[25] 



Length 20, diam. 8-5 mill. 



Humboldt Lake, Nevada. 



'Move attenuated than ^S'. Haydcni, the last whorl less tumid, 

 and the aperture more narrow. 



21. Succinea ovalis, Gould. 



Plate 3, figure 33. 



Ovate-conic, A^ery tliin, pellucid, shining, very minutely 

 striate, spire acute, suture slightly impressed ; whorls 3, the 

 last compressed and elongate; aperture produced, elongated, 

 broadly rounded below, more than three-fourths the total 

 length. Light yellowish horn color. 



Length 12, diam. 6 mill. 



New England to "Wisconsin and southwards to Maryland 

 and Kentucky. 



22. Succinea DeCampii, Tryon. (Nov. sp.) 



Plate 3, figure 33. 



Ovate-conic, rather thick for the genus, translucent, finely 

 striate, surface very much polished; spire short, acute, suture 

 moderate; whorls 3, very oblique, narrow, flattened; aperture 

 narrow ovate, columella slightly incurved. Yellowish ash 

 color, spire golden, edge of aperture black. 



Length 10, diam. 5 mill. 



Marshall, Michigan. W. H. DeCamp. 



Narrower, thicker and more polished than S. ovalis. It also 

 differs in color and size. ■ The black-edged peritreme is re- 

 markable, and is present in all the adult specimens I have 

 examined. 



23. Succinea Higginsi, Bland. (Nov. spect) 



Plate 3, figure 34. 



Depressed-oval, thin, pellucid, somewhat shining, pale horn 

 colored ; spire short, obtuse, suture deep ; whorls 3, convex, 

 the last rather depressed ; columella scarcely arched, above 

 conspicuously plicate; aperture angularly oval, frequently 



