JAPANESE MOLLUSK8, OSTRACEA. 145- 



Pecten hastingsii Melvill. Journ. of Conch., Y, p. 279, pi. 2, f. 7. 

 Japan (Hastings, Deut). 



Pecten mollitus Reeve. C. Icon., sp. 100. Japan. 

 Amusium japonicum Gmel. 



East coast and Inland Sea (Stearns) ; Yedo and Nagasaki 

 (Lischke). 



Amusium obliteratum Linne. Japan (Dkr.). 



Amusium pleuronectes Linne. Japan (Dkr.). 



Vola laqueata Sowerby. Lischke, J. M. C, II, pi. 12, f. 1, 2 ; Phil., Abbild., I, pi. 

 1, f. 1 (P. antomi). 



Nagasaki Harbor and Yokohama (Stearns); Hakodate (Schrenck); 

 Yedo (Lischke) ; off Kobe in 50 fathoms ; between Is. of Sikoku and 

 Nippon, 50 fathoms (Challenger). 



Vola excavata Anton. Phil., Abbild., I, p. 201, pi. 2, f. 1 ; I'ecten sinensis Sowb. 

 Japan (Dkr,). 



Vola puncticulata Dkr. Dkr., Index, p. 244, pi. 11, f. 10, 11 (young) ; Pilsbry, 

 Prof. Acad. Nat. Sci. Phila., 1891, p. 473, pi. XIX, f. 1, 2, 3 (adult). 



A single large specimen collected by Mr. Stearns. 



Vola inaequivalvis Sowerby. Conchyl. Cab., p. 236, pi. 62, f. 5-8. 



South Japan (Dunker). 



(Ostracea). 



OST-RMIBIE. 



Ostraea gigas Thunberg. Lischke, Jap. Meeres-Conch., I, p. 174 (-(-0. laperousii 

 Schr. and 0. talienwhnnensis Crosse). 



Nagasaki (Lischke) ; Enoshima (Stearns) ; Yokohama (Mts.) ; 

 Hakodate (Schrenck) ; also found on Asiatic mainland. 



Only young and moderate sized specimens show the purple color 

 markings outside. One specimen collected is the largest on record, 

 surpassing the measurements given by Thunberg. The length of 

 the ligament area is proportionately greater than in smaller speci- 

 mens. Measurements of four examples are as follows : 



Total length 443 mm. 

 Total length 248 mm. 

 Total length 246 mm. 

 Total length 242 mm. 



greatest breadth 95 mm. 

 greatest breadth 52 mm. 

 greatest breadth 44 mm. 

 greatest breadth 44 mm. 



All of these are narrow and parallel-sided. 

 10 



