Fossils from the Upper Musashino of Kaznsa and Shimosa. 1 ol 



Family Saxicavidae. 



Genus PANOPF, Menard.^^ 



1S2. Panope f/eii^fosa (Gould). 



PI. VI. Fig. 14, 15. 



Panopcea (jejierosa. Gonlcl, Proc. Bost. Soc. Nat. Hist., vol. Ill, p. 215. Wilke's 



Expedition, p. 385, pi. XXXIV, fig. 507. Otia Conch., p. 165. Brauns, Geol. Env. 



Tokio, p. 36, pi. Ill, fig. 14. Tokunaga, Foss. Env. Tokyo, p. 38. Dall, Tert. 



Fauna Florida, pt. lY, p. 880. Arnold, Pal. d Strat. Mar. Plioc. a. Pleist. San 



Pedro, California, p. 182. 

 Glycimeris generosa. H. and A. Adams, Gen. PiBC, Moll., p. 350. Gabb, Pal. Cal., II, 



89. Keep, West Coast Shells, p. 209, fig. 178. Pilsbry, Cat. Mar. Moll. Jap., 



p. 117. 



This shell excellently figured hy Braniis in his work above 

 cited is very variable in shape as well as in thickDess. The 

 typical form is rather thin-shelled, nearly equilateral, transversely 

 oblong, anteriorly rounded, posteriorly subtruncate, with the 

 proportion of length to height equal to about 10 to 6.6 on an 

 average. But there is also a more elongated arcuate form 

 characterized by a thick and solid shell with the length nearly 

 twice the height. 



Dall in his ,, Tertiary Fauna of Florida" p. 831, mentions 

 two varieties of the species which he calls ^olida and globosa, of 

 which var. solida seems to correspond to our longer form, although 

 I can not assert it with certaint}^, as he does not give figures of his 

 so-called varieties. 



In our plate, the typical as well as the longer form is figured. 



Fossil occurrence in Japan. — Otake (frequent), Tega, Semata. 

 Also Oji and Shinagawa. 



Fossil occurrence in America. — Miocene, Pliocene and 

 Pleistocene of California. 



Living. — Northern Japan. West Coast of N. America from 

 Puget Sound to San Diego. 



1) Often written erroneously Panop.,a (Zittel's Texi-book of Palaeontology edited by 

 Eastman 1913, p. 500). 



