riLOPHORUS.] PILOPHOKEI. 115 



white; podctia short, erect, simple, verrucoso-granulate or sub- 

 pulverulent (K + yellowish). Apothecia small, subglobose, para- 

 physcs thickish; spores ellipsoideo-fusiform, 0,016-0,022 mm. loug, 

 0,004-0,005 mm. thick. Cromb. Grevillea, xv. p. 15. Stereocaulon 

 cereolus Ach. Meth. p. 316 ; Borr. in Engl. Bot., Suppl. t. 2667. 

 S. cereolinuin Sm. Eng. PI. v. p. 233 pro parte ; Tayl. in Mack. Fl. 

 Hib. ii. p. 83. Lichen (Isidiuni) cereolus Ach. Prodr. (1798) p. 89. 

 Stereocaulon condomitum var. cereolinum Ach. pro parte, Cromb. 

 Lich. Brit. p. 17 pro parte. To this also belongs P. fibula (non 

 Tuck.) Leight. Ann. Mag. Nat. Hist. 1869, vol. iv. p. 201 ; Lich. PI. 

 p. 76, ed. 3, p. 69 pro parte. Brit. Rvs. : Leight. n. 383 ; Larbal. 

 Lich. Hb. n. 5. 



When sterile, this closely resembles Stereocaulon pileatum, from which, 

 when fertile, it is easily distinguished by the simple spores. The basal 

 thallus is normally granuloso-diffract, sometimes becoming more or less 

 pulveraceo-delitescent. The podetia vary somewhat in length and thick- 

 ness, and at times become more or less glabrous. The apothecia are 

 typically solitary, and in old plants, as observed by Acharius (Lich. Univ. 

 p. o33), become compound and conglomerate. On the basal thallus there 

 occur frequent cephalodia, which are tuberculose, brownish, with the 

 gonimia glomernlosely arranged. It is intimately allied to P. Jlbula 

 Tuck. (Nyl. ex Oromb. Grevillea, xv. p. lo), a similar American plant 

 which (ex Nyl. in litt.} differs in the thicker spores (0,018-0,025 mm. 

 long, 0,007-0,008 mm. thick). 



Ilttb. On moist shady rocks in upland and subalpine situations. 

 Dixfr. Local and scarce in the mountainous tracts of N. England, N. 

 Wales, S.W. Scotland, the S.W. Highlands, among the Grampians, and 

 in W. Ireland. B. M.: Cader Idris and Dolgelly, Merionethshire; Tees- 

 dale and Eglestone, Durham ; Borrowdale, Cumberland. New Gallo- 

 way, Kirkcudbrightshire ; Achrosagan Hill, Appin, Argyleshire ; Ben 

 Lawers, Perthshire; Ben Nevis, Inverness-shire; hills o"f Applecross, 

 1! is..<hire. Dunkerron, co. Kerry; Kylemore and Salrock Road, Conne- 

 rnara, co. Galway. 



2. P. stnunaticus Nyl. ex Cromb. Journ. Bot. 1875, p. 140 



(nomen). Thallus determinate or subeffuse at the base, verrucoso- 

 granulate, greyish-white ; podetia short, stoutish, verrucoso-granu- 

 late (K + yellowish). Apothecia moderate or submoderate, sub- 

 globose, beneath as if strumosely appendiculate, paraphyses mode- 

 rate ; spores oblongo-ellipsoid, 0,018-0,024 mm. long, 0,006-0,009 

 mm. thick. 



Differs from the preceding in the thallus being firmer, not pulverescent, 

 and especially in the peculiar form of the apothecia, resulting from the 

 turgescent perithecium. The podetia are simple, somewhat crowded, 

 occasionally very short, so that the apothecia appear subsessile. The 

 cephalodia' are similar to those of P. cereolus. 



Hub. On shady ledges of schistose rocks in subalpine districts. Distr. 

 Local and scarce in N. Wale.*, among the Grampians, and in the N.W. 

 Highlands, Scotland. B. M. : Cader Idris, Merioneth. Glen Lyon, Perth- 

 shire ; Mori-one, Braemar, Aberdeenshire. 



i 2 



