MICKOGLJENA] VBREUCAKIACB^ 309 



round the ostiole ; paraphyses slender, distinct ; asci elongate- 

 clavate, 4-8-spored ; spores ellipsoid, colourless, muriform, 0,019- 

 38 mm. long, 0,011-18 mm. thick; spermogones with slender 

 bent spermatia, 0,018-32 mm. long, 0,001 mm. thick. — Yerrucaria 

 modesta Nyl. in Bot. Not. 1853, p. 164 ; Leight. Lich. Fl. ed. 3, 

 p. 492. V. Carrollii Nyl. ex Cromb. Lich. Brit. p. 119 (1870); 

 Leight. Lich. Fl. p. 455 ; ed. 3, p. 487. Sphseromphale Carrollii 

 Mudd Man. p. 283, t. 5, fig. 115 (1861). 



Hab. On trees. — Distr. Bare in S.W. England and S. Ireland. — 

 B. M. Bamsley Park, Gloucestershire ; Eostellan, Cork. 



2. M. isidioides A. L. Sm. — Thallus yellowish-brown, smooth, 

 crustaceous, rather thick, areolate, the areolje crowded, convex. 

 Perithecia immersed in the areolae, minute; perithecial wall 

 brownish below, darker upwards, dark-brown towards the ostiole ; 

 paraphyses slender, persistent, conglutinate ; spores 8 in the 

 ascus (or fewer), ellipsoid-fusiform, colourless, then becoming 

 brown, muriform, rather large, 0,030-46 mm. long, 0,012-16 

 mm. thick. — Vermearia isidioides Borr. in Engl. Bot. Suppl. 

 t. 2622, fig. 1 (1830); Carroll in Journ. Bot. iv. p. 25 0866); 

 Cromb. Lich. Brit. p. 117; Leight. Lich. Fl. p. 454 ; ed. 3, 

 p. 486. Pertusaria isidioides Hook, in Sm. Engl. Fl. v. p. 160 

 (1833). Porina isidioides Tayl. in Mackay Fl. Hib. ii. p. 102 

 (1836). Endocarpon isidioides Leight. Angioc. Lich. p. 20, t. 6, 

 fig. 4 (1851). Dermatocarpon isidioides Mudd Man. p. 270 

 (1861). 



Hah. On rocks. — B. M. Glengariff near Bantry, Cork (the only 

 locality). 



3. M. corrosa Arn. in Flora Ixviii. p. 155 (1885). — Thallus 

 whitish or dirty-white, warted or granular and dispersed or 

 obsolete. Perithecia minute, black, embedded in the swollen 

 thalline warts (when present), the upper part protuding ; peri- 

 thecial wall dimidiate ; paraphyses distinct, slender, loosely 

 coherent ; asci .subcylindrical ; spores 8 in the ascus, ellipsoid- 

 fusiform, colourless, becoming muriform, 0,018-22 mm. long, 

 0,007-011 mm. thick. — Limboria corrosa Koerb. Syst. Lich. Germ, 

 p. 376 (1855). 



Var. nericiensis A. L. Sm. — Thallus and perithecia more 

 developed and larger than in the species, internally similar. — 

 Micrpgleena nericiensis Hellb. Nerikes Lafflora, p. 123 (1871). 



The species has not been recorded in Britain. Both the specimens 

 were collected by H. B. HoU, and called by him Verrucaria dispersa. 

 The thallus is broken up into the small scattered warts that form 

 the bases of the perithecia ; the spores are at first simple, then 

 finally septate and muriform. 



Hab. On rocks in alpine regions. — Distr. Rare in N. Wales and 

 the Scottish Grampians. — B. M. Cader Idris, Merioneth ; Ben Lawers, 

 Perthshire. 



