04 BULLETIN OF THE 



to the elevations on the presutural band ; these are proportionally stronger and 

 more prominent near the apex, and become obsolete on the last part of the 

 last whorl; suture distinct; whorls moderately full; base subconic, slightly 

 constricted for the short canal ; incremental lines distinct, stronger on the last 

 whorl ; fasciole somewhat excavated, smooth except for the curved incremental 

 lines ; surface of the shell rather vitreous ; aperture of the (not adult) shell 

 rather wide ; anal notch wide, rather shallow ; outer lip arched ; canal hardly 

 differentiated, short, narrow; pillar straight, anteriorly attenuated. Max. Ion. 

 of shell, 9.5 ; of last whorl, 5.2 ; of aperture (not quite adult), 3.5 ; max. lat. 

 of shell, 3.5 mm. 



Habitat. Gulf of Mexico, at Station 100, off Morro Light, in 400 fms. 



This, after thorough study, seems distinct from any descril)ed form, and, 

 though not adult, is without doubt a Drillia. Specimens on which the trans- 

 verse sculpture is exceptionally strong have a somewhat different aspect, and 

 are rougher than the one figured. The sculpture is sharp, and the angle of the 

 bent ridges is peculiarly abrupt. The surface is not shagreened, though the 

 aspect of the shell recalls that of some of the shagreened Mangilias. 



C. Shells smooth, vitreous, 

 Drillia oleacina Dall. 



Plate XI. Fig. 8. 

 Pleurotoma {Drillia) oleacina Dall, Bull. M. C. Z , IX. p. 66, August, 1881. 



Habitat. Gulf of Mexico, at Station 21, in 287 fms., and off Morro Light, 

 Havana, in 292 fms. Antilles, Station 261, near Grenada, in 340 fms. 



The most perfect specimens of this form under magnification show fine 

 spiral incised lines over the last whorl, but to the naked eye the vitreous glis- 

 tening surface appears perfectly polished. It is possible that these species 

 would belong to the group of Spirotropis, to which similar shells have been 

 referred, but it is hardly worth while to put them there until the dentition is 

 known. 



Drillia smirna Dall. 



Plate XI. Fig. 7. 



Pleurotoma {Drillia) smirna Dall, Bull. M. C. Z., IX. p. 66, August, 1881. 



Habitat. Gulf of Mexico, off Cape San Antonio, 413 fms., and Station 100, 

 off Morro Light, Havana, in 400 fms. Also at U. S. Fish Commission Station 

 2150, near Old Providence, W. I., in 382 fms., ooze, temperature 46°.0 F. 



With the exception of the type, the specimens found so far are all quite 

 young. 



