PELTIGERA.] PELTIGEKET. 293 



Brit. p. 29. Peltlgera canina g. scuta ta Mudd, Man. p. 83. Peltidea 

 fi-tifatd Gray, Nat. Arr. i. p. 427; Hook. PL Scot. ii. p. 60 ; Sra. 

 Eng. Fl. v. p. 215. Lichen scuhtus Dcks. Crypt, fasc. iii. (1793) 

 p. 18 ; With. Arr. ed. 3, iv. p. 71 j Eng. Bot. t. 1834. Lichenoides 

 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 tlie sinuato-lobed tballus, minutely granulate 

 above, and by tbe crisp and usually sorediate, though sometimes naked, 

 margins ; otherwise it is closely allied to P. polydactyla. The apothecia, 

 which are rare, are aclnate on very short lobes, and become dark-brown 

 or blackish in dried plants. 



Ilab. Among mosses on the trunks of trees, rarely on turf walls, in 

 wooded upland districts. Distr. Local and scarce in the mountainous 

 tracts of W. and N. England, S. and N. Wales, S. and Central Scotland ; 

 apparently rare in N.E. and S.W r . Ireland. B. M. : Shauklin, Isle of 

 Wight ; Elburton, Kingsbridge, South Brent, and near Harbertou, Devon- 

 shire ; Tregawn and Withiel, Cornwall ; near Oswestry, Shropshire ; 

 near Edwinsford, Carmarthenshire ; Ilafod, Cardiganshire ; Dolgelly and 

 Llyn Bodlyn, Merionethshire ; Hoggart's Wood, Cleveland, Yorkshire ; 

 Ambleside, Westmoreland. New Galloway, Kirkcudbrightshire ; Col- 

 linton Woods, near Edinburgh ; Inverary and Barcaldine, Argyleshire ; 

 Tlie Trossachs and Glen Lochay, Perthshire ; S. of Fort William, Inver- 

 ness-shire ; Glenferness, Nairnshire. Near Belfast, co. Antrim ; Killarney, 

 co. Keriy. 



8. P. horizontalis Hoffm. Deutsch. Fl. 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 ; rhizinae few, scattered, blackish-brown. Apothecia large, 

 orbicular or elliptical, transverse, plane, reddish- or blackish-brown, 

 the margin subcrenulate ; spores 6-Snae, 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. 132; 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 A, v.Brit. Exs. : 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. ntfescens. 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. 



Hob. 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 



