BARNES — NORTH AMERICAN MOSSES. 351 



acuminate, above coarsely and irregularly dentate, costa divided or 

 obsolete: capsule sub-erect, oblong, sub-symmetric; lid not known; teeth 

 long subulate, densely articulate; cilia more or less elongated, nodulose. 

 Bot. Centrabl. 44: 423. 1890. On trees: Washington. 



509. Thamnium alopecurum Sch. — Plants robust: primary stems 

 stoloniform, radicant, stout, with erect or inclined stems 8-12 cm. long; 

 stems simple up to a certain height and distantly foliate, then branching; 

 branches close, sub-distichous, having a dendroid aspect: tufts large and 

 lax, dark green: branch leaves erect spreading, loosely imbricate, oval ob- 

 long, acute, coarsely dentate above; costa strong, ridged dorsally, vanish- 

 ing near apex; cells rounded, oval or oblong, a little longer at base: diocious: 

 pedicel smooth, arcuate at summit: capsule oblique or sub-horizontal, oval 

 or oblong, contracted below orifice; lid conic, long rostrate. Husnot, Muse. 

 Gall. 347. — In damp places along rocky clififs: British Columbia. 



510. Thamnium Leibergli Britton. — Dioicous: perichsetial leaves, 

 ecostate, with recurved apices, entire or slightly serrulate; leaves costate to 

 just below apex, entire or slighty serrulate below, coarsely serrate above: 

 pedicel 1 cm. long, falling oflE with capsules when old; inner peristome, 

 with three appendiculate regular cilia as long as the teeth or occasionally 

 irregularly united into one or two and scarcely appendiculate. Bull. Torr. 

 Bot. Club 1 6: 211. 1889.— On quartzite ledges, Idaho. 



511. Thamnium Holzingeri Een. & Card. — Green, slender, rather re- 

 sembling in habit small forms of Isotheoium myosuroides: primary 

 stems creeping, stoloniform, secondary ascending or decumbent, more or 

 less shrub-like, pinnate; branches complanate, generally attenuate: lower 

 stem leaves small, erect spreading from a broadly deltoid base, ligulate-ob- 

 tuse; costa vanishing about base of acumen; upper leaves larger, distich- 

 ous, complanate, slightly asymmetric at base, oblong ligulate, obtuse or 

 sub-obtuse; costa vanishing far from apex, sometimes forking above; branch 

 leaves smaller, with the costa shorter and the lower margin inflexed: upper 

 leaves acute; all the leaves plane and crenulate-serrulate on the margins, 

 coarsely and irregularly dentate at the apex; cells parenchymatous, in- 

 crassate, short, chlorophyllose, roundish or sub-hexagonal above, ovate or 

 oblong in the middle, sub-linear below, alar small rather obscure sub-quad- 

 rate or roundish; inner perichsetial leaves sub-vaginant, oblong lanceolate, 

 long loriform-acuminate, serrulate; costa thin; cells narrower: pedicel 

 smooth; capsule erect, oblong, sub symmetric, constricted under orifice 

 when dry; lid conic, obliquelybeaked; teeth yellowish, lanceolate-acuminate, 

 subulate; segments narrowly split along divisural line, cilia 2 long nodose 

 Bot. Gaz. 19: 239. 1894.— Oregon. 



512. Plagriothecinm denticulntum microcarpum Ben. & Card. — Cap- 

 sule very short and turgid, scarcely 1.5 mm. long; pedicel thick, flexuous, 

 often geniculate at base. Bot. Gaz. 14: 98. 1889. — Idaho; Washington. 



