1902.] NATURAL SCIENCES OF PHILADELPHIA. 425 



from 19 to 21^ mm. and are in every way larger and finer speci- 

 mens. 



Polygyra andrewsae (W. G. Binn.). 



Tlie typical form of this fine species was quite abundant all 

 along the ridge from Clingman Peak to INIt. Mitchell. It is partial 

 to the hellebore ( Veratruyn viride) which grows rankly in the open 

 spaces, and was usually found either roosting beneath the large 

 leaves or hidden in the grass around the roots. The shells are 

 exceedingly fragile and w'ere often crushed between the fingers in 

 the slight pressure occasioned by lifting them from their hiding- 

 places. They are uniformly of a dark olive-green color, with a 

 thin, narroAV, concave lip. Of sixty-five specimens the largest was 

 27^ mm. in diameter, the smallest 22^, average 2Aj^. Compared 

 with Roan mountain specimens they differ only in size, being on 

 the average slightly larger. Of thirty-nine Roan specimens the 

 smallest was 19, the largest 22iV. The shells from both localities 

 are alike in the extreme fragility, narrow lip and shape. And in 

 both places this form is found only on the highest parts of the 

 mountain. 

 Polygyra andrewsae normalis Pilsbry. 



This form is purely a cove dweller and is rarely found at an 

 elevation of more than 5,000 feet. From 1,200 to 4,000 is about 

 its usual range. It occurred sparingly on both sides of the river 

 at Paint Rock (alt. 1,200 feet), and on Bluff mountain as far up 

 as Baker's (alt. 3,000 feet). These specimens were of the usual 

 type and varied from 35J to 37J in diameter. 



It also occurred at Tyson's Cove (alt. 4,000 feet), Meadow Cove 

 and Wilson's Cove (alt. 3,500 feet). Those from Wilson's were 

 the largest yet seen. Of thirty-seven specimens, the largest was 

 40^ mm. in diameter, the smallest 34, average 37 J. They vary con- 

 siderably in shape, frequently becoming subconical as shown by the 

 following measurements: 37-^ x 32, 41 J x 35J, 39:} x 35 and 

 38.} X 28}-. Occasional pale-green albinos occurred. 



Polygyra andrewsae intermedia n. subsp. 



Throughout this region, occupying the higher levels from 3,500 

 to 5,000 feet, and thus ranging above the var. normalis, but below 

 the typical anclrewsce, w^as found a well-marked race which cannot 

 be satisfactorily assigned to any of the recognized varieties. It is 



