Fossils from the Upper Musashino of Kaznsa and Shiinosa. 1 gQ 



261. Vetter ieiu'dia toèieana, Yokoyama. 

 PI. XIII. Figs. 6, 7. 



Shell very small, thick, triangulnrl}^ ovate, moderately 

 convex, somewhat oblique and inequilateral with anterior side 

 shorter than posterior, rounded in front and behind. Antero- 

 and postero-dorsal margins straiglit, meeting each other at 

 somewhat less than a right angle, so that the beaks appear 

 pointed. Surface radiately ribbed; ribs about thirteen in number, 

 flatly rounded, separated by very narrow valleys, crenulate. Inner 

 margin coarsely crenate. Lunula longly ovate, distinct, smooth. 

 Main teeth accompanied by an anterior lateral. Length 2.2 

 millim. Height 2.1 millim. Thickness L7 millim. 



Fossil occurrence. — Otake, Tega, Shito (numerous). Oji. 



Family Astarlidae. 



Genus A STA RTF., Sowerby. 



262. JLstarte borealis, (Chemnitz). 



PI. X. Fig. 11. 



Astarte borealis. Forbes, Mem. Geol. Siirv., vol. I, p. 413, 184G. Wood, Cra," Moll 



Biv., p. 175, pi. XVI, figs. 3a-d. 

 Astarte corragata. Lovén, lud. Moll. Scaud., p. 37. Middendorff, Beitr. z. Malac. 



Boss., Ill, p. 46, pi. XVII, figs. 4-9. 

 Astarte arctica. Möller, Ind. Moll. Greenl., p. 19. Forbes and Hanley, Hist. Brit. 



Moll., I, p. 461, pi. XIX, fig. 7. 

 Venus borealis. Chemnitz, Conch. Cab., vol. VII, pi. XXXIV, fig. 42. 



A single left valve which, however, undoubtedly belongs to 

 the species above named. It is thick, much compressed, broadly 

 ovate, somewhat longer than high, rounded in front, truncate 

 behind. The surface is smooth and has an indistinct flattened 

 carina behind. Inner margin smooth. Length 15.3 millim. Height 

 14.1 millim. Depth 2.9 milhm. In shape it comes closest to what 

 Middendorff calls var. lactea (loc. cit., pi. XVII, flgs. 8, 9). 



Fossil occurrence in Japan. — Shito. 



Fossil occurrence in Europe. — English Crag. 



Living. — Northern Japan (Kurile Islands). Behring Strait. 

 Britain (deep water). Arctic seas. 



