282 American Midland Naturalist Monograph No. 6 



Three species, on trees: one in Japan and Korea, one in Nepal, and the 

 following: 



1. SCHWETSCHKEOPSIS DENTICULATA (Sullivant) Brotherus 



(Leskea denticulate Sullivant) 



Plate XXXVI 



Light green, soft, silky: stems usually 2-3 cm long, sometimes more, irregu- 

 larly branched, paraphyllia none; stem-leaves erect-spreading, close, concave, 

 ovate, somewhat decurrent, abruptly and narrowly acuminate, 0.4-0.9 mm long, 

 0.3-0.4 mm wide, plane-margined, sometimes slightly striate, marginally 

 undulate-denticulate; ccostate; apical leaf-cells dorsally uni-papillate, the 

 median oblong-oval to elongate-rhomboidal, sometimes vermicular, about 4-8:1, 

 about .005-.008 mm wide, the marginal uni-seriate and curvi-linear, the alar 

 forming a large group of quadrate incrassate cells; branch-leaves smaller and 

 less abrupdy acuminate, with more oblong and shorter cells: seta yellowish- 

 red, slender, tortuous, erect; capsule erect or nearly so, oblong, about 2-3 : 1 ; 

 operculum conic-rostrate, about two-thirds as long as the urn; peristome about 

 the same width as the teeth; no cilia; no annulus; fruit rarely found. 



Mostly on bases of trees, rarely on rocks, occurring in Asia and from Con- 

 necticut to the Mississippi River and south to the Gulf. 



Apparently rare in our region. Butler Co.: On base of tree, 2 mi. s.e. of Browns- 

 dale, Aug. 18, 1935. Sidney K. Eastwood. McKean Co.: Lewis's Run, Bradford, No- 

 vember 24, 1895, and Limestone Creek, Bradford, December, 1896. D.A.B. (figured). 

 The latter issued as Grout's No. 134, North American Musci Pleurocarpi. 



Family 33. Sematophyllaceae 



Autocoius or dioicous; antheridial clusters gemmiform, small; archegonial 

 clusters on very short, usually rooting, perichaetial branches: slender to robust, 

 cespitose, green to yellowish or brownish, often lustrous: stem without central 

 strand, creeping to ascending, mostly irregularly branched, sometimes more or 

 less regularly pinnate; paraphyllia none; leaves pluriseriate, mostly uniform 

 and symmetric, of various forms; costa double, very short or none; cells mostly 

 prosenchymatous, smooth or papillose, in the leaf-angles one row being oblong, 

 inflated, thin-walled: capsule exserted, mostly cernuous to pendent, mostly oval 

 to oblong, usually unsymmetric, collum weak; exothecial cells collenchymatous; 

 annulus none; peristome-teeth as long as the segments, the latter rarely lacking, 

 the teeth mostly entirely separate, mainly dorsally striate, lamellae mostly well- 

 developed, inner peristome free, basal membrane high, segments mostly carinate 

 and lance-subulate, rarely filiform, cilia usually present; spores mostly small; 

 !id from a convex-conic base slenderly rostrate; calyptra mostly cucullate and 

 glabrous. 



A rather large family almost exclusively of tropic and sub-tropic distribu- 

 tion and mostly living on trees; in our region there occurs but one genus, as 

 follows: 



