Mosses — Grimmia and Schistidium. Ill 



densely barred, sometimes perforated, but rarely bifid. It is 

 found on rocks and "walls in mountainous districts, is abundant 

 near Llyn Ogwen, Carnarvonshire, and elsewhere about Snow- 

 don, and was discovered near Forfar by Mr. George Donn, 

 after whom it is named. It fruits in March, April, and 

 October. 



Grimmia ovata, the oval-fruited Grimmia, is a larger 

 species, having stems half an inch long or more ; more or 

 less compactly tufted, branched and fastigiate, with leaves 

 of firmer texture, more opaque, more erect when dry, and 

 more crowded than in the last species ; the margin in the 

 lower part recurved, which it is not in Donniana, the 

 nerve broader, but less defined, and less prominent at the 

 back, and the perichastial leaves more erect and sheathing. 

 The capsule is of firmer texture, erect, oval, of a darker 

 hue, being reddish brown, and excerted on a longer pedicel ; 

 the annulus is large and dehiscent, and lodged in a groove 

 on the margin of the lid, which is longer and rostellate. 

 It too is found on alpine rocks, particularly on the Breadalbane 

 and Clova mountains. On Snowdonit is rare. Fruiting season, 

 October and March. 



Another very distinct species, with dark green foliage, and 

 densely tufted stems of little more than half an inch long, was 

 discovered on trap rocks in King's Park, Edinburgh, by Mr. 

 R. Brown, and to which the name of Grimmia leucophma, or 

 hoary Grimmia, has been assigned. While growing, the leaves 

 are widely spreading ; but when dry they are closely imbri- 

 cated, concave, ovate, or elliptical, with plane margins, the 

 upper ones suddenly tapering into very long hair-points, the 

 lower ones muticous. The capsule is elliptical or oblong, of a 

 reddish brown, erect and excerted, perfectly smooth when dry, 

 and with thick walls, the lid variable in length, conico-rostel- 

 late, sometimes conical and mammillate, not quite half as long 

 as the capsule, and wearing a calyptra five lobed at the base, 

 and covering one-third of the capsule. The teeth of the peri- 

 stome are densely barred, the bars externally prominent ; they 

 are also deeply bi-trifid and perforated, and are spreading 

 when dry. 



G. leucophaia fruits in April. It has been found in various 

 localities — on the coast of Fife ; at Fairhead, on basalt ; Abbey 

 Craig, near Stirling ; and at Salcombe, in Devonshire. 



Grimmia unicotor, or the dingy Grimmia, grows also on 

 alpine rocks, in broad, incoherent lurid patches, with stems 

 from one to two inches long, more or less branched, the 

 branches flexuose, brittle, and fastigiate, leafless below, but 

 often having slender ramuli, with small ovate imbricated leaves, 

 like those of G. spiralis, but more crowded. The leaves of this 



