MUSEUM OF COMPARATIVE ZOOLOGY. 93 



It would seem, from the figure of Mr. Watson's imperfect type specimen, as 

 if it must approach very closely to one of the varieties probably of D. nucleata, 

 or possibly of D. Dalli. 



There are, however, in the Fish Commission dredgings, half a dozen ex- 

 tremely puzzling forms of this general character, which further study and 

 material are needed to elucidate. 



Drillia Verrillii Dall. 



Plate XI. Fie. 3. 



Pleurotoma (Drillia) Verrillii Dall, Bull. M. C. Z., IX. p. 68, August, 1881. 



Habitat. Station 19, 310 fms.; Station 20, in 220 fms. ; both in the Gulf 

 of Mexico. 



This small, but very elegant species, is referred to under the head of D. lis- 

 sotropis, to which it is related. It differs in its smaller size, shorter whorls, 

 absence of fine spiral striae, and in the short stout ribs, swollen and angulated 

 at the periphery. 



Drillia havanensis Dall. 



Plate XI. Fig. 5. 



Pleurotoma [Drillia) havanensis Dall, Bull. M. C. Z., IX. p. 67, August, 1881. 



Habitat. Station 16, 262 fms. ; Station 19, 310 fms. ; Sigsbee, off Havana, 

 450 fms. ; Yucatan Strait, 640 fms. 



No more specimens of this species have been found in the collection. Clio- 

 nella aglaophanes Watson should be compared with it. 



Drillia premorra n. s. 



Plate XI. Fig. 18. 



Shell waxen white, with a vitreous white smooth rounded nucleus of nearly 

 two whorls and eight subsequent sculptured whorls. Spiral sculpture of an 

 undulated more or less nodulous narrow band in front of the suture, separated 

 by the fasciole from an angulation, which in the upper whorls is peripheral, 

 and on the last whorl forms a well marked shoulder ; in front of this on the 

 upper whorls are one to three, and on the last whorl between the angle and 

 the anterior end of the canal about a dozen, small sharply elevated threads 

 with much wider interspaces, threads which are, where they intersect the trans- 

 verse ridges, modified by small sharp noduktions. Transverse sculpture of 

 (on the last whorl 14 to 18) sharp-edged low narrow oblique strongly bent 

 ridges rather than ribs, evanescent on the base and fasciole, but corresponding 



