136 VITRINID^E. 



tion. Lingual membrane with tricuspid centrals and laterals, 

 and aculeate bifid marginal teeth. 



Subgenus TENNENTIA, Humbert, 1862. 



Shell internal, at the posterior part of the mantle, shining and 

 a little convex above, flattened below, the apex posterior and 

 recurved to the right and base. 



Mantle free in front. 



Genus UROCYCLUS, Gray, 1864. 



Animal limaciform, elongated; tail tapering, carinated above, 

 with mucous pore without horn-shaped process ; mantle granular, 

 anterior, with a narrow anterior perforation ; locomotive disk 

 longitudinally tripartite ; respiratory and anal orifices on the 

 right slightly anterior margin of the mantle ; orifice of com- 

 bined generative organs behind and below right eye-peduncle. 

 Jaw smooth, with or without median projection. Lingual mem- 

 brane with tricuspid centrals, bicuspid laterals, aculeate and bifid 

 marginals. 



Shell-plate internal, flattened, oval, very thin, a little convex, 

 not spiral. Africa. 



Differs from Parmarion in the anterior position of the respira- 

 tory orifice, and the want of a caudal horn-shaped process. 

 Dendrolimax and Elisa, Heynemann, are synonyms. 



Genus PARMARION, Fischer, 1856. 



Mantle adhering to the body by a small portion of its margin, 

 with a large free anterior lobe enveloping the sides, and behind 

 nearly the whole, of the shell, leaving a dorsal opening through 

 which is seen the shell. Sole tripartite ; foot truncate behind, 

 with a mucous pore. Visceral mass convex behind and well 

 separated from the foot. Marginal teeth bicuspidate. 



Shell internal, calcareous, thin, oval, slightly convex, covered 

 by a smooth epidermis which extends beyond the margin on the 

 sides and posteriorly, enveloping the visceral mass. 



Girasia, Gray, was described a little earlier, but was not well 

 defined, and contained a mixture of other genera, Parmacella 

 and Urocyclus. The true Parmarion is Asiatic. 



