North American Helicidae. 359 



Say thus describes this species in Nicholson's Encyclopaedia, — 



"H. ALBOLABRIS. 



" Shell thin, fragile, convex, imperforated ; with six volutions, whorls 

 obtusely wrinkled across, and spirally striated with very fine impressed 

 lines, a little waved by passing over the wrinkles, both becoming extinct 

 towards the apex, which is perfectly smooth; aperture lunated, not 

 angulated at the base of the column, but obtusely curved, lip contracting 

 the mouth abruptly, widely reflected, flat and white. 



" Length of the column three-fifths of an inch ; breadth one inch." 



The form of the shell referred to by Say has been confounded 

 by European authors with H. exoleta Binney {H. zaleta Say), 

 from which, however, it is entirely distinct. Dr. Leidy, from 

 whom I sought information on the subject, wrote to me in 1857 

 as follows : " There is no doubt, I think, that H. alholdbris and 

 H. exoleta are distinct species, as their internal anatomy is 

 quite different." This effectually disposes of the hypothesis of 

 Deshayes, who, writing of the latter species (Fer. Hist.), re- 

 marks, — " II est a presumer que 1' examen de 1' animal donnera 

 la preuve qu'il est identiquement semblable a celui de 1' alhola- 

 bris." I may add that figs. 19, 20, pi. 10, in Chem. ed. 2. 

 Helix, and fig. 6, pi. 46 A, in Fer. Hist., are of H. exoleta, which 

 is erroneously placed in the synonymy of JET. alholabris. 



It will be seen that I do not concur with Dr. Binney in sepa- 

 rating H. major from H. alholabris. Dr. Binney writes (1837), 

 in the Boston Journal, — "Mr. Conrad informs me that he 

 obtained this shell {H. major) several years since, in Alabama, 

 and considered it a new species, but was deterred from pub- 

 lishing it as such, by the generally received opinion that it was 

 only a variety of H. alholabris. ." He observes also, — " this was 

 probably Mr. Say's view, as the specimens figured by Ferussac 

 were received from him." 



In the "Terrestrial Mollusks," Dr. Binney thus remarks on 

 H. major : — 



