e : 4 # Ê : u 
REVUE BRYOLOGIQUE on 
The occurrence of this form in the sheltered conditions in which 
it occurred, in company with 7”. inermis, elc., conferms M" Nichol- 
_ son’s observation of the plant (Rev. Bry. 1905, 4). In one of the 
forms the Gemmi plant had pale, almost erect leaves, with a 
pale mucro ; the laiter however was, I believe, due to bleaching. 
Encalypta vulgaris Hedw. S. side of Gemmi, 2200 ie PE 2 : JA 1 GE 
E. streptocarpa Medw. cfr. — Boulders, Choleren Schlucht, 
Adelboden ; and Blau See, Kandersteg. x 
ORTHOTRICHUM ALPESTRE Var. MACROTHECA var. nov. — À forma 
typica differt : — capsula pedicello æquilongo fere dimidia parte 
emergens vel etiam exserta, major, crassiuscula, saturale fusca. 
 Hab. On sycamore in churchyard, Adelboden ; July 20, 1906 ; 
H. N. Dixon. On beech near entrance to the Pailla Valley, 
Gavarnie, H°*-Pyrénées ; Aug. 12. 1902 ; W. E. Nicholson. 
The characters here given may not at first sight appear strong- 
ly marked, but it must be remembered that the species of this 
section, (e. g. O. alpestre, O. stramineum, O. Rogeri, O. pallens) 
are themselves separated by slight and not too casily defined 
characters, as is clearly evidenced by their synonymy, and also by 
the fact that certain varieties have been referred alternately to 
one or another of them. In typical 0. alpestre the capsule is 
usually rather leptodermous, and pale brown even when old, and 
is almost immersed or slightly emergent only ; in the variety itis 
‘of a much stouter texture, ultimately dark brown, with darker 
coloured, more solid peristome teeth ; and is always at least half 
emergent above the perichætial bracts, not unfrequently fully 
exserted, In consequence the appearance of the cushions is very 
different trom that of ordinary 0. alpestre. Moreover — à fact. 
which weighed considerably with me in deciding to describe it as 
__a new variety — the characters are such that by none of the Keys 
_tothe genus known to me could this plant be lraced to its right 
species. The plant from the Pyrenees which I also refer to this’ 
variety is one which at the time gave rise to much difficulty, and 
which was tentatively referred by Mons. Thériot to, and recorded 
as O. Rogeri var. defluens Vent. (Rev- Bry. 1905, 70), though 
with some hesitation.’It agrees very closely with the Adelboden 
plant, and I have little hesitancy in referring it Lo this variety. 
I may mention that in both of these plants I find some conside- 
rable variation in the degree of overlapping in the guard-cells of 
the stomata ; and I am inelined to doubt the value of this charac- 
ter in defining species. | 
Intermediate forms ally the var. macrotheca lo O. alpestre type. 
\ 
Thus De Culmann tells me he has a Norwegian form of alpestre 
