sometimes also on the trunks of old trees (willow and ash) in maritime
and upland districts.—Distr. Local, though common where it occurs, in
the Channel Islands, S. and W. England, aud S.W. Highlands, Scotland.
—B. AI.; Kozel and coast of the Island of Jersey. Shiere, Surrey (in
f ru it); near Maidstone, K e n t; near Lewes, Sussex ; Cheddar Cliffs,
near Porloch and Yatton, Somersetshire; Weston-super-AIare (in fruit),
Brinscomb, and near Cirencester, Gloucestershire; Alalvern and Aston,
Worcestershire; Blaxton,Yorkshire; Eden,Westmoreland. Barcaldine,
Argyleshire.
10. L. placodiellum Nyl. Flora, 1865, p. 210.—Thallus small,
somewhat firm, adnate, granulate or granulato-areolate, placodioidco-
radiate a t th e circumference, olive or dark-olive, the radii and granules
convex. Apothecia no t seen rightly developed.— Cromb.
Journ. Bot. 1882, p. 272.—Leptogium dijfraetum Kremp. Flora,
1861, p. 268, is a prior name, bu t had previously been given to a
species of Collema.
This resembles a small condition of Collemodium fragile, but it is readily
distinguisbed from this and allied species by its placodioid appearance.
In one British specimen young apothecia are sparingly present.
Hah. Cn calcareous rocks in upland hilly districts.—D k tr . Extremely
local and scai'ce, in W. England.—B. AI.; Cleeve Hill, Somersetshire.
11. L. muscicola F r. Sum. Veg. (1846) p. 122.—Thallus pulvinate,
fllamentoso-frutioulose, rounded or slightly compressed, dark-
brown or olive-black; branches minute, cylindrical, suberect or
decumbent, intric ate, somewhat obtuse a t the apices. Apotheoia
subterminal, moderate, appressed, brownish-red, the margin thin,
entire, p a le ; spores 1-septate (bilocular), ohlongo-fusiform, 0 ,0 2 3 -
27 mm. long, 0,007 ram. thick.—Nyl. Syn. i. p. 134, t. iv. ff. 1 1 -
1 5 ; Cromh. Lioh. Brit. p. 1 0 ; Leight. Lioh. Fl. p. 27, ed. 3, p. 34.
—Polychidium muscicola Gray, Nat. Arr. i. p. 4 0 2 ; Mudd, Man.
p. 49, t. i. f. 9. Collema muscicola Hook. Fl. Soot. ii. p. 72 ; Sm.
Eng. F l. V . p. 2 1 4 ; Tayl. in Mack. Fl. Hib. ii. p. 111. Lichen
muscicola Sw. N. Act. Ups. iv. (1784) p. 248 ; Dicks. Crypt, fasc. ii.
t. 6. f. 9 ; W ith . Arr. ed. 3, iv. p. 4 6 ; Engl. Bot. t. 2264.—B rit.
E x s . : Leight. n. 395 ; Larb. Lioh. Hb. n. 122.
This plant is unlike any of the Collemei, resembling when dry and sterile
some young and paler state of Parmelia lanata. The thallus is composed
of somewhat large elongate cells, which become smaller and siibangular
at the surface, the gonimic granules, which are scanty, being here and
there aggregate in the cells. The branches, which are rigid when dry,
are numerous and intricate, the lower ones sometimes anastomosing.
The apothecia are horizontal, very much broader than the branches,
while occasionally one is common to two or three of the branches.
Hah. Among mosses on rocks and walls, in maritime, upland, and
subalpine districts.—Distr. General and not uncommon in mountainous
regions, chiefly of W . Britain, rare in the Channel Islands, and in E. and
W. Ireland.—B. M .: Quenvais, Island of Jersey. South Brent, Bottor
Rock, and near Hunter Tor, Devonshire; Cader Idris, Drews-y-nant and
Ty Gwyn, near Dolgelly, Alerionethshire ; Llanberis Pass and Snowdon,
Carnarvonsliire; Beaumaris, Island of Anglesea ; near Oswestry, Shropshire
; Teesdale, Durham; Kentmere, Westmoreland. New Galloway,
Kirkcudbrightshire ; Ben Cruachan and Loch Oreran, Arayleshire; Ben
Lawers and near St. Fillans, P e rth sh ire ; Oraig Guie, Braemar, Aberdeenshire.
Luggelaw, CO. Wicklow ; Killarney, co. K e iry ; Kylemore,
CO. Galway.
Subgen. 2. EULEPTOGIUM Cromb. Journ. Bot. 1874, p. 133.-—
Thallus more or less foliaceo-memhranaoeous, oeUulari'-oorticate on
both surfaces; inte rn ally with entangled tu b u la r c av itie s; gonimia
moniliform. Apotheoia le c an o rin e ; spores variously divided.
Fig. 18.
Leptogium lacerum F r.—a. Fragment of a thalline lacinia showing the fimbriature,
X 80. h. Texture of section of the thallus, X 200, ection of a
young apothecium in dry state, X 30, and o', the same of an older apothecium.
d. Theca with a paraphysis, X 350. e. Spores, " ~ '
of thallus (moistened) with two spermogones, X 30.
spermatia, X 500.
X 500. / . Section
g. Sterigmata and
12. L. lacerum Gray, Nat. Arr. i. (1821) p. 401.—ThaUus thin,
lacero-laciniate, longitudinally rugulose, olive-brown or leaden ;
laciniæ subimhricate, subascending, crisp and ciliato-dentate a t the
margins. Apotbecia small, scattered, concave, brownish- or pale-
red, the thalline m argin thickish, entire ; spores ovoid, or narrowed
at either apex, irregularly murali-looular, 0 ,0 3 4 -4 8 mm. long,
0,010-16 ram. thick.—Nyl. Syn. i. p. 122, t. ii. f. 6 ; Mudd, Alam.
ft I