LEPTOGIUM | COLLEMACEE 75 
The bright-green colour of the thallus is persistent both in a moist 
and dry condition. 
Hab. Among mosses on shady walls, rarely on rocks.—Distr. 
Very local and scarce throughout the British Isles.-—B. M. Henfield, 
Sussex; Garn, Denbighshire; Appin, Argyll; Blarney, Cork ; 
Killarney, Kerry. 
Var. scotinum Koerb. Syst. Lich. Germ. p. 419 (1855).— 
Thallus lobes rounded, entire, slightly larger than those of the 
species ; otherwise similar.—Lichen scotinus Ach. Lich. Suec. 
Prodr. p. 128 (1798). Leptogium scotinum Fr. Summ. Veg. 
p. 122 (1846); Cromb. Lich. Brit. p. 8, pro parte & Monogr. i. 
oy os 
Ezxsicc. Mudd n. 6; Cromb. n. 109; Johns. n. 7. 
Hab. Similar to the species.— Distr. General and common where 
it occurs in Great Britain; not recorded for Ireland—-B. M. Hoyle 
Sands, Cornwall; Poynings, Sussex; Chew Magna, Somerset; near 
Cirencester, Gloucester; Garn, Denbighshire; Bettws-y-Coed, Car- 
marthenshire ; Lake Ogwen and Capel Curig, Carnarvonshire ; Bilsdale 
and Buckden, Yorkshire; High Force Inn, Teesdale, near Stanhope 
and Wear Valley, Durham ; by the Kent, Westmoreland ; Whitehaven 
and Alston, Cumberland; Appin and I. of Lismore, Argyll ; Killin 
and Ben Lawers, Perthshire. 
20. L. lacerum S. F. Gray Nat. Arr. i. p. 401 (1821).— 
Thallus of rather large subimbricate lobes, longitudinally 
wrinkled, subascending, crisp and finely crenulate and denticu- 
late at the margin, bluish lead-coloured or dark-brown. Apo- 
thecia rare, small, scattered over the lobes, brownish or pale-red, 
with a thickish entire margin; spores ovoid or broadly fusiform, 
irregularly muriform, 34-48 yp long, 10-16 p» thick.—Mudd Man. 
p. 47; Cromb. Lich. Brit. p. 8 & Monogr. i. p. 69 ; Leight. Lich. 
Fl. p. 32; ed. 3, p. 28. Lichenoides saxatile tenue rufescens Dill. 
in Ray Syn. ed. 3, p. 77, n. 89 (1724). Lichenoides pellucidum, 
endivie foliis tenuibus crispis Dill. Hist. Muse. p. 143, t. 19, 
fig. 31 a, B. (1741). Lichen atro-ceruleus, laciniatus & ciliatus 
Hall. Hist. Stirp. Helv. iii. p. 94 (1768). Lichen tremelloides 
Lightf. Fl. Scot. ii. p. 842 (1777) (non Linn. fil.); Huds. FI. 
Angl. ed. 2, p. 537. L. lacerus Liljeblad Svensk. Flora p. 335 
(1792); Ach. in K. Vet. Acad. Handl. xvi. p. 18 (1795). 
L. Tremella Roth Tent. Fl. Germ. i. p. 503 (1788)? With. Arr. 
ed. 3, iv. p. 72 (1796). L. lacer Sm. Engl. Bot. t. 1982 (1809). 
Collema lacerum Ach. Lich. Univ. p. 657 (1810); Hook. Fl. 
Scot. 11. p. 72 & in Sm. Engl. Fl. v. p. 213; Tayl. in Mackay FI. 
Piss, 3; p.. 111, 
Ezxsicc. Croall n. 488 ; Johns. n. 166; Larb. Lich. Cesar. n. 4 ; 
Mudd n. 5. 
Well characterized by the lacerate margin of the thallus; the 
whole plant is very thin and, when moist, subpellucid. 
Hab. Among mosses on the ground and on old walls in shady places. 
