of mollusca. 77 



3. Pelicaria. 



Shell spiral ; spire of adult covered with an enamel coat ; aperture 

 ovate ; outer lip sinuous, sharp -edged. Operculum like Struthio- 

 laria ? 



1. P. vernis, t. 5. f. 3. t. 91. f. 6 ; Adams, Gen. Moll. t. 27. f. 6. 



4. Trichotropis. 



Shell top-shaped ; whorls keeled, edged with a horny fringe ; 

 mouth ovate, angulated in front ; outer lip simple, acute, angulated. 

 Operculum horny, ovate ; apex sometimes curved ; nucleus apical, 

 small. — Adams, Gen. Moll. f. 6 a, b. 



a. Spire conic ; whorls contiguous. 



1. T. bicarinata, Sowerby, t. 24. f. 7. 



Operculum of Trichotropis bicarinata ovate ; nucleus oblong, on 

 the outer side of the front edge. Mantle enclosed, with two slight 

 canals on the middle of the outer edge. Siphon not distinct, very 

 small, smaller than the canal on outer lips. Foot oblong, rather 

 truncated and double-edged in front. Tentacles subulate, blunt, 

 lateral. Eyes sessile, rather above the outer hinder part of their 

 base. Male organ small, behind base of right tentacle. Rostrum 

 broad, short, annular, with a terminal perpendicular mouth. Lin- 

 gual membrane short, broad, with broad lateral expansions. Teeth 

 3 ' 1 ' 3 ; central three-toothed, acute, denticulated (?) ; inner lateral 

 recurved at the tip, entire ; outer subulate, arched, simple. 



These teeth differ considerably from those of Tropiphora borealis 

 figured by Loven ; and that author described the animal as having a 

 long retractile proboscis, with the tentacles united by a membrane, 

 which is certainly not the case in this species. 



b. Spire very short ; whorls subseparate. Separatista. 



2. T. Blainvilliana, Petit, Journ. Conch, ii. 1852, t. 1. f. 5. 



5. Calcarella. 



Shell like a small Trichotropis bicarinata, but very thin, and the 

 outer lip angularly produced. 



1. C. spinosa, Soul. Journ. Conch. 1850, i. 217. t. 



6. SlNUSIGERA. 



Shell turbinate, ovate, dextral, imperforate ; whorls keeled ; nu- 

 cleus sinistral ; aperture ovate, corniculate in front ; outer lip with 

 two claw-like lobes ; the middle one a prolongation of the keel, the 

 other nearer the canal ; lips thickened, reflexed. Operculum thin. 



Gregarious ; floating on the sea. 



