62 COCKERELL: MOLLUSCAN FAUNA OF COLORADO. 



Republican. — Records are at present entirely wanting ; probably 

 some of the eastern Unionidae, &c. may exist, the neigh- 

 bouring state of Kansas boasting no less than forty-nine 

 species of Unio, two of Margaritana, and twelve of Ano- 

 donta, while Nebraska has also numerous species belonging 

 to these genera. 



Arkansas. — The eastern portion of this division has no records 

 as yet, but Anodonta dejecta Lewis, Unio lachrymosus Lea, 

 and other species occur in the Arkansas River in Kansas. 

 The mountainous portion of the Arkansas basin is the 

 eastern limit of a few species belonging to the Rocky 

 Mountains, Agriolimax 7nontaniis Ing., and Patula cooperi 

 Binn., extending as far east as Pueblo Co., while Patula 

 cronkheitei Newc.,* Microphysa ingersollii Bland, Pupa 

 Blandi Morse, P. corpulenta Morse, and P. alticola Ing., 

 have been found in Western Custer Co. Vitrina pellucida 

 Miill. occurs in Custer Co., and V. Pfeifferi Newc. in Lake 

 Co., Hyalina radiatula Alder in Custer and Pueblo Cos., 

 and the var. viridescenti-alba Jeffr. f in Custer Co., H. 

 arborea Say is frequent in Custer, Chaffee, and Pueblo 

 Cos. ; in Custer Co. Patula striatella Anth. is found 

 abundantly with it, as well as Conulus fulvus and Helix 

 pulchella var. costata. Cochlicopa lubrica Miill. occurs 

 abundantly near Swift Creek, in Custer Co., at about 

 8,400 feet altitude. The species of Pupa are numerous 

 and puzzling. The common species in Custer Co. is 

 P. blandi Morse, which presents various forms, one of 

 which Mr. C. F. Ancey, to whom specimens were sent, 

 refers to P. bigranata Rossm. Probably they are all refer- 

 able to P. marginata Drap. as varieties. Dr. V. Sterki 

 remarks that specimens of one of these forms which I sent 



* This ascends as high as 10,000 feet altitude. Mr. H. A. Pilsbry 

 informs me that it is probably to be considered a variety of the European 

 P. ruderata Stud. 



f H. viridula of American authors : it seems to me identical with the 

 European form. 



J.C, vL, Jan., 1889. 



