Fossils from the Muira l'eu insula ami its Immediate North. ] j | 



Fossil occurence. — Naganuma Zone (Naganuma), 

 Family Solenidae. 



Genus Solen, Linné. 



134. Solen gordonis, Yokoyama. 



i 



Pl. VII. Fig. 23. 



Shell linear, straight, with upper and lower margins straight 

 and parallel; anterior end truncate, nearly perpendicular and 

 straight or even slightly concave with angles a little rounded; pos- 

 terior end also truncate, straight, perpendicular, with angles some- 

 what more rounded than those of the anterior. 



A single specimen present is 100 millim. long, and 19 millim 

 high at the anterior and 20 millim. at the posterior end. 



This species is very closely akin to Solen beckii Philippi 

 (Abbild., Ill, p. 43, Solen pl. II. fig. 1) from an unknown locality, 

 in which, however, the anterior end is more oblique and the 

 posterior more rounded. 



Living. — Western Japan (Awaji Island). 



Fossil occurrence. — Miyata Zone (Shimo-Miyata). 



Genus Solecurtus, Blaisville. 



135. Solecurtus abbreviatus, Gould. 



Pl. VII. Figs. 12, 13. 



Solecurtus abbreviatus. Gould, Otia Conch., p. 164. Reeve, Conch. Icon., Solecurtus, pi. 

 II, fig. 5. Clessin in Syst. Conchi Cab. Mart. u. Chem., vol. XI, pt. 3, Solenaceae. p. 93, pl. 22, 

 fig. 3. 



The shell is thin and rather compressed, transversely oblong, 

 more than twice as long as high, anteriorly and posteriorly broadly 

 rounded, the posterior end sometimes appearing obliquely sub- 

 truncate rather than rounded. The ventral border is somewhat 

 excavated in the middle, while the dorsal border is nearly straight, 

 the arching being very slight. The beak is nearly median, the 

 anterior side being only very little longer than the posterior. -The 

 surface is concentrically wrinkled, with a distinct radiating gf< 



