102 ^i"t- 1— M. Yokoyaina : 



whorl, slightl}' curved and oblique, the lovrer end being more 

 forward than the upper, with broader interspaces, fused with one 

 another at the lower suture. ( )ccasionall3^ two or three costellse 

 unite together to form a broad flat varix. Spiral striations very 

 faint, visible only on interspaces which are provided at the lower 

 end with a transverse pit. Periphery bluntly angulate. Base 

 abruptly narrowed, with only faint indications of costelhe, besides 

 a few feeble spiral threads. Aperture squarish, the inner lip 

 being bent into an angle somewhat greater than n right angle 

 Outer lip thin, nearly straight. Anterior margin of the aperture 

 broadly rounded. Height ll.^millim. Diameter 3.2 millim. 



Fossil occurrence. — Otake, Shito. Oji in Musaslii (frequent). 



147. Turhonilla {Mormuln ?) serohieulafa, Yokoyama. 



PI. IV. Fig. 38. 



Shell medium-sized, elongate-conic. Nuclear whorls three 

 with the axis at right angles to that of tlie shell. Post-nuclear 

 whorls about fourteen, moderately convex, longitudinally costel- 

 late. Costellte blunt, generally straight though rarely somewhat 

 flexuous or curved, nearty vertical, slightly nari-ower than inter- 

 spaces, separate above, fused below at the suture, with a pit at the 

 lower end of each interspace, occasionally forming a broad flat 

 varix (by fusion of two or three costellae). The number of costellae 

 is about twenty-three on the body-whorl on which they end at the 

 subangukte periphery wdiich is marked b}^ a spiral cord formed by 

 the fusion ot the lower ends of the costellae. Base only with 

 coarse lines of growth, rather flat, tlie convexity being very shght. 

 .Sutures deep. Aperture subquadrate. Inner lip bent at an obtuse 

 angle in the middle. Outer hp thin. Height 11 millim. Diameter 

 2 millim. 



This shell is like the preceding, but the whorls are more 

 numerous and have no spiral striations. 



Fossil occurrence. — Otake (rare). Oji in Musashi. 

 Living. — Central .Ja]>an. 



