56 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



Measurements: 



Maximum Minimum Altitude Diameter Number of 



diameter diameter umbilicus whorls 



mm. mm. mm, mm. 



Type 24.3 20.0 15.5 2.2 57* 



Paratype 26.0 21.3 16.4 2.4 57* 



24.6 20.3 15.7 2.3 57* 



22.7 18.7 14.2 2.1 57., 





Average 24.4 20.7 15.45 2.25 574 



Type: Cat. No. 4132, Beri-y Collection. Paratypes in the 

 collection of the California Academy of Sciences and the pri- 

 vate collection of George Willett. 



Type Locality: Among loose talus on higher portion of 

 southern end of South Coronado Island, Lower California; 

 George Willett, December 13, 1918; 12 specimens. 



Remarks: The Coronado Islands have for long been the re- 

 puted home of a snail belonging to the /;'a.y^//-group of Ephi- 

 phragmophora which passed for many years as the Helix car- 

 penteri of Newcomb, but Bartsch has lately reminded us that 

 Newcomb's shell is almost certainly a mainland race of quite 

 different affinities, and has therefore renamed the island sub- 

 species coronadoensis (Bartsch, :16, p. 617), an action with 

 which I am in accord. As there seemed to have been no collec- 

 tions of coronadoensis made within recent years, and the exact 

 island of the group from which it came in the first place is still 

 uncertain, Mr. George Willett took advantage of a brief visit 

 to South Island in December, 1918, to undertake a special 

 search for this snail. At first only the common E. stcarnsiana 

 (Gabb) was encountered, but finally in the southern part of the 

 island, he found not only a thriving colony of what I take to be 

 typical coronadoensis, but also a considerable number of speci- 

 mens of the somewhat larger, pale-colored form here described. 

 At the time, although found in a colony of its own, Mr. Willett 

 took the latter to be merely an "albino" mutation of the other. 

 This it may essentially be, but there are grounds, nevertheless, 

 for believing that it represents considerably more than simply 

 a sporadic variant. 



Some readers will no doubt recall, as a previous attempt to 

 give systematic recognition to an albinistic variation of one of 



