SCHIZOMA. | COLLEMEL, 39 
towards the extremities. In Journ. Bot. 1874, J. c., it was observed that 
this species probably constituted a separate genus, though, as neither form 
of fructification was then known, it might be retained as an anomalous 
section of Collema. I have since detected the spermogones in Great 
Britain, and I hope the apothecia may be also discovered. The de- 
scription of the thallus of Collema radiatum Somm. (possibly an Ompha- 
larva) and its habitat given by Sommerfelt, Lapp. p. 121, as well as the 
account of its internal structure and of the spermogones given by Fr. fil., 
Lich, Arct. p. 288, do not at all correspond with our plant; the two can- 
not be identical. On the thallus is rarely seen a parasitic fungus, viz. 
Spheria schizomatis.Cromb., which must not be mistaken for the apothecia. 
Hab. On decayed mosses and the ground in crevices of rocks in alpine 
places.— Distr. Extremely local, being confined ey to one or two 
of the S. Grampians, Scotland.—B.M. : Ben Lawers and Craig Calliach, 
Perthshire, 
14. COLLEMA Wigg. Prim. Fl. Hols. (1780) p. 89; Nyl. 
Mém. Soc. Sc. Nat. Cherb. iii. (1855) p. 164.—Thallus usually 
orbicular or suborbicular, membranaceo-lobed, very rarely squamu- 
lose or granulose; gonimia moniliform, cortical layer not discrete. 
Apothecia lecanorine; spores 8ne, simple or generally multilo- 
cular, colourless ; hymenial gelatine usually bluish, rarely wine-red 
with iodine. Spermogones more or less immersed, sterigmata 
shortly articulate, rarely simple; spermatia straight, obtusely in- 
cerassate at either apex. 
As now limited, this genus is more compact than formerly, though it 
still includes several species, diverse in thallus and fructification, as 
will be seen from the following sections. These differences, however, 
are not of sufficient importance to warrant its division into several genera. 
In various species a thin section of the thallus, when dry, becomes 
reddish or blood-red with iodine, in consequence, as Nylander observes, 
of the gonimia being so coloured. In the cine in which the spermo- 
gones have been detected, except in those belonging to Section A, the 
‘ spermatia are identical in size, viz. 0,0035-0,0040 mm. long, 0,0007 mm. 
thick, or vary so slightly that the difference is scarcely perceptible. There 
is every reason to believe that some Nostocs are undeveloped states of 
different species of this and perhaps also of the following genus. 
A. LEMPHOLEMMA (Koerb. 
Syst. Lich. (1855) p. 400). 
—Thallus thinnish, dif- 
form; gonimie granules 
moniliform. §Apothecia 
innate; spores simple ; 
spermogones with simple 
sterigmata. d 
a. Hymenial gelatine wine-red Ue et f 
with iodine. Fig. 10. 
1. C. chalazanum Ach. Lich. Collema myriococcum Ach.—a. Section 
. r of an apothecium, x 30. 8. Two 
Univ. (1810) p. 630.—Thallus thece and a paraphysis, x 350. ¢. Two 
pulvinate, thinnish, difformi- spores, X 500. d, Storigmata, and 
lobate or laciniate, crenulato- e, spermatia, x 500. 
