CETRARIA. | CETRARIEI. 219 
Form 2. acanthella Nyl. Mém. Soc. Cherb. v. (1857) p. 100.— 
Thallus as in the type, but very much spinuloso-denticulate through- 
out. Apothecia few.—Cromb. Journ. Bot. 1870, p. 96; Leight. 
Lich. Fl. p. 98, ed. 3, p. 93.—Cornicularia spadicea y. acanthella 
Ach. Lich. Univ. (1810) p.612. Coralloides fruticuli specie fuscum, 
spinosum Dill. Muse. 112, t. 17. f. 31 B. 
Distinguished by the entirely hispido-spinulose or setulose thallus. In 
this country the apothecia are very rare. The spermogones are frequently 
present in herbaria specimens. 
Hab. On the ground among mosses in upland districts.—Distr. Local 
and scarce in W. and N. England, N. Wales, and among the N. Gram- 
ians, Scotland.—B. M. : Clifton, near Bristol; Dolgelly, Merionethshire ; 
arudale, Yorkshire; Prestwick Carr, Northumberland. Clova Mts., 
Forfarshire; Hill of Ardo near Aberdeen, 8. of Lochnagar, Braemar, 
Aberdeenshire ; Glen Nevis, Inverness-shire. 
5. C. odontella Ach. Syn. (1814) p. 230.—Thallus densely fru- 
ticuloso-ceespitose, depressed, narrowly laciniate; laciniz plane, linear, 
thin, palmately ramoso-divided, spinulose at the margins, spadiceous, 
chestnut-brown or pale spadiceous, paler at the base, or sometimes 
blood-coloured (K_, CaCl_). Apothecia terminal, concolorous, 
the margin denticulate ; spores 0,007-010 mm. long, about 0,0045 
mm. thick.—Cromb. Journ. Bot. 1882, p. 272.—Lichen odontellus 
Ach, Prodr. (1798) p. 213. 
This usually forms minute depressed tufts, and somewhatresembles form 
hispida of the preceding species, but is distinguished by the plane thin 
lacinia. The thallus closely allies it to C. crtspa, from which it is, however, 
separated by the characters given. In the only specimen found in this 
country, apothecia and spermogones are absent. 
Hab. Among mosses on rocks in es tracts.— Distr. A single 
specimen from the N, Grampians, Scotland—B. M.: Cairntoul, Braemar, 
‘Aberdeenshire. 
40. PLATYSMA Nyl. Mém. Soc. Cherb. v. (1857) p. 100; Syn.i. 
p- 301.—Platisma, Hoffm. Deutsch. Fl. ii. 
(1795) p. 138 pro minima parte (ut sectio Lo- _, 1&0 
barie).—Thallus fruticulose or membranaceo- B*) a Pi 
dilated, erect, ascending or appressed, more or 6 | 
less rigid, lobed or laciniate, concolorous on both 
sides or discolorous ; medullary layer with the 
filaments loosely interwoven ; cortical layer more 
or less cellular, very rarely with tubulose cavities. 
Apothecia discolorous from thallus, marginal i 
or submarginal, rarely adnate on the back of Fig. 43. 
the apices of the laciniz, the margin entire or Platysma comméxtum 
crenulate; hypothecium colourless; spores sub- — Nyl.—a. Section of 
ellipsoid ; hymenial gelatine bluish withiodine, —_ upper portion of the 
Spermogones marginal, globulose; sterigmata arte x 200, Fe 
somewhat simple or pauci-articulate ; sper- ee Sea 
matia various (not cylindrical). c. Sterigmata and 
sperinatia, x 00. 
