Lecanora.] LICHENES. 137 



a base of cortical matter, and is of the same wax yellow, but more di- 

 luted than the disk throughout its substance ; in younger apothecia it 

 appears almost colourless. It is always pellucid and striated. The 

 disk consists of a number of eminent points, with which it is somewhat 

 rough. Moisture causes it to assume a convex shape. 



13. L. varia, Acii. Thallus between powdery and tartareous, 

 in scattered pieces, cracked, indeterminate, of a pale sulphur 

 yellow ; apothecia crowded, irregular, often confluent, slightly 

 convex ; the disk of a pale yellowish-green ; the border pow- 

 dery, waved, nearly obliterated. Ach. L. Un. p. 379, var. £r. 

 symmicta. 



On palings at Derriquin, County of Kerry. There appears to be- 

 long to the thallus a very thin white pulverulent substratum. The disk 

 becomes of a dusky brown by age. It seems to accord with the 

 Acharian variety above quoted. On dissection the central part of the 

 apothecium is seen filled with much green parenhymatous matter as 

 well as a little whitish cortical substance above and below the latter : 

 the lamina poligera appears as a very thin convex layer almost colour- 

 less, pellucid and striated ; the disk is somewhat more opaque, but 

 seems to lose much of the yellowish tinge when saturated with mois- 

 ture. The apothecia seem almost gelatinous when wet, and the thallus 

 considerably greener. We have in Kerry a variety, as I suppose, very 

 common on siliceous rocks, the thallus being less powdery, and rather 

 scattered in somewhat tartareous, flattish granulations, in other respects 

 agreeing with the species above defined. 



14. L. intricata. Ach. Substratum of the thallus subtar- 

 tareous, black, cracked ; scales flat, crenato-sublobate, dis- 

 persed or collected into areola, whitish sulphur-coloured ; apo- 

 thecia plane or convex; the disk olive-coloured; the border 

 waved. Ach. L. Un. p. 380. Lichen polytropus, Eng. Bot. 

 t. 1264. the upper figure. 



On old red sandstone rocks, at Kilceanagh, County of Kerry. The 

 thalloclal border to the apothecia is very distinct. The colour of the 

 disk and of the border sometimes changes from olive to a brownish- 

 orange. The apothecia commence as minute points on the scales. A 

 variety, if not distinct species, occurs at Blackwater Hill, with the sub- 

 stratum dispersed and inconsiderable, the scales so minute as to be 

 scarcely observable by the naked eye ; they are besides nearly entire, 

 the apothecia more convex, their border less waved, and above all, the 

 diameters of the apothecia far exceeding that of the scales : it may for 

 the present be termed the (3. comminuta, of our species. 



15. L. parella, Ach. Thallus tartareous, whitish, plaited 

 and warty, subdeterminate; apothecia. numerous, large, crowded, 

 central; their disk pruinose, slightly flesh-coloured, concave; 

 their border very thick, tumid, and even. Ach. L. Un. p. 370. 

 Eng. Bot. t. 727. 



On siliceous rocks ; common. In shade the thallus becomes very 

 thin and scattered, but the thickness of the thallodal border to the apo- 

 thecia remains unaltered. On the bark of Sycamore at Derriquin, oc- 

 curs a variety so exactly intermediate between this and Variolaria 



K 



