108 Art. 1.— M. Yokoyau-a: 



159. Ijeptofttyrn ptjf/nuen, Yokoyania. 

 PI. V. Fig. 17. 



Shell small, turbinate. Whorls four, rapidly gruwiug, shoulder- 

 ed, the surface above the shoulder a little sloping and below an- 

 gulate in the middle. The sculpture consists of spiral threads 

 which are commonly alternately large and small. The shoulders 

 are marked with a large thread above which, that is to say, on the 

 sloping slielf, there are two larger ones. The angle below the 

 shoulder is also marked with a coarse thread. On the body-whorl, 

 between the shoulder and the angle, there is another coarse thread, 

 though somewhat weaker, and between the latter and the angulate 

 periphery there is also a similar one. Between the coarser threads 

 there is generally found a weaker one as stated above. The base is 

 flatly convex with several spiral threads. Growth-lines generally 

 distinct between the threads and looking like minute striations. 

 Umbilicus perforate, rather small but deep. Aperture circular. 

 Height and diameter 4 millim. 



Fossil occurrence. — Tega (frequent). 



Living. — Central Japan. 



1(»0. Ijepfofltfßra erassilirfifa, Yokoyama. 

 PI. V. Fig. 22. 



Sliell small, turbinate. Whorls about four, angulate in the 

 middle with the surface above the angle flat and gently sloping, 

 below vertical, spirally ornamented with threads and cords which 

 are altogether fi.ve on the penultimate whorl, one at the angle and 

 two both above and below tlie same, the two above being weaker 

 than the other three. On the body- whorl there is another strong 

 -cord at the periphery which makes it angulate. The spaces be- 

 tween the cords are longitudinally finely striated by incremental 

 lines. Base abruptly narrowed, rather flattened, with several spiral 

 -threads which gradually diminish in size toward the narrowly 

 perforate umbilicus. Aperture circular. Height and diameter 3.5 

 millim. 



