80 GENERA OF SHELLS. 



of its whole length : the last whorl being but little 

 larger than the preceding one, the shell has the form of 

 an elongated pyramid: surface generally striated or 

 tubercular and sometimes varicose. 



C. giganteum, palustre, sulcatum, telescopium, ebeninum, 

 nodulosum, vulgatum, obeliscus. granulatum, aluco, echina- 

 tum, erythra3onense, muricatum, radula, crassum, decolla- 

 tum, obtusum, semigranosum, asperurn, lineatum, vertagus, 

 fasciatum,subulatum, heteroclites,zonale, semiferrugineum, 

 torulosuin, tuberculatum, morus, ocellatum, litteratum, atra- 

 tum, eburneum, punctatum, lima, perversum, muscarurn, 

 septemstriatum, ferrugineum, dislocatum. 



PLEUROTOMA. Shell either turreted or fusi- 

 form ; terminated inferiorly by a straight canal 

 more or less elongated. Lip at its upper part 

 having a fissure or emargination. 



P. imperialis, auriculifera, muricata, echinata, flavidula, 

 interrupta, crenularis, cincta, unizonalis, lineata, spirata, 

 fascialis, birnarginata, buccinoides, cingulifera, virgo, baby- 

 lonia, undosa, marmorata, tigrina, crispa, albina, nodifera. 



TURBINELLA. Shell turbmated or subfusi- 

 form, channelled at base. Columella with three 

 to five compressed, transverse plaits. 



Distinguished from voluta by the canal at the base 

 of the aperture : from murex by having no varices, 

 and from fasciolaria by the direction of the folds on 

 the columella. 



T. scolymus, rapa, napus, pyrum, pugillaris, rhinoceros, 

 cornigera, ceramica, capitellum, mitis. globulus, leucozona- 

 lis, rustica, cingulifera, polygona, carinifera, infundibulum, 

 craticulata, lineata, nassatula, triserialis, variolaris, ocellata. 



