134 Art. P. — M. Yokoyama. 



Yokosuka Zone (Yokosuka); Naganuma Zone (Naganuma); Upper 

 Musashino of Musashi and Shimosa. 



Fossil occurrence in foreign countries. — Glacial and Pliocene 

 of England; Scaldisien of Belgium; Pliocene of Italy; Miocene of 

 Austria, Poland, Volhynia in Russia, Switzerland, etc. 



Living: — Central Japan: Atlantic (Iceland, Norway. Great 

 Britain, Holland, France, the Eastern Coast of North America) 

 and Mediterranean. 



168. Lucina contraria, Dunker. 

 Pl. X. Fig. 8. 



Lucina contraria. Dunker, Index Moll. Maris Japon., p. 215, pl. XIII, figs. 12-14. 

 Lasaea striata. Tokunaga, Foss. Env. Tokyo, p. 53, pl. Ill, fig. 14. 

 Lasaea rubra. Brauns, Greol. Envir. Tokio, p. 43. 



A few examples. The shell is orbicular in shape and strongly 

 convex with the ventral border crenulated. The surface shows 

 irregular concentric riblets crossed by fine radiating striae. Height 

 11 millim. Breadth 105 millim. Depth 4,5 millim. 



What Tokunaga described as Lasaea striata is undoubtedly 

 this species; I was convinced of this on studying the specimens 

 from Oji and Shinagavva. He was probably right in identifying 

 Lasaea rubra Mont, of Brauns with his species. 



Fossil occurrence: — Miyata Zone (Shimo-Miyata and Kami- 

 Miyata); Upper Musashino of Musashi and Shimosa. 



L i vi n g : — ( 1 e n t ral Ja pa 1 1 . 



109. Lucina spectabilis, Yokoyama. 

 Pl. X. Figs. 10, 11, 12. 



Shell large, moderately thick and swollen, transversely 

 roundly ovate, longer than high, somewhat inequilateral, the 

 anterior side being shorter than the posterior; anterior end some- 

 what produced, narrowed and obtuse, posterior margin broadly 

 rounded, passing gradually into the arcuate ventral margin, but 

 making an obtuse angle with the sloping postero-dorsal margin; 

 antero-dorsal margin sloping and slightly excavated. The 





