56 HELIX. 



the typical specimens runs in the opposite direction from H. 

 Haydeni, H. Hemphilli, H. strigosa, there is considerable evi- 

 dence that this is only an extreme form of a series representing 

 varietal developments from a common t} T pe. This relationship 

 is almost demonstrated by the magnificent suites of specimens 

 of these species in the Museum of the Philadelphia Academy. 



H. STRIGOSA, Gould. PL 10, figs. 32-36, 42. 



Umbilicated, moderately solid, irregularly costulately striate, 

 scarcely shining, whitish or light yellowish, variegated and 

 banded with chestnut; whorls 5, convex, the upper ones often 

 carinate-margined, the last rounded or more or less obsoletely 

 angulated, shortly descending in front. Diam. 15-25 mill. 



Oregon, Nebraska, Idaho, Utah, etc. 



With this are to be united the usually more elevated and smaller 

 form H. Cooperi, W. G. Binney (figs. 35, 36), and H. Bruneri, 

 Ancey. Dr. Fischer described some thirty years ago a Helix, 

 supposed to be from New Caledonia, which, on account of a 

 fancied resemblance to the European H. cespitum, he called H. 

 cespitoides. The locality was soon shown to be erroneous, and 

 Pfeiffer rather carelessly made it a synonym of H. cespilum. 

 Ancey has recently declared it synonymous with H. Cooperi, 

 and I agree with him. The figure of it, as published by Dr. 

 Fischer, represents a specimen in which the bands have coa- 

 lesced so as to give a uniform light chocolate-color, a rather 

 frequent variation in the species of Anguispira. 



H. HEMPHILLII, Newcomb. PL 10, figs. 31-39. 



Widely umbilicated, rather thin, corneous white, with obscure 

 brownish lines, transversely rugosely striate; whorls 5, convex 

 to planulate above, the last acutely carinated or bicarinated, 

 descending in front, the base convex, lightly striated. 



Diam. 15 mill. 



Nevada, Colorado. 



The juvenile is acutely carinate, and shortly hirsute. Assum- 

 ing H. strigosa to be the parent and normal form, this is almost 

 certainly an intermediate between it and H. Haydenii, Gabb,"one 

 extreme of the series, as H. Idahoensis, Newcomb, is probably 

 the other extreme. 



