Jennings: Manual of Mosses — 4. Fissidentaceae 75 



In swampy woods and along streams, quite widely distributed in the 

 cooler portions of the Northern Hemisphere, reaching the northern United 

 States and south to Missouri, Ohio, North Carolina, Georgia, and Tennessee. 

 It occurs in eastern Pennsylvania and in Ohio but has not yet been found in 

 western Pennsylvania. 



10. FiSSIDENS SUBBASILARIS Hedwig 

 Plate XVI 



Cespitose in wide mats, 5-10 mm high, erect or ascending, green, brownish 

 tomentulose at base: stems branching at base; leaves usually in 10-18 pairs, 

 crisped when dry, widely spreading to ascending, close, imbricate, those in 

 middle of stem often largest, the largest reaching about 1.5 mm, the sheath 

 reaching about three-fifths the length of the leaf, leaf oblong, rather obtuse, 

 but apiculate with a pointed cell, non-bordered, minutely crenulate below, 

 irregularly serrate above, the inferior lamina ceasing abruptly at the base; leaf- 

 cells incrassate, and rather obscure, small, about .007-. 01 2 mm, roundish- 

 hexagonal; the costa ending considerably below the apex: seta smooth, arising 

 from basal part of stem, ascending, usually about 3-5 mm long and reaching 

 about to the top of stem, light chestnut-color; capsule cylindric-oval, about 1.5 

 mm long, smooth, chestnut-color to dark brown, tapering at base, erect or very 

 nearly so; calyptra narrowly cucullate; operculum conic, obliquely rostrate to 

 about one-half the length of capsule; peristome rich chestnut-color, strongly 

 trabeculate, not papillose, the teeth slightly inserted, bifid to about the middle 

 into two slender prongs; spores smooth, pale yellowish pellucid, round, about 

 .016-. 018 mm in diameter. Mature in late autumn. 



On earth and on rocks and bases of trees, Ontario and southwards 

 through our Eastern States to the Gulf. 



Now known from the following counties: Allegheny. Butler, Fayette, Indiana, Mc- 

 Kean, Somerset, Tioga, Washington, and Westmoreland. Specimen figured: On base of 

 white oak, Douthett, southern Butler Co., O.E.J. Dec. 27, 1908. 



3. OcTODiCERAS Bridel 



{Conomitrium Montagne) 



Plants slender, fasciculately branching, floating, filiform: leaves remote, 

 lance-linear, short-auriculate : flowers monoicous, the male axillary, the female 

 on elongated branchlets; seta short; capsule thin-walled, erect, very small, 

 without stomata; calyptra minute, conic, undivided, covering only the rostrum 

 of the operculum; opserculum conic-rostrate; peristome-teeth variously laciniate 

 or entire and evidently degenerate; annulus none; spores about .018-.025 mm. 



This genus includes about 20 species of aquatic mosses more or less resem- 

 bling Fontinalis in general appearance, widely distributed over the earth, — 2 

 species occurring in eastern United States, one already found and another 

 likely to be found in our region. 



Key to Species 



A. Large much-branched plants, up to 15 cm. long: seta shorter than the capsule 



1. O. debile 



