— 272 — 



114. Pterygoneuron Juratzka. 



A. Capsule immersed; calyptra mitrilorm. Leaves with long 

 rough hairpoint. 



l.P.SUbsessile Bridel. — Gymnostomum Brid,; Pterygoneuron 

 Jur.; Pharomitrium Schimper. 



Leaves suboval or obovate subacute not reflexed, papillose at 

 back. Capsule oval-globose; pedicel shorter; lid rostrate; peri- 

 stome none. Stem 2 — 5 m. m. high. — Sand and clay t. 

 Eur. Austria: Berggren. Germany: Schultze> Amer. Can.: Ma- 

 coun. 



B. Pedicel exserted; calyptra cucullate. Leaves with smooth 

 point. 



2.P.caTifoliuin Ehrhart. — Pottia Ehrh.; Pterygoneuron Jur. 



Differs also from the last in leaves smooth at back. — Clay 

 soil, often on walls. Eur. not uncommon. Sweden! France: 

 Husnot. Amer. Can.: Macoun; Drummond. 

 S.P.Iamellatnm Lindberg. — Tortula Lindb.; Pterygoneuron 

 Jur.; Barbula cavifolia Schimper. 



Differs from the last: Leaves papillose at back, faintly reflexed 

 below; costa shorter excurrent. Capsule ohlong-cyUndric; peri- 

 stome slightly twisted, loosed with difficulty; basal membrane 

 clathrate. Stem somewhat higher. — Wet clay soil r. Eur. 

 France: Bescherelle. Austria: Berggi-en. 



115. Didymodon Hedwig, in part. 



A. Leaves gen. entu-e; cells small at least the upper, r. (in 

 Stegonia) large. 



a. Leaves not reflexed, often involute. Peristome not twisted. 



I. Stegonia. Leaves close also when moist, smooth entire 

 very broad concave or involute; cells large. Perichetial leaves 

 not sheathing. Stem short. Monoecious. Spores large. 



II. Trichostomum. Leaves not imbricate when moist, us. 

 crisped when dry, papillose us. narrow. Spores small. 



1. Pasilli. Peristome sUghtly twisted. Plants small; stem 

 very short. Monoecious. 



2. Crispuliformes. Peristome not twisted. Dioecious. Plants 

 larger. 



b. Leaves not involute gen. reflexed. 



aa. Leaves half- sheathing, sometimes dentate above. 



III. Erythrophyllum. Leaves reflexed papillose us. pointed 

 by a long pellucid apical cell; basal cells long, hyaline or finally 

 reddish. Perichetial leaves sheathing. Peristome pale straight. 

 Tufts us. rusty red. Us. synoecious. 



