OF WESTERN PENNSYLVANIA 301 



Alaska south to the northern United States, and southwards 



in the mountains. Rare in our iregioii. 



McKean : In deep, densely shaded ravines, altitude 



1700 feet, along Marilla Brook, one-half 

 mile above Bradford, April 21, 1897. 

 D. A. B. (Figured). 



3. Hylocomium brevirostre [Ehrhart] Bryologia Europsea. 



(Hypnuin brevirostre Ehrhart; H. interruptum Bridel). 



(Plate XLIV) 



Robust, rigid, forming large, swollen tufts of a dark but 

 glossy yellow-green : stems much-divided, up to 12-15 cm. 

 long, erect to arched-procumbent, irregularly pinnately 

 branched, the branches unequal, attenuate, not complanately 

 arranged, but bushy, paraphyllia rather small, branched, stems 

 reddish-brown ; stem-leaves somewhat crowded, spreading to 

 squarrose, about 2-A mm. long, cordate-ovate to triangular- 

 ovate, abruptly narrowed to a rather long channeled acumen, 

 the base notably with large rounded, sub-clasping, and some- 

 what decurrent auricles, the margins finely and regularly 

 denticulate, the leaves when dry much plicate ; branch-leaves 

 smaller, narrower, more ovate, less squarrose; perichsetial 

 leaves sheathing at base, subulate-acuminate, squarrose, apical- 

 ly serrate ; costa of stem- and branch-leaves double and reach- 

 ing to about one-third the length of the leaf: seta flexuous, 

 about 2 cm. long, dextrorse and arcuate above, castaneous; 

 capsule turgidly ovate-oblong, horizontally inclined, the urn 

 about 2 mm. long, castaneous, arcuate and constricted below 

 the mouth when dry; lid conic-acuminate, about 1 mm. long; 

 annulus usually 2-seriate, rather wide; peristome hypnoid, 

 teeth orange-yellow, dorsally lamellate, cross-striolate below, 

 papillose above, moderately trabeculate, confluent and inserted 

 at base; segments slender, about as long as teeth, yellowish, 

 carinately gaping, finely spinose-papillose above, the basal 

 membrane about two-fifths as high; cilia usually 2, short, no- 

 dose-appendiculate ; exothecial cells laterally strongly castane- 

 ous-incrassate, rounded-hexagonal to rounded-rectangular; 

 spores about .021-024 mm., oblong to round, castaneous, 

 moderately incrassate, somewhat papillose, mature in early 

 spring. 



In deep, shaded ravines and in swamps on locks and at 

 the bases of trees, usually confined to mountainous regions; 

 Europe, Asia, northern Africa, and, in North America, from 

 Nova Scotia to Ontario and sottth in the mountains to North 

 Carolina. Rather common in our region. 



Blair : T. C. Porter. (Porter's Catalogue). 



Cambria : T. P. James. (Porter's Catalogue). 



