OCT., 1900.] MAMMALS OF THE YUKON KECIION. 31 



rang' out ticross tlic ^vater, ,so that, if not to ])e seen, the}' at least 

 reminded us of their presence nearly' all the time. When alarmed, 

 they stand erect on their haunches near their l)urrows and violently 

 utter their sharp, high-pitched dlehetij dick as long as the exciting 

 cause is in sight, always emphasizing each cry ]jy vigorously slapping 

 their short tails against the groiuid behind them. As a rule they were 

 quite wary, and it was not possible to get within gunshot without some 

 concealment and careful stalking. The limit of the range of the spe- 

 cies along the river is near Fort Selkirk. The last specimen secured 

 was caught near Rink Rapids, but I learned that (juite a colony of 

 ground squirrels exists on the west bank of the river just boloAV Fort 

 Selkirk. 



Spermophilus osgoodi Merriam. Fort Yukon Ground Squirrel. 

 Hpcrmnph'dm ot^ijuodl Merriam, Prof. AVash. Acad. Sci., II, 18, March 14, 1900. 



From Fort Selkirk, near the limit of Spermo2)ldlwiple8ius in the inte- 

 rior, nearl}" to Circle, we saw no signs of ground squirrels of an}' kind. 

 Just before reaching Circle, however, we began to see unmistakable 

 signs of them and were soon attracted to a small colony by their click- 

 ing calls which reached our ears as we floated down in midstream. 

 The call is executed in about the same time as that of S. pleHiux^ but 

 its pitch is nuich lower and its effect on the ear is utterly different. 

 It suggests the click of castanets. On going ashore we found their 

 burrows and connecting paths scattered over (juite an area on the hill- 

 side. The colony occupied the open hillside and a few ledges of loose 

 rock, and even extended down into a thicket of alder and willow at 

 the foot of the hill. The animals were very shy and became much 

 excited at our approach. Their long tails were very noticeable in 

 marked contrast to the short ones of 8. jpledus^ which we had been 

 accustomed to seeing. Fifteen specimens were secured.^ At this 

 time (Aug. 14) they were all very fat and in splendid postbreeding 

 pelage; the entire underparts were rich ferruginous without a trace of 

 any othei* color; the back was very dark, and the long tail was full 

 and bushy . One specimen was pure glossy black with faint shadowy 

 indications of vermiculation on the back. Among the specimens in 

 the National Museum from Fort Yukon are several in this melanistic 

 condition, showing that it is not uncommon. The range of this spe- 

 cies on the Yukon begins a])out ^0 miles above Circle and extends at 

 least to Fort Yukon and probably to the mouth of the Tanana. 



Arctomys caligatus Eschscholtz. Hoary Marmot. 



Six specimens of the hoary marmot were secured in the AVhite Pass 

 region and about Lake Bennett, where it was common. It is confined 



* ThiH valuable series was unfortunately destroyed. 



