1008.] MAMMALS. 193 



specimens, taken late in September, agree very well with spatulatus 

 from Alaska in corresponding pelage. The series of adults taken 

 early in July at Fort McPherson are in a very pale, washed-out 

 pelage. It is highly probable that this condition results from some 

 mineral in the sediment-laden water of Peel River. Specimens from 

 the comparatively clear waters of Great Slave Lake, also taken in 

 July, do not exhibit this bleaching to a degree approximating the 

 condition in the Peel River examples. 



Five adults from the Athabaska and Great Slave Lake region 

 average in measurements: Total length 546, tail vertebrae 264.4, hind 

 foot 75; five specimens from Fort Franklin average 499, 218.8, 74.6. 

 This series includes several youngish individuals; the largest in the 

 series, an adult male, measures 540, 244, 80. Five adults of both 

 sexes from Fort McPherson average 544, 251, 7(>. 



The muskrat is quite generally distributed throughout the northern 

 region, nearly to the limit of the forest. Richardson mentions that 

 the species extends its range nearly to the mouth of the Mackenzie; 

 and Russell speaks of it as abundant near the mouth of Peel River 

 in the summer of 1894. 6 Tyrrell speaks of seeing it in all the streams 

 to the southeast of Athabaska Lake during his exploring trip in that 

 region in the summer of 1892.** 



J. Alden Loring reported it common at Edmonton in September, 

 1894, and along the trail between that point and the mountains in 

 the early autumn of 1895. In 1890 he frequently observed it in the 

 same region during the summer, and noted it in the valleys and foot- 

 hills between Jasper House and Smoky River in the early autumn. 

 A male, taken at Henry House, September 6, 1895, and another from 

 Edmonton, have been referred to F. spatulatus by Osgood;' 



During the hrst year of Fort Anderson's existence (outfit 1861), 

 500 muskrat skins were traded; for the next year 1,500 skins figured 

 in the returns. 



MacFarlane states that this animal occurs on the lower Anderson 

 to its outlet, though less commonly than on the Mackenzie. He gives 

 data regarding the number traded and sold during different series of 

 years, and the notable reduction in numbers during certain years on 

 account of unusual seasonal conditions or other causes. He states 

 that the animals are subject to a liver disease which kill-- them by 

 thousands. They are said to have two or three litters during the 

 summer. 6 



"Fauna Boreali-Americana, I, p. 117. 1829. 



&Expl. in Far North, p. 138, isns. 



'Ann. Rept. Can. Geol. Snrv., VIII (new sar.), |. 13D, 1896. 



'' \. A. Fauna. No. 1!». p. .'IT. 1900. 



' Fro.-. F. S. Nat. Mus., XXVIII, pp. 7.T7. 738, 1905. 



44131— No. 27—08 13 



