OF WESTERN PENNSYLVANIA 149 



oblique or vertical connections between the plates, the lamellee 

 and divisural indistinct, the inner peristome more or less close- 

 ly adherent to the teeth, the segments narrov/, the cilia 2-3 

 and rudimentary, the basal membrane about two-fifths the 

 height of the teeth; spores large, .024-.030 mtti., yellowish- 

 pellucid, minutely roughened ; exothecial cells incrassate, yel- 

 lowish-pellucid, irregularly rounded-quadrate to hexagonal, the 

 upper four or five rows much snialler, rounded to transversely 

 elongate, reddish-pellucid : synoicous : mature in June. 



On earth, rocks, walls, and decaying logs. Temperate 

 regions and mountains of Europe, Algeria, Asia, and North 

 America from Greenland to Alaska and south to the northern 

 United States. Rare in our region. 



Allegheny : Sloping shaly hillside, F"ern Hollow, Pitts- 



burgh, June 8, 1909. G. K. J. (Figured). 



2. Bryum pseudotriquetrum [Hedwig, p. p.] Schwaegrichen. 

 (B. ventricosuin Dickson). 



This species is practically similar to Bryuiii binnnii in every- 

 thing except that it is dioicous. According to Dixon and Jame- 

 son's Handbook the paler, more lax-leaved, and more flaccid 

 plants usually belong to B. bint urn while the more rigid and com- 

 pact specimens are B. psendotriqiietnim, — but this is not always 

 the case. 



This species has much the same habitat and the same range 

 as does B. bimuiii, but in our region seems to be rare. In Porter's 

 Catalogue it is reported from Cresson, Cambria County, by 

 James, and in the Carnegie Museum are specimens from two lo- 

 calities in AIcKean County which were distributed as this species, 

 but which prove to be synoicous and typically B. biiiiuin. 



3. Bryum bimum [Schreber] P)ridel. 

 (MniiiiJi biiiiHin Bridel). 

 (Plate XIX) 



Rather loosely but deeply cespitose and matted together 

 with a chestnut-colored tomentum : stems usually 3-6 cm. high, 

 rather sparsely branching; leaves long-decurrent, 2-3. min 

 long, elliptic to oblong-lanceolate, shortly acuminate, the mar- 

 gins revolute almost to apex, serrulate above ; costa reddish, 

 strong, percurrent to excurrent; leaf-cells rhomboid-hexagonal, 

 the basal inflated-rectangular, the marginal in three or four 

 rows linear-prosenchymatous and more or less yellowish- 

 pellucid, forming a distinct border ; lea\es when dry more or 

 less shrunken, twisted, and appressed: seta 2.5-5.5 cm. long, 

 slender, flexuous, lustrous, castaneous ; capsule 3-^ mm. long,- 

 pendulous, brown, sub-cylindric, tapering to a neck which is 

 but slightly shorter than the rest of capsule, slightly con- 



