MUSEUM OF COMPARATIVE ZOOLOGY. 87 



maries are strongly marked and slightly swollen on the summits of the ribs ; 

 the secondary spirals, very faint or absent behind the periphery but present in 

 the interspaces in front of it, are finer tlian in tlie last species, and more nu- 

 merous; the fasciole is wide, nearly smooth, undulated, and little excavated; 

 the aperture is narrow and long, the notch shallow, the interior not lirate, the 

 inner lip simple with a thin callus, the canal wide, straight, rather long; the 

 ribs are seven on the penultimate whorl, narrower and less prominent, as is 

 the varix, than in the last species. Lon. of shell, 19.5 ; of last whorl, 11.0 ; of 

 aperture, 8.0 ; max. hit. of shell, 5.5 mm. 



Habitat. Gulf of Mexico, at Station 36, in 84 fms. 



This shell is more slender, the primary spirals stronger, the other sculpture 

 weaker, than in D. eucosmia. The color is also different. In the variety canna 

 the last whorl is stouter in proportion to the spire than in this species. 



Drillia acestra n. s. 



Plate X. fisr. 7. 



Shell long, slender, pale olive-color with a translucent white tip, nine- 

 whorled, with a smooth vitreous rounded two-whorled nucleus ; fasciole wide, 

 steep, excavated, marked with close-set fine even spirals ; it is bounded be- 

 hind by a sharply cut elevated thread, a little space in front of the suture ; 

 the whorl in front of the fasciole is covered with close-set, strong, subequal, 

 flattish spirals, with narrow channelled interspaces ; these spirals, from two on 

 the four apical whorls, increase to seven on the penultimate whorl, and eleven 

 (behind those on the canal) on the last whorl ; here they are a little more 

 widely separated, and have one or two intercalary fine threads in the inter- 

 spaces ; on the canal there are six primary threads alternating with somewhat 

 smaller secondary ones ; transverse sculpture of gently elevated ribs (eight on 

 the penultimate whorl), which vary in different specimens as to elevation and 

 strength ; in the type specimen figured they begin at the fasciole and fade on 

 the base ; the varix is strong and protrudes, there is a touch of livid color in 

 front of it, which is seen nowhere else on the shell ; aperture whitish, throat 

 slightly livid, not lirate ; notch deep and strong, outer lip thin, contracted for 

 the canal; inner lip with a thin elevated callus, pillar straight, canal rather 

 short, recurved. Max. lon. of shell, 19.0 ; of last whorl, 9.8 ; of aperture, 7.0 ; 

 max. lat. of shell, 5.5 mm. 



Habitat. Station 101, off Havana, in 400 fms. Variety (?), Station 248, 

 near Grenada, in 161 fms. 



The specimen I have referred to as a variety may be distinct ; it has twelve 

 ribs, a narrower and less marked fasciole, and the spiral sculpture is much less 

 elevated and sharp. But the general aspect is so similar that I dare not sepa- 

 rate them without a larger series of specimens. 



