28 INDEX TO PLATES. 



PLATE XYI. 



Helix tudiculata Binney, p. 117. 



PLATE XVII. 



Fig. 1. Helix pclchella Miiller, p. 175. Lin- 

 gual booklets, p. 209. 



Fig. 2. Helix mixuscula Binnej-, p. 221. 



For Plate XVII a, read Plate XVIL 



Fig. 3. Helix labykixthica Say, p. 202. Lingual 

 booklets, p. 260. 



Fig. 4. Helix chersixa Say, p. 243. 



PLATE XVIII. 



Helix Xuttalliaxa Lea, p. 159. 



PLATE XIX. 

 Helix Townsendiana Lea. p. IGl. 



PLATE XX. 

 Helix Vaxcotiteeexsis Lea, p. 1G6. 



PLATE XXI. 



Helix coxcata Say, p. 1G3. 



PL.A.TE XXI L 



Helix profunda Say, p. 177. Lingual booklets, 

 p. 179. 



