THE MOLLUSCA OF COLORADO. PART IP 



By Junius Henderson 

 Genus OREOHELIX Pilsbry 



Oreoheliz strigosa Gld. Fig. 3. 



Patula strigosa. Grand River, Binney 

 5, 623. Blue River and Saguache, Yarrow 

 68, 930. North Park (E. A. Barber), Boulder 

 and Magnolia (Henderson), Black Lake 

 Creek (Cockerell), Larimer County (S. M. 

 Edwards), Vanatta Mss. 



Patula strigosa hemphilli Newc. Williams 

 Canyon, Binney 6, 168. See Cockerell 14, 

 Fig. 3.— Oreohelix strigosa. 102; Sampson 46, 102; Stearns 52, 62. 



Form globosula Ckll. (Described from 

 one immature specimen) Black Lake Creek, Cockerell 14, loi; Binney 7, 170. 



The confusion in the literature of this genus makes it impossible to be certain about 

 the records of the various subspecies, and the large number of named forms of less than 

 specific or subspecific value, some of which, at least, have been described from single 

 specimens, has not assisted in bringing order out of chaos. The differences in color, 

 number and width of bands, elevation of spire and deflection of last whorl toward the 

 aperture are so marked even in specimens found together, and various forms which 

 appear quite distinct when viewed separately pass into each other by gradation so insen- 

 sible when considered in large series, that their separation becomes more a matter of 

 opinion than of fact. Even such extreme forms as hemphilli are found in large series 

 of specimens to pass into typical strigosa in such a way that no line can be drawn between 

 them. 2 It is difficult to say whether some of the forms should be considered forms of 

 strigosa or cooperi, or whether they should be designated as varieties, subspecies, mutants 

 or forms. It was once said that cooperi was the comnaon form in Colorado but the 

 majority of specimens from east of the Front Range are now referred to strigosa an,d its 

 varieties, while we have seen no living cooperi. The majority of specimens examined by 

 the writer have two rather wide spiral bands, a few have one or two fine additional lines 

 and a very few immature specimens have quite a number of obscure lines on the base. 

 The species is common in the foothills and mountains from Boulder to Lyons and south- 

 ward. We have found it fossil at Bear Canyon. Our finest specimens were collected 



» Part I of this paper was published in Vol. IV of these Studies, pages 77 to 96 inclusive, and included 

 an introduction, bibliography, locality list, key to species and an annotated catalogue of the Pelecypoda. In 

 the citations of former records herein the figures in bold-faced type refer to the numbers of the publications 

 listed in the bibliography in Part I, and the figures in light-faced type refer to the pages. The illustrations 

 in this part are all electrotyped from originals used in the publications of Smithsonian Institution, by com-tesy 

 of the authorities of that institution. The introductory remarks in Part I included a list of the species added 

 to the recorded fauna by this paper. Since it was pubKshed records of four more species have been added, 

 namely: Bifidaria pilshryana St., B, hordeacella Pils., B. procera Gld., and Lymnaea leai Baker, besides the 

 hothouse specimen of Vitrea alliaria Drap. 



' PiLSBRy, Man. Conch., VIII, p. 115; Stearns 50, 96, 51, 74s, 746. 



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