58 BULLETIN OF THE 



in two directions ; remainder waxy white, with the peculiar waxy lustre of 

 abyssal shells ; form rather short-fusiform, spire subturreted by the concave 

 aute-sutural baud ; spiral sculpture of about twenty-tour flattened threads, with 

 wider interspaces, before the band on the last whorl ; only two or three of these 

 threads visible on the upper whorls ; they pass over all the transverse ridges 

 and are a little stronger over them. Next the suture are small, short, appressed 

 plications, with a tendency to pair, and even to unite above, thus becoming 

 staple-shaped ; the ante-sutural band is excavated, smooth except for the termi- 

 nations of the plicae, which cease near its posterior border ; near the anterior 

 border the spiral threads begin, crossing sharply-projecting short oblique pli- 

 cations (thirteen on the last whorl) which disappear half-way from the pe- 

 riphery to the anterior end of the canal, and are somewhat angulated just in 

 advance of the ante-sutural band ; notch broad and deep ; outer lip thin, pro- 

 jecting ; pillar short, thin, twisted ; canal short, broad. Lon. 8.5 ; of last 

 whorl, 5.75 ; of aperture, 4.5. Max. lat. 4.5 mm. 



Yucatan Strait, 640 fms. 



There is some variation in form and sculpture of this species ; the above is 

 from a perfect specimen of average characters. I suspect it to be a Bcla ; the 

 form of the notch, however, more nearly resembles what is usually understood 

 by Mangilia. It has no resemblance to any of the Northern forms._ 



P. (Mangilia) comatotropis n. s. 



Shell white, porcellanous, eight-whorled ; first three whorls with ten to 

 eighteen distinct deeply fiexuous transverse riblets and a narrow longitudinal 

 belt near the suture ; succeeding rather abruptly to this the sculpture of the 

 remaining whorls consists of (on the earlier ones) two or three, or (on the last 

 whorl) up to eleven sharp revolving ridges, the one next before the suture 

 being the most prominent ; these are crossed by delicate distinct raised lines 

 following the lines of growth (on the last whorl about twelve to one milli- 

 meter) which are most evident in the interspaces ; suture appressed from 

 above and below, forming a grooved, slightly projecting riblet ; notch not 

 deep, less than semicircular ; aperture rather narrow and short ; pillar smooth, 

 entirely free from callus ; margins simple, not thickened. Lon. of shell, 6.0 ; 

 of last whorl, 3.75 ; of aperture, 2.5. Lat. of last whorl, 2.5 ; of aperture, 1.0 

 mm. Deft, about 27°. 



Cape San Antonio. 640 fms. 



This somewhat recalls the comparatively gigantic Pleurotoma oxytropit Shy. 

 and Drillia Kennicottii Dall, but is clearly not the young of any described 

 tee. 



P. (Mangilia) lissotropis n. s. 



Shell small, Blender, Bomewhal bluntly tipped, with six whorls, shining with 

 the lustre of paramne ; nucleus rather large, bullate, Bmooth, translucent, 

 shining; remaining whorls with trail at, should) on the last 



