CALYPTB^A. 93 



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

 frequently 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 Natidse. Grlycime- 

 ris, fig. 97 ; Natica, fig. 327, 328. 



CALPUENUS. Montf. 1810. Otiti-tjm verrucomm, Auct. Dis- 

 tinguished by the small circular tubercle at the back of each 

 extremity of the shell. PI. xx. fig. 441. 



CALTPTEACEA. 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 opercu- 

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

 guished : 



1. CALTPTBiEA. Conical ; apex central, septum spiral, cup- 



shaped, or forked; mchiding Infundibulum, fig. 234 to 238. 



2. Ceepidula. Apex terminal ; septum flat, reaching half 



way across the aperture. Pig. 239. 



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



Pig 240. 



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



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



5. Cemoeia. a slit near the apex. Pig. 244. 



6. PissuEELLA. A slit upon the apex. Pig. 245. 



7. EiMULA. A slit near the margin. Pig. 243. 



8. Akcylus. Apex curved sidewise. Pig. 246. 

 CALTPTEACEA. 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 

 genera included in this family are Crepidula, Calyptrsea, Capu- 

 lus, Hipponyx, and Notrema. 

 CALTPTE^A. Lamarck. Fam. Calyptracea. Lam. and Bl. — 

 Bescr. Conical, patelliform, irregular, with an internal, lateral, 

 salient plate or septum, varying in form. — Obs. The species of 

 this genus or family are divided very properly in the British 

 Museum Synopsis according to the character of the septum, 

 reserving the name Calyptrsea (or Calyptra) for species with a 



