(i36) 



Little Salmon River. I refer specimens here with rather 

 narrower leaves more closely placed on stems and branches 

 than in the preceding (717). 



Brachythecium albicans (Neck.) B. & S. Skagway, on 

 rock. Sterile (797)- 



Brachythecium Starkei (Brid.) B. & S. Lake Lindeman. 

 In these specimens the costa extends about | up or is shorter 

 and double (719). 



Brachythecium rcjicxnm Starke. Lake Lindeman (718). 



Brachythecium Idahcnse R. & C. Dawson, on earth and 

 rock. This species is evidently most closely related to colli- 

 num from which it is distinguished principally by the nar- 

 rower leaves. The costa of the leaves near the ends of the 

 branches terminate in a spine, with the leaf surface on either 

 side papillose by the projecting upper ends of the cells. This 

 roughening of the back of the leaf occurs in coUinum, but 

 to a less degree and it makes these two species close to those 

 of Bryhnia, or rather, brings those species almost too close 

 to Brachythecium, it would seem. The perichaetial leaves 

 of both collinum and Idahense are somewhat variable, usually 

 rather abruptly acuminate with one or two coarse teeth at 

 base of acumen (720). 



Brachythecium petrophilum R. S. Williams sp. now 



In low, dense tufts or sometimes in thin mats with long 

 creeping stems and short subpinnate branches. Stem leaves 

 1.5 mm. long by .4 mm. wide, narrowly ovate-lanceolate, 

 about one-half costate, serrulate all round, more or less de- 

 current and margin reflexed near base, not very concave and 

 scarcely or not plicate. Median leaf-cells linear flexuous up 

 to .065 mm. long and .005 mm. wide. Alar cells short and 

 broad not forming a distinct cluster. Branch leaves very 

 similar to stem leaves but mostly a little smaller, with longer 

 costa ending in spine on back and adjacent cells sometimes 

 papillose by the projecting upper ends. Inner perichaetial 

 leaves pale, ecostate, gradually narrowed to a slender, flexu- 

 ous, serrulate point, with rarely 1 or 2 coarse teeth at its base. 

 Capsule nodding, curved, with lid about 2.5 mm. long and 1 

 mm. broad. Lid conical, its height about equal to basal di- 



