162 A MANUAL OF MOSSES 



southern Canada south to Virginia, Pennsylvania, Ohio, Mon- 

 tana and Oregon. 



All Pennsylvania specimens in the Carnegie Museum Her- 

 barium which were labeled M. rostratum are non-collenchymatous 

 and the leaf-cells are definitely arranged in series radiating 

 from the costa. The species is reported from our region as 

 follows : 



Cambria : James. (Porter's Catalogue). 



Lycoming : McKimm. (Porter's Catalogue). 



6. Mnium cuspidatum Linnaeus, Hedwig. 

 (Mnium sylvaticum Lindberg). 



(Plate XXI) 



Loosely cespitose in large light to dark patches : stems 

 branching with sterile shoots prostrate or sub-erect, in our 

 specimens usually about 1.5-3 cm. high, reddish, radiculose be- 

 low r ; leaves decurrent, oblong-oval, acute, the upper tending to 

 obovate, those on the branches more rounded or oval, all 

 shortly cuspidate and serrate in the upper half or two-thirds 

 with a single row of short one-celled teeth, occasionally some 

 teeth two-celled, the border of 3-5 rows of incrassate, linear, 

 yellowish-pellucid cells ; costa confluent with the border in the 

 apiculate apex or ending a little below the apex ; leaf-cells 

 about .020-.025 mm., incrassate, somewhat collenchymatous, 

 hexagonal to somewhat rounded, the basal tending to rec- 

 tangular: seta solitary, pale yellowish or brownish, erect; 

 capsule pale yellowish or brownish, sub-pendulous, oblong- 

 oval, rather abruptly narrowing to the seta, the base and 

 mouth brown ; operculum conic-obtuse ; teeth yellow, lance- 

 linear, papillose above, divisural indistinct ; inner peristome a 

 little shorter, the basal membrane extending to the middle 

 or a little above, the basal part of the segments more or less 

 irregularly fenestrate with rounded holes, the upper part of 

 the segments finally gaping or breaking apart ; cilia three, 

 linear, somewhat appendiculate, the inner peristome brownish- 

 pellucid, the tips of the segments and the cilia being paler and 

 papillose ; spores rounded, faintly papillose, yellowish, about 

 .030 mm. in diameter: synoicous, mature in May. 



In moist woods on earth, stones, rotten logs, etc. Common 

 and widely distributed over the temperate parts of Europe, 

 Asia, and of North America. 



Allegheny : Moon Township, April, and May 18, 



1902. J. A. S. : Power's Run, April 28, 



1907, and Schenley Park, Pittsburgh, 

 May 29, 1907. O. E. T- and G. K. J. ; 

 Aspinwall. April 9, 1905, October 25, 



1908, Fern Hollow, January 21, 1906, 



