1917.] NATURAL SCIENCES OF PHILADELPHIA. 155 



whorls of the spire with about nine slightly protr active axial ribs, 

 which do not cross the concave anal fasciole. There are numerous, 

 acute, spiral threads alternating with smaller ones. On the penult 

 whorl there are seven of the larger threads below and two or three 

 above the anal fasciole. Between the alternating threads are still 

 finer spiral striae. On the last whorl, where the axial ribs become 

 irregular, partly obsolete, the spiral sculpture remains the same; 

 there being about 28 larger spirals below the shoulder. The anal 

 fasciole is minutely striate spirally. 



Length 51.4, diam. 13.5 mm. 



Length 53.4, diam. 13.5 mm., length of aperture 25.5 mm.; 11 

 postnepionic whorls. 



Type No. 2904. 



This differs from D. henekeni by the more slender shape, with much 

 lower ribs, which become weak and irregular on the last whorl.' The 

 inter-liral spaces are densely, finely striate, while in D. henekeni they 

 are smooth. 



In many specimens the spirals do not alternate in size as described 

 above, the intervals having fine, unequal or subequal spiral striae. 



Drillia soala n. sp. 



The shell is fusiform, whorls strongly convex, concave just below 

 the suture. Penult whorl with sixteen acute axial ribs, nearly 

 vertical except for a short backward curvature below the suture, 

 where the ribs diminish abruptly in size. In the intervals there are 

 fine, rounded, spiral threads, scarcely as wide as their interstices; 

 between them much more minute growth-lines may be seen. There 

 is a strong, latero-dorsal varix. The aperture is somewhat broken. 



Length 45.5, diam. 17 mm. 



This species resembles D. squamosa in form but the acute not 

 nodose longitudinal ribs, the regular revolving sculpture at once 

 separate it from that species. On the other hand it is related to 

 D. venusta but is at once distinguished by its long anterior canal, 

 fewer longitudinal ribs and more numerous spirals. The fine lines 

 of growth between the spiral lines are wanting in D. venusta. 



Type and a broken specimen are No. 2932. 



Drillia hexapleura n. sp. 



A small species with nearly straight sided spire upon which the 

 limits of the whorls are difficult to make out. Sculpture of 6 very 

 broad, low, rounded axial ribs, continuous from whorl to whorl. 

 These are crossed by strong spiral cords, which are a little narrower 



