66 BOOK OF SPECIES. 



and girded with a white line at its sutures. W. 

 29.56. 



ROTELLA. 



Orbicular, shining, devoid of epidermis ; spire ex- 

 tremely shorty sub-conoid ; lower face of the shell 

 convex, and callous ; mouth half-rounded. 



R. LiNEOLATA. Couical - couvex, smooth^ 

 with a gibbous callosity on the base^ and the aper- 

 ture somewhat heart-shaped; varying in colour, 

 and markings often obliquely rayed. Sow. 357. 



TROCHUS. 



Conical, spire elevated, sometimes abbreviated; 

 aperture transversely depressed; margin of 

 outer lip disunited from the body at the upper 

 part ; columella arcuated, more or less oblique 

 at the base ; operculum horny. 



S. AGGLUTiNANS. Couical, sub-umbilicatcd, 

 coarse, obtusely plaited, semi-pellucid^ dirty white, 

 and the whorls tiled ; base concave, and the pillar- 

 lip sickle-shaped. Attaches to itself stones, &c. 

 Diam. li. W. 29. 69. 



T. CCELATUS. Sub -conical, with oblique 

 somewhat scaly plaits on the upper part, and 

 transverse spinous ribs at the base of the whorls, 

 green or greenish white ', base covered with con- 

 centric rows of small umbricated scales ; pillar 



