156 PROCEEDINGS OF THE ACADEMY OF [April, 



in the intervals. Each whorl of the spire has two of these cords 

 below and one above the concave anal fasciole, in which a few weak 

 spiral striae may be seen. On the last whorl there are 11 spirals 

 below the fasciole, the intervals somewhat distinctly marked with 

 growth-striae. There is a stout varix behind the outer lip. The 

 aperture is rather narrow. 



Length 8, diam. 3.5 mm.; about 6 whorls remaining. 



The small number of spiral cords and very wide axial ribs dis- 

 tinguish this species. It is closely related to the Pliocene D. acucincta 

 Dall, 1890, a very much larger species. The strong varix behind 

 the lip of D. hexapleura shows that it is adult. 



Drillia mimula n. sp. 



The shell closely resembles D. parkeri in ribbing, except that the 

 ribs do not extend so far down on the last whorl. The whorls and 

 the whole shell are shorter, the last much more abruptly contracted 

 below. The smooth embryonic shell has only 1| bulbous whorls, 

 the ribs beginning strongly in the middle of the second whorl. There 

 is a microscopic sculpture of crowded spiral striae. Aperture broken. 



Length 16.5 mm. (broken anteriorly), diam. 5.8 mm.; nearly 10 

 whorls. 



Type No. 2925. 



Drillia esculenta n. sp. 



The shell is fusiform, of 10 whorls, the first 2§ forming the 

 embryonic shell are smooth and convex. Subsequent whorls are 

 concave in the upper third, then convex, with sculpture of rounded, 

 slightly protractive axial ribs, which become lower and arched back- 

 ward as they cross the concave zone. There are 15 ribs on the penult 

 whorl; last whorl having a stout dorsal varix. A few ripples along 

 growth-lines may be seen, more obliquely protr&,ctive than the ribs. 

 In the intervals and more weakly over the ribs there are crowded, 

 very fine spiral threads. The aperture is broken, but the inner lip 

 is continuous, rather heavy, and built forward. 



Length 13.3, diam. 5 mm. 



Three specimens are in the lot, the figured type having been bored 

 by a predaceous gastropod. The minute sculpture differentiates 

 it from other species of the same horizon. 



Type No. 2922. 



Drillia orthopleura n. sp. 



The shell is slender, fusiform, with sculpture of strong longitudinal 

 ribs, continuous from whorl to whorl, and smooth except for fine 



