Fossils from the Miura Peninsula and its Immediate North. 75 



Fossil occurrence. — Yokosuka Zone (Yokosuka). 

 Living. — Central Japan. 



Family Skeneidae. 



Genus Skenea* Fleming. 



74. Skenea nipponica, Yokoyama. 



Pl. V. Fig. 1. 



A few specimens of a very small shell, only 2 millim. in 

 diameter, smooth, almost discoidal, having a few quickly growing- 

 whorls with subconcave base and a deep open umbilicus. Aperture 

 obliquely oval. 



This species is allied to Skenea planorbis (Fabr.) (Forbes and 

 Hanley, Brit. Moll, III, p. 156, pl. XXIV, figs. 1-3) of the 

 northern seas, from which it is, however, distinguished by a 

 somewhat flatter shell, more quickly growing whorls and a smaller 

 umbilicus. 



Fossil occurrence. — Yokosuka Zone (Otsu). Upper Musa- 

 shino of Shim osa. 



Living. — Central Japan. 



Family Capulidae. 



Genus Catyptreea, Lamarck. 



75. Calyptrœa raammilaris, (Broderip). 



Pl. IV. Fig. 5. 



Calyptrau mammiluris. Try on, Manual of Conchology, vol. VIII, p. 1:20, pl. 34, figs. 64-75, 

 78-81. 



Trochita mammilaris. Sowerbt, Thes. Conch., V, p. 65, pl. 450, figs. 69-71. 



A specimen of a flatly conical spiral shell nearly circular in 

 outline, about 4 millim. in height and 9 millim. in diameter, with 

 a spiral diaphragm within, whose- columellar margin is twisted, 

 undoubtedly belongs to the above-named species. The apex is 

 subcentral, and the surface is roughly and unequally concentrically 

 striated. 



Fossil occurrence. — Miyata Zone (Kami-Miyata). Upper 

 Musashino of Kazusa. 



