'78 * Art. 6.— M. Yokoyama: 



This species, when compared with the foregoing ones, has 

 flatter whorls, the more obliquely receding aperture and the shell 

 growing to a larger size. The callus has various shapes, some- 

 times very large so as to cover the whole umbilicus or, as is more 

 usually the case, small and leaving a greater or less part of the 

 umbilicus open, but in every case it has always a transverse 

 groove running across its surface. The spire may be elevated or 

 somewhat depressed; when elevated it approaches a conical 

 shape, as the whorls of the spire are more or less flattened. 



Fossil occurrence. — Miyata Zone (Okine Nagai); Yokosuka 

 Zone (Yokosuka and Otsu); Naganuma Zone (Naganuma); Upper 

 Musashino of Musashi, Shimosa and Kazusa. 



Living. — Central Japan ; China; Australia; Indian Ocean. 



Family Scalaridae. 



Genus Scalaria, Lamaick. 

 80. Scalaria turriculoides, Yokoyama. 

 Pl. V. Fig. 12. 



Shell small, rather thin, turrete; whorls about seven, very 

 convex, longitudinally ribbed; ribs somewhat oblique and curved, 

 thick, elevated, many (about fifteen on the penultimate whorl) 

 separated by intervals of a little greater breadth which are 

 ornamented with very tine spiral lines only observable with a 

 strong lens; some of the ribs are specially large and thick so as 

 to appear like varices. Aperture quite circular, continuous, 

 thickened and flattened at margin. Umbilicus covered. A single 

 specimen measuring 12 millim. in height and 5 millim. in the 

 greatest diameter. 



This species is closely allied to Scalaria turricula Sow. 



(Thes. Conch., I, Scalaria, p. 92, pl. XXXIII, fig. 61, pl. 



XXXIV, fig, 88) originally from the West Indies, but reported by 



Sowerby also from the Strait of Corea. But the fossil form has 



.closer and thicker ribs than the living. 



Fossil occurrence. — Koshiba Zone (Koshiba). 



