TURBINELLA. 6*7 



The animal (of Vasum) is slow-moving, timid and inactive, 

 shrinking quickly within the shell on the slightest alarm. The 

 operculura is ovate, acute, with an apical nucleus; it is very 

 thick, claw-like, and partially free at the hind part. The denti- 

 tion resembles somewhat that of the Buccinidae, differing in the 

 lateral teeth: it differs widely from the Nassidse, and quite as 

 much from that of the Fasciolariinae or Peristerniinre. 



Synopsis of Genera. 



Genus TURBINELLA.. Lam. Thick, obconic, smooth, last whorl 

 large ; spire obtuse, apex: papillary ; aperture oblong, narrow ; canal long 

 and straight ; columella with several strong, transverse plaits in the 

 middle ; outer lip thin, simple. Animal unknown. 



Subgenus CABICELLA, Conrad. Columella-folds decreasing in size from 

 above, as in Mi-tra, base canaliculate and not emarginate. The above 

 characterization is somewhat vague, but the small group of fossils referred 

 to it may be said to resemble Turbinella in essential characters, the 

 difference being that the folds are situated lower down on the pillar, and 

 that the shell is thinner.* 

 C. PR^ETENUIS, Conrad. PI. 3, fig. 35. Eocene, Claiborne, Alabama. 



Genus VASUM, Bolten. Shell oval, oblong, solid, tubercular or 

 spinose, with spinose fascicles below ; spire short, apex not papillary ; 

 aperture oblong ; canal short, somewhat recurved ; columella with several 

 transverse folds in the middle ; outer lip thickened and sinuous. Denti- 

 tion, PI. 2, fig. 1, 



Genus TURBINELLA, Lain. 



I adopt Lamarck's generic name in preference to that of 

 Mazza, Klein, because the latter included several groups, and 

 was only limited to its present signification by Messrs. H. and 

 A. Adams, whilst the former author cites as his sole type a species 

 which possesses the distinctive characters now assigned to the 

 genus. The difference between the shells of Tarbinella and 

 Vasum is not such as to indicate any differential characters in 

 the animals (unfortunately that of Tarbinella is unknown) and 

 the separation of these genera is merely a matter of convenience 



* Conrad has formed a genus Mazzalina (uncharacterized), for a 

 Claiborne fossil, which seems to have suggested to him the recent genus 

 Mazza ( Tarbinella). The type is, I believe, more nearly related to 

 Lagena from which it does not appear to have any differential characters 

 I see vol. iii, p. 235 ). 



