30 INDEX TO PLATES. 



sents specimens from the Western States ; the lateral figures 

 represent New England forms. The lingual booklets are 

 represented after the description, page 185. p. 183. 



PLATE XXVIII. 



HELIX TRIDENTATA Say. This plate represents the 

 form called by Mr. Say Helix fallax. p. 183. 



PLATE XXIX. 



Fig. 1. HELIX ELECTRINA Gould, p. 236. 

 Fig. 2. HELIX INDENTATA Say, p. 242. 

 Fig. 3. HELIX ARBOREA Say, p. 235. 

 Fig. 4. HELIX CELLARIA Mil Her, p. 230. 



PLATE XXIX a. 



Fig. 1. HELIX CAPSELLA Gould, p. 239. 

 Fig. 2. HELIX LORICATA Gould, p. 145. 

 Fig. 3. HELIX OTTONIS Pfeiffer, p. 238. 

 Fig. 4. HELIX SAXICOLA Pfeiffer, p. 174. 



PLATE XXX. 



Fig. 1. HELIX PERSPECTIVA Say, p. 256. 

 Fig. 2. HELIX STRIATELLA Anthony, p. 217. 

 Fig. 3. HELIX LIMATULA B i n n e y . Lingual booklets, 

 after the description undetermined, p. 219. 

 Fig. 4. HELIX INTERNA Say, p. 247. 



PLATE XXXI. 

 HELIX FULIGINOSA Say, p. 222. 



