Japan. 31.

(4) 32. T.. SHIKAMA.

(5) On. Some. Mesosaurus. Skeletons. kept. in. Japan. 33.

(6) 34. T.. SHIKAMA.

(7) On. vertebrae,. ward. as. vertebra. Mesosaurus. preserved. lateral. right. last. and. are. which. and. Some. Skeletons. anteriorly. side. upward. in. left. Caudal. posteriorly.. Total. longitudinal. b. Longitudinal. C. Ditto. length. of. dorsoISaCral. of. d Dittoof. caudal. Maximum. ･e. length. as. region. 1. aS. reglOn. 14. Width. of. dor-sal. aS. 1･eglOn. (9tb) f e/c･-I,････････.････････-･･-･-･･････････････････････10･30 as g Number of cervIC Vertebrae preserved‥‥‥‥‥‥‥‥. 2. 上 Ditto. 4. of. caudal. vertebrae‥.‥.‥‥..‥‥‥‥‥‥‥‥‥…. No.. 4. 223. mrn. 1.3. 199. i.48. 100. 82. 54. Preserved. 3. 243. 23. 1.2. preserved. -I---･-･-･-.--･･.･-A.･･.. transverse. up-. curved. No.. 2. 322. re(qlOn‥‥‥‥._‥‥.‥‥‥‥‥‥.‥ユ.78. region. side. much. No.. preserved.‥‥.‥.‥‥‥‥.204＋. cervic. lateral. femur.. with. No. a. 35. Japan. their. setting. contacts. preserved. kept. 223. 63. 38. (13th). (loth). 0.32. 0.2 6. 4. 3 1.2. 14. 32. Vertebra Cervic. vertebra. Little. 2. is. known. vertebrae,. no･. vertebrae It. in. moderate. broad one. and. in. of. seen. Dorsal All. known; detached. bones. the. of become. Bones. ･served･. large. carry. long. and. very. straight･. in outline. depressed. and. The. may. seen. median. of. the. tinct. splne. posterior. with. long. carrylng. centrum sutures. of. bone many. costa, not. little. them･. 7th, 8th, 13th. the. in. and Ventral. JOlnted･. perfectly. between. in. process. con且uent Neural. than. dorsal. with splne. and. a. of the. 14th. large,. thick,. There trigonal. little. vaulted. are. Posterior. vaulted. facet. other.. node. features. ventral lateral surfaces.. each. a. portion. tolerably. surface. is. which. bones).. the. the. centrum. distinctly these. portion,. lateral Anterior. pores･. larger. this. in. Seen. node. and. there. although. like. most. node. than margln. view,. half. preverte-. Ventral. lateral. vaulted. the. of. transverse. depressed. minute a. portion. sides. wider. aS. 2. of. dorsal. quadrate,. LoⅦer. margln.. anterior. 3 (especially. molds. posterior. In. portion. median. with. distinctly. and bones. bones,. 20. lateral. right. view,. anteroposteriorly.. central. correspond no.. run. anterior. preserved. and. posteriorly,. ventral. 3 does. and posterior margins･ little undulated but smooth, fine striations like splneS. small. and. succeeding. attachment and. in. and. posterior･. portion. though. In. splneS･. are. ventral. larger. gradually. 2; striations. long. trigonal. node. Dorsal,. column･. pores. no･. of than. Bnely. ventral. than. no.. there. and. colnmn. anterior undulated Ventral a surface. mhute. bone. higher. Of it longer. margln. small. of. Neural. curved･. 4. preserved.. ridge. no･2retain23bonesand. from. neural. with. many. 15tb. dorsal. last. relatively. longitudinal of it gently. retains. the. 3.. no.. 1 and. no･. i bone. ･succeding. are. cervicals･. margins. anterior. sides. Vertebrae. 1. vertebra. bones. ･although. brae. bone. the. hence. lateral. and. Median. view･ lateral. both. anteroposteriorly as. lト12. No.. skeletons.. 3, respectively,. dorsal. ventral,. has. these. of. does. 3. no･. and. ventral. and. vertebrae. their. with. ･sized, subquadrate centrum. 4. Mesosaurus. that. said. cervic. does. known. are. is. about 2. smooth. for. capitular Neural splne. are. seen. in. dis-. general.

(8) T.. 36. SIIIKAMA. I/I .FO.I-'J. タ. ニノ. Jl-. .∼∫. ′. ′. D161Z5. CA Textfig･. 5･. Right. (lower left) bent. outline,. backward. end. bluntly. sacral side vertebrae. higher. than Of. in. Brst. in. itudinally,. aspect. and. respectively. Caudal. at. known. general. and. of. caudal. vertebrae.. right). with. to not. the. much. dorsal. runs. straight. anterior. vertebra half of caudal. of. to. lateral. than. liked. view,. centrum. and. anterior. posterior.. Its. and. lateral. but. that. of. asthat. of丘rst. sacral. expose. distal. vertebrae. known,. i.e.. In. their. posterior. and. 4 in. and. rather. shorter,. skeleton canal. It. 1.4mm. is. 1, 14 in. sacral. no.. a. 1,. no.. neural. offirst. no.. rather. Neural. marglnS.. one.. to. preceding. quadrate,. upward bone second. centrum.. of. middle. dorsal. the. with. posterior. second through. right. projected. curved. 12th. 2. no.. Well. distinctly. costae,. posterior. so. are. In. undulated long,. 1 and. no.. They. outline･. eminent,. third. which. wide. Almost. 13th. (upper),. longer. margln. preserved･. bone. from. vertebrae. ;. (lower. caudal. anterior. are. them. long,. little broader. l･6mm. 15th-16th. of. 36th. and. vertebrae of. dorsal. similar. side. and. 56. vertebra. Two. splne. cA dorsal. projected.. Sacral. ventral. 15. lateL-al. long-. and bones. 2, 12. in.

(9) On. 3. no.. 32. and. Mesosaurus in. hibited. narrow,. spiny. ones.. straight. costalike. of. as. succeeding. bent. lateral. backward. longer. view,. skeleton. bones. is. polnt. Of. Short. anterior. centrum･. hence. side. while. RoMER. there. arch,. are. In. series･. a. series. Dimensions. of. are. vertebrae. follows. as. No.. Transverse. width. Eeigbt. of. neural. of. longitudinal. Length. baemal. of. Length. aS. centrum‥. ‥. middle‥‥‥. 2. 5.￣5. 7.4. 6.9. of. transverse. ditto. ‥. 8.6±. -. 6.6± 7.1± l.0. 3. -. No.. Clユ. 4.0. No. 6.3. process. 3. No.. ‥‥‥‥‥‥. 1.. No.. 6.0±. 4.8. 6.1. 7.6±. 7.1. -. 1.5＋. 3. No.. i. 5.5. 6.8±. 6.0. 6.8±. No.. 2. 5.1. No.. 3;. 5.3. 7.4. -. 6.5-. 1 -. 7.i.＋. 8.2. 9.7. (R). (R). 7.4. 6.2. 3.0. 2.2±. 4.8. 9.5. -. 2. No.. 5,8. -. 3. No.. 1.. No.. 6.8. 5.3. 6.6. 5.2. 7.1. D3 -... 2. No. 4.9. 3. No. 7.1 7.5. 3. 1.. 3. 1.. 5.0. 5.0. 1.9. ---…･＼. /一■■■■■---I-I--. 7.8. 2.0±. 6.3. (L). D2 ･-･￣. 7.9. -. No.. ‥. Dl 2. 3:. of. ditto‥‥‥‥.‥‥.‥‥. C12 1. consists. ノー/＼-----------一-----∼. preserved.‥.‥ of. splne-. 4.3±. /ノ■■■■･■■■-I-I-･■■-･･･---■ー-----＼. No.. 2. No.. 5.8. ‥‥‥‥‥‥‥‥. length. up-. distinct. arch‥‥‥‥‥.‥‥‥‥.. width of. at. ditto. splne. Maximum. Maximum. ditto. of. h･eight. Maximum. of. side. are. is preserved... C1 I.0 ヽ-------I._. length. point′ lateral.. haemal. series. 一一-----･/. longitudinal. a. at. left. :. C9. Median. of column. middle. becomes､. lateral. there. caudal. of. Ⅴ-Shaped. splne. right. type. of forward,･. splny,. setting. Mesosaurus. and. arch. portion. projected. of 23rd. the. posterior. median. their. ventral■. and. narrow,. far. succeeding. median. their. of In. points. haemal. 4 the. no･. skeleton. caudal. at. 4 is twisted. have. construction･. breaking. 2. and. no.. bones 24th. of. in the. of. least. at. the. bones. 12th. centrum;. of. in. So. its. anterior. posterior colum. preceding. that. out. in. points. bones;. sncceeding. points. from. and. margln.. from. long,. splne. Vertebrate. posteriorly.. and. upward,. backward. subquadrate. distinctly. centrum. of Neural. preserved. posteriorly. of. forward. projected. reCurVed･. 24tb. composed. as. bones. of. has. and. shorter. transversally. runs. be. tO. trlgOnal. long. bones. ventral. construction. sinus. margin. projected. shorter. breaking. general. recurved. carry. elongate than. third. at. succeeding. gently. process. margln. 23rd. ward.. with. seems. Anterior. and. archiform. it. transverse. posterior. between. high,. ex-. well. 9 bones. have. gradually the. of. follows. centrum,. gradually. becoming. Centrum. than. are. anterior. higher. quadrate, longest. splne. bones. 4 is concerned, : An eminent. no･ as. central. while. 5. and bones. Succeeding. 9 bones. of anterior Neural margln.. γentral. restoration,. bones. of. posteriorly. splneS,. Centrum. those. little. smaller. neural. McGREGOR's. to. construction. and. 37. Japan. 4.. no.. of. photo. in. According. Outline. gradually. kept. Skeletons. respectively.. caudals.. becoming. long,. a. 62. Mesosaurus. 4. no.. X-ray. the. Bones. and. in. has. Some. 1.8＋. 1.. No. ,6.8 9.5±. -. 2.5＋. 2. No. 5.3. -. 7.6. 3.

(10) T.. 38. D5. D4 No.. i. 5.7. 2. No.. No.. 6.7. ■7.2. SHZKAMA. 3. 6.4. 10.2±. 3.6. 5.0. 1. No.. D6. No.. 2. 5.5. 6.3. 7.6. 10.8±. N. No.. 1. 18.8＋ 4.5. 5. 1.8±. No.. 3. No.. 6.2. ユ.0.0 8.i. -. .8. 1. 2. No.. 6.1. 7.8. 6.9. 11..6. i.2±. -. 3. 8.9 3.5. -. .0. No. 6.3. 7.3. -. .4. 4.9. -. D9. D8. 2. 7.0. 7.6. 2. D7. No.. 6.9. .9 7. 1.3±. 3. 5. 8.1. 2.3±. o.. Dユ.0 ー--･■･･･-＼. Dlユ. ､､--■-■■--】一一------一一■---. ､---------------､､. ノーーーーーーーーーーーーーーーーーーーーー′. ノーーーーーーーーーーーーーーーー･--･･-ノ. ′′--･一一-/. i. No.. No.. 2. 6.9. 7.5. 6.8. 9.7. No 〇. 3 6.. .6. 1. No.. 2. No.. 7.3. 8.6. 7.6. 9.6. 6.0. 5. .9. 1.. No.. 7.6. 8.7. 8.7. 10.3±. 4.3. 4.9. 5.5. 5.7. 2. No.. 3. No.. 6.3. -. 1. No.. 6,9. 8.8. 8.2. 10.4±. 9.0. ∼. 2. 3. -. 9.5. -. 4.4. No.. 6.7. 5.8. .6. 1.0±. 1..4. 】_6±. -. Dl.3. Dユ.2 ∼∼. No.. No.. 9.2. .7 3. 3. 7.0. 8 4.2. No.. 1.4±. D14. ヽ---------一--------一→--. 一-′ヽ---------------㌔.. /一---------------------〟. 1. 6.6. No.. 2. No.. 8.0. 6.4. ユ.1,.5±. .8.4. 5.7. -. 1. No.. 1..5±. 2. No.. 6.9. 7. 1.. 8.4. ユ.i..2±. 9.0. 叩 -. 7.5. 3. 4.1. 4,8. 6.1±. 5.2. 1{o. 3. No.. 7. 1.. 6.8. 1. No,. 7. 0. -. 4.7. 6.4. 5,5. 6.0. 2. 7.8. No.. 3. 7.5. 1.i.9. 10.4. -. -. D15 No.. 1. No.. 7.3. 7,8. 7.9. 11.5. 10.8. -. 2. 3. 10.7. -. 5.2. No. 6.7. 6.7＋. 1.2±. -. Dユ7. Dl.6. Dl.9. Dユ.8. /一-￣--￣--￣------一-￣-ーー一叫､＼. 1. No.. No,. 2. 6.8. 8.7. 7.0 2 .8.. 11.5. No.. 3. 7.1. No.. No.. 2. 7.6. 8. 6. ユ.0.6. No, 7.4. No.. 1.. 2. No.. 6.8. 8.2. 7.3. 11.6. 4.7. No.. 3. No.. 7.6. i.0. 6. 1.0. 1. -. 7.8. ユ0.1.. 9.8 5.5. 8.2. 5.1. 7.8. 6.9. 7.3. 2. D22. D21.. 7.4 6.9±. 8.3± '7.0. 1. No. 7.7. 2. No. 7.2. No.. 1.. 7.3 9.0±. 10.2. -. 3. 10.1j=. 6.2＋ 7.2. 6.5. 3. 8.2 11.4. --. 4.4 7.1. D23. Sl.. ヽ--ー･･. /I-----￣-￣------･-J. No.. No.. 2.5. 3.0. D20. No. 8.1.. 7.5. ∼. 1.. 7.7. 7.3. 2. 0. --. i. 6.8. 3. No. 8.7. 2. No.. 3. 6.1＋. 7.3 9.2±. 1.i..2. --. No.. -＼. 一一■■-■--■■--･-￣一. /-----ーハし-･･----･. ､. 1. No.. 2. /一----一′ー_. No.. I. No.. 8.3. 6.6. 9.5. ll.8. 8.2. 11.9. 1.0. 1.±. 2. No. 6.4. I. N. o.. 8. 6 1.5. i.. 7.9 2.8±. 6.7. 6.6. 9.3. 13.6. 7.4±. 6.8±. 2.

(11) on. S2. some. Mesosaurus. CAI. in. 39. Japan. CA3. CA2. ヽ-. J. ′----------ーー--------＼. kept. Skeletons. CA4 ヽ----------------. ヽ------･･＼. /----------------･･･一･. ′-------･････････････････一′. ′ノーーーーーーー. No.1. No.2. No.1. No.2. No.1. No.2. No.4. 8.6. 7.5. 7.7. 8.5. 6.9. 8.1. 8.5. 10.2. 8.0. 10.2. 9.0. 10.7. No.1. No.. No.2. No.1. 8.2. No.2. -. 8.6. 9.5 1,0. 0. 8.3. 1.0.1.. 5.3＋. 7.3. 9.6±. 6.8＋12.5. 8.6＋. CA5. 12.5＋12.9. 13.6. CA6. 13.6＋. 13.4. CA9. CA8. CA7. No.4. 6.4. -. 13.5±. CAユ.0. 12.4＋. CAl.1 ー-----. J. ヽ-. ′---ノ＼-----●■-/ノーーーー､--＼. No.. 2. No.. 4. 2. No.. 4. No.. No.. 2. No.. 4. No.. 2. No.. 4. 2. No.. No.. 2. No.. 2. No.4. 8.1. 6.3. 6.3. 7.1. 7.0. 6.5. 6.0. 6.3. 6.3. 9.5. 8.4. 8.4. 8.5. 7.7. 7.0. 7.1. 7.8. 5.2±. 3.1＋. 6.7±. -. 6.5. 4.8 7.4. ll.5. 13.7±. 1ユ.1. 9.9＋. 8.5±. CAl.3. CA12. 8.4十. -. 7.8±. CA14. 6.6＋. 5.0十. CAl.5. CAl.6. 8.2. 10.0. 3.1 6.2. 4.0. CA17. 5.4. CA19. CAl.8. CA20. ′--/ヽ･■■■■---. ′一-一一-------I-/ヽ------------. No.4. No.4. No.4. No,4. No.4. No,4. 6.7. 7.i.. 6.3. 7.0. 7.4. 7.2. 6.2. 6.8. 7.2. 6.6. 5.2±. 6.9. 5.5. 5.7. 5.8. 5.0. 5.1. 5.4. 5.0. 5.7. 7.2±. 6,4 5.6＋. 5.5. 6.2. 7.0. 7.2±. 7.3. 7.0. 7.7±. 8.1_±. 7,2. 4.9. 6.3. 4.9. 6.2. 6.0. 7.0. 5.7. 6.0. 6.7. 6.7. 8.4. 9.2. 10.1. 8.5. 9.0. 6.7 9.7. 6.5. 8.3±. 9.4. 8.2. 2. No.. 4. No.. 6.7. 7.0. 6.9 5.7. 4.3±. 2. 8.9. CA22. No.. 4. 8.8. 4.2±. -. CA21. No.. CA23. No.. 2. -. No.. 4. 3.2. ∼. 2.4. -. CA24. CA25. CA26. CA28. CA27. CA29. CA30. /メ---------ノヽ----------→＼. 4. 3. 4. /ノーーーーーーーノー. 3. No.. No.4. No.4. No.4. No.4. No.4. No.4. No.4. No.. 7.3. 7.1. 6.9. 7.0. 6.4. 7.7. 7.7. 6.9. 4.9＋. 7.3. 7.0. 7.0. 5.3. 5.0. 5.0. 5.6. 5.8. 5.7. 5.6. 5.7. 3.5. 6.0. 3.6. 5.9±. 3.5. 3.9. 4.9. 4.0＋. 4.7＋. 4.8＋. 5.3. 6.7. 7.0. 7.3. 7.1. 7.4. 7.0. 6.5. 6.8. 8.5. 7.1. 6.2. 2.5. 2.3. CA33. CA34. CA38. CA39. 7,3. 7.0. 6.8. 6.9. 6.8±. 6.9. 6.9. CA32. CA3ユ.. No.. _. No.. No.. 4. 6.6＋. 2.5. CA35. CA36. CA37. CA40. /一------------少'-㌔. No.. 3. No.. 7.0. 6.6. 4.2. 4.2＋. 4. No.. 3. -. 6.0. 5.0. 7.3. 6.3＋. No.. 4. No.. 3.8＋. No.. -. 4.2十 5.6. 3. No.. No.. 3. No.. 3. No.. 3. No.. 3. No.. 6.7. 6.0. 6.0. 6_2. 6.2. 5.3mm. 5.3. 5.6. 5.2. 5.3. 5.4. 4.3. 5.6. 5.0. 6.9. 6.2. 6.5. 5.9. 5.6. 6.2. 4.9. 4,5. 3.9＋. 4.7. 4.9. 2.8. -. _. -. 3. 3. 3.

(12) 40. T.. SIiIKAMA. Costa Costae. are. of them, dislocated. in. but. ventral dorsal. costae▲. costae,. and. 5th. 7th are. costae. 3. separated. correspond. Left. second. right. side,. to. 3rd,. skeleton. of. skeleton. 3 cervical. portion. proximal Anterior. Succeeding coming. much. in. of. its. each. dorsal. the. costae. of. with. straight. Surface. of. bone. facet. margln. marked of. with. vertebrae. costae. γentral. view. in. lateral. view. banana. backward.. distal. bones. dichocephalous. in. 2 and. of skeleton. not. and like. their no･. pachyostosed･. outline. are. MaximuDI. *. Number. Width. as. along. less. or. 3 is fully. construction. at. distal. preserved,. end. por-. broken in. preserved. long. not. with. The same of dorsal side. aspect 2･ Tenth its succeeding skeletonno･ and. baoad capitulum. relatively dorsal Distal of vertebra. bone. and. the. much. 3, proximal. itself longer. than. costa. end. dorsal. wide. longitudinal. many丘ne. Dorsal of. jointed costae. antero-posterioly･. small. striations.. follows.. 2. C2* No.. 3. No.. {. preserved. be-. and. portions no･. more. no･. ;. outline proximal. meets. tuberculum. with as. portion. long. No.. as. and. in. Cl*. Length. the. on. in general. projected. many. and. hooked. and. skeletons. costa. bonesof. 2 have. ventral. anterior. Dimensions. 9th. and no･. by. which bones.. while. in size;. distal. dense,. in. abruptly 9th dorsal showing. marked. dorsal. antero-posteriorly;. and. platy. curved. projected. skeleton. skeleton,. vertebrae,. small. strongly. seen. weakly. left 8tb. the. and. In preservation. As. portion,. and in. seen. beside. costae;. second. jointed. are. run. pachyostosed,. other･. Right. portion･. capitulum. and. and. distally･. costae. proximal. is. short. curved. wide. much. wider. to. appressed. tion. splny are. rather. bones. Right. the. of. right with. angle of 90o ; distal end sharply 4 dorsal costae narrow, relatively. an. at. portion. bones. very. are. 3, they. no･. side. and. jointed. are. left 20 dorsal. left. the. dorsal. dorsal. costae. 2 they. no･. left arst. 13th. to. known.. dislocated.. are. Posterior of. 9th. be. skeleton.. and. 21 and. on. costae. the. to. are. and. from. with. right. preserved. and dorsal. right. paired 22 left. at least 3 left and vertebrae in a portion posterior of In skeleton no. 3, there unpreserved.. are. costae,. are. costae. all. 20. apart. 23. and. cervial. their. on. mostly. preserved. vertebrae. castae. right. 6th,. bones. other. fourth. paired. or. unpreserved. found. preserved. JOlnted. from. cervical. 19th. is. are. are. 4. all palrS. retains. costae. are. one,. are. detached. costae. to. first. loth. has. there. costa. left. except. to. no･. 1,. narrow. costa. 2. 2 which. no･. They. position･. no･. is. 3 left. may. the. and. costae. preserved. them. long. preserved Right丘rst. sacrum･ are. skeleton. skeleton 3 some. no･. Skeleton. sides･. separated. to. orlginal. In one. 1 and. no･. their. lateral. in. preserved. well. skeletons. from to. If this. very. anterior. border‥. as. preserved. ‥‥. 2. 3. No.. {. R. L. L. R. L. L. 7.5. 6.5. 5.2. 9.2. 8.1. 8.0. 0.7. 0.8. 3.0. 1.0. 0.5. 1.6＋.

(13) On. C3* 2. No.. Some. Skeletons. Mesosaurus. C4* 3. No.. kept. 2. No.. 1. No.. No.. 2. L. L. R. 9.6. 9.6. 1.0.6. 2.0. 0.8. 1..9. L. L. R. 34. 5. 25. 2. ユ..7. 1.5. L. R. 23.4. 24.4. 2. 1.3. 1.9. 3. No.. No.. R. L. R. L. 13,6. 21.7. 20.7. 30.4. 2. 0. 2. No.. No.. L. 1.2±. 1.4. R. L. 20.8. 24.9. R. 22. 6. 1..4. 2. No.. No.. No.. 3. {. 1_9. L. R. L. R. L. 23.9±. 23.2. 33.6. 32.0. 1.9. 1.9. 2.9. 2.8j=. 1. No.. R. 2. 1. No.. No.. L. R. L. R. L. 37. 9. 31.. 8. 38.0. 40.7. 30.8. 33.6. 2.0. 2.0. 3.7. 3.7. 2.2. 1.9. 2. No.. No.. 3. 1. No.. {. 一----■-■-ノ→-----I---I-･ヽ. L. R. L. R. L. R. L. R. L. 29.2. 43.2. 21.2＋. 32.8. 39.2. 38.3. 46.7. 33.2. 4.5. 2.9＋. 2.15. 2.1＋. 2.2＋. 2.6. 1. No.. 2. No.. R. L. 36.5＋. 3.2. 2.2＋. 3. No.. ＋. ′･----ノー-r. 38.5. 4.1. R. L 36.8. 10.8＋. 4.3. 2.0＋. 4.1. 1. 4.7. No.. ー-r. 45.5. No.. 1.. R. L 38.6. R. L 37.6 2.7. 2. No.. R. 2.0.2＋. 2.4. R. 2.9. +. R. L. R. L. 31..7. 37.8. 36.3±. 4,0. 2.0. 2.5. 3.4. 4.7j=. No.. 1.. No.. {. 〔. R. L. R. L. 39. 5. 41.. 6. 39. 8. 40.0±. 2.5. 2.7. 3.1. 3.0. 4.8. 2. No.. 3. No.. ′-･･-･･････････････-一--. R. L. L. R. L. R. L. 32.7十. 43.2. 37.0＋. 36.1.. 35.1. 2.6. 2.1.. 2.8. 3.1. 5.0. 1. No.. No.. 2. R 32.2十. 2.6＋. L. R. L. 48.6. 42.2＋. 3.1. No.. 3.9＋. 5.6. 1. No,. 良. 43･0 3･2. L. R. 2･5. No.. L. R. L. R. 48.6. 42.5＋. 37.9. 3.7＋. 2.8. 3.0. 4.5. No.. 1. No.. ＋. R. 27.5＋. L. R. 36.6. 42.3. 3.0. 2. 3.2. No.. 2. 3. ⅠJ 39.7. No.. ^. L. 38.9＋. 3.5. 3. No.. --･･｢. L. 良. 41･2十30･9＋ 3.9. 3.0. 3.1. R. L. 47.1. 2.6. 1. ＋. 40_0＋ 4.0＋. 4.3±. R. L. 26.6＋. 34.i. 2.8. 3.2. Dl.7. {. 26･3＋47･5. 3.0. {. D16. {. L 34. 4. 42.3. 2.3. 3. ＋. 47.7. R. R. D15. ′-I-〟------r. 28.7＋. 3. 32. 9. 2. {. ｢. D14 1. 4ユ.6. 6.5. No.. ′一---------一＼--･････････････････---. R. No.. No. {. D].3. 38.i.. {. 2. -･一人----r. 31.. 7. 一人---I---＼. 4.8. 3. 4ユ. 1. L. 6.5. No.. ---＼. No.. L. 46.5. 4.8. 1. No.. 2.2. ′--一一山･･. D12. ′----一一. 2.4. 41..5. 2.3十. 3. ′------一人-一-. 38.6＋. L 34. 9. Dlユ.. {. 39.6. R. 34. 8. 2. {. Dl.0. /----一人--････ヽ. 3. D9. --------ノー･一-. No.. No. {. D8. No.. 2. {. 39.8 2.7. 3. D7. ＋. {. 2.1. 1.6. {. D6. R. 28.5. 2.4. {. {. 31.9. 31. 6. L. 27.2. D5. {. No.. 3. ＋. D4. 2.4. 1.2. {. L. 1..7＋. 1. {. 18.2. 1. L 22. 0. D3. ′----一人-･･････････■･･･････････････････-ヽ. No.. 3. No.. D2. 1.5. 4J. {. ＋. 6.2. No.. Japan. Dl. {. 1. in. -. 2.5. -1----一ー､-. L. 32･2＋ 3.2. 良 36･6 3.1. 1. No. -. I. L. R. No.. 3.9. 3. {. L 36.9＋. 37･1＋47･0 2.6. 2. -㌔-------. 3.5＋. R. L. 29.9＋. 22.8＋. 2.8. 2.8.

(14) 42. T.. SIIIKAMA. D19. Dl.8 No.i.. 2. No.. 3. No.. {. No.. R. L. 37.2. 37.0±. 2.5. R. L. 47.0. 39.0. 3.0. 3.8. R. L. 20.6＋. No.. 19.2＋. No.. No.. R. L. 6.7＋. L 39.0＋. 15.8＋. 20.0. 3.8. 2.7. 2.4. 1.5. 1.0±. 1‥9＋. No.. R. 2.1. -. 3. No,. 2. No.. L. R. L. R. L. 37.4. 27.8＋. ユユ.2＋. 1,5.6. 24.1. 20.6＋. 2.8. 1.8＋. 2.1. 3.2. 2.5＋. 1. 3.6. R. {. L. D22. No.. 1. {. 24. 1. 27.9. L. R 40.2. D21 2. ー-----r. {. 3. L. D20 1. No. ＋. 35.5. 3.0. 2.6. 2. ＋. R. 22.6. 2.5. 3.9＋. 1. ＋. {. 3.2. 2.5＋. D23 2. No.. No.. No.. 3. 1. No.. 2. ＋. L. R. lユ..7. L. R. 1.4.9＋. ユ8.2. 10.8. 2.9. 2.3. 1.9. Many in. small. the. 21st. and. of. scapula,. right. vertical detached Clavicle. a. it.. from alld. Scapula. 2. no.. Left the. shoulder. are. coracoid. Left. upward. and. with wide. antero-posteriorly fossa. glenoid skeleton. this a. specimen,. distinct. coracoid. but. incision; strongly. side. turning. upward. in. skeleton. like, rather. thin. Scapula. that fore curved.. with. smaller. gently. projected. broken of. column of. running. and. skeleton. 3. no.. parallel better. with each other, preserved 2. Right scapula-coracoid. preserved. and. skeleton Fore column.. vertebrate. generally. part. humerus,. preserved. limb. right a. in. are. it.. with. in. off, hence. skeleton Of. margln. Coracoid. no.. 2. scapula. set. no.. 3. its inner. coracoid,. of. than. fossa. glenoid low. Dorsal. them. and. end. straight scapula. while and. of of. unknown. in preservation,. well. side. scapula-coracoid. between. relatively. little thicker. anteriorly.. relatively. margln.. portion. fairly. with. distinct. a. dorsal. incision. scapula a. than. curved. Anterior. and. has. and. general. is preserved. no.. blade. sharply. does. preserved.. set.. margin.. are. running. anteriorly. 3 tolerably. no.. and. coracoid. Scapula-coracoid semicircular. outer. is. scapula-coracoid. turning. not. con且uent 3 than in. in skeleton no. outline in skeleton no. 2 with its. and. girdle. 20th. ulna-Tradius,. vertebrate. fore. skeleton,. scapula-coracoid,. the. the. with. column. vertebrate. interclavicle and. jointed. 2. no.. right. humeri to. vertical. between. skeleton. left. Both. manus.. the. seen. wide.. humerus,. 3 does. no.. axis are. left. and. of left. part. humeri;. especially Bone. costae.. from. bones. 0.3mm. are. dorsal. detached. and. and. left. ; skeleton. longitudinal. skeleton to. coracoid. manus. and their. of. long. They. 23rd. to. Several. other.. 4.7mm. about. 15th. splny. each. with. right. left. and. ulna-radius no. 1 with limbs. long,. 2.. no.. skeleton. from. fore limb girdle and 1 no. retains right and. Skeleton left. in. portion. aggregated. mm. 1.5±. preserved. narrow,. dorsal.costae. Shoulder. ancL. are. relatively. and. 氏 1.2.2. 2.0±. proximal. right. sized,. dislocated. l.2＋ costae. γentral. distinct. L. 9.0. in. showing that. eminently. of.

(15) on. some. in skeleton undulated it a little broken.. no.. Mesosaurus. 2 in. the. of. process. in. kept. Skeletons. 43. Japan Hind. preservation･. l. 2. No. length. longitudinal. Maximum Ditto. of. as. coracoid. Maximum. height. Ditto. of. of. Eeigbt. of. glenoid. distally･. reptilian. humerus.. curved.. EntepICOndyle. Surface. 1.. men. Distal. the. on. tolerably tions. its. on. 2;. no.. the. is. of. straight. the. 2 shows. but. shows. an. distal. corner. a. line.. Head. foramen. due. almost. Maximum. length. as. Maximum. width. of. broken. of. left. alike bone. of. straight. marglnS. as. portion. preserved. 2. in. than. its proximal end. of. Ulna. outline.. a. to. mm. depression. the. state. of preand. with. 1. No.. ends gently. of. the. portion. left little. ulna more. them. curved.. carry. 3. L. R. L. R. L. 35･1. 36.7. 36.8. 30.Omm. 1.1.8. ユ.i.･ 1.. ll.8. 11..6. 10.5. 5.3. 4.8. 3.8. 2 and Right. undeveloped straight. 3, and. ulna. of. Also. proximal. curved. 2.6. 4.2. no.. preserved.. strongly. rather. No.. 34･9. preserved. are. 1. ′一---一人-----･r. no.. former.. 01ecranon. broken.. mucb. Proximal Of them. latter. distal. and. in skeletons. preserved. only. general no.. are. the. and. radius in. proximal. radius in. preservation much. preserved‥‥‥‥‥.‥‥‥‥.. distalmargin.......,.,................... and. distal. of 3･7×1･1. unexpanded. No.. Ulna. 3;. no.. in. Seen. margln.. proximal. of. aS. distinct. a. and. narrow,. margln. ∼. Ditto. of skeleton. in skeleton. obsolete small,. very. humeri. condylar. broken. stria-. EcteplCOndyle. entepicondylar little. skeleton. striations. parallel. both. the. on. Capitullum. corner･. specimen･. Several. is preserved. of humerus. side. in. seen. longitudinal. carries. in. distally. long-. foraenteplCOndylar ; foramen sublenticular,. growth. with. a. marglnS･ run. Which. as. as. moderately. lateral. splne. much. long. distinct. a. condyle. of. and. posterior. recurved. respectively･. portion. straight. both. like. gently. projected. posterio-distal. servation. ends. correspond. eroded anterior. in. seen. distal. 17.6. relatively. while. striarions. no.. be. straight. with. many丘ne. lower. Anterior. in diameters;. straight. of entepicondyle portion proximal 3･0×1･4mm in diameters and. may. tolerably. portion. and. size,. may. and. Of enteplCOndyle. moderately 1.. no.. body. with. almost. wide. bearing. and on. -. straight. of skeleton. upper. and. skeleton. large,. sized,. 8.9 5.4×4.1. 18.5. --. comparison. margln. striation. ridge-like. in. Anterior. margln. transversally. run. 8.4. 1l.8. ･‥･‥‥‥‥･‥‥……‥--･. slender,. posterior. large. 13.8. 7.7. 5･8. scapula. Shaft. humerus. Right. ユ.3.4 ‥‥---･. preserv.d‥.‥‥‥‥. short. it flat and. of. itudinally. no.. as. 3. 1.0. 8皿m. fossa.‥.….‥‥.‥.‥‥‥.--. relatively. expanded. preserved. No.. 1.2. 8. preserved. preserved‥‥‥‥‥.‥‥----. girdle shoulder margln Of of fore. Humerus. as. scap山a. ‥‥‥･---･----. as. scapula. of. Lengtb. of. preserved. as. coracoid. Diametern. of. margin. better. skeleton. are. than. radius;. and. shaft. 2. portion. They. margln,. in. no.. much the. tolerably. While. distal.

(16) 44. T.. SHIKAMA. No.. 2. 3. No.. ∼. RR. LU. ユ8.9. 16.3. RU Maximum. length. Width. distal. of. Carpal. carpal. skeleton on. left side. the. trigonal. or. 2.1. from. ulnare, Brst. in. relatively. of. radiale. distal. length. Maximum. of. Maximum. it. of. width length. Maximum. it. of. Maximum. width. of. Diameter. of smau lst distal. Ditto Ditto Ditto. of. of. 2nd. First. carpal. and. with. served. in right. second. to. ximally. (a, b). are. it as. as. preserved. ‥‥‥‥‥‥‥. preserved‥‥‥‥‥‥.‥.‥‥‥ of. carpal. left. distally.. 3. R. L 3.1. 2. 2mm. 2.1. 1.9. 2. 1. 3.3. 3.2. 2. 9. 2.3. 2.2. 2. 9. 2.5. 3.1. 3. 9. 1.9. 2.1. 3.5. R. 1_7. 2.5. third manus. Shaft in. preserved. and. 2.2. left. left. of. manus. proximal. small straight manus. sized,. of. Three. a. and. rod-like. AIso. two. 2.4. skeleton. no.. little expanded proximal. pro-. phalanges. skeleton.. Metacarpal I. II. ⅠⅠⅠ. No.3No.3. No.2. No.. No.3. ⅠV 2. {. R length. Width. of. as. preserved. ,.‥... proximalendaspreserved‥. 5.6. 6.9. 2.1. 1.9. 6.3. -. Proximal No. ⅠⅠ 2.5. Pelvic. girdle. and. aft. limb. L 3.9＋. 7.2. R. L. 良. 6.5. 7.4±. 5.2. 1.7. 1.7. 1.0. -. phaiange. 3. No.. 2. a. b. 3.1. 2.8. 3.3mm. 1.3. 1.5. 1..8. ⅠⅠⅠ. 2. 5.8. 1.8. -. No. ′----ノー------ヽ. ′--･-----. Maximum. 3,. pre一 metacarpals be They may. 2 respectively.. no.. narrow.. and. in. preserved. phalanges･. of skeletons. bone. ones;. first. in outline.. 1.5. metacarpals. and. sub-. 2.5. ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥. and. ossicle. No.. ‥‥‥‥‥‥‥‥‥‥‥...‥‥... carpal. and. size,. 2. radiate...........”.......... carpal.. second. fourth. preserved. ‥..‥‥‥. preserved‥‥‥‥‥‥‥‥‥‥‥. centrale. third. together. as. aS. in. subquadrate. preserved‥‥‥..‥‥‥‥..‥‥. ossicle. distal. to. and. of. distal. of 4th. as. small. large. of. limbs,. subcircular;. preserved.‥..‥..‥‥‥.. intermedillm. of. width length. Maximurn. as. ulnare. Carpus. both. No.. Maximum. second. and. outward･. ulnare 4th. though. centrale. innerside. centrale. ossicle and. ; those. arrangement. distal carpals. and. subtrigonal. in. second. and. Small. dislocated. and. position. intermedium,. intermedium. carpals. 2.9. 3.0. intermedium,. Ulnare,. preserved. subtetragonal･. distal. second. are. orlglnal. successively. retains. Centrale,. of radiale･. their. near. arranged. 2 also. 3.1. 2.1. disintegrated. although. impressions･. are. no･. preserved,. LR 16.5mm. 3.2＋. ‥‥‥.‥‥‥‥…. rather. by. 3.0. preserved‥‥.‥.‖‥‥. preserved. are. 3. no･. as. as. are. known. are. distal. end end. bones. skeleton. they. preserved‥‥....‥‥‥‥..... of proximal. Ditto. of. as. L.

(17) On. Skeleton. right. right left tibia,丘bula. in. well. ilium,. left. and. Rigbt. ilium. anterior. and. portion. 2. no.. its. gently. nearly且at. that. no.. set. and. left. of. right. 2 retains left limb. limbs;. femur,. tibia,丘bula. and. is also. higher. posterior. distal. Skeleton. no,. which well preserved. 1 with its inner set upward, side Left ilium it upward. of preserved. subtrigonal,. dorsal. curved but. ischium,. left aft. and. 4= retains right aft limb. Bone. section.. right. 45. ilium,. metatarsus.. and. side. Japan. right. no.. outer. in. pubis,. and丘fth. in skeleton. preserved. in skeleton and in its longitudinal. left. and. 4 retains. no.. kept. Skeletons. ischium. right Skeleton. preservation. Skeleton. metatarsi.. Mesosaurus. 1 retains. no･. left femora,. and. Some. portion. than. wide. Surface. marglnS.. rather. rugose. straight. with of. proximal. 3. with. concentric. lineations. Right outer. pubis. side. marglnS;. curved inently long. anterior. and. general Right. men･. ; its. ward. outline. pubis. general. Rigbt. longer. and. gently. and. its surface. of skeleton. 1 is. with. no･. 1 preserved. no.. but. small. with. posterio-ventral. recurved.. its. turning. higher by. distinct. em-. end. Bone known. its. with. irregularly. than. impression fora-. obturator. distal. portion. up-. side. turned. up-. subtrapezoidal.. skeleton. 2 preserved. no.. high. than. its. with. antero-posteriorly, Proximal. dorsal. proximal. portion. upward. straight. portion. Right. smooth.. and. outer. almost. with. marglnS.. nearly且at its. and. ischium,. outline,. its. moderately. suboval. skeleton. recurved. turning. served. of. pubis. nearly. outline. ischium Bone. ward･. of. distinct. margin Left. antero-posteriorly･ its. below. partially in general. subtrapezoidal foramen. Obturator. projected;. 2 preserved. no･. of. skeleton Bone upward.. set. ischium with. γentral. bone. the. of. of skeleton. subtrapezoidal. Ilium. widest. 1 pre-. no.. outline. Iscbium. Pubis. {. 1. No.. 2. No.. No.. {. Longitudinal Maximum. Ditto. preserved. much. trochanter. as. curved. obsolete. distally. convex. latter.. the. 2No.1No.2. {. R. L ユ.8.1＋. R. L 9.2. 1. prlmitive. reptile.. relatively. Proximal. margln. Straight. Surface. of. bone. no.. smooth. 13.5. R. _. R. 17.1mm. -. Both. 6.3 10.0±. and. 3.. The. slender. very. distal. and. ends. Proximal. margin. distinctly. former. usually. longitudinal. many. 7.7. -. slender.. distal. while. 8.3. 7.9. but. size. proximal. straight. 1, 2 and with. 7.5±. 12.2±. body. with. long,. in skeletons. -. -. in comparison. short a. 5.3 3,5＋. Shaft. seen. as. 1.9.5. 5.8. relatively. unexpanded.. almost. 14.4. 15.6. ‥‥.‥.. also. R. No.. proximal. portion‥‥‥‥‥‥‥‥‥‥‥ of distal portion. not. than. as. of. width. Femur and. length. R. 1. wider. short. stria-. tions. No.. 1. Maximum Width Ditto. length of proximal of. distal. as. preserved‥‥‥‥‥‥ margln. aS. preserved. margln‥‥‥‥‥‥‥‥‥‥. ‥. No.. 2. 3. No.. No.. 4. {. {. R. L. R. L. L. R. 35.8. 35.2. 36.7. 36.8. 29.9. 21.5＋. 6.8. 6.7. 4.9. 5.0. 5.6. 6.4. 5;0. 5.3. 6.1. 4.6. 4.3. mm.

(18) T.. 46. Tibia 1. no.. tibia of. and丘bula. and and. proximal. margin. projected; distal. strongly proximal. at. than. and. long. gently. and. inner. parallel. nearly. margln distal. than. wider. a. distinctly. portion. inner. 2,. no.. curved;. end. distal. on. rod-like;. portion. proximal. marglnS. run. margln. skeleton. tolerably. from. than. Outer. in. seen. skeleton. larger. Fibula. margln. length. lineations. narrow,. outer;. distal. distal. 2;. no.. portion.. As. one.. total. of. One-third. Tibia. distal. expanded. while. skeleton ones.. right. inner. than. transverse. margin.. curved. 4 retains. no.. straight,. four. to. in. preserved. tolerably. curved. margin. three. and. with. nearly. distal. On. with. curved distinctly. more. are. sides. left. retain. much. shaft. polnt. 3. no.. both. of. SHIKAMA. both. and. curved. ′ribia. 1. No.. 2. No.. 3. No.. 4. No.. ＋. Maximum. length. Width. as. preserved. of proximal. Ditto. distal. of. as. end as. end. ‥‥‥‥‥. L. R. 21.7. 22. 6. preserved‥... preserved......... L. L. 2l.7＋. R. 18. 6. 22. 1.. 3.8. 3.4. 4. 1.±. 2.7. 4.0. 3.7. 3.6. 3.1. 4.0. 3.6. Fibula 1. No.. No.. 2. No.. 4. No.. 3. ＋. Left. and. axis pes. and. the. directly. All. astragalus. to. gonal,. a. is. 4.. with. long.. high. 4.3±. 6.0. 6.9. 7.5. 6. 1. 6.8. skeleton. no.. in. left. loosely. with. each. Median between. high. and丘fth. is regarded. other. upper of. astragalus. transversally and丘fth one. transversally. next. and. inner. and. skeleton. small. margin margin calcaneum.. of. distal bone. centrale; 2 and. no.. skeleton. Astragalus. to. area. medial. in. unpreserved. straight portion. as. the. of. a. 4 well. oblique. proximal. and. mm. Astra-. first to丘fth. preserved. tarsal. tarsal. with. the. respectively,. tarsal. set. axis. covering. are. 23.5±. 2 dislocated.. no.. longitudinal. sized,. the. of. of skeleton their. distal. ones. right. distal. calcaneum. large. 4. 9. Fifth. fossa than. 7.1. large. same. undulated.. relatively longer than than. second. jointed. longer. JOlnted. and. small. 6.9. with丘bula. to fifth metatarsals. bone no.. 6.5. with. are. transversally,. gently. subtrigonal,. higher. of. long. spoinding. closely. one. bones. than. marglnS. tarsals. this. right. tarsal. higher. of. L 21. 5. There. Brst. with. L. 25.3. bones. ; right. They. R. 24.6. 2 and. no.. arranged. jointing. jointing. position. in the. are. tibia一色bula.. between. skeleton. position. calcaneum. of. tarsals. of. in orlginal. preserved galus. bones. tarsal. R. L. 23.9. 4.. no.. subquadrate, and. three. notched,. other corre-. Calcaneum. three marglnS and recurved First fourth distal metatarsus. and bones in size. First and丘fth triwith. three. other. bones. subquadrate. and.

(19) Mesosaurus. Some. On. kept. Skeletons. in. 47. Japan Astragalus ′-ーー-ー'-＼. No.. No.. 2. 4. {. R Maximum. longitudinal. Maximum. as. width. length. 2. R. 8.7. 7.2. 6.3±. 7.0. 5.8. ....‥‥. Medial. distal. 1.st. centrale. 2nd. tarsal. distal. tarsal. ヽ------------ヽ. ヽ■■-----------㌧. No.. L. 8.2±. preseoved..‥‥‥‥‥‥‥‥... preserved. Calcaneum ′--･/. as. ′-----一-'＼--■･･･■･････-･■●･-ヽ. 4. No.. ′---′. 2. No.. 4. No.. 2. No.. No.. 4. 2. No.. No.. 4. ー-r. {. /-I-し-------r. R. L. 氏. L. R. 良. R. L. R. 7.0. 6.8. 6.0. 1.8±. 2,8. 2.0. 3.0±. 4.1.. 3.4. 2.7. 2.7. 1.8. 5.4. 5.3. 4.8. 1.6±. 2.4. 1.5. 2.1±. 2.8. 2.1. 2.i.＋. 2.3. 1.6. 4tb. distal. 3rd. R. tarsal. distal. R. 5tb. tarsal. J. L. distal. tarsal. ヽ-･･･＼. ノーーーーーーーー. 2. No.. No.. 4. 2. No.. No.. 4. 2. No.. ＋. r人----■-､. R. R. L. R. 2.4±. 1..7. 2.7＋. 3.8. 3.0. 3.9mm. 1..5＋. 2.5. i..7. 2.5±. 3.4. 2.5. 2.7. digits. of. Left丘ve. R. L. L 3.1. in orlglnal. served. arrangement tarsi,. but right position, First bones. metatarsal. of. Shaft. ones.. Two. phalanges. of by. known. phalange. digit. second phalanges. are. three are. of. left. formula. in. ones. pes. relatively. long,. panded.. Dist礼l middle. other. are. skeleton. digit. of丘ftb. in the. left pes. in the. skeleton. of. preserved. left pes. preserved. no.. 4.. no.. 2. being are. of One. in. unpreserved and. narrow. phalange. slender very. phalange. one. short,. digit. of負fth in. 4.. no.. and. trigonal. and. projected. 2. No.. Width. length of. as. preserved‥‥‥‥‥‥‥. proximal. as. end. preserv∂d‥‥‥‥. No.. 2. L. No. R. phalangial. ⅠⅤ No. L. 2. pbalange. No.4 R. 16. 1. 13.8. 18.2. 15.3. 3.2. 2.3. 3.6. 2.6. No.. distally･. 4. No.. L 19.7± 3.6. No.. The. No.. 1,. 2. No.. 4. No.. L. L. 氏. L. R. 9.6. 8.8. 12.5. 13.5. 12.0. 4.2±. 3.7. 3.0. 2.2. 2.2 pba】ange. ⅠⅠ. No.4. ex-. ends. ⅠⅠ. Ⅴ 2. 2. No. R. 4. digit and. Proximal. 4. in. rod-like.. Metatarsus ⅠⅠⅠ. and digit. fourth. distal. proximal. and. Four. bone. Proximal. both. proximal. of. 4.. no.. the. Ⅰ. Maximum. phalanges. fourth. specimens.. distal. is preserved. As. of. phalange. these. portions. 4 and. of. phalanges. bones. with. than. shorter. Four. two. 2-3-4-5-6,. no. skeleton 2. Three. no.. phalange. and. from丘rst. distal. and. meta-. all. longer. and of skeletons no.2 one in skeleton no. 4 and. 2.. no.. of. in. metatarsal.. in of. pre-. well disturbed. thickest. proximal. in丘rst. are. are. gradually. Both. distinct. 2. no.. and. becomes. are. left pes. the. Mesosaurus. of. digit. impression. in. preserved. the. this. preserved digit. shortest. 4. no.. of. skeleton. of. slender.. Brst. third. impressions. and. is most. ones. right. ones. Metatarsal. straight. less expanded;. or. more. longest.. one. while丘ftb. to丘fth. 2 and. no.. skeleton. 4. No. L. 2. ⅠⅠⅠ. No.4. R. L. 16.9. 4.7. 3.1. 5.3. 3.7. R. 2.6. 2.8. 2.0. 3.2. 2.2. No.. 2. No.4. L. R. 7.2. 5.1. 3.4. 2.2.

(20) T.. 48. SⅢIKAMA. Ist. ⅠV 4. No.. No.. R 6.2. 2. No.. middle. 2. No.4. No.. 4. No.. 4. No.. 2. L. L. 3.7. 2.9. 4.4. 3.0. 3.4. 4.5±. 4.6＋. 2.3. 2.7. 2,1. 2.1＋. 2.2. 1.7. 1..8. 1.5. 3rd. middle. R. Distal. phalange. L. pbalange. IV 4. 4. R. iⅢ. ⅠI. No.. R. R. No.. No.. 2. L. 4. No.. 2. R. L. 4. No.. R. 2.4. 2.7. 2.4. 1.7±. 1.8. 2.1. 1.9±. 2.2. 1.7. 1.5. 1.5. 1.9＋. 1.6. 2.3. 1.8. belong. to. skeletons. Stereosternum from. is. these. accepted,. similar. than. to. tumidum. but. geographicaly,. from. a. in. age. the both. but. type. lower. species. that. Gondwanaland. of. but. they. distinct. is. this. because. all. Mesosaurus. type.. South. Africa to. nearer. is. tenuidens. are. species. separated. lived. might. the from. Even. of. both. the. latter,. McGREGOR. it is much. outline;. tumidum. humerus.. formation. dis-. and. and. as. brasiliensis. the. Karoo. noteworthy. the. of. construction of to brasiliensis belong. in general be. synonym. 1869.. RoMER, region. HuENE, 1956. of If brasiliensis. Junior treat. long. cervical Mesosaurus.. the. the. It may the. synonym. to. may. 1869. than. brasiliensis.. grown. from. brasiliensis. to. very. junior. a. 80cm. is about. longer. GERVAIS,. Mesosaur･us. Paulo. not. the tumidum. not. GERVAIS,. skull. convenient. mainly. are. Sao. becomes. skeletons. them. of. ienuidens. be. judging. other,. as. former. it may. thinks. humeri. by. fully. a. the. conspeciBc,. each. from. brasiliensis. S. tumidum. writer. above. CopE. Stereosternuni. treates. are. mentioned. tumidum. tinguished. judged. -mm. 1.3. :. These. 1952. 4. No.. R. 4.8. Remarks. 4. No.. R. No,. R. 2. No.. Ⅴ. 9.0. ⅠⅤ. No.4. L. 2. No.. phalange. ⅠⅠⅠ No.. 4. ⅠV. R. 2.2＋. 2nd. pbalange ⅠⅠⅠ. R. L 10.0. 2.4. middle. ⅠⅠ. Ⅴ. in the. same. continent.. Skeleton before. -9th and. were. and. cervical skull to. about. 0.74. total. length,. than. McGREGOR's. 毒s about As 缶rale. new. that. doubled. ringed. length.. total. fact. observed. Growth. lines. ossi丘cation. between. caudal them. 2 is. larger. skeleton. rather it may seen. near. vertebrae. a. S. tumidum skeleton. narrow. that. of on. 3. no.. is. in. smaller. McGREGOR. is medical. there. seen. also. and side;. cen-. femur. and. anterior-. ventral. 582mm, 690mm. is about. of humerus This is. consists. fossa. might. animal. by restored 2 in size.. no.. progress.. regions McGREGOR,. respectively,. the. skeleton. and. vertebrae. 3 is smallest,. skeleton. noteworthy in distal portion. ; centrum is. and. long of. no.. be. still in. was. there. in size. by. skeleton 443mm. length. total. McGREGOR's. no.. reconstructed hence. the. 1 isnext. no.. skeleton. long,. tarsus.. indicate. centrum;. that. so. 770mm a. in. of. 2 in. bone;. reconstructed 63 and. WOuld long, hence. Skeleton. no.. the. of. its skull, cervical if these unpreserved. retain. become. 82mm. 787mm.. attain. not. 14th. post. basis. reglOnS. caudal be might. does. vertebrae. the. on. long. 322mm. caudal. restored. and. 2 of. no.. may in. the. posterior transverse.

(21) On. process. erior. aquatic. from. projects In the. are. of the. centrum. least. at. E･D･. (1866). in. haemal. and. 49. Japan. arch. from. projects. post-. in. 2 breaking. 3 series and caudal points fully 3, is no･ splne not of skeleton neural to insufBcient be due the ossification may. Such. animal.. References CopE,. kept. Skeletons. individual. young. centrum･. with life. Mesosaurus. anterior. There. centrum･. vertebrae･ con fluent. Some. Palaeontology. Vertebrate. :. selected of. Brazi一.. Proc.. Amer.. Phil.. SocリVOl.. 23,p.7.. McGREGOR,. J･H･ Final Rio. HuENE,. de. F･ V･. SIiIKAMA,. (1937). Mesosaurus de. brasiliensisn.. Estadias. das. Minas. sp.. from. de. Carvae. the. Permian de. Pedra. of do. Brazil. Brazil.. :. Osteologie. 92, abt. Palaontologie bd.. Systematische. und. A,. pp.. Stellung. von. Mesosaurus.. Palaeon-. 45-58.. Phylogenie der Niederen Tetrapoden, (1966) : und : Vertebrate Paleontology, Chicago. (1953) Chicago. of the Reptiles, (1956) : Osteology T. OzAKI, H. : from and On A Reptilian Skeleton (1966). pp.. 243-245.. A･ S･. For皿ation WooDWARD,. On. :. Commissas. Janeiro.. tographica, RoMER,. (1908). Report. A･S･. of. Paulo,. Sam. (1932). :. Z汀TEL's. Brazil.. Trams.. Textbook. Proc. of. Pal.. Soc.. Palaeontology,. the. JapリN.SリnO. rev.. edリVOl.. Palaeozoic 64. 2, p. 271..

(22) Explanation. Mesosaurus Ventral. brasiliensis side. of. No･. of. Plate. 2. McGREGOR. 1 skeleton,. stored. in. the. Crown. Prince's. Palace. (No. 2942).. ×0.82,.

(23) Sec.. T. SHIKAMA. ⅠⅠ,Plate. 2. L叫唱私′. i( メ. ･tl .TPL. 7:i. -i. 価普 H-. A i. >. -･モ. ･智恵1:. I. _7. 港-1･r! 渇. ∼.. lヰ iー. i ′lこ. 一. J -しLIL. }. V. :1 ＋{'1 =立. ..∼ Y 】. S. TrT. ＼. 也. JO 屯√. 憾ニー. I. ㌔. あ. ●/. L. .. A. イ. rL. )-. F妄';. ′. -I毒. I. f. 1J. ∴†鷲. l l. ぜ. ち †. I. 旬:i. !1. ●′. .∫. tご′てrし暮. 蔦. ･′. }. .∫ ノ. ＋r>. ､(. メ. ′ヽ. ノ′. -:. ー. it. f. illJ L,. 守､善 ∫. A. 良. ヽ. LL ′′. さ＼. }■. J5. t. 1. 澄壷ニ‥･-'. Ozaki. photo..

(24) Explanation. Mesosaurus Dorsal. brasiliensis side. of. No.. 2. of. Plate. 3. McGREGOR skeleton,. stored. in. the. Crown. Prince's. Palace. (No･ 2950-1)I. xO･57.

(25) Sec. ⅠⅠ,Plate. T. SHIKAMA. 蘇;=,?I ヰ宇妄'∼ ≠. 串こサー. /I. :f遥.. J. 藁卦q･秘孟貢ぎ. †ふI. 熱ア. 屯:. ∼.. 磨. 一T 1 もヽ､t. ㌔. >_i. ･9省一ゝ. r･き. Y. 菱官. 1.BE環･ホ1 ナも由ヽ. a. ㌔. *･ノ. rF-. 叫. ;(. 砿. ∫. t. ?. 読.7達て邑せ･t.. ㌔. ㌔: *J. 冬青､一骨 d▲(. 一r. 一丁. 句■. 一. A Fざ.. べ ti. qP, ′. ′. }hJ. 与-･ヂ㌔ ,∼. lJ.-. ■ヽ I.J♂. ＋i. ･這ト. I<. I. * d. Ozaki. photo.. 3.

(26) Explanation. Mesosaurus The. same. brasiliensis. specimen三of. of. Plate. 4. McGREGOR that. shown. in. the. Plate. 3.. ×0.74..

(27) T.. StIIKAMA. Sec. ⅠⅠ,Plate. r. 4. ;yj章 I J.. 妻. %'&. i. J. 磨. .,?ih. 9 ヽ. .準薮叫･f-← メ. 一Jj. I.. ー.. アン. I. 磨. ㌔. 轡. ､軒 J*. サー書. pl †戦. ,tL馬♪ 一i￣. 貰′;∼. t摂. を与甘. A. 軍/. メ. /&7･. ､jb `■. メ. r i(. 準. *. J t■.. ＋. A. IS･一斗も琳. Lぎ. 専 #･. 午. jノ. !I. ) ”. 鹿. r､丑 JTi4 .?. /. Ozaki. photo｡.

(28) F:Ⅹplanation. Mesosaurus ventralside. xO.84.. brasiliensis of. No,. Plate. of. 5. McGREGOR 3. specimen,. stored. in the. Crown. Prince's. Palace. (No･. 295012)･.

(29) T.. Plate Sec. ⅠⅠ,. SHIKAMA. ■サ I. i 一､㌢. ∫ ､▲lJ. 書. ′ ?. 秦チ.i ▼d. ㌔. ぎ. ♭キ､. ′･1. ヽ.. ＼. ヽ､. l:. / S'. ◆一. -I-. ･. 】. ヽ. ′､っ. -. ㌔. i ヽ一. >←. LYl. I 主It. '!5. ゝ三. 節. Li. ヽ. i. 音凄 I i. ∫. 蚤三寒･S{ :tL,i l. .阜r. ♯･y. 也. 九. L＋.. r. 7. 1. 篭妄`哀. 与転＋J. ?i. ＼､ ′､声事書. 1I. iも .. 7,: J. √ ●. ･'rh.. ,･繁1. I.7..'望;Lて. Ozaki. photo.. F与. '･へご∴輯 '′▲-. 5.

(30) Explanation. Mesosaurus. Dorsal. brasiliensis. side. of. P2-2780).. No･. Plate. 6. McGREGOR.. 4 skelton, x1.. of. Stored. in. the. National. Science. Museum,. Tokyo. (NS-MT.

(31) T.. SHIKAMA. Sec. ⅠⅠ, Plate 6. f,小ミ (” ヽ. q. ノゝ. ･,屯. ∼;. ). a.. I-,. ㌔. 一√†. ′. :漕. #! f. ●J. 与笥. >. 一 k. ＼. >. ti. ､. ヽ1. .撃. .-. >･;i '>4bL. I. -iL一. ∫ ∼. や. I. 1^ ヽ ■ゝ. Ozaki. photo.. eLL. メ. ､ごiI.

(32)