OF CONCnOLOGY. 23'7 



Length 20, diam. 8'5 mill. 



Humboldt Lake, Nevada. 



More attenuated than S. Haydcni, the last whorl less tumid, 

 Hnd the aperture more narrow. 



21. Succinea ovalis, Gould. 



Plate 3, figure 23. 



Ovate-conic, very thin, 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, Tryt^n. (Nov. sp.) 



Plate 2, figure 23. ' 



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. spec.) 



Plate 2, figure 24. 



Deprcssed-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 



