74 DICRANACE^E. 



Hab. Alpine rocks ; very rare. Clova ; Wales. Fr. late summer. 



The greater number of the above characters are subject to more or less variation. 

 In the compact var. alpestre (Cynod. subalpestre Kindb.) the papillosity of the leaves 

 almost disappears, and the perichfetial bracts hardly differ from those of C. polycarpum ; 

 it is indeed placed under that species by Boulay, and may be looked upon as a connect- 

 ing link between the type and the present sub-species. The smallness of the distinctive 

 characters as described above, justifies, I think, its present arrangement as a sub- 

 species rather than as a separate species, although I am not aware that this view has 

 been taken by any of the authorities since C. Miiller (Syn. II, p. S9 1 )- 



3. Oynodontium virens Schp. (Bryum virens Sw. ; Oncoph. 

 virens Brid., Braithw. Br. M. Fl.) (Tab. XIV H.). 



Plants tall, robust, 2-3 inches high, bright green above, 

 brown or black below, in dense tufts, stems repeatedly forked. 

 Leaves spreading, not increasing in length above, slightly crisped 

 when dry, from an oval or oblong amplexicaul base gradually 

 narrowed and lanceolate, acute or obtuse, carinate ; margin 

 recurved, entire, or sub-serrate above ; nerve reaching apex or 

 slightly excurrent ; cells of leaf-base rectangular, pellucid, shorter 

 and broader towards the margin, becoming shorter and incrassate 

 above, in the limb shortly rectangular and almost quadrate, 

 smooth. Seta rather short ; capsule dark reddish brown, oblong- 

 cylindrical, arcuate, gibbous, with a sharp distinct struma, smooth. 

 Peristome teeth large, regular, cleft to the middle. 



Var. jS. serratum B. & S. Leaves widely spreading, coarsely 

 serrate in the upper part. 



Hab. Wet rocks and stony ground on high mountains. Common on the 

 Grampian range ; elsewhere rare. The var. /8 in similar situations. Fr. late summer 

 and autumn. 



This fine species varies much in size, in the magnitude of the cells and the 

 thickness of their walls, and in the length, form and serrature of the leaves ; and no 

 clear line can be drawn between the type and the var. serratum. It cannot easily be 

 mistaken for any other moss, at least when examined under the microscope. 



* Oynodontium Wahlenbergii R. & C, Rev. Bry. 1892, 



p. 74. (Cynodontium virens var. Wahlenbergii Schp., Syn. ; 



Oncoph. Wahlenbergii Brid., Braithw. Br. M. Fl.) 



(Tab. XIV. I.). 



Resembling C. virens but usually shorter ; leaves more 

 distant, more strongly crisped when dry, from an obovate base 

 suddenly contracted to a longer, narrower, subulate, flexuose 

 point. Capsule slightly shorter and thicker. 



