BARNES — NORTH AMERICAN MOSSES. 335 



rate alar ones; costa double, distinct; perichsetial leaves serrulate, abruptly 

 narrowed to long, hair -point-like acumen: capsules straight, sub-erect, 

 cylindric, wide mouthed; segments free, longer than teeth; lid conic, 

 short apiculate: monoicous. Mac. Cat. 173.— On decayed tree trunks: 

 Lake Nepigon. 



418. Pylaissea Selwynii Kindb.— Differs from P. intricata in denser, 

 darker green tufts: leaves broader, short-acuminate, reflexed to acumen at 

 one border or both; the short alar and marginal cells more numerous: cap- 

 sule short oval; segments adhering to two-thirds of teeth. Mac. Cat. 174. 

 — Very abundant on old cedar fences: Ottawa. 



4 19. Pylaissea fllari-acuminala C. M. & Kindb.— Agrees with P. vel- 

 utina in leaves filiform acuminate, but acumen distinctly denticulate, 

 often twisted; alar cells more numerous: capsule thicker, oblong; peristomial 

 teeth nearly free from segments; lid not found. Mac. Cat. 174. — On logs 

 subject to inundation: Revelstoke, B. C. 



420. Hoinalothecinm sericeum Sch. — Stem pinnate, creeping; branch 

 leaves narrow, ovate lanceolate, short-decurrent, long subulatft or fili- 

 form acuminate, plicate, faintly denticulate nearly all around or sub-entire; 

 margin scarcely reflexed; cells narrow, alar quadrate; costa long, vanish- 

 ing in base of acumen; perichaetial leaves scarcely plicate, attenuate to a 

 filiform point: capsule erect, sub-cylindric, straight or slightly curved; 

 teeth pale; segments .«hort, basilar membrane high, to one-third the seg- 

 ments; cilia none; annulus broad: dioicous. Mac. Cat. 176. — On bark of 

 trees: Vancouver Island; on rocks: Rocky Mountains. 



420a. Homalothecium sericeoides 0. M. & Kindb. — Differ from H. 

 sericeum in branch leaves more densely crowded, not decurrent, narrower, 

 heteromorphous; some long acuminate, sub-entire, less reflexed at mar- 

 gins; others short-acuminate, strongly reflexed at margins to serrulate 

 acumen: capsules and seta unknown. Mac. Cat. 175. — Crevices of granite 

 rocks: Revelstoke, B. C. 



421. Uomalothecinm Nevadense subulatum Ren. & Card. — Leaves 

 long acuminate subulate, generally less plicate. Hedwigia 32: 253.1893. 

 H. sericeoides C. M. & Kindb., Mac. Cat. 175. — Washington; Idaho; 

 British Columbia. 



422. Homalothecium corticolum Kindb.— Tufts dense, glossy: stems 

 pinnate, creeping; branches densely crowded, curved: stem leaves ovate, 

 abruptly narrowed to recurved or straight acumen; branch leaves ovate- 

 oblong, acute or short-acuminate, straight; all leaves more or less denticu- 

 late and reflexed all around ; alar cells quadrate, not numerous, marginal 

 also quadrate, others oblong-rhomboidal; costa stout, vanishing above 

 middle; perichaetial leaves entire, long-acuminate: capsule cylindric- 

 oblong, larger, slightly curved; teeth yellow; segments with high basilar 



