516 



NOKTH AMERICAN FAUNA. 



[NO. 27. 



Pinus divaricata (Ait.) Du M. de C. Banksian Pine. 



This is the only species of pine on the lower Athabaska and north- 

 ward. Between Edmonton and Athabaska Landing it forms exten- 

 sive forests in several places. Along the Athabaska and Slave rivers 

 it apj^ears only occasionally, usually where high gravelly banks ap- 

 proach the river. It is common, however, on the rock}^ hills about 

 Fort ChipeAvyan and Smith Landing, and is the predominating tree 

 on the rolling sand}^ plains on Smith Portage and about Fort Smith. 

 It occurs commonly on the Simpson Islands and about the Northern 

 Arm of Great Slave Lake. On my route to the northward of Fort 

 Rae it was seen in many places on Grandin Eiver, reaching a diam- 

 eter of 18 inches, but not growing very tall. Xorth of the height of 

 land it was rare, but I saw many trees on a portage a few miles north 

 of the outlet of Lake Hardisty. 



On the Mackenzie it is common north to about latitude 64° 30'. 

 About Fort Simpson in suitable localities it forms groves of well- 

 grown trees, reaching a diameter of 18 inches. A tree 11 inches in 

 diameter near the base, examined at Fort Simpson, had 102 annual 

 rings. On the north slope of the Nahanni Mountains, 75 miles below 

 Fort Simpson, the species ascends to about 1,000 feet and then be- 

 comes a dwarfed shrub and disappears. On the southern slopes of 

 the same mountains it occurs as a fairly well-grown tree to about 

 2,000 feet, near the summit. 



In the country to the eastward of our routes it was detected by the 

 Tyrrell brothers as far north as Selwyn and Theitaga lakes ; and by 

 J. W. Tyrrell on Kipling Lake, a few miles east of the eastern end of 

 Great Slave Lake. 



The wood of this pine is put to A^ery little use in the region, except 

 for fuel. 



Larix laricina (Du Eoi) Koch. Tamarack. 



The tamarack is found throughout the region north to the limit of 

 the forest, occurring mainly in muskegs, where it is sometimes the 

 predominating tree. Since its wood is tougher than any other native 

 to the region, it is used to a considerable extent to form the keels and 

 gunwales of boats, and for other purposes where extra strength is re- 

 quired. 



We observed this tree in suitable places in all the country traA^ersed 

 on our journeys from the Saskatchewan north to the lower Mackenzie. 

 It is rather common along the southern shores of Great Bear Lake, 

 where the largest one seen, near Leith Point, was about 12 inches in 

 thickness at the base, but was not over 30 feet in height. While trav- 

 eling along this shore in the autumn of 1903 I first noted the leaves 

 of the species beginning to change color on September 12, near Mc- 

 Yicar Bay, Two days later its yelloAv foliage gave a decided impress 



