Fossils from the Upper Musashino of Kazusa and Shimosa. 35 



2<». Te^t'eht'ti suaviti ivn, Yokoyama. 

 PI. I. Fig. 24. 



Shell turrete- Whorls about eleven, the first two smooth and 

 rounded, the following slightl}^ convex and longitudinally weakly 

 plicate on the upper whorls, the plicae generally disappearing on 

 the lower ones. Usually there is a somewliat depressed spiral area 

 in the upper part of the whorls dividing the plicae into two very 

 unequal parts, of wliich the upper often looks like an elongated 

 tubercle (found just below the suture). Periphery rounded. Base 

 rather abruptly narrowed, convex, generally only with coarse 

 flexQOus lines of growth. Inner lip broadly angulate, making the 

 aperture look four-sided. Canal very shoit, somewhat recurved. 

 Height '2'1 millim. Diameter 6 millim. 



This shell resemldes the preceding in sculpture, but is not so 

 subulate in shape. 



Fossil occurrence. — Shito (frequent). 



27. Terehra tstiboiatta, Yokoyama. 

 PI. XIII. Fig. 12, 13. 



Shell subulate, large. Whorls about sixteen, the upper two- 

 üfths flat, the lower three-fifths slightl}^ convex, longitudinally 

 plicate and spirally threaded. Plicae generally weak, numerous, 

 equal or unequal, sometimes indistinct, oltlique on the flat portion 

 of the whorls, nearly vertical below, varying in number (up to 

 thirty on the body-whorl). Spiral threads more or less unequal, 

 often fine and indistinct, also varying in number ; but there is 

 invariably a coarse one at the boundary between the flat and con- 

 vex portions of the whorls. Above this thread there are two, the 

 one just below the suture and the other midway between it and the 

 boundary one. The latter is somewhat elevated, the surface above 

 as well as below it appearing a trifle excavated. Below the boun- 

 dary-thread, there are several finer ones which may be close and 

 many, or distant and few. The intersection-points between the 



