154 A MANUAL OF MOSSES 



A cosmopolitan common on earth in pastures, etc., also on 

 dry banks, stones, walls, etc. 



Allegheny : Vacant lot, Pittsbm-gh, May 31, 1905 O 



E.J. 

 Butler : Bank of Buffalo Creek, West Winfield 



May 26, 1906. O. E. J. 

 Center : Sandy Barrens near Scotia, July 16, 1909. 



O. E. J. 

 Clinton : Roadside, Lock Haven to Vilas, July iS, 



1908. O. E. J. 



Huntingdon : Hillside near Birmingham, Mav 17, 1904 

 O. E. J. 



Mercer : West Branch, April 14, 1894, and along 



retaining wall, foot of Cliff Street, Brad- 

 ford, May 26, 1897. D. A. B. 



Westmoreland : Chestnut Ridge, above Hillside, ^lay 23, 



1909. O. E. J. (Figured). 



8. Bryum argenteum [Linnaeus] Hedwig. 

 (Plate XX) 



More or less densely cespitose, more or less whitish and 

 silvery green: stems short, radiculose, with numerous lateral 

 innovations ; leaves closely imbricated, deeply concave and so 

 numerous that the branches are terete and julaceous, leaves 

 small, about 1 mm. long, widely ovate or obovate, slightly or 

 not at all decurrent, margins plane, entire, acute to long-acumi- 

 nate, when dry silvery shining and hardly altered in shape; 

 costa thin, wide, disappearing in upper third of leaf; leaf-cells 

 rhomboid-hexagonal above, below rectangular, all somewhat 

 pellucid and incrassate, the lower half of the leaf more or 

 less chlorophyllose, the upper half colOiless : seta slender, lus- 

 trous, usually chestnut-colored below, pale above, often dark 

 when old, flexuous, 1-1.5 cm. long; capsule about 2 mm. long, 

 oblong, the neck short and hardly tapering, by a quick turn at 

 the apex of the seta pendent and often touching the seta at 

 its wider part, somewhat constricted below the mouth when 

 dry and empty, dark brown when old ; annulus wide, revoluble ; 

 peristome-teeth linear lanceolate, yellowish-pellucid, hyaline at 

 apex, trabeculate, lamellate, divisural zigzag; segments nearly 

 as long, carinately split and gaping, faintly yellowish-pellucid, 

 cilia as long as segments, three in number, appendiculate, basal 

 membrane half as high as teeth ; exothecial cells quadrate to 

 hexagonal, densely incrassate and orange-pellucid, the upper 

 eight to ten rows smaller, less densely incrassate, rounded- 

 quadrate to laterally elongate; operculum convex, apiculate, 

 orange; spores .010-014 mm., smoothish, yellowish-pellucid: 

 dioicous : mature in October to November. 



