PELTIGERA. ] PELTIGEREI. 293 
Brit. p. 29. Peltigera canina 3. scutata Mudd, Man. p.83. Peltidea 
scutata Gray, Nat. Arr. i. p. 427; Hook. Fl. Scot. ii. p. 60; Sm. 
Eng. Fl. v. p. 215. Lichen scutatus Decks. Crypt. fase. iii. (1793) 
p. 18; With. Arr. ed. 3, iv. p. 71; Eng. Bot. t. 1834, Lnchenoides 
subfuscum, peltis horizontalibus planis Dill. Muse. 205, t. 27. 
f, 104 c.— Brit, Exs.: Leight. n. 262 pro parte; Cromb. n. 44. 
Well characterized by the sinuato-lobed thallus, minutely granulate 
above, and by the crisp and usually sorediate, though sometimes naked, 
margins; otherwise it is closely allied to P. polydactyla. The apothecia, 
which are rare, are adnate on very short lobes, and become dark-brown 
or blackish in dried plants. 
Hab. Among mosses on the trunks of trees, rarely on turf walls, in 
wooded upland districts.—Dvstr. Local and scarce in the mountainous 
tracts of W. and N. England, 8. and N. Wales, 8. and Central Scotland ; 
apparently rare in N.E. and 8.W. Ireland.—B. M.: Shanklin, Isle of 
Wight; Elburton, Kingsbridge, South Brent, and near Harberton, Devon- 
shire; Tregawn and Withiel, Cornwall; near Oswestry, Shropshire ; 
near Edwinsford, Carmarthenshire ; Hafod, Cardiganshire; Dolgelly and 
Llyn Bodlyn, Merionethshire; Hoggart’s Wood, Cleveland, Yorkshire ; 
Ambleside, Westmoreland. New Cinllaway, Kirkeudbrightshire ; Col- 
linton Woods, near Edinburgh; Inverary and Barcaldine, Argyleshire ; 
The Trossachs and Glen Lochay, Perthshire; 8. of Fort William, Inver- 
ness-shire ; Glenferness, Nairnshire. Near Belfast, co. Antrim; Killarney, 
co. Kerry, 
8. P. horizontalis Hoffm. Deutsch. FI. ii. (1795) p. 107.—Thallus 
expanded, rotundato-lobed, smooth or obsoletely impresso-unequal, 
somewhat shining, sinuato-crenate and slightly undulate at the 
margins, dull- or brownish-green when moist, pale-glaucous or pale- 
brown when dry; beneath white and reticulate with black or 
brownish-black subvillose nerves, which are pale at the circum- 
ference ; rhizine few, scattered, blackish-brown. Apothecia large, 
orbicular or ellipticai, transverse, plane, reddish- or blackish-brown, 
the margin subcrenulate; spores 6-Snex, fusiform, 3-septate, 
0,030-42 mm. long, 0,006-7 mm. thick.—Mudd, Man. p. 84; 
Cromb. Lich. Brit. p. 29; Leight. Lich. Fl. p. 110, ed. 3, p. 104.— 
Peltidea horizontalis Gray, Nat. Arr. i. p. 427; Hook. Fl. Scot. ii. 
p. 60; Sm. Eng. Fl. v. p. 215; Tayl. in Mack. Fl. Hib. ii. p. 153. 
Lichen horizontalis Linn. Mant. (1771) p. 182; Huds, Fl. Angl. 
p. 543; Lightf. Fl. Scot. ii. p. 849; With. Arr. ed. 3, iv. p. 72; 
Eng. Bot.t.888. Lichenoides subfuscum, peltis horizontalibus planis 
Dill. Muse. 205, t. 28. f. 104 .4,3—Brit. Hxs.: Leight. n. 108; 
Mudd, n. 62; Cromb. n. 45; Larb. Lich. Hb. n. 249; Bohl. n. 37. 
The thallus sometimes spreads very extensively, and, except in its 
larger size, is similar to that of P. rufescens. From this as well as from 
the other species of the genus, the horizontal apothecia and the deter- 
minately 3-septate spores render it very distinct. The apothecia are 
usually very numerous, and occasionally become somewhat large, 
Hab. On shady rocks and the mossy stumps of felled trees in upland 
districts. —Distr. General though not very common in the mountainous 
tracts of Great Britain, and probably of Ireland; most frequent on the 
