16 ART. 20. — M. YOKOYAMA. 



Height 55 millim.; breadth 50 millim. 



In the general outline of shell and number of radiating 

 ribs, the Japanese form resembles L. pretiosa Desh. (Descr. des 

 Anim. sans Vert., II, p. 64, pi. 78, figs. 16-19) from the 

 Calcaire Grossier Inférieure of the Paris Basin, but it is much 

 larger and more oblique. 



3. Venericardia nipponica Yok. 



Several impressions of this characteristic shell were found 

 in a piece of sandstone containing remains of Crassatella fusca 

 above mentioned. 



