64 COLLEMACEI. [lEPTOGIUM. 



1 . L. rliyparodes Xyl. Flora, 1865, p. 210.— Thallus diffuse, 

 thin, furfuraceous or subgrauulato-unequal, diffract, brownish-red 

 or blackish- brown (I -f 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 eDipsoid, 

 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.— 

 GolUma psorelhim Xyl. Flora, 1 8G5,p. 602; Cromb. Joum. 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 subbiatoriue. 

 Occasionally specimens gro-wing on moist shady rocks are more obscure 

 and less developed with nearly biatorine apothecia; this state is 

 Collema psorellum Xyl. 



Hab. On damp rocks and stones (schistose) in subalpine and alpine 

 .ocalities. — Distr. Very local and rare among the S. Grampians, Scotr 

 and. — B. M.: Craig Calfiach, on the summit and above Loch-ua-Gat, 

 Ben Lawers, Perthshire. 



2. L. tenuis simimi Koerb. Syst. Lich. Germ. (1855) p. 419. — 

 ThaUus eftuse, squamuloso-granulose, olive- or brownish-green ; 

 squamules laciniato-dissect or crenato-iucised, 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 muraH-locuIar, 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. Fl. v. 

 p. 213. Poh/chidium teiiiiissimicm Gray, Xat. Arr. i. p. 401. Lichen 

 tenuissimus Dicks. Crypt, fasc. i. (1785) t. 2. f. 8 ; ^Yith. Arr. ed. 3, 

 iv. p. 61 ; Eng. Bot, t. Ii27.— Brit. Exs. : 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. lacerum var. puliinatum, which it resembles. The apothecia, 

 usually sparingly present, have the margin sometimes shghtly connivent, 

 and are often comparatively large and deeply urceolate. 



Hah. On the ground among mosses and short grass in maritime and 

 upland districts. — Distr. Sparingly here and there throughout England, 

 verv rare in Scotland and Ii-eland. — B. M. : Near Norwich, Yarmouth, 

 Norfolk ; Reigate Hill, Sun-ey ; Hastiugs and Twineham, Sussex ; San- 

 down, Isle of Wight ; near Penzance, Cornwall ; Snowdon, Ciirnarvon ; 

 near Easby, Cleveland, Y'orkshu-e. New Galloway, Kirkcudbrightshire ; 

 neux Cramond, Edinbm-gh ; Appin, Argyleshire ; Ben Lawers, Perthshire. 

 Middleton, CO. Cork. 



3. L. humosum Nyl. Mem. Soc. Cherb. v. (1857) p. 00 : Syn. i. 

 (1858) p. IV-K — ThaUus eftuse, thinnish, consisting of lobulate gra- 

 nules closely aggregate (with larger lobules here and there inter- 

 mixed), brown or brownish-black. Apothecia small, somewhat 



