250 PROCEEDINGS OF THE ACADEMY OP 



Helix fidelis, Gray. (Aglaja.) Am. Joiirn. Concli., VI. 207, pi. ix. 

 fig. 1, 9. 



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

 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. Conch., 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. Conch., VII. 177. 



Helix Tryoni, Newc. (Euparypha) 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. (TJielidomus.) Am. Journ. Conch., VII. 177. 

 Lingual membrane only. 



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

 Lingual membrane only. 



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

 fig. 3, lingual. 



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

 203, fig. 2. 



Helix loxodon, Pfr. (PlagioptycJia.) Am. Journ. Conch., VIL 177. 



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

 ribless. 



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

 See last species. 



Helix monodonta, Lea. (Plagiopiycha.) 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. (PlagioptycJia.) Am. Journ. Conch., VII. 178. 



Jaw with median projection and no anterior ribs. 



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



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

 ix. fig. 4, 16. 



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



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

 Jaw different from generic description of Helix in having no anterior ribs 

 — and in having a median projection to its cutting edge. 



