COCKERELL : MOLLUSCAN FAUNA OF COLORADO. 63 



him are very much like P. badia (marginata) from Anti- 

 costi I. and also greatly resemble P. sterri v. Voith from 

 Geissberg, Switzerland, of which he has been good enough 

 to send me specimens. Then there is a small species which 

 I have provisionally called P. color adensis sp. nov., but 

 forbear to describe it until it has been compared by Mr. 

 Pilsbry with authentic specimens of P. Rowelli Newc. 

 The only two Colorado species of the Leucochila section 

 are also from this district, — P. arizonensis Gabb, from El 

 Paso Co. according to Tryon (but not found since), and a 

 minute Leucochila which I have found very sparingly at 

 about 8,400 feet in West Custer Co., to which I have 

 given the name P. montanella sp. nov., but do not 

 describe it pending further investigations. Dr. v. Sterki 

 writes that he has obtained a minute Leucochila from 

 Minnesota, which is very distinct from all other species, 

 and suggests that it may be identical with mine. Succinea 

 avara Say occurs in Custer and Pueblo Cos., and another 

 species, doubtfully referred to iS. stretchiana Bland, is from 

 Chaffee Co. S. pfeifferi Rossm. is found at West Cliff in 

 Custer Co. at 7,700 feet altitude. Limncea truncatula 

 Miill is abundant in Custer Co., the only other JLimncBa 

 known from the district being a variety or sub-species of 

 L. palustris, from Chaffee Co. Physa hypnorum and a 

 small variety of P. heterostropha Say, occur near West 

 Cliff, Custer Co., while the hot springs at Wellsville pro- 

 duce a very distinct sub-species of P. heterostropha, which 

 I call P. cupreonitens sp. nov.* No species oi Planorbis 



* P, cupreonitens ; parvula, nitida, pellucida, cuprascens. Smooth, 

 pellucid, shiny, red brown or copper colour, whorls 4, somewhat convex, 

 suture rather deep ; spire sub-acute, of moderate length ; mouth pearly 

 within, oval, inclining to pyriform, not greatly attenuated above. Columella 

 slender, straight. Inner lip a whitish film, not thickened. Long. 7^, lat. 

 4^ mill. ; spire, long. 2^ mill. Forms somewhat analogous to this are 

 Physa hypnorum var. cuprella, from Sussex, England, and especially Physa 

 acuta var. minima, which is only 7 mill, long, shiny and semitransparent, 

 but of a PALE HORN COLOUR instead of coppery. It, like P. cupreoniteiis. 



