!•'. 'ss! Is from the M iura Pfinineulä and its [m mediate North. | 4 | 



Fossil occurrence. — Miyata Zone (Motowada); Kbshiba Zone 

 (Koshiba); Naganuma Zone (Kikkozan). Lower Musashino of 



Kazusa. 



Living. — Northern Japan (Bay of Hakodate). 



Genus IVootlia. Deshayes. 



177. Woodia concentrica, Yokovama. 



Pi. XI. Fig. 7. 



Shell small, moderately thick, flatly convex, nearly orbicular, 

 almost equilateral; anterior and posterior borders roundly truncate, 

 the truncation being more marked in the posterior than in the an- 

 terior border; surface concentrically striated, with striae unequally 

 distant and somewhat lamellar, though becoming obsolete toward 

 the beak; a rounded edge runs from the beak to the postero- ven- 

 tral corner, the surface behind it being slightly concave. Inner 

 margin flattened and forming a smooth narrow field. Muscular 

 impressions ovate. 



We possess only two specimens of the right valve, both meas- 

 ming 4 millim. in height and length, and 13 millim. in depth. 

 The teeth consist of one main tooth and of a distinct anterior and 

 posterior lateral. 



This species is closely related to Woodia digitaria (L.) found 

 in the English Crag (Wood, Bivalves, suppl. p. 141, pi. X, rig. 8) 

 and in the Atlantic, but lacks the oblique elliptical markings of 

 the latter. 



Fossil occurrence. — Naganuma Zone (Naganuma). 



Family Crassatellidae. 



Genus f'raasatelia, L/AMARCK. 



178. Crassatella heteroglypta, (Pilsbry). 



Pl. XI. Figs. 10, 11. 



Cra$h;atellites> heteroglypta. Pjlsbry. Cat. Mar. Moll. Jap., p. 135. 



Crassatella ja pcnica. Sowkrby, Jour. Linn. Soft XX, p. 399. pl, XXV, fig. 19. Not Cras- 

 satella Japonica Dunker. 



