OF CONCHOLOQY. 3 i9 



36. n. VoYAKA, Newc. 



Gallon Creek, Trinity Co., California, (Voj.) 



37. H. STRIGOSA, (Gould.) 

 "Interior of Oregon," Gould. 



38. H. Cronkheitii, Ncwc. 



Southern Oregon, (Gabb.) Northern California, (Voy.) 



39. H. DuRANTi, Newc. 



Santa Barbara Island, (Dr. Cooper.) 

 ■iO. H. Whitneyi, Newc. 

 Lake Tahoe, (Dr. Cooper.) 



41. H. Breweri, Newc. 



Lake Tahoe, (Dr. Cooper.) Mammoth Grove, Calavaros 

 Co., (Master Willie Hillebraud.) 



42. H. FULVA, Drap. 



Lake Tahoe, (Dr. Cooper.) 



43. II. COXSPECTA, Bid. 

 San Francisco, (Rowell.) 



The six last named are minute species, one of which, JT. 

 fulva, Drap., {chersina, Say,) inhabits Europe and the Atlantic 

 States, and was found by Dr. Cooper somewhat largely devel- 

 oped, on the boundary between California and Nevada. No 

 tangible difference can be detected between the European, 

 Eastern and Western American shells, except in size, which 

 is a character of but secondary importance. 



The following is an attempt at grouping the species, with 

 reference to their afl&nities, rejecting those that I have not had 

 an opportunity of examining: — 



a. H. FIDELIS, INFUMATA, ARROSA. 



b. " NlCKLINIANA, CaLIFORXIEXSIS, ToWX^SEXDIAXA. 

 C. '' RAMEXTOSA, BrIDGESII, EXARATA. 



d. " Ayresiaxa, ixtercisa, crebristriata. 



e. " Dupetithouarsi, Traski, Hillebraxdi. 



/. " DEVIA, COLUMBIAXA, LORICATA. 



g. " Kellettii, tudiculata, and var. (?) of Kellettii. 



h. " FACTA, GaBBII, RUFO-CIXCTA, 



i. " Tryoxii, areolata, Paxdora. 

 h. " Carpexterii, Eowelli, Cooperi. 



