102 COLUMBELLIDyE. 



Sy/iojjsis of Genera. 



COLUMBELLA, Lam. Shell Strombitbrm, t'usitbini or obovate ; smooth 

 or longitudinally or transversely ribbed or striate ; inner lip excavated 

 in the middle, crenulated or denticulated in front ; outer lip usually 

 inflected, thickened within and crenulated in the middle, 



CoLUMBELLA (restricted). Shell Strombiform, with short spire. Den- 

 tition, PI. 2, flg. 18. 



NiTiDELLA, Swainson. Shell oval, smooth, with elevated spire ; 

 aperture somewhat eifuse below ; columella with two small anterior 

 plications ; outer lip somewhat thickened. 



Alia, H. and A. Adams. Shell thin, smooth, with moderate spire ; 

 aperture oval ; inner lip finely crenulated, outer lip thick, not callous 

 in the middle, striate within. 



MiTRELLA, Risso. Shell Mitriform, smooth, with moderate spire ; 

 columella smooth or with a few anterior rugosities ; outer lip smooth 

 or crenulated within. 



Atilia, H. and A. Adams. Shell fusiform, smooth or longitudinally 

 plicate ; spire elevated, sharp ; last whorl suddenly narrowed into a 

 beak or short canal in front. 



Anachis, H. and A. Adams. Shell oval-fusiform, longitudinally 

 ribbed, spire elevated ; last whorl not narrowed in front ; aperture 

 nari'ow ; collumella straight ; outer lip nearly straight, crenulated 

 within. Dentition, PI. 2, lig. 20. 



Seminella, Pease. Shell very small, fusiform, longitudinally costate, 

 usually decussated ; lip slightly emarginate above, Urate or denticulate 

 within . 



MiTROPSis, Pease. Shell fusiform, more or less costate or plicate 

 longitudinally ; aperture narrow ; lip dentate within, sinuated above ; 

 columella callous, plicate. 



Perhaps not distinct from Seminella. 



Conipea, Swainson. Shell oval, Mitriform, smooth, with moderately 

 elevated, convex spire ; inner lip reflected in front ; outer lip incurved 

 and thickened in the middle, and crenulated within. 



Meta, Reeve. Shell coniform, with short, conic s\V\ve ; aperture 

 narrow ; outer lip nearly straight, crenulated within. 



Strombina, Morch. Shell fusiform, turriculated ; spire elevated, 

 sharp ; whorls gibbous, nodulous ; inner lip with a rather thick callus ; 

 outer lip thick, sinuous behind ; anterior canal well fonned. Dentition, 

 PI. 2, fig. 19. 



iEsopus, Gould. Shell fusiform, gibbous, bi'oadly truncate in fi-ont ; 

 aperture lunate, with a posterior callus on the body ; columella smooth, 

 vitreous ; suture abnormally ai'cuate near the aperture. 



