HANDBOOK OF BRITISH HEPATIC/E. 



239 



Ireland, in sub-alpinc districts, on walls and rocks, 

 England. (Fr. May, June.) 



Growing in flat smoky brown or olive patches, 2 

 to 4 inches broad. Stems densely 

 matted. Branches ascending, of 

 nearly equal diameter, pointed 

 at the apex, rigid, slightly com- 

 pressed. Flagellae flexuous, at- 

 tached here and there by tufts 

 of rootlets. Leaves distichous, 

 scarcely broader than the stem, 

 imbricate (figs. 164, 165), ovate, 

 acutely notched, margin narrow, 

 crenulate. Texture thin but 

 firm, dark olive brown. Dioi- 

 cous. Involucral leaves three 

 or four pairs, double the size 

 of the stem leaves and less 

 concave. The upper pair closely embracing each 

 other. Inner involucre of two smaller leaves, with 

 two or three dentate lobes. Calyptra 

 obovate, reticulate. Barren pistillidia 

 eight to twelve. Capsule buff coloured ; 

 valves punctate,striate. Spores roundish, 

 irregular, ii-15/a diam., reddish brown. 

 Perigonial leaves on separate shoots, 

 shorter than the ordinary leaves. Anthe- 

 ridia axillary, mostly solitary, shortly 

 pedicellate. Leaf cells minute and 

 hexagonal, those along the margin transparent 

 (fig. 166). 



Gymnomitrium obtusum, Lind. 

 Dioicous. When tufts are crowded stems 



164. 



165. 



166. 



