1908.] BOUNDARIES OF REGION TREATED. 125 



sued, both to take advantage of the current and to avoid the numer- 

 ous bars, and this greatly increases" the distance. The banks at the 

 head of the river are low (see PI. XVIII, fig. 1), but rapidly in- 

 crease in height. The bordering country is mainly swampy and is 

 well wooded. The more gently sloping banks are grassy or wooded, 

 and a dwarf willow (Salix reticulata) is a conspicuous shrub for 

 some distance below the lake. Snow fell during the first night, and 

 the next day. September 29, we kept on down the river. We soon 

 descended the rapid, keeping close to the right bank, and accomplish- 

 ing the passage in safety. At the lower end of the rapid great quanti- 

 ties of ice still remained on the southern bank of the river. Mount 

 Charles (PL XVIII, fig. 3), just below the rapids, presents a rather 

 steei), sparsely wooded slope to the river. It is said to be upward of 

 1,500 feet high and is mainly composed of limestone. Below here the 

 river broadens out, inclosing several low islands, and has a less im- 

 petuous current. We encamped on the left bank only a few miles 

 from the mouth and the next forenoon reached Fort Norman ; thence 

 we ascended the Mackenzie to Fort Simpson. This part ' of our 

 journey is elsewhere (p. 37) described in sufficient detail, and need 

 not be alluded to further. 



NOTE ON BOUNDARIES OF REGION TREATED. 



The present report relates to the natural history, especially to 

 the higher vertebrates, of the northern parts of the provinces of 

 Alberta and Saskatchewan (north of latitude 55°), the unorganized 

 territory of Mackenzie, and the islands of the Arctic Sea to the 

 northward of the latter division." In addition the northern part 

 of the old province of Alberta (south to about latitude 53°) has been 

 included, both because it was traversed by our parties and because it 

 seems desirable to record the results of field work previously done by 

 the Biological Survey in that region. 



The literature of the Athabaska-Mackenzie region has been 

 searched thoroughly for notes on natural history. Of the thousands 

 of notes thus secured, many of which are buried in narratives of 

 travel or official reports, and thus practically hidden from the 

 natural history student, only those have been utilized which have 



"Since the greater part of this paper was prepared the territories of Atha- 

 baska ami Assiniboia have been abolished, and their area is now mainly in- 

 cluded in the present provinces of Alberta and Saskatchewan, whose boundaries 

 have been extended and otherwise changed. It was therefore deemed advisable 

 to make the wording of the report conform to these new boundaries. The 

 provinces Of Alberta. Saskatchewan, and Mackenzie, therefore, are to be con- 

 sidered as understood since 1905. The map (see frontispiece) accompanying 

 this report shows the new boundaries. The parallel of 55° marked the southern 

 boundary of the old territory of Athabaska. 



