^8 ART. 2. S. TOKÜNAGA. 



OSTREID/E. 



164. OSTREA OIGAS Tiiunb. 



PL IV. Fi.us. 5 a and h. 



Brauns, Geol. Env. Tokio, p. 48. — Lisckke, Jap. ^leere^i-Coiich., I., 

 p. 174, and II., p. 160, and III., p. 114.— Schkenck, :Mo11. Anuirl. 

 and Nord-Jap. Meeres, p. 475. — Reeve, Monogr. Ostrea Sp., 21. 



Synonym : — 0. talienwanensis Cross ; 0. laperousii Schrenck. 



Oji and Shinagawa (frequent). 



Living : Tokyo Bay, Cböshi (Shimösa), Wadanohara (Riku- 

 zen), Nagasaki, ïchifu, and Talienwan. 



165. OSTREA DENSELAMELLOSA Lke. 



PL IV. Figs. 6 a and b. 



Brauns, GeoL Env. Tokio, p. 58. — Morse, Sliell-Mound of Omoii.— 

 LisCHKE, Jap. Meeres-Conch., I., p. 177. 



Oji and Shinagawa (frequent). 



Living : Tokyo, Sumoto (xlwaji), South Shikoku, Bungo, 

 and Loochoo Is. 



166. OSTREA IRREGULARIS Tok. 

 PL IV. Figs. 7 a and b. 



Shell small, very irregular, convex ; valves nearly equal in 

 length and breadth ; surface plaited or spinous, somewhat foliat- 

 ed, concentric striations usually invisible. 



Tabata (very abundant). 



Living specimens were collected near Misaki (Sagami). 



