24 TORINIA — OMALAXIS. 



Subgenus Episcynta, Mcirch, 1815. 

 T. inornata, (I'Orb. PL 6, figs. 32, 33. 



Shell convex ; whorls 5, smooth, glassy white, shining, roundly 

 carinate at the periphery ; base convex ; umbilicus moderate, 



smooth ; aperture oval. Diam. 3 mill, 



St. Thomas^ West Indies. 



The smoothness of the shell, its glassy appearance, its minute- 

 ness and the simple umbilicus are perphaps enough to rule this 

 subgenus out of the family. 



Genus OMALAXIS, Desh., 1830. 

 0. Pernambucensis, Watson. PI. G, figs. 35, 36. . 



Shell discoidal ; whorls about four, contiguous, except the last 

 which is slightly dissolute, convex, obsoletely spirall}' threaded, 

 longitudinall}^ ribbed ; color white, glassy or porcellanous ; 

 umbilicus very wide, exposing all the whorls ; aperture oval, lip 

 not in contact with the whorl above. Diam. 2"5 mill. 



Fernamhuco. 

 0. NOBiLis, Verrill. PI. 6, fig. 31. 



Shell planorbiform, upper surface nearly flat, base very con- 

 cave ; whorls 5, nearly quadrangular, the two peripheral angles 

 strongly granosely carinate, peripheral area spirally ribbed, sur- 

 face of the shell with radiating, elevated growth-lines ; color 

 pale chestnut, irregularly and indistinctly banded with whitish 

 chestnut; base spiralh" striated ; aperture trapezoidal with the 

 outer corners angular and the inner corners rounded. Opercu- 

 lum thin, horny, multispiral, slightly concave. Diam. 11 mill. 



• Chesajjeake Bay. 



Uvfigured Species. 

 0. LiRATA, Yerrill. Newport, R. I. 



