298 American Midland Naturalist Monograph No. 6 



alae, narrowed, sometimes striate when dry, margin plane or slightly recurved 

 at the base; costa reaching to the middle or a little farther; median leaf-cells 

 narrow to linear, about 8-15:1, the apical shorter, the basal shorter, the median 

 basal enlarged, rounded to oblong ,incrassate, sometimes porose, the alar some- 

 what smaller, oblong to sub-quadrate, incrassate and somewhat opaque; stem- 

 leaves similar, rather scattered, usually smaller and narrower, about 1.5x0.6- 

 0.7 mm, narrowly triangular-ovate; perichaetial bracts more or less erect, partly 

 sheathing: seta papillose in the upper half, brown to blackish, stout, 1.5-2.0 

 cm long, sinistrorse below, sometimes dextrorse above; capsule about 1.5-2.5 x 1 

 mm, turgidly oval-oblong, blackish when old, dcrsally gibbous, horizontal to 

 sub-erect, somewhat unsymmetric; lid conic-acute about 0.6-0.8 mm long; annu- 

 lus simple, persistent; peristome-teeth castaneous, confluent at base, strongly 

 irabeculate and lamellate, prominently margined by the projecting lamellae, 

 dorsally cross-striolate below, hyaline and papillose at apex; segments narrow, 

 carinately split but usually not widely gaping, yellowish, nearly as long as 

 teeth, the basal membrane about one-third as high; cilia 2, nodose, hyaline, 

 appendiculate below, about as long as the segments; spores smooth, medium- 

 walled, brownish, about .013-.017 mm, mature in autumn. 



In streams, or on moist rocks, in non-calcareous habitats; Europe. Asia, 

 Hawaiian Islands, and from Newfoundland to British Columbia and south in 

 the mountains to Alabama; Florida. Very common in our region. 



Now known from the following counties: Allegheny, Armstrong, Beaver. Bedford, 

 Butler, Centre, Erie, Fayette, Greene, McKean, Washington, and Westmoreland. Speci- 

 men figured: Wildwood Hallow, Allegheny Co., Nov. 19, 1908. O.E.J, and G.K.J. 



12a. Brachythecium flagellare var. homomallum 



(Bryologia Europaea) Jennings 



(B. plumosum var. homomallum Bryologia Europaea) 



Plate LVII 



This variety differs from the type of the species in having the leaves dis- 

 tinctly falcate-secund and branches curved at tip. It is said to be generally 

 smaller with narrower leaves and with the capsule small and ovate. In the 

 same pockets with typical B. flagellare can often be found specim.ens with 

 characters approaching more or less closely the variety. The following pocket 

 of specimens perhaps typical of the variety: 



McKean Co.: Gate's Hollow, Bradford, April 18, 1897. D A.B. (figured). 



5. Cirriphyllum Grout 



Dioicous: robust, widely cespitose, whitish to yellowish-green, rarely darker, 

 mostly lustrous: stem creeping to ascending, often stolon-like, pinnately to 

 fasciculately branched, often with flagellae; branches ascending to erect, more 

 or less densely-leaved and julaceous; leaves uniform, often spreading, often 

 drying imbricate, very concave, somewhat weakly plicate, ovate to oblong from 

 a somewhat narrowed and decurrent base, more or less abruptly lanceolate to 



