928 



MONOGRAPHS OF NOKTII AMKKICAN KODENTIA. 



under the head of A. caligatus: — "There is a living animal of this species now 

 in the Zoological Gardens. It was brought to England by Mr. King, Surgeon 

 to Captain Back's overland Expedition, and is figured and described in his 

 recent work under the appellation of Arctomys ochanaganus, derived from the 

 riser upon whose banks it was caught. The Arctomys pruinosus of Pennant 

 is perhaps the same with caligatus, but the brief account of it in Arctic 

 Zoology is insufficient to determine." This specimen, as Audubon and Bach- 

 man inform us, is also the original of their Arctomys pruinosus, to which they 

 likewise refer the A. caligatus of Eschscholtz. 



Middendorff, in 1851, partly from a comparison of descriptions and fig- 

 ures and partly upon theoretical grounds, considered the large Marmot of 

 Kamtschatka as specihcally identical with the A. pruinosus of Audubon and 

 Bachman, both of which (including also the A. empetra of authors and the 

 A. melanopus of Kulil) he considered as identical with A. monax. Hence he 

 strangely employs this name for the designation of the Kamtschatkan species, 

 previously named A. camtschatica by Brandt. At the same time, he was 

 inclined to regard the A. caligatus, owing mainly to differences of color, as dis- 

 tinct from the Kamtschatkan Marmot and from the A. monax of North America. 



Dr. Richardson, apparently on the authority of Harmon and the fur 

 traders, gave the range of A. pruinosus as extending from latitude 46° to 62° 

 in the Rocky Mountains. Pennant's specimen is said to have come from 

 Hudson's Bay, and there are specimens in the present collection from Wash- 

 ington Territory, Forts Good Hope, Liard, and Yukon, in the Mackenzie 

 River District, and from Fort Henry, Alaska. Ross gives its range as extend- 

 ing northward to the Arctic Circle. It hence probably ranges from the 

 Columbia River northward, west of the Rocky Mountains to the Barren 

 Grounds, thence eastward to Lake Athabasca, and possibly to Hudson's Bay. 

 All the specimens in the collection of the National Museum, however, from 

 the region about Hudson's Bay, belong to A. monax. 



Table CXXXIX. — Measurements of three specimens of Arctomys rmilNOSUS. 



