284 American Midland Naturalist Monograph No. 6 



ly trabeculate; segments about as long, slender, rarely split, the cilia 1 (or 2), 

 about one-half to two-thirds as long as segments, the basal membrane about 

 two-fifths the height of the peristome; lid comparatively large, the beak oblique, 

 subulate, and about two-thirds to three-fourths as long as the urn; spores 

 smooth, yellowish-incrassate, usually chlorophyllose, about .014-.018 mm, 

 mature in summer or early autumn. 



On wet non-calcareous rocks, mainly in ravines in hilly or mountainous 

 districts; Asia, and from Newfoundland southwards to Georgia. 



Probably not common in our region. Allegheny Co.: Haysville Hollow, September 

 20, 1908. O.E.J.; on damp rocks under hemlocks, Wildwood Road, November 19, 1908. 

 O.E.J, and G.K.J. Fayette Co.: On damp rocks in deep hollows and ravines, Ohio 

 Pyle, September 1-3, 1906, and September 1-3, 1907. O.E.J, and G.K.J, (figured); also 

 May 30-31, June 13, and July 4, 1908. O.E.J.; Ohio Pyle, June 15, 1902. J.A.S. 

 Somerset Co.: Near Trent. C. M. Hepner, July, 1932; and Clear Run, Laurel Ridge, 

 C.M.B. Oct. 6, 1935. On wet rock in stream. Westmoreland Co.: Four collections 

 in Laurel Hill and Chestnut Ridge Mts. C.M.B. 1934-45. 



2. Sematophyllum marylandicum (Mueller) E. G. Britton 



{Rhaphidostegium marylandicum Jaeg. & Sauerb.; Hypnum marylandicum C. Mueller) 



Plate LII 



Dark green loosely interwoven, matted mosses with often subsecund at 

 stem- and branch-tips, oblong-ovate, shortly acuminate to acute, 1.5-2 mm 

 long, concave, entire, margin not reflexed; median leaf-cells linear, about 8- 

 12:1, shorter, incrassate, and pellucid at base, alar cells inflated in a small 

 group, apical cells about 2-4:1, rhomboid-oblong; spores ripe in spring. 



On wet stones and ledges in cool mountainous habitats from New Eng- 

 land to Georgia. 



This species is very difficult to distinguish from Hygrohypmim eugyrium 

 var. Macktyt, but the Hygrohypnum has usually a faint double costa, some- 

 times lacking, and the walls of the outer alar cells are much thinner than are 

 the walls of the inner cells. 



McKean Co.: Cathrine Swamp. C.M.B. Sept. 2, 1948 (figured). Somerset 

 Co.: Bluehole Creek, Laurel Ridge. C.M.B. On rock in stream. July 5, 1948; and H. 

 N. Mozingo, wet rock in stream, near Mt. Davis, Aug. 26, 1945. 



3. Sematophyllum adnatum (Richard, Michaux) Britton 



(Lesked adnata Richard; Rh. microcarpum Jaeger; Leskea microcarpj 

 Bridei; Rhaphidostegium adnatum Bryologia Ejropaea) 



Small, in tangled, thin, green to golden-green mars: stems prostrate, with 

 short and incurved branches; leaves rather closely imbricate when dry, sub- 

 homomallous, the upper usually distinctly secund, narrowly oblong-lanceolate, 

 the apex rather shortly acuminate, subserrulate to entire, margins quite broad- 

 ly reflexed; costa double but very short and faint; median leaf-cells linear-fusi- 

 form, flexuous, about 8-12:1, shorter and wider at the base, tov/ards the angles 

 a border of sub-rectangular and scarcely inflated cells and at the extreme angle 

 a few distinctly inflated alar cells: seta short and smooth, abou.t 5-8 mm long; 

 ca lyptra more or less persistent, cuculiate, reaching to a little below the mouth 



