BRITISH LICHENS

APPENDIX 403
In view of much modern work on green algre and on lichen gonidia,
we are at once in a difficulty as to the distinction between the algal
groups cited. The leading characteristics of the 'British species or
varieties are noted, with distribution and collectors as given in the text;
they have been placed by Lesdain according to the key as follows :-
1. A. Hyphoo anastomosing.
C. fragilis B. de Lesd. tom. cit. 330.-Thallus whitish or
greyish, fragile, vaguely and minutely squamulose, the hyphre
with obscure red corpuscles.
(Red corpuscles on Crocynia hyphre have been noted clsewhere liS of
animal origin.)
Hab. On decayed mosses or rocks.-Dislr. Clapham, Yorkshire;
near Cramond, Corstol'phine and Liberton, Midlothian (MacAndrew).
C. rigidula B. de Lesd. tom. cit. 331.-Thallus whitish not
fragile, crustaceous, covering the mosses (Ie + yellowish).
Hab. On decayed mosses on rocks.-Dislr. Pitlochry, Perthshire
(MacAndrew).
C. Andrewii B. de Lesd. tom. cit. 332.-Thallus greyish, soft,
very fragile, spongy, occurring in small scattered granules, or
concrescent and sinuate at the circumference.
Hab. On mosses.-Dis/r. Gisburn, Yorkshire (MacAndrew).
C. mollissima B. de Lesd. 1. c.-Thallus dull-white soft, very
fragile, spongy, crustaceous broadly expanded, mostly continuous,
sinuate at the circumference.
Hab. Among mosses on calcareous rocks.-Distr. Clapham Craven,
Yorkshire (Rebden).
Hyphoo not anastomosing.
C. tephra Hue tom. cit. MI.-Thallus ashy-grey soft, fragile
in solitary granules or a few united, indeterminate.
Hab. On mosses or walls.-Distr. Balerno, Midlothian (l\IacAndrew).
II. A. Hyphro anastomising.
C. lanuginosa (p. 385) val'. inactiva B. de Lesd. tom. cit. 356.
The authors recognize six varieties and one form of this, hitherto, the
only British species. Lcsdain remarks, howf>ver, that var. inacliva is
of small importance as the reaction K-, is variable.
llab. On decayed mosses.-Dis!r. Pitlochry, Perthshire (Mac.
Andrew).
f. stricta B. de Lesd. tom. cit. 339.-The meshes formed by
the hyphal very narrow.
Hab. On living mosses.-Di8tr. Invcrmoidart, Argyll (l\lacvicar).
Var. albescens B. de Lesd. tom. cit. 362.-Thallus white.
Hab. On rocks.-Distr. Aberfoyle, Perthshire (MllcAndrcw).