I'YKENOrSIS.] PYRENOrSEI. 25 



local and scai'ce, in N. Wales and S.W. Ireland. — B. M. : Near Barmouth, 

 Merionethshire. Near Killarney, co. Kerry. 



4. P. phyUiscella Nyl. Mora, 1875, p. 102.— Thallus cffuso, 

 sqnamulose, dark-brown, sciuaraulcs somewhat suhverrucoso-uuequal, 

 subadnate, aggregate but not contiguous, rotundato-difform. Apo- 

 thecia eudocarpoid, very minute, 5-15 in each thalline s(|uamule ; 

 cpithecium punctit'orm, concolorous, with thin thalline margin ; 

 spores Sua), oblongo-ellipsoid, 0,005-7 ram. long, 0,008 mm. thick ; 

 paraphyses few ; hymcnial gelatine bluish, the theca3 dark-violet with 

 iodine. — Cromb. Grevillea, iii. p. 190; Leight. Lich, Fl. ed. 3, p. 14. 



The squaniules of the thallus are composed of minute aggregate 

 granules, which are usually distinct from each other, though here and 

 there becoming contiguous. Its nearest ally is P. iasmanica Nyl., rather 

 than any of our British species, though at first sight it sf)mewhat resembles 

 P. fuscdf.ula. The apothecia are numerous and crowded in the fertile 

 squamules; and the spermogones are not unfrequeut, Avith spermatia 

 thin, oblong, or fusiformi-oblong. 



Hub. On quartzose boulders in subalpine streams. — Diafr. Extremely 

 local and scarce, among the Central Grampians, Scotland. — B. M. : 

 Ben-y-gloe, Blair Athole, Perthshire. 



5. P. homceopsis Xyl. Flora, 1868, p. 312. — Thalh;s effuse, thin, 

 subgranulose, unequal, subareolate, reddish -brown. Apothecia 

 minute, lecanoroid, concolorous, pale within, the margin counivent, 

 cpithecium narrow, colourless ; spores Suae, 0,011-18 mm. long, 

 0,007-10 mm. thick ; paraphyses slender ; hymenial gelatine red 

 or tawny wine-coloured with iodine. — Cromb. Journ. Eot. 1869, 

 p. 48 ; Lich. Brit. p. 2 ; Leight. Lich. FL p. 15, ed. 3, p. 14. 



This is closely allied to P. (/ruimdifera, Nyl., from which it differs 

 chiefly in the larger spores and gonimia, as also in the thallus being 

 internally paler, especially under the apothecia. In the few specimens 

 gathered, the thallus, except in one instance, was associated with Lecanora 

 frustulosa, and for the most part sterile. 



Hah. On mica-schist rocks in alpine places. — Dtstr. Very local 

 and rare, having been found only on two of the S. Grampians, Scotland. — 

 B. M. : Summits of Ben Lawers and Craig Calliach, Perthshire. 



6. P. furfurea Nyl. ex Cromb. Journ. Bot. 1874, p. 332.— 

 Thallus efiuse, thinnish, granulato-areolate, brownish-black or black, 

 when moist rubricosely blackish or rubricosely reddish. Apothecia 

 minute, at length nearly urceolariform, the margin tumid ; spores 

 8nae, 0,010-12 mm. long, 0,007-8 mm. thick ; hymenial gelatine 

 wine-red with iodine. — Leight. Lich. Fl. ed. 3, p. 14. — Collema 

 farfareum ~Sy\. Flora, 1865, p. 353 ; Carroll, Journ. Bot. 1865, 

 *p. 286 ; Cromb. Lich. Brit. p. 3 ; Leight. Lich. Fl. p. 17. 



According to Nylander, in litt., this somewhat anomalou.-: species 

 is perhaps referable rather to the genus Phyllisciim , to which it approaches 

 in the structure of the thallus. " This, which superficially is rubricoso- 

 reddish, as in Pi/renopsis, is internally colourless, gelatinose, and excavated 

 with minute, frequent, cellular cavities, among which are scattered 

 somewhat large, oblong, simple, glaucous gonimia, as in Phyllisctim, which 



