Pterofjonium.] BRYACE^. 289 



the middle ; paraphyllia small, polymorphous. Flowers dioe- 

 cious. Calyptra cucullate, large, covering the capsule to below 

 the middle. Capsule erect, cylindrical-oblong. Operculum 

 rostrate. Peristome small ; teeth short, linear-lanceolate, 

 strongly and distantly articulate ; segments very short, imper- 

 fect ; cilia none. Annulus very narrow. 



1. P. filiforme, Hedw. Plants widely cespitose, appresged, 

 bright or yellowish green ; branches and branchlets prostrate all 

 in one direction, filiform and flagelliform : leaves concave, 

 appressed and imbricate when dry, nari'owly reflexed on the 

 borders, serrate at the apex ; costa simple, ascending to the 

 middle, or shorter and bipartite ; cells of the basilar angles few, 

 not chlorophyllose ; perichsetial leaves pale, thin, the inner 

 oblong, short-acuminate, minutely serrate at the apex, costate 

 at base. — Muse. Frond, iv. 18, t. 7 ; Bryol. Eur. t. 466 ; Sulliv. 

 Mosses of U. States, 105. JVec/cera Jiliformis, Muell. Syn. 

 ii. 89. 



Var. cristatum. Leaves cristate-serrate at the apex ; costa 

 stronger, ascending higher. — Leptohymenium cristatu)n, 

 Hampe, Linnosa, xxx. 459. 



Var. minus. Leaves obscurely papillose, scarcely dentate 

 at the apex ; costa short, basilar, scarcely distinct ; segments as 

 long as the teeth. 



Hab. Roots of trees or shaded rocks; Nortliern States and Canada; 

 var. cristatum in California {Bolander, Bauer) ; the last in the Adirondack 

 Mountains, on rocks (Lesquereux). 



The description refers to the very common European form, ■which is, 

 however, rare in America, but is replaced by a number of varieties not 

 distinct enough to authorize specific separation. 



110. PTEROGONIUM, Swartz. (PI. 6.) 

 Primary stems very slender, with few distant pale leaves, the 

 secondary robust, in dense wide divisions ; branches and branch- 

 lets curved to one side. Leaves crowded, spreading when 

 moist, imbricate when dry, broadly ovate or obovate-acuminate, 

 serrulate, scarious, glossy ; costa flat, bipartite, vanishing below 

 the middle ; cells of nearly the whole base obliquely oval, those 

 of the middle and top linear-fusiform, all very small and 

 smooth. Flowers dioecious. Calyptra cucullate, with a few 



