Fossils from th<> Miura Peninsula and its Immediate North. 37 



On comparing this species with the living forms figured by 

 Tuyon in his Manual of Conchology, it resembles Liptôthyra 

 paucicostata Dall (vol. X. p. 248, pi. 63, tig. 27) so much, that 

 there is hardly any difference between the two. But our specimen 

 being imperfect. I can not determine it with certainty. 



Fossil occurrence. — Yokosuka Zone (Otsu). 



Living. — Dali/ s species lives on the coast of California, 



Family Trochidae. 



Genus Ctilorosfoma, Swainson. 



95. Chlorostoma miyatense, Yokoyama. 



Pl. V. Fig. 33. 



Shell small, flatly conical, pointed at apex; whorls about six, 

 of which the first one and a half are nuclear and smooth, the 

 others flatly convex with shallow but broad canaliculated sutures, 

 spirally costellated; costellœ subequal, six on the penultimate 

 whorl with the two uppermost granulate, separated by interspaces 

 of nearly equal breadth which are finely but distinctly cross-striate 

 by incremental lines. Periphery sharply angulated, projecting, 

 crenulate by lines of growth. Base flat, with many unequal 

 spiral threads crossed by lines of growth and appearing granulate. 

 Umbilicus wide, deep, funnel-shaped with surface flat and only 

 with lines of growth ami with margin angular and crenulate. 

 Aperture squarely rhombic with breadth somewhat greater than 

 height. Inner lip smooth, the callus being partly spread over the 

 base. Outer lip simple, sharp. The colour of the shell seems to 

 have been white with pink blotches, as the latter are more or less 

 distinctly preserved, though in a faded condition. Height C> 

 millim., diameter 8,5 millim. Two specimens. 



The close ally of this species is Chlor otioma yundlachi Phil. 

 (Syst. Conch. Cab. Mart. u. Chemn., vol. I, part III, p. 226, pl. 

 34, tig. 13) from Cuba which Pilsbry in Tryon's Manual of 

 Conch ology (vol. XI, p. 1<S5) considers as an immature form of 

 C. scalare Axtox. Anyhow, oui- shell has a sharper periphery 

 and a flatter base. 



