GENERA OF SHELLS. 63 



known by the projection of the penultimate whorl into 

 the aperture. 



H. vesicalis, gigantea, polyzonalis, monozonalis, pulla, 

 lineolata, mutata, pomatia, aspersa, vermiculata, Alonensis, 

 versicolor, naticoides, picta, galactites, hremastoma, mela- 

 notragus, extensa. lucana, globulus, melanostoma, cselatura, 

 microstoma, maculosa, Richardi, Bonplandii, planulata, 

 labrella, ungulina, pellis-serpentis, Senegalensis, unidentata, 

 cepa, heteroclites, discolor, lactea, zonaria, guttata, Mada- 

 gascarensis, Javanica, Peruviana, simplex, cidaris, citrina, 

 algira, verticillus, olivetorum, plariospira, Barbadensis, sinu- 

 ata, hippocastanum, bidentalis, argilacea, -vittata, alauda, 

 arbustorum, candidissima, nernoralis, hortensis, sylvatica, 

 Pisana, splendida, serpentina, Niciensis, variabilis, fruticum, 

 neglecta, cespiturn, ericetorum, intersecta, carthusianella, 

 carthusiana, diaphana, concolor, velutina, obvoluta, Cook- 

 iana, pileus, papilla, punctifera, plicatula, planorbella, sea- 

 bra, cariosa, crenulata, planorbula, macularia, maritima, stri- 

 gata, muralis, rugosa, cornea, linguifera, incarnata, cinctella, 

 cellaria, nitida, plebeium, personata, hispida, rotundata, api- 

 cina, striata, conspurcata, conica, conoidea, pulehella, albo- 

 labris, hirsuta, perspectiva, lineata, thyroidus, minuta, laby- 

 rinthica, multilineata, appressa, palliata, inflecta, clausa, 

 obstricta, elevata, interna, chersina, gularis, ligera, solitaria, 

 jejuna, concava, dealbata, profunda, alternata, irrorata, inor- 

 nata, indentata, fallax, egena, tridentata, monodon. 



CAROCOLLA. Shell orbicular, more or less 

 conoid or convex above, outline sharp and an- 

 gular, or keeled ; aperture broader than long, 

 contiguous to the axis ; lip subangular, often 

 dentated or plaited beneath. 



The sharp edge of the last whorl, their being always 

 orbicular, and sometimes considerably depressed, are 

 the characteristics of this genus. 



