TO 188^ 1 '] PROCEEDINGS OF THE NATIONAL MUSEUM 303 



This fine species borders on the subgenus Leucosyrinx, but has the 

 operculum, solid habit, and strong sculpture of Pleuro t oma as restricted. 



Subgenus GENOTA H. & A. Adams. 

 Section DOLICHOTOMA Bellardi. 



Genota Carpenteriana (Gabb). 



rieurotoma (Surcula) Carpenteriana Gabb., Proc. Cal. Acad. Sci., in, p. 183, 1865. 



Hab.— Monterey, Gabb. Santa Barbara Islands, Cooper; XL S. Fish 

 Commission Station 2838, in 44 fathoms, mud, off Cerros Island, Lower 

 California. 



This interesting species, of which but few specimens are known, be- 

 longs to the section Dolichotoma, of which the type is the fossil Pleu- 

 rotoma catapkracta of Brocchi. This form has a rather thick, stout, 

 blackish operculum, recalling that of Conns, but of which the apical 

 point is frequently broken or worn away. The scar on the inner side 

 of the operculum is concentric and strong, but covers only the wider 

 part of the appendage. This section of the Pleurotomidce is frequently 

 furnished with obscure thickened ridges on the pillar; they can be found 

 in most specimens by cutting into the apical whorls even if the shell 

 has no indication of ridges at the aperture. 



The foot of this species is narrow, double-edged, and truncate in front, 

 not auriculate, moderately pointed behind ; the sides of the foot and 

 surface of the body are irregularly dotted with small, and larger, round 

 pustular elevations. The animal has a purpuriferous gland, and in the 

 case before me, in dying, the fluid expelled from this gland appears to 

 have dyed the whole body of the animal deep purple, which, under the 

 action of the alcohol and time, has become largely brownish. The 

 tentacles are wide and small, with a small, well defined eye on the outer 

 angle. The verge is small, subcylindrical, except near the tip, which 

 is (naturally or otherwise) somewhat flattened, clavate, and decidedly 

 phalliform, terminating in a large subconic smooth papilla with a thick- 

 ened girdle at its base. The gills and osphradium as usual. The pro- 

 boscis is short, much attenuated anteriorly. There is a large poison 

 gland situated as in Bela, and the individual teeth are much like those 

 of Bela; for instance, those of B. Gonldii as figured by Verrill (Trans. 

 Conn. Acad., v, PI. lvii, Fig. 6a), but with the base of insertion less 

 deeply notched than in that species, and with a slight angulation, not 

 a -barb, near the point. 



Genus DRILLIA Gray. 

 Drillia Harfordiana Reeve. 



This species, which reaches at least as far north as Vera Cruz, Mex- 

 ico, was collected at the Abrolhos Islands, near Porto Allegre, Brazil. 



