OF WESTERN PENNSYLVANIA 81 



Widely distributed in temperate regions on shaded soil, 

 in our region especially in and about greenhouses. Our speci- 

 mens show considerable variation in the arrangement of the 

 leaf-cells, either in rows or not so, and in the capsule, the 

 latter varying from erect and symmetric to arcuate. The 

 spores in our specimens are much smaller than is indicated in 

 some descriptions. 



Allegheny : In flower-pots, Phipps Conservatory, Schenley 

 Park, Pittsburgh, March 20, igio. O. E. J. 

 (Figured). 



Elk : James. (Porter's Catalogue). 



3. Fissidens obtusifolius Wilson. 



(Plate X) 



Small, densely gregarious, sometimes forming cushions, 

 usually growing at right angles to the substratum, pale green : 

 stems comparatively stout, in our specimens about 3-6 mm. 

 long, mostly simple; leaves of fertile plants about 4-8 pairs, 

 of sterile shoots about 6-12 pairs, distichous, vertical, in 

 fertile shoots closely placed, the lower small, obovate to ob- 

 long, the upper much larger, oblong, ascending to erect, obtuse, 

 the clasping portion extending above the middle, non-margined 

 except for a few elongate cells at the end of the sheathing 

 portion, entire, the apical leaves reaching to 1.5 mm. long by 

 0.3 mm. wide ; cells rounded to quadrate-hexagonal above, a 

 few at the margin of the base rectangular (up to 4:1), at the 

 apex of the sheath a few marginal cells elongate to linear, all 

 incrassate ; costa strong, disappearing shortly below the apex, 

 the dorsal lamina becoming narrow or disappearing at the 

 base : seta comparatively stout, erect, or upcurving, in ours 

 about 1.5-2.0 mm. long, brownish, smooth; the capsule erect, 

 oblong-oval to oblong-obovate, somewhat narrowed below the 

 mouth, smooth, brownish ; operculum hemispheric-apiculate to 

 very shortly rostrate; peristome yellowish-pellucid, trabecu- 

 late, the teeth lanceolate, acuminate; capsule walls with cells 

 incrassate, quadrate to hexagonal ; spores smooth, .018-023 

 mm. Mature in autumn. 



On wet rocks from New England to Minnesota, Colorado, 

 Texas, and Alabama. Rare in our region. 



F>eaver : Gorge of Little Beaver Creek, on sides of large 

 sandstone rocks in dashing current and often 

 inundated, Smith's Ferry, October 1, 1910. O. 

 E. J. (On the Ohio-Pennsylvania State Line.) 



In West Virginia on walls of Lock No. 9, Monongahela 

 River, a short distance south of the West Virginia-Pennsyl- 

 vania State Line, July 3, 1909. O. E. J. 



