ffypnum.] BRYACE^. 371 



/Species of uncertain relation. 



114. H. SUbfalcatum. Plants prostrate, intricate, cespi- 

 tose, bright green, glossy ; stems irregularly branching : leaves 

 distant, distichous, coniplanate, obliquely oblong, acute, spread- 

 ing, horizontally subfalcate by curving backward, serrate-den- 

 tate at the apex ; borders reflexed toward the base ; costa short, 

 double, the nerves of unequal length ; areolation narrowly fusi- 

 form or linear, a little shorter and broad at base. — Plagio- 

 thecium siihfalcatum, Aust. Muse. Appal, n. 366 ; Sulliv. Icon. 



Muse. Suppl. 90, t. 67. 



Hab. Crevices of rocks, in the mountains of New Jersey and New 

 York (Austin); always sterile. 



This species may be referable to a difierent subgenus. 



Subgenus XVI. AMBLYSTEGIUM. (PI. 6.) 

 Plants very small, sometimes widely expanded, creeping, 

 irregularly ramose and ramulose, without stolons. Leaves 

 spreading uniformly or subsecund, lanceolate or oval-lanceo- 

 late, generally simply costate to the middle or to the apex. 

 Flowers monoecious, rarely dioecious. Capsule suberect or cer- 

 nuous upon a smooth pedicel, oval or oblong-cylindrical, sub- 

 arcuate, of soft texture. Operculum large, mamillate, blunt or 

 apiculate. Teeth of the peristome solid, closely articulate; 

 segments entire ; cilia more or less perfect. The texture of the 

 leaves is soft, the areolation j^arenchymatous or loosely prosen- 

 chymatous, never linear or vermicular. — Amhlystegium^ 

 Schimp. 



* Leaves opaque / areolation parencJxymatous, more or less 

 cJiloro2:)hijUose : floicers monoecious, except in n. 115. 



115. H. minutissimum, Sulliv. & Lesq. Plants very 

 small, pale green ; stems prostrate, scarcely 1 cm. long, with 

 bundles of radicles, subpinnately divided into short erect or 

 spreading branches : leaves loose, open, narrowly lanceolate, 

 more or less distinctly serrulate on the borders, ecostate or 

 marked with short strias ; areolation large, oblong ; perichaetial 

 leaves large, long-acuminate, coarsely dentate above : flowers 

 with scarcely any paraphyses : capsule minute, subovate, more 



