1917.] NATURAL SCIENCES OF PHILADELPHIA. 71 



steep limestone slopes, not in the rock slides. Dead shells plentiful. 

 The vicinity is covered by a thick coat of lime dust from the cement 

 plant. It is strange that any live examples were found under the 

 circumstances. 



Sta. 49, west slope of first gulch that enters the canyon from the 

 north below the Devil's Slide depot. Oreohelix haydeni form gabhiana 

 (Hemph.) under sagebrush, mountain maple, scrub oak, wild cherry 

 and other shrubs at the edges of limestone slides, common alive, 

 dead shells plentiful. The narrow-leafed cottonwood grove in the 

 bottomland beneath the slides yielded: 



Vitrina alaskana Dall. Pyramidula cronkhitei anthonyi 



Vallonia gracilicosta Reinh. Pils. 



Pwpilla blandi (Morse). Zonitoides arhorea (Say). 



Sta. 50, pools beside the railroad track half a mile below Sta. 49. 



Succinea rusticana Gld. Aplexa hypnorum (L.). 



Lymncea proxima Lea. Paludestrina longinqua (Gld.). 



Physa crandalli Baker ? 



Sta. 51, below Sta. 50, opposite (north of) the railroad tunnel, 

 just east of a dry gulch that comes in from the north. Oreohelix 

 haydeni form gabhiana (Hemph.) plentiful in edges of rock slides. 

 The following were also found: 



Vitrina alaskana Dall. Pyramidula cronkhitei anthonyi 



Euconulus fulvus alaskensis Pils. Pils. 



Zonitoides arborea (Say). 



Sta. 52, across the mouth of the gulch just mentioned, west of 

 Sta. 51, thence along the base of the canyon wall for some distance 

 around the curve. Oreohelix haydeni form gabbiana (Hemph.), less 

 common than at Sta. 51. 



Sta. 5.3, east-facing slope southwest of Sta. 52, west of the railroad 

 tunnel, separated from Sta. 52 by a hundred yards or so of slope 

 free from rock slides, where we found no snails. Oreohelix haydeni 

 form gabbiana (Hemph.), a few found alive, dead shells plentiful. 



Sta. 54, a mile down the canyon from Sta. 53, on an east-facing 

 slope where the wagon road approaches the railroad. Oreohelix 

 haydeni hybrida (Hemph.), plentiful under poison ivy in rock slides. 



The Oreohelices from stations 48, 49, 51, 52, 53 and 54, all belong 

 to the haydeni group. Hence the soft anatomy is the same and shell 

 characters alone must be relied upon in their separation. Not a 

 single example has as strong spiral sculpture as tj-pical haydeni or 



