r> NAS6ID.5. 



Subgenus ADINUS, H. and A. Adams. Shell subulate, spirally striated ; 

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

 callosity at hind part ; outer lip grooved 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 plait ; outer lip dentated, internally 

 crenulated. Margin of operculum serrated or entire. Dentition, PI.'), 

 figs. 22 to 25.* 



The following "subgenera" mny be rel Mined as convenient. 

 UToup (lesio-untions, although the species, varying much in their 

 sculpture cauuot :i.hv:iys 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 \vith a 

 channel at the hind part continued up the spire. 



Subgenus ALECTRION, Montf. Spire elevated, whorls glabrous, polished 

 or papillary ; inner lip spreading ; outer lip denticulate, not var 

 externally, 



Subgenus ZEUXIS, II. 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 den 

 anteriorly.f 



Subgenus ACICULINA, H. and A. Adams. Shell turrited, polished, smooth 

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

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



Submenus 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. 



is. II. am! A. Adams in their " Genera of Recent Molli 

 made a Genus Amycla in Columbellidse, and included in it 

 :cs which are decidedly Nassids ; the dentition of one of tin 

 oiisly placed species, N. (Bucc.) cornicula, Olivi (PI. 3, fig. 24), has 

 ligured by Troschel as a type of thatof the genus Amycla, which h 

 lingly removed to Nassidae. 



f ^ASSODONTA, II. Adams. Shell oval; spire short, last whorl su! 

 anteriorly; aperture sinuated in front, canaliculate behind; cohimella 

 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 Zei/.ri*. 



