250 PROCEEDINGS OF THE ACADEMY OP 



Helix fidelis, Gray. {Aglnja.) Am. Journ. Conch., VI. 207, pi. ix. 



fig. 1, 9. 



Jaw said to be ribless, but a better specimen found normal, Proc. Pliila. 

 Ac. N. Sc, 1872, 136. 



Helix redimita, W. G. Binn. (Arionta.) Am. Journ. Conch., VI. 

 206, pi. ix. fig. 11. 



Helix tudiculata, Binney. (^Arionta.) Am. Journ. Concli., VI. 208, 

 pi. ix. fig. 7. 



Helix Townsendiana, Lea. (Arionta.) Am. Journ. Conch., VI. 206. 

 Helix reticulata, Pfr. (Arionta.) Am. Journ. Conch., VII. 177. 

 Helix Nickliniana, Pfr. {Arionta.) Am. Journ. Couch., VII. 177. 

 Helix Tryorri, Newc. (Euparyplia) jaw, W. G. B. Am. Journ. 

 Conch., I. 93, pi. vi. fig. 2-10. 

 Showing variation in number of ribs. 



Helix Gossei, Ad. {Coryda.) Am. Journ. Conch, VII. 177. Lingual 

 membrane only. 



Helix aspera, Fer. (Thelidomus.) Am. Journ. Conch., VI. 204. 



Helix notabilis, Shuttl. (Thelidomus.) Am. Journ. Conch., VII. 177. 

 Lingual membrane only. 



Helix pemphigodes, Pfr. (Cysticopsis.) Am. Journ. Conch., VII. 177. 

 Lingual mcrahraue only. 



Helix tumida, Pfr. (Cysticopsis.) Ann. Lye. N. H. of N. Y., IX. 283, 

 fig. 3, lingual. 



Jaw, ditferent from generic description, figured in Am. Journ. Conch., VI. 

 203, fig. 2. 



Helix loxodon, Pfr. {Plagioptycha.) Am. Journ. Conch., VII. 177. 



Unlike the generic description, the jaw has a median projection, and is 

 ribless. 



Helix diaphana, Lam. {Plagioptycha.) Am. Journ. Conch., VII. 178. 

 See last si)ecies. 



Helix monodonta, Lea. (Plagioptycha.) Am. Journ. Conch., VII. 

 178. See last. 



Helix Albersiana, Pfr. (Plagioptycha.) Amer. Journ. Conch., VII. 

 178. Jaw same as in last species. 



Helix macroglossa, Pfr. (Plagioj)tychn.) Am. Journ. Conch., VII. 178. 

 Jaw with nu'dian projection and no anterior ribs. 



Helix varians, ^Ike. (Polymita.) Am. Journ. Conch., VI. 206, lingual. 

 Helix muscarum, Lam. (Polymita.) Am. Journ. Conch., VI. 204, pi. 

 ix. fig. 4, 10. 

 Jaw ribless, lingual widely differing from the usual type of Helix. 



Helix graminicola, Ad. (Polymita.) Amor. Journ. Conch., VII. .178. 

 Jaw dilh Tful I'roni generic description of Jfdix in having no anterior ribs 

 and in liaving a median projection to its cutting edge. 



