178 American Midland Naturalist Monograph No. 6 



In streams and falls, occasionally in swamps. Europe, Africa, Canada 

 and the United States. 



Known in our region only from a creek west of Linesville, Crawford County, Pa., Aug. 

 4, 1909. O.E.J. (Det. by Winona H. Welch). 



10. Fontinalis Lescurii Sullivant 



Loose, soft, green to glossy golden-green: stems long, reaching sometimes 

 3 or 4 dm naked and blackish below, dividing and branching irregularly except 

 sometimes at the apex, where the branches may be arranged pinnately; leaves 

 erect-spreading, soft, obscurely three-ranked, concave, clasping at the base, 

 lance-ovate to lance-oblong and rather acuminate to a somewhat obtuse apex, 

 slightly denticulate at the apex, usually about 4-6 mm long; median leaf-cells 

 about 12-15:1, elongate-linear, flexuous, the apical and basal shorter and 

 broader, the alar enlarged oblong, inflated, forming quite distinct auricles; 

 perichaetia numerous towards the base of the stems, perichaetial leaves sheath- 

 ing, the inner rounded-obtuse, broadly oval, reaching nearly to the apex of 

 the mature capsule: capsule short, sub-cylindric, enclosed by the closely fold- 

 ing perichaetial leaves until almost mature, about 2.5:1; lid long-conic; peri- 

 stome-teeth red-orange, papillose, about 20-25-articulate, the inner peristome 

 more or less compeltely united into a lattice-work at the apex but free and 

 merely appendiculate below; spores mature in summer. 



On stones in streams from Nova Scotia to Georgia and west to Tennessee 

 and Oklahoma. 



Rare in our region. Huntingdon Co.: T. C. Porter. (Porter's Catalogue). -Mc- 

 Kean Co.: Bradford. D.A.B. (Porter's Catalogue). 



2. DiCHELYMA Myrin 



Dioicous; antheridial shoots small, gemmiform; archegonial shoots long; 

 slender to robust, shining, green to golden-brown, blackish below; branching 

 various, the branches recurved at the apex; leaves 3-seriate, falcate-secund to 

 circinate, lance-subulate from a slightly decurrent base, carinate-plicate, weakly 

 serrate; costa complete to long-excurrent; median leaf-cells linear, narrow, the 

 alar not wider; inner perichaetial leaves long, tubular, sinistrorsely wound 

 around the seta: seta long; capsule ovate, soft, brownish; peristome-teeth 16, 

 lance-linear, obtuse, papillose, spreading either when damp or when dry, often 

 more or less cleft or divided along the median line, trabeculae low and dis- 

 tant; inner peristome longer and sometimes falling away with the operculum, 

 segments filiform, more or less united; lid about as long as urn, conic, mostly 

 oblique and curved; calyptra enclosing the whole capsule, split along one side, 

 sinistrorse; spores small and uniform in size. 



A rather widely distributed genus of 5 or 6 species; 4 species occurring in 

 North America; 2 species in our region. 



Key to the Species 



A. Leaves subulate; costa long-excurrent 1. D. capillaceum 



A. Leaves acute; costa complete or almost so, subpercurrent to slightly excurrent 



2. D. pallescens 



