COLLEMA. ] COLLEMEI. 51 
; 
Lich. Brit. p. 5, and C. subplicatile, var. meizolobum Nyl., Cromb. Journ. 
Bot. 1874, p. 334; but these are connected by intermediate states, The 
apothecia are rare and scarcely seen in the larger condition. 
Hab. On calcareous walls and rocks, rarely among mosses on the 
ground in upland districts—Distr, Probably general and common in the 
hilly and mountainous tracts of Great Britain and Ireland.—B. M.: 
Shanklin, Isle of Wight; Plymouth, Elburton, Paington, Ogwell, and 
near Kingsbridge, 8. Devon; St. Minver, Cornwall ; Bathampton Downs, 
Weston-super-Mare, and Cheddar Cliffs, Somersetshire; Leigh Woods, 
near Bristol, Gloucestershire; Tenby, Pembrokeshire; Beaumaris, Island 
of Anglesea; near Buxton, Derbyshire ; Pentregaer, Oswestry, Shrop- 
shire; Redcar, Cleveland, Yorkshire; near Whitehaven, Cumberland. 
Appin, Argyleshire; Killin and Ben Lawers, Perthshire; S. of Fort 
William, Inverness-shire. Killarney, co. Kerry; near Kylemore and 
Recess, Connemara, co. Galway. 
17. C. melenum Ach. Lich. Univ. (1810) p. 636.—Thallus de- 
pressed, lacero-luciniate, greenish- or olive-black (I wine-red in thin 
section); lacinize more or less elongate, somewhat broad and imbricate, 
the margins elevated, undulate, crisp and crenate. Apothecia mode- 
rate, sessile or slightly elevated, submarginal, plane, reddish-brown 
or blackish, the thalline margin somewhat granulate ; spores ovoid, 
2-3-septate and irregularly divided, 0,021-27 mm. long, 0,009- 
11 mm. thick.— Mudd, Man. p. 37; Cromb. Lich. Brit. p. 5 
pro parte; Journ. Bot. 1874, p. 334; Leight. Lich. Fl. p. 19 pro 
parte, ed. 3, p. 20.—Lichen meleenus Ach. Prodr. (1798) p. 180. C. 
auriculatum var. pinguescens Nyl. Flora, 1872, p. 353 ; Cromb. Journ. 
Bot. 1878, p. 183; Leight. Lich. Fl. ed. 3, p.17 (cfr. Nyl. Flora, 
1883, p. 534). 
The depressed orbicular thallus, and the form of the laciniz readily 
distinguish this from the allied species. In favourable situations it is 
often considerably expanded, and then in old plants becomes centrifugal. 
The apothecia are not uncommon, generally numerous, situated 
towards the margins, and at length slightly convex and concolorous 
with the thallus. On the sterile thallusis rarely seen a parasitic Obryzum, 
which must not be confounded with the spermogones. 
Hab, On calcareous rocks and old walls in maritime and upland 
districts. —Distr. Local and scarce in N. England, the W., Central, and N. 
Highlands of Scotland.—B.M.: Near Buxton, Derbyshire; Teesdale, 
Durham ; Kendal, Westmoreland; near Alston, Cumberland. Island of 
Lismore and Appin, Argyleshire; Killin, Ben Lawers, and Craig Tulloch, 
Perthshire; Craig Guie and Morrone, Braemar, Aberdeenshire; Coygach, 
Sutherlandshire. 
Form 1. marginale Ach. Lich. Univ. (1810) p. 637.—Thallus 
elongato-laciniate, lacinize narrow, canaliculate, the margins crisp 
and crenate. Apothecia marginal, scattered, the thalline margin 
prominent and entire —Mudd, Man. p. 37; Cromb. Journ. Bot. 1874, 
p- 334 ; Leight. Lich. Fl. ed. 3, p. 21.—Collema marginale Hook. Fl. 
Scot. ii. p. 71; Engl: Fl.v. p. 210; Tayl.in Mack. Fl. Hib. ii. p. 109. 
Enchylium marginale Gray, Nat. Arr.i.p. 397. Lichen marginalis 
E2 
