The Species of the Genus Larix. PAS 
Within both areas, it goes southwards to about lat. 45°N., 
that is to say, as regards the western area, a trifle south 
of the Columbia River, and north again to about the 
Fig. 7. Group of L. Lyallii, forming forest line above Lake Louise, Al- 
berta, Canada. Ca. 2000 m. (Aug. 1924. C. H. Ostf. phot.). 
boundary line between Washington and British Columbia; 
in the eastern area, it follows the boundary between Bri- 
tish Columbia and Alberta northwards to the neighbourhood 
of Mount Hooker. On the west, it runs a little nearer to 
the coast than, and on the north-east, a little beyond the 
