NATURAL SCIENCES OF PHILADELPHIA. 243 



Lingual membrane ^ud jaw as usual iu the subgenus,' the latter 

 with over twelve ribs. 

 Helix germana, Gould. {Mesodon.) 



California, Mr. Henr}^ Hemphill. 



Jaw more resembling the t3'pe usual in the subgenus Stenotrema 

 than Mesodon, the ribs, eleven in number, being broad and crowded. 



Lingual membrane as usual in Helix. 



There are forms of H. germana closely connecting the species 

 with H. Columbiana, Lea. The jaw of the latter is described by 

 Dr. Cooper as strongly arched, with eight broad ribs. 



Helix griseola, Pfr. (Fruticicola.) 



Bosque Co., Texas. Mr. Hugo W. Ericsson. 



Jaw with about ten broad, crowded ribs, denticulating the cut- 

 ting margin ; upper margin with membranous attachment. The 

 jaw is somewhat of the type figured by Moquiu Taudon for that 

 of Helix hispida. (See our fig. 214, p. 159, 1. c.) 



Lingual membrane as usual in the genus Helix. The reflected 

 cusps of the teetli are short, stout. Marginals with blunt denti- 

 culations. 



Helix sequoicola, J. G. Cooper. (Arionta.) 



Jaw as usual in the subgenus.' Ribs from four to six. 

 Lingual membrane as usual in the subgenus. Central and 



lateral teeth with short, stout cusps. Marginals with two bluntly 



bifid denticles. 



Helix exarata, Pfr. (Arionta.) 



Santa Cruz, California, Mr. Henry Hemphill. 



Lingual membrane and jaw as usual in the subgenus,^ the latter 

 with six ribs. 



Helix Traski, Newcomb. {Arionta.) 



Los Angeles, California, Mr. Henry Hemphill. 



Lingual membrane and jaw as usual in the subgenus,- the latter 

 with eight ribs, five stout, three slight. 



' See note 1 to p. 242. 



2 In Arionta the jaw is strongly arched, ends blunt ; anterior surface with 

 a few, stout, distant ribs, projectius far beyond, and deeply scalloping 

 either margin. See our figure of that of H. redimita in Am. Journ. of 

 Couch. VI. pi. ix. fig. 11. For lingual dentition, see our fig. 284, p. 1G4, 

 of Land aud Fresh-water Shells of N. A., I. 



