160 A MANUAL OF MOSSES 



to Georgia and west to Wyoming. (Lesquereux and James in 

 their manual say: "More generally on quartz or schistose 

 rocks.") Although frequently reported from the eastern part 

 of Pennsylvania, the only report of this species in our region 

 is : 



Cambria : James. (Porter's Catalogue). 



2. Mnium orthorrhynchum (Bride!) Bryologia Europ;.ea. 

 ( Astrophyllinn orthorrhynchum Ljndberg). 



Quite similar to M. serratnin but the leaf-cells only about 

 .015-.018 mm.; densely tufted; leaves close, oblong-lanceolate, 

 doubly spinose-serrate from below the middle ; costa usually 

 ending in the apiculation, toothed dorsally above ; leaf-cells 

 angular, hexagonal to quadrate, incrassate, non-collenchyma- 

 tous : seta solitary, red ; capsule elliptic-oblong, tapering into 

 the neck, straight and more or less horizontal, brownish ; 

 operculum shortly rostrate; dioicous, antheridial Mower dis- 

 coid. Mature in late summer. 



On moist rocks, usually calcareous, along cool shaded 

 ravines and streams : Europe, Asia, North America from 

 Greenland to British Columbia south to Colorado, Montana, 

 New York, and Pennsylvania. In our region one report : 



Blair : Porter. (Porter's Catalogue). 



3. Mnium serratum Schrader, Schwaegrichen. 

 (M. marginatum Beauvois ; Astrophyllinn margingtum Lindberg). 



(Plate XXI) 



Loosely cespitose in soft tufts, rather dark green : stems 

 and lower leaves often deep reddish tinged, stems slender, 

 rather short, usually 1.5-3 cm. in our specimens, simple or 

 branched below with erect branches; leaves rather remote, 

 strongly decurrent, the lower ovate-lanceolate, the upper ob- 

 long spatulate-lanceolate, all acute and apiculate, the strong 

 red border sharply doubly serrate, the leaves when dry more 

 or less twisted but hardly crispate ; costa in upper leaves con- 

 rluent with the border in the apiculus but in the middle and 

 lower leaves and often even the upper leaves of sterile shoots 

 the costa ends below the apex, not spinose ; leaf-cells from 

 .020-.030 mm. in diameter, irregularly rounded, somewhat 

 incrassate, strongly collenchymatous, the basal elongate : seta 

 mostly single; capsule horizontal, yellowish to brown, oval- 

 oblong, tapering at neck; peristome yellow or sometimes 

 brown, inserted, the teeth lance-linear, pellucid yellowish- 

 brown, papillose above, strongly trabeculate, divisural faint ; 

 segments a little shorter than teeth, papillose above, slender, 

 cilia 3 (2), the basal membrane reaching somewhat above the 

 middle; spores, smooth, rounded, about .025-.030 mm.; oper- 

 culum stoutly short-rostrate: synoicous : mature in spring. 



