MICROGL^NA] VERRUCARIACEiE 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. — Verrucaria 

 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. Sphderomphale Carrollii 

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



Hah. On trees. — Distr. Rare in S.W. England and S. Ireland. — 

 B. M, Barnsley Park, Gloucestershire ; Rostellan, Cork. 



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

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

 Perithecia immersed in the areolie, 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. — Verrucaria isidioides Borr. in Engl. Bot. Suppl. 

 t. 2622, fig. 1 (1830); Carroll in Journ. Bot. iv. p. 25 (1866); 

 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). Derrnatocarpon isidioides Mudd Man. p. 270 

 (1861). 



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

 localit}'). 



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. — Limhoria 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. — ■ 

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



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

 were collected by H. B. Holl, 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. 



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

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

 Perthshire. 



