CALYPTR^EA. 91 



CALLOSITY. A term used in general zoology to express those hard 

 horny tumidities formed in the skin of some animals, (such as 

 the Dromedary, for instance) in those parts which are most fre- 

 quently used. It is not used in this sense by Conchologists, who 

 apply it to those undefined tumidities or bumps which appear on 

 the inner surface and hinge of some bivalve shells, and to the 

 thickening over the umbilicus of Naticae. Glycimeris, fig. 67. 

 Natica, fig. 327, 328. 



CALPURNUS. Montf. Ovulum verrucosum, Auct. Distinguished 

 by the small circular tubercle at the back of each extremity 

 of the shell. Fig. 441. 



CALYPTRACEA. Lam. A family belonging to the first section of 

 the order Gasteropoda, Lam., the shells of which are described 

 as always external, covering the animal, and having no oper- 

 culum. The genera contained in this family may be thus distin- 

 guished. 



1. Calyptr^ea. Conical; apex central, septum spiral, cup- 



shaped, or forked; including Infundibulum. Fig. 234 to 238. 



2. Crepidula. Apex terminal ; septum flat, reaching h al 

 across the aperture. Fig, 239. 



3. Capulus. Conical ; apex obliquely curved, no septum. 



Fig. 240. 



4. Emarginula. Apex curved backwards ; a notch in the 

 anterior margin ; including Parmophorus. Fig. 241, 242. 



5. Cemoria. A slit near the apex. Fig. 244. 



6. Fissurella. A slit upon the apex. Fig. 245. 



7. Rimula. A slit near the margin. Fig. 243. 



8. Ancylus. Apex curved sidewise. Fig. 246. 

 CALYPTRACEA. Bl. The second family of the order Scutibran- 



chiata. Bl. thus described: "Shell more or less conical, not 

 spiral, or very slightly so ; aperture large and entire." The ge- 

 nera included in this family are Crepidula, Calyptrsea, Capulus, 

 Hipponyx, and Notrema. 

 CALYPTRiEA. Lam. Fain. Calyptracea, Lam. and BL— Bescr. 

 Conical, patelliform, irregular, with an internal, lateral, salient 

 plate or septum, varying in form.— 06s. The internal appendage 



