24 KPnEBACKT. [PTRKXOPSIS, 



rhickish, difFracto-rimosc, dark- or rubricose-brown, within sub- 

 concolorous or darker in the lower portion. Apothecia superficial, 

 urceolate, minute, subconcolorous or slightly darker, the margin thick, 

 elevated, entire; spores Snse, 0,010-12 mm. long, 0,005-6 mm. 

 thick ; hymenial gelatine, especially the theoae, bluish with iodine. — 

 Carroll, Journ. Bot. 1866, p. 22 ; Cromb. Lich. Brit. p. 2 ; Leight. 

 Lich. Fl. p. 14, ed. 3, p. 14. — CoUema liamaJeum, var, hcpmatopis, 

 Somm. Suppl. Fl. Lapp. (1826) p. 117. 



From Euopfi's hcemalea, with which it here grows associated, this is 

 exterually distinguished by the thicker thallus and the minute urceolate 

 apothecia. With us it is not usually seen with apothecia, though, when 

 present, these are numerous. The spermogones in otherwise sterile 

 plants are frequent, with very minute ellipsoid spermatia. 



Hab. On shady mica-schist rocks in alpine places. — Distr. Ex- 

 tremely local and rare, among the S, Grampians, Scotland. — B. M. : 

 Summit of Ben Lawers, Perthshire. 



2. P. fuscatula Nyl. Mem. Soc. Cherb. v. (1857) p. 143. — 

 Thallus effuse, noduloso-granulate, dark-brown or brownish-black, 

 the granules agglomerate and confluent in somewhat depressed glo- 

 raerules, which are more or less discrete and irregularly scattered. 

 Apothecia small, somewhat impressed, concolorous, the margin con- 

 nivent; spores 8n8e, 0,008-0,010 mm. long, 0,0045-0,0050 mm. 

 thick: epithecium yellowish : hymenial gelatine bluish, then violet, 

 with iodine. — Leight. Lich. Fl. p. 16, ed. 3, p. 14 : Cromb. Journ. 

 Bot. 1874, p. 332. 



This is a small species, characterized chieily by the noduloso-graniform 

 thallus, which either spreads moderately over the substratum, when the 

 o^lomerules are more discrete, or more frequ?utly occurs in small inter- 

 rupted patches. The apothecia are rarely met with rightly developed, 

 though the spermogones are more common ; they are very minute, with 

 spermatia oblong or oblougo-cylindrical, 0,002 mm. long, about 0,0005 mm. 

 thick. 



Hah. On granitic and schistose rocks in maritime districts. — Distr. 

 Bather local and rare, having been found only in the Channel Islands, 

 N. Wales, and the S.W. Highlands of Scotland.- — B. M. : La Moye 

 and Boulay Bay, Island of Jersey. Near Barmouth, Merionethshire. 

 Island of Lismore, Argyleshire. 



3. P. subareolata Xyl. Lich. Scand. (1861 ) p. 27, vomcn. — Thallus 

 effuse or subeffnse, thinnish, diftracto-areolate, blackish, areola some- 

 what plane. Apothecia small, innate, subconcolorous, the epithecium 

 impressed ; spores 8na3, 0,015 mm. long, 0,008 mm. thick ; hymenial 

 gelatine bluish, then wine-reddish with iodine. — Cromb. Journ. 

 Bot. 1882, p. 271. — To this also apparently is referable Verrucaria 

 imhrkla Tayl. Hook. Journ. Bot, vi. (1847) p. 153. 



This species is comparable with P. concordntuJa Nyl., from which, 

 among other characters, it at once differs in the smaller spores. The 

 British specimens seen are not very typical, the apotliecia being sparingly 

 present, minute and scattered, but for the most part not well developed. 



Hah. On moist schistose rocks in mountainous districts. — Distr. Verv 



