GENERA OF SHELLS. 73 



N. glaucina, albumen, mamillarisj mamilla, melanostoma, 

 aurantia, conica, plumbea, ampullaria, canrena, cruentata, 

 millepunctata, vitellus. helvacea, collaria,monilifera, labrel- 

 la, rufa, unifasciata, lineata, fulminea, maculosa, vittata, 

 castanea, Marochierisis, arachnoidea, zebra, zonaria, Chinen- 

 sis, Javanica, cancellata, triseriata, duplicata, rugosa, heros, 

 pusilla. 



JANTHINEA. 



JANTHINA. Shell ventricose, conoid, thin, 

 pellucid. Aperture triangular : columella 

 straight, produced beyond the base of the lip : 

 lip having a sinus in the middle. No opercu- 

 lum. 



J. communis, exigua. 



MACROSTOMIANA. 



Shell ear shaped, aperture much dilated, the margins disu- 

 nited, no columella, no operculum. 



SIGARETUS. Shell subauriform, nearly or- 

 bicular, pillar lip short and spiral. Aperture 

 entire, much dilated, longer than broad, mar- 

 gins disconnected. 



S. haliotideus, concavus, laevigatus, cancellatus per- 

 spectivus, maculatus. 



STOMATELLA. Shell orbicular or oblong, 

 auriform, imperforate. Aperture entire, am- 

 ple, sublongitudinal ; lip effuse, dilated, gaping. 



Distinguished from stomatia by not having the trans- 

 verse rib of that shell, nor the right lip so much ele- 

 vated: and from haliotis, by wanting the foramina 

 which mark that genus. 



