172 MITRING. 



Avhorls simple ; aperture dilated ; inner lip with a produced, de-. 

 fined callus ; outer lip thin, smooth within, effuse anteriorly. 



bulimoides, Reeve. Schrceteri, Desk. 



picta. Reeve. 



Sub-gen. mutyca, H. and A. Adams. 



Shell subulate, thin ; spire much longer than the aperture, 

 whorls finely striated; aperture effuse anteriorly; outer lip thin, 

 simple. 



ancilloides, Sivains. bellula, A. Adams. 



Sub-gen. aidone, H. and A. Adams. 



Shell fusiform, smooth, polished ; spire acuminate, as long as 

 the aperture ; inner lip excavated, with two obtuse plaits in the 

 middle ; outer lip thin, simple. 



insignis, A. Adams. 



Genus VOLUTOMITRA, Gray. 



Shell ovate or fusiform, smooth, covered with an epi- 

 dermis, whorls simple ; columella with oblique plaits ; 

 outer lip thin, simple, arcuated. 



Ex. V. Groenlandica, Gray, pi. 19, fig. 2. 



Dr. Gray has examined the teeth of this genus, and 

 finds them to resemble those of Scaphella Turneri among 

 the Volutidaj, having a single conical apex and bifurcate 

 base. 



