Jennings: Manual of Mosses — 31. Hypnaceae 271 



rostellatc; peristome-teeth with rather distant articulations, ciha short and 

 unequal; annulus 1-seriate; spores mature in autumn; dioicous. 



On moist earth and rocks in cool ravines, etc., mostly in hilly or moun- 

 tainous regions; Europe, Asia, and from northeastern Canada to Ohio and 

 Minnesota, and southward in the mountains to North Carolina. Not yet 

 reported from^ our region but to be expected, — especially in the more moun- 

 tainous portions. 



2. IsoPTERYGiUM ELEGANS [Hooker] Lindberg 



(Hypnum elegan<: Hooker; Isothecium elegans Bridel; 

 Plagiothecium elegans Suliivant) 



Plate LXVIII 



Small, densely cespitose, thin, pale shining green: stems branching irregu- 

 larly, the branches slender, partly procumbent, partly ascending, numerous, 

 usually pointing one way; usually there are also axillary, gemmiferous branch- 

 lets; leaves complanate, sub-distichous, the points usually pointing downwards, 

 lustrous, little changed when dry, about 1-1.5 mm long, lance-oblong to ovate- 

 oblong, rather gradually narrowed from about the middle, then abruptly nar- 

 rowed to a fine, short acumen, the base rounded, non-decurrent, plane-mar- 

 gined, entire except at the acumen where a little denticulate; costa double and 

 short, faint or sometimes reaching one-third the length of the leaf; median 

 leaf -cells narrowly linear, about 20-30:1, about .004-. 007 mm, pointed, hardly 

 differentiated at the angles; perichaetial leaves lance-acuminate: capsule turgid- 

 ovoid, slightly inflated at the curved neck, nearly symmetric but horizontal or 

 sub-pendent by a curve in the upper part of the seta, when dry and empty 

 somewhat wide-mouthed, turbinate, costate; peristome hypnoid, yellow, teeth 

 broadly lanceolate, blunt, segments entire, cilia 3, rather slender, as long as 

 the segments; annulus simple; lid conic, obtusely pointed; spores mature in 

 spring. 



On rocks or earth usually in moist, cool crevices of ledges, etc., in hilly 

 or mountainous regions in woods: Europe, Asia, and from Arctic America to 

 northern United States and south in the mountains to North Carolina and 

 Tennessee. 



Armstrong Co.: At small waterfall, west bank Allegheny River. 2 mi. n. of Parkers 

 Landing. C.M.B. June 10, 1934. McKean Co.: D. A. Burnett. (Porter's Catalogue). 

 Westmoreland Co.: On rock clifF, Meadow Run at Jacobs Creek. C.M.B. Aug. 18, 

 1945 (figured). 



3. IsoPTERYGlUM DEPLANATUM (Sullivant) Mitten 



(Hyprium deplanatum Sullivant; Rhynchostegium deplanatum Schimper); 

 Plagiothecium deplanatum Grout) 



Plate LXIX 



Golden-green, lustrous, small, flattened: stems prostrate, irregularly pin- 

 nately branching; leaves 2-ranked, imbricate, giving stems and branches a 

 plaited appearance, thin, concave, ovate-lanceolate, gradually long-acuminate, 

 s-errulate all around, more sharply so above, plane-margined; median leaf-cells 



