OF WESTERN PENNSYLVANIA 321 



broadly linear, prosenchymatous, about 8-12:1, the basal a 

 little shorter and wider, the alar either not differentiated or a 

 few sub-quadrate to rectangular and incrassate : seta slender, 

 about 1.5 cm. long, castaneous, somewhat twisted; capsule 

 oblong, about 2-3:1, about 2 mm. long, slightly curved and 

 somewhat inclined when young, when old and empty arcuate, 

 horizontal, plicate, castaneous, and constricted below the 

 mouth ; annulus large, double ; lid conic ; exothecial cells small 

 and rounded in three or four series at the rim, gradually be- 

 coming oblong-rectangular or irregular-oblong below, the 

 upper more or less distinctly castaneous-collenchymatous ; 

 peristome small, the teeth lance-subulate, papillose above, 

 dorsally transversely striolate below, strongly trabeculate and 

 lamellate, slightly confluent at base ; segments nearly as long, 

 narrow, not split, papillose, yellowish, basal membrane about 

 two-fifths as high ; cilia strong, nodose, often about as long as 

 the segments, 1 or 2 in number; spores more or less greenish- 

 yellow, about .008-.011 mm., papillose, rather thin-walled. 



On rich woods-humus in moist w r oods or in peat bogs ; 

 Europe, and from Canada to Georgia and Texas. Uncommon 



in our region. 



Cambria : Ebensburg. T. P. James. (Porter's Cata- 



logue). 



Crawford : In swamp near Hartstown, May 29-31, 



1909. O. E. J. and G. K. J. (Figured). 



McKean : East Branch Swamp, Bradford, July 1, 



1896. D. A. B. 



19. PLAGIOTHECIUM Bryologia Europe. 



Antoicous or dioicous, rarely polyoicous : usually more or 

 less robust, mostly softly cespitose, bright to yellowish or 

 whitish-green, lustrous: stems creeping to ascending, or in 

 thick cushions erect, with ascending and small-leaved stolons, 

 mostly irregularly branched ; branches often elongate-flagelli- 

 form ; paraphyllia none; leaves uniform, obliquely inserted, 

 non-plicate, distichous, concave from a narrow 7 and more or 

 less decurrent base, broadly lanceolate to ovate, acuminate, 

 mostly plane-margined and entire ; costa short, mostly double, 

 sometimes none ; median leaf-cells chlorophyllose, elongate- 

 rhomboid to linear, thin-walled, the basal shorter and wider, 

 the alar lax and hyaline : seta long, reddish, drying twisted ; 

 capsule erect to cernuous, with collum, oblong to cylindric, 

 symmetric to weakly dorsally gibbous, drying wrinkled or 

 smooth and often arcuate; annulus mostly revoluble ; peris- 

 tome-teeth yellowish, confluent basally, lance-subulate, mostly 

 hyaline-bordered, the divisural zigzag, the teeth dorsally cross- 

 striate, numerously lamellate ; lid convex-conic, acute to rarely 

 rostrate. 



