Fossils from the Upper Musashino of Kazusa and Shimosa. 99 



if not for the faint spiral lines said to be found in tlie latter. I 

 would unite the two. 



Fossil occurrence. — Otake. 



Living. — Central Japan. 



142. Odostotnia (Ofletta) neo feline, Yokoyama. 

 PI. IV. Fig. 33. 



Shell small, ovate-conic. Whorls al)out live and a half, of 

 which one and a half are nuclear. Post-nuclear ones convex, 

 shouldered a httle below the sutures giving the shell a tabulated 

 appearance, spirally ribbed. Ribs flatly rounded, a trifle broader 

 than the interspaces which are finely longitudinally striate, three 

 on the first post-nuclear whorl, four on the next one, six on the 

 penultimate and more than ten on the ultimate. Of the four ribs 

 of the second post-nuclear whorl, the uppermost is much narrower 

 than the others. Of the six ribs of the penultimate whorl, the 

 uppermost is very faint and close to the suture, the next one 

 rather distinct, but weak, the succeeding three larger and nearly 

 equal in size, while the lowest one is somewhat weaker, though 

 strong when compared with the second. On the body-whorl, the 

 first subsutural rib is very weak, the next one somewhat stronger, 

 the following still stronger and nearly equal in size, though they 

 again diminish in size and get closer toward the caudal end of the 

 shell. Periphery rounded. Base convex. Umbilicus open. 

 Aperture oval, with posterior corner blunt and anterior rounded. 

 Tooth weak but distinct, on the some level as the umbiHcal hole, 

 the peristome anterior to it being a little reflexed outward. 

 Height 3.2 miflim. Diameter 1.6 millim. Height of body-whorl 

 seen from apertural side 1.6 miflim. 



The species is closely related to Odostomia felix Dall and 

 Bartsch (Notes on Pj^ramidellidte before cited, p. 358, pi. XXI, 

 fig. 2) now living in Japan. But the latter has fewer ribs 

 ..and the umbihcus closed. 



Fossfl occurrence. — Shisui (very rare). Oji in Musashi. 



Living, — Central Japan. 



