135 



Along the Rocky mountains as far south as Fort Staunton, New 

 Mexico. Lat. 33° 30'. — Very common in the " Bad Lands" and rocky 

 portions of the upper Missouri. Seldom^ perhaps never, seen below 

 Fort Pierre. 



20. SpermopMlus franklini, Eich. — Gray Gopher. — Northern Illi- 

 nois and Wisconsin, and to Minnesota and Saskatchewan. — One 

 specimen of the above species was taken near the mouth of the Loup 

 Fork of the Platte. Quite rare. 



21 . SpermopMlus tridecem-lineatus , Aud. & Bach. — Striped Gopher ; 

 Prairie Squirrel. — Eastern Michigan to the plains of the Missouri, and 

 south to Red river, Arkansas, and Fort Thorn, N. M. — Very abun- 

 dant on all the prairies of the northwest. 



22. Spermopliilus Toivnsendii, Bachman. — Townsend's spermophile. 

 Rocky mountains to the north. Several specimens were collected near 

 Fort Laramie. 



23. Cynomys ludovicianus. — Prairie Dog. — Milk river and upper 

 Missouri ; west towards the Rocky mountains ; south to Red river ; 

 southwest to the Upper Rio Grande, and a short distance into 

 Sonora? — Very abundant from the mouth of the Niobrara to the 

 mountains ; found in great rtumbers in the valley of the Yellowstone 

 and along the Missouri, above Fort Union. 



24. Arctomys fiaviventer , Bachman. — Yellow-footed Marmot. — 

 Black Hills, Neb. — This animal is very rare, but one specimen having 

 been secured on the upper Missouri. The skins of only two indi- 

 viduals are in the museum of the Smithsonian Institution. 



25. Castor canadensis, Kuhl. — American Beaver. — Throughout the 

 entire area of North America. — The history of this animal is more 

 interesting than that of any other on the upper Missouri. In the 

 palmy days of the trapper the beaver became very scarce in the west ; 

 but since the price of their fur has become so low as to render the 

 business of trapping them an unprofitable pursuit, they have multi- 

 plied to an enormous extent, so that all the little streams flowing 

 from the mountains literally swarm with them. Their skins, how- 

 ever, are still a considerable article of trade. 



26. Geomys hursarius, Itich. — Pouched or Pocket Gopher. — Mis- 

 souri to Minnesota and Nebraska. — Very abundant on the rich bot- 

 toms around Council Bluffs and Big Sioux, where they do much mis- 

 chief in the gardens. One specimen was taken near the mouth of Big 

 Sioux, and a second on the Niobrara. 



27. Thomomys rufescens, Maxim. — Fort Union Gopher. — Fort 

 Pierre to Fort Union, on the Missouri. — This gopher seems to take 

 the place of the Geomys hursarius from Fort Pierre to the mountains. 

 Two specimens were collected at Fort Union, and one at Fort Ran- 

 dall, on the Missouri. 



28. Jaculus hudsonius. — Jumping Mouse. — Nova Scotia, (Labrador, 

 Pennant,) to southern Pennsylvania, and west to the Pacific ocean. — 

 Very rare. Only two specimens were obtained near Fort Union. 



S9. Perognatlms Jlavus, Baird. — Upper Missouri, along eastern 

 slopes of Rocky mountains to Sonora and Chihuahua ; and along the 

 Tiio Grande to Matamoras. — Collected on the Loup Fork during the 

 summer of 1857. 



