508 LICHEXACEI. [PERItrSARIA. 



A peculiar plant, looking, with its white spurious margin, as if allied 

 to Lecidea coarctata, but with all the essential characters of this genus. 

 Superficially it still more resembles L. carneolutea (Turn.), but among 

 other characters at once differs in the simple spores. Nylander observes 

 (Lich. Scand. p. 197) that there are scanty gonidia towards the base of 

 the apothecia and that their margin consists chiefly of minute crystals of 

 oxalate of lime. In the two British specimens the thallus is almost 

 obsolete. 



Hab. On the bark of alders in mountainous regions. Distr. Seen only 

 from the S.W. Highlands of Scotland and N. Wales. B. M. : Appin, 

 Argyleshire. 



25. P. inquinata Fr. fil Bot, Not. 3867, p. 108. Thallus sub- 

 determinate, areolato- or verrucoso-rimose, greyish (K , CaCl ). 

 Apothecia innate, one or several in each areola, the ostioles some- 

 what plane, variously flexuose, and rotundate, the margins irregular, 

 thin, persistent, paler ; spores 0,025-30 mm. long, 0,014-18 mm. 

 thick. Leight. Lich. PI. ed. 3, p. 235 ; Cromb. Grevillea, xix. 

 p. 59. Lecanora coarctata eJ. inquinata Ach. Lich. Univ. (1810) 

 p. 353. 



Might readily be taken for a Lecanora allied to L. gibbosa or L. cinerea, 

 as noted by lh. M. Fries (Lich. Scand. p. 311). The microscopical 

 characters of the apothecia, however, show its true place, though, with 

 the following, it has in other respects a connection with the Aspic-ilia 

 section of Lecunora. In the few fragmentary British specimens, which 

 are well fertile, the thallus is thinnish, though elsewhere it varies in 

 thickness, according to the nature of the substratum. 



Hab. On rocks in maritime and upland situations. Distr. Very local 

 and scarce in N.E. England (Gunnerton Craggs, Northumberland), W. 

 Ireland, and the S.W. Highlands of Scotland. B. M. : Barcaldine, 

 Argyleshire. Lettermore, Connemara, co. Galway. 



26. P. nolens Nyl. Flora, 1864, p. 489. Thallus determinate, 

 smooth, areolato-rimose, greyish (K , CaCl ). Apothecia innate, 

 not prominent, two or more approximate, colourless within ; the 

 ostioles plane, difform, rotundate or oblong, black, whitish at the 

 margins ; spores 0,030-42 mm. long, 0,015-22 mm. thick. 

 Carroll, Journ. Bot. 1865, p. 289 ; Cromb. Lich. Brit. p. 61 ; 

 Leight. Lich. PI. p. 245, ed. 3, p. 235. 



Probably not specifically distinct from the preceding, to which it is 

 intimately related ; though differing, among some minor characters, in the 

 larger spores. In his observations upon the original specimen gathered 

 by him. Admiral Jones (Nat. Hist. Soc. Dublin, May 1864) says: "In 

 the beginning this plant might be supposed to be ' Urceolaria,' but the 

 Urceolarian appearance is of short duration. There are no prominent 

 warts as in Pertusaria, but the nuclei are in masses, as in this genus, and 

 the ostioles are irregular in form with a white pulverulent margin. 

 Internally the plant is altogether a Pertusaria in asci, spores and 

 paraphyses." 



Hab. On rocks in maritime districts. Distr. Only very sparingly in 

 N.E. and W. Ireland. B. M. : Glenarm, co. Antrim ; Lough Feagh, 

 Connemara, co. Galway. 



