64 COLLEMACEI. [LEProcIUM. 
1. L. rhyparodes Nyl. Flora, 1865, p. 210.—Thallus diffuse, 
thin, furfuraceous or subgranulato-unequal, diffract, brownish-red 
or blackish-brown (I+ wine-red). Apothecia small, at first con- 
cave, becoming somewhat plane and at length biatorine with ex- 
cluded margin, concolorous or reddish; spores ovoid or ellipsoid, 
attenuate at one or the other apex, submurali-divided, 0,020-35 
mm. long, 0,011-16 mm. thick.—Carroll, Journ. Bot. 1865, p. 287 ; 
Cromb. Lich. Brit. p. 7; Leight. Lich. Fl. p. 35, ed. 3, p. 26.— 
Collema psorellum Nyl. Flora, 1865, p. 602; Cromb. Journ. Bot. 1866, 
p. 22; Lich. Brit. p. 3; Leight. Lich. Fl. p. 26; vide Cromb. Journ. 
Bot. 1874, p. 335. 
The thallus, which has the gonimia more or less scattered, sometimes 
‘spreads extensively, and occasionally becomes almost evanescent. The 
apothecia are at first urceolate and sometimes at length subbiatorine. 
Occasionally specimens growing on moist shady rocks are more obscure 
and less developed with nearly biatorme apothecia; this state is 
Collema psorellum Nyl. 
Hab. On damp rocks and stones (schistose) in subalpine and alpine 
.ocalities.—Distr. Very local and rare among the S. Grampians, Scot- 
and.—B. M.: Craig CGalliach, on the summit and above Loch-na-Gat, 
Ben Lawers, Perthshire. 
2. L. tenuissimum Koerb. Syst. Lich. Germ. (1855) p. 419.— 
Thallus effuse, squamuloso-granulose, olive- or brownish-green ; 
squamules laciniato-dissect or crenato-incised, congested into a dense 
crust. Apothecia moderate or large, urceolate, reddish-brown, the 
margin entire, thick, paler; spores ovoid or oblong, narrower at 
either apex, irregularly murali-locular, 0,024-34 mm. long, 0,011— 
13 mm. broad.—Mudd, Man. p. 46; Cromb. Lich. Brit. p.’7; Leight. 
Lich. Fl. p. 35, ed. 3, p. 26.—Collema tenuissimum Sm. Eng. FI. v. 
p- 213. Polychidiwm tenaissimum Gray, Nat. Arr.i. p.401. Lichen 
tenuissimus Dicks. Crypt. fase. i. (1785) t. 2. £. 8; With. Arr. ed. 3, 
iv, p. 61; Eng. Bot. t. 1427.—Brit. Exvs.: Mudd, n. 4: 
Well distinguished by the external character of the thallus from the 
allied species of the subgenus, and by the internal structure from states 
of L. lacerwm var. puloinatum, which it resembles. The apothecia, 
usually sparingly present, have the margin sometimes slightly connivent, 
and are often comparatively large and deeply urceolate. 
Hab. On the ground among mosses and short grass in maritime and 
upland districts.—Distr. Sparingly here and there throughout England. 
very rare in Scotland and Ireland.—B, M.: Near Norwich, Yarmouth, 
Norfolk ; Reigate Hill, Surrey ; Hastings and Twineham, Sussex ; San- 
down, Isle of Wight; near Penzance, Cornwall; Snowdon, Carnarvon ; 
near Easby, Cleveland, Yorkshire. New Galloway, Kirkeudbrightshire ; 
near Cramond, Edinburgh ; Appin, Argyleshire ; Ben L: P i 
Middleton, ’co. Cork. ean Rar eR Ss 
3. L. humosum Nyl. Mém. Soc. Cherb. v. (1857) p. 90; Syn. i. 
(1858) p. 119.—Thallus effuse, thinnish, consisting of lobulate gTa-~ 
nules closely aggregate (with larger lobules here and there inter- 
mixed), brown or brownish-black. Apothecia small, somewhat 
