fi 



NASSTD.E. 



Subgenus Adinup, H. and A. Adams. Shell subulate, spirally striatod , 

 columella abruptly truncated at base ; inner lip corrugated, witb a 

 callosity at hind part ; outer lip groovecl internally, externally margin- 

 ated . 



NASSA, Lam. Shell ovate, ventricose, body whorl variously sculptured ; 

 aperture ovate, with a short, reflected, truncated, anterior canal ; 

 inner lip smooth, often widely spread over with enamel, with a posterior 

 callosity or blunt dentiform i>lait ; outer lip dentated, internally 

 crenulated. Margin of operculum serrated or entire. Dentition, PI. 3, 

 figs. 22 to 25.* 



The Ibllowinoj "subgenera" may be rctahuvl as convenient 

 group (lesignations, although the s])ecies, varying niueh in their 

 sculjjture cannot always be positively assigned. 



Subgenus Arcularia, Link. Body whorl gibbous on the back; spire 

 produced; callus of inner lip greatly extended and covering the spire. 



Subgenus Naytia, H. and A. Adams. Shell smooth ; aperture with a 

 channel at the hind part continued up the spire. 



Subgenus* A LECTRION, Montf. Spire elevated, whorls glabrous, poli.shcd 

 or papillary ; iimer lip spreading ; outer lip denticulate, not variccd 

 externally. 



Subgenus Zkuxis, H. and A. Adams. Spire elevated, smooth, or longi- 

 tudinally plicate, polished ; inner lip with the callus defined, or some- 

 what spreading ; outer lip externally variced, sometimes dentate 

 anteriorly.f 



Subgenus Acicdijna, 1L and A. Adams. Shell turrited, polished, snuxHh 

 or longitudinally plicate : inner lip with the callus sharp, straight, 

 defined ; outer lip produced in the middle, variced externally. 



Subgenus Phrontis, H. and A. Adams. Spire elevated, acuminate, 

 whorls ribbed or nodulose, distinctly shouldered ; inner lip smooth, with 

 an extended, thickened callus, outer lip with an external varix. 



■ Messrs. IL and A. Adams in their "Genera of Recent Mollusca," 

 have made a Genus Aniycla in Columbellidae, and included in it some 

 species which are decidedly Nassids ; the dentition of one of theso errone- 

 ously jilaced species, N. (Bucc.) cornicula, Olivi (PI. 8, fig. 24), has been 

 figured by Troschel as a type of that of the genus Amycla, —which he has 

 accordingly removed to Nassidse. 



t Nassodonta, H. Adams. Shell oval ; spire short, last whorl sulcate 

 anteriorly ; aperture sinuated in front, canaliculate behind ; columella 

 callous, plicate anteriorly ; lip acute, thickened and dentate within, with 

 an anterior marginal denticulation. Operculum and animal unknown. I 

 have included the .single species in Zeiixis. 



