— 70 — 



costa .020-025 mm. wide and up to .100 mm. or more long. Cross-sections of 

 costa show in the ventral half about 4 guide-cells with a few accessory cells or 

 even i or 2 rows of accessory cells nearly as large, in addition to the row of 

 mamillose cells on ventral surface. The dorsal half of costa consists of a 

 stereid band, the outer row of cells a little larger than the others with a 

 distinct central strand of small, irregular, thin-walled cells. (Plate 16.) 



Yukon River bluff, just below Dawson. Collected April 6, 1899, on rock 

 (587). 



Funaria hygrometrica arctica Berggrn. Lower Klondike River. The 

 specimens are mostly from 12 to 20 mm. high. Spores up to .024 mm. The 

 spores of hygrometrica run up to .016 or .018 mm. (691). 

 Bryuin Dawsonense R. S. Williams, sp. nov. 



Synoicous and autoicous. Tufts low, i. 5 cm. high, and dense. Stems 

 branching. Outer perichaetial leaves ovate-lanceolate, upper stem leaves 

 ovate, about 2.5 mm. long with costa excurrent the length of 2 or 3 short cells. 

 Lower stem leaves much smaller and costa not quite percurrent. Leaves 

 entire, or sometimes minutely serrulate towards apex with revolute margins 

 from base to near apex or in very young or lower leaves margins scarcely 

 revolute. Marginal cells Yz down in upper leaves narrowed and much elong- 

 ated in 3 or 4 rows but only slightly changed toward apex. Inner 

 perichaetial leaves small, lanceolate pointed, with percurrent costa. Median 

 leaf-cells rhomboidal to hexagonal, mostly 2 or 3 times longer than broad, 

 about .050 mm. long. Lower cells sometimes pitted. Capsule with lid up 

 to 2.5 mm. long. Sporangium oblong, scarcely or not contracted below 

 mouth and rather abruptly narrowed when dry to the shorter collum. Peri- 

 stome yellowish below, the lower plates of teeth mostly twice wider than 

 high, gradually becoming nearly square above; lamellae 16-18, irregularly 

 connected by 1-3 cross walls between adjoining lamellae; segments narrow 

 and narrowly perforated, separated by mostly 2 cilia, a little shorter and often 

 long appendiculate. Annulus broad, of 3 rows of cells. About 3 rows of 

 transversely elongated cells about mouth of capsule, the cells near middle 

 becoming somewhat rectangular and in collum scarcely elongated and sinu- 

 ous walled, with oblong stomata about .040 mm. long. Spores smooth or 

 nearly so, up to .025 mm. (Plate 17.) 



Dawson, on damp earth. In good fruit Aug. 28, 1898. This plant is un- 

 doubtedly close \.o pendulum differing in the short pointed leaves, more dis- 

 tinctly bordered and in the long cilia, some of which are finely appendiculate 

 (585). 



M. Philibert left me in doubt as to just what he considered this plant 

 and I have finally ventured to describe it as a distinct species rather than a 

 variet}'- oi pendulum. 



Bryum conditum R. S. Williams, sp. nov. 



Dioicous. Male plants discoid. Tufts up to 3.5 cm. high. Stems and 

 branches more or less radiculose. Outer perichaetial leaves oblong-lance- 

 olate, with a gradually narrowed base, up to 4.5 mm. long. Upper stem 

 leaves a little shorter with broader base, all entire, with costa excurrent for 



