MONODONTA. 417 



spadiceus, Phil. turgidulus, Brocc. 



stigmatarius. A. Adams. imedo, A. Adams. 



sulcarius, A. Adams. variegatus, A. Adams. 



textillosus, A. Adams. zebrides, A. Adams. 

 turbinoides, A. Adams. 



Genus CRASPEDOTUS, Philippi. 



Shell nearly conoidal, axis imperforate, whorls cancel- 

 lated, convex ; columella twisted, forming a false umbi- 

 licus, and with a strong tooth narrowing the aperture ; 

 outer lip internally sulcate, externally with a conspicuous, 

 marginal varix. 



Sy?i. Olivia, Cantraine, not Bertoloni. Otavia, Gray, 

 not Risso. 



Ex. C. Otavianus, Cantraine, pi. 47, fig. 4. 



The name used by Cantraine was employed previously 

 by Bertoloni for a genus of Sponges. A single recent 

 species of Craspedotus only is known, offering the striking 

 peculiarity, in this family, of a variced outer lip. 



Genus MONODONTA, Lamarck. 



Shell conoidal, imperforate, whorls granular or trans- 

 versely sulcate, the last rounded; aperture oval; co- 

 lumella with teeth and a concave pit ; outer hp internally 

 triple, the outer belt porcellanous, the middle perlaceous, 

 the inner with an elevated, porcellanous border. 



Sy7i. Labio, Oken, not Gray. Monodontes, Montf. 

 Odontis, Sow. Trochidon, Swains. Monodon, Schiceigg. 

 Unidens, Schinz. 



Ex. M. canalifera, Lamarck, pi. 47, fig. 5. Shell, 

 M. labio, LimKBiis, fig. 5, a. 



VOL. I. 3 H 



