132 MANUAL OF NATURAL HISTORY. 



30. FAMILY. HoAr-Keels (Trichotropidse). Teeth 



in seven rows ; tongue short and broad ; eyes 

 on lower halves of tentacles ; mantle with a 

 rudimentary siphon; operculum ovate, annu- 

 lar ; shell spiral ; aperture nearly simple in 

 front ; columella without plaits. 



31. FAMILY. Coral-Parasites (Pediculariidse). Eyes 



on outer bases of tentacles ; mantle enclosed, 

 simple in front ; operculum none ; shell non- 

 spiral ; apex lateral ; aperture very wide ; 

 columella simple ; outer lip thin. 



32. FAMILY. Egg-Shells (Amphiperatidse). Lateral 



teeth pectinate ; mantle lobes expanded, co- 

 vering the sides, of the shell, bearded exter- 

 nally ; operculum none ; shell porcellanous, 

 smooth; outer lip with the edge inflexed. 

 (Ovulum, Lamck.) 



33. FAMILY. Cowries (Cyprseidse). Outer lateral 



teeth conical; eyes sessile on outer bases of 

 tentacles ; mantle-lobes expanded, covering 

 the shell ; operculum none ; shell involute, 

 the last whorl enrolling and concealing all 

 the others ; spire none ; columella toothed. 



34. FAMILY. Carriers (Onustidse). Eyes sessile on 



outer bases of tentacles ; mantle simple in 

 front ; foot compressed, formed for jumping 

 not walking ; operculum horny, sub-annular ; 

 shell trochiform ; whorls more or less covered 

 with fragments of shells, &c. (Phoridce, Gray; 

 Xenophoracea, Phil.) 



35. FAMILY. Chambered-Shells (Calyptridse). Eyes 



