328 AMERICAN JOURNAL 



ON A SPECIES OP HELIX FROM CALIFORNIA, 

 SUPPOSED TO BE NEW- 



BY WM. H. DALL, ACTING DIRECTOR SCI. CORPS, W. U. 

 TELEGRAPH CO. RUSSIAN EXTENSION. 



Helix (Conulus) chersinella, n. sp. — Plate 21, fig. 4. 



Description. — Shell small, somewhat elevated, smooth, ex- 

 cept that the lines of growth are occasionally indented ; um- 

 bilicus minutely perforate ; aperture semilunar and slightly 

 oblique ; whorls rotund, four and a half to five in number ; 

 suture impressed, not deep ; lip not thickened or reflected. 

 Color yellowish, translucent. 



Dimensions. — Maj. diam. 014 in., min. diam. 0*13 in., alt. 

 (in type) 0'09 in. 



Locality. — "Big Trees," Calaveras Co., Cal. (Teste New- 

 comb.) 



Cabinets of Newcomb, Smithsonian Institution, and Dall. 

 Eight specimens. 



This small species has relations with Helix chersina, Say, 

 and Helix indentata, Say. 



It resembles the former in its small size and many whorls, 

 but differs in color and depressed spire, though sometimes al- 

 most as acute. It is related to the latter in its color and in- 

 dented lines of growth, but differs in its greater number of 

 whorls and much smaller size, and in the proportional size of 

 the last whorl. It has as many whorls as Helix arborea, Say, 

 Whitneyi, Newc, or Breweri, Newc., of three times the size, 

 and is from a different locality than the two last mentioned. 

 The rotundity of the whorls may well be noted. 



The localities of the smaller Helices which have been found 

 west of the Rocky Mountains, are as follows: — 



H. Mazatlanica, Pfr. Mazatlan,? California. 



