arthopyrenia] pyrenulace^ 323 



innate and hemispherical, many being congregated in each spot ; 

 perithecial wall dimidiate ; paraphyses numerous, branching, in- 

 distinct ; spores 4 to 8 in the ascus, colourless, at length brown, 

 oblong, 1-septate, rather large, 0,020-28 mm. long, 0,005-7 mm. 

 thick ; hymenial gelatine tinted blue or violet with iodine. — 

 Verrucaria aphorisasa Stirton in Grevillea iii. p. 36 (1874) ; 

 Leight. Lich. Fl. ed. 3, p. 467. Specimen not seen. 



Hab. On bark of elm at Grantown, Elgin. 



Groioing on rocks, sand or' soil (or on mosses) ; spores l-septate. 



14. A. saxicola Massal. Symm. Lich. p. 107 (1855). — Thallus 

 whitish or bluish-grey, thin, effuse or in patches, pulverulent. 

 Perithecia minute, black, shining, semi-immersed ; paraphyses 

 mucilaginous, indistinct ; spores 8 in the ascus, colourless, oblong- 

 elongate, 1-septate, slightly constricted, colourless, 0,020-21 mm. 

 long, 0,005 mm. thick. — Verrucaria saxicola Cromb. in Journ. 

 Bot. xiv. p. 362 (1876)? Leight. Lich. Fl. ed. 3, p. 461. 



Distinguished by the extremely minute perithecia, which are 

 comparable with those of Microthelia dispora. 



Hah. On calcareous rocks. — Distr. Eare in W. England. — B. M. 

 Duntisborne, Gloucestershire. 



15. A. spilobola A. L. Sm. — Thallus black, thin, evanescent. 

 Perithecia black, small, somewhat prominent, crowded or aggre- 

 gate ; perithecial wall entire ; paraphyses stoutish, entangled and 

 indistinct ; asci oblong-ovate ; spores colourless, oblong-ovate, 

 1-septate, 0,015-20 mm. long, 0,005-8 mm. thick; hymenial 

 gelatine not tinged with iodine. — Verrucaria spilobola Nyl. in 

 Flora Iv. p. 363 (1872); Leight. Lich. Fl. ed. 3, p. 469. 



Nylander states that the gonidia are green and often 4-connate. 

 In the specimen examined the gonidia are cells of Trentepohlia. 



Hab. On rocks. — B. M. Craig TuUoch (the only locality). 



16. A. arenicola A. L. Sm. — Thallus gelatinous when wet, 

 dusky-olive-green, evanescent when dry. Perithecia black, hemi- 

 spherical, semi-immersedj ostiole slightly depressed with a minute 

 pore ; perithecial wall entire ; paraphyses slender, branched ; 

 spores colourless, oblong-ovoid, 1-septate, the cells granular, lower 

 cell somewhat tapering, 0,021-22 mm. long, 0,008 mm. thick ; 

 asci and spores pale-brownish with iodine. — Verrucaria arenicola 

 Leight. Lich. Fl. ed. 3, p. 470 (1879). 



The thallus forms a thin layer over the sand ; the dark, mucil- 

 aginous character is evidently due to the presence of blue -green algse. 



Hah. On wet sand-banks. — B. M. Shelton Eough near Shrews- 

 bury, Shropshire (the only locality). 



17. A. areniseda A. L. Sm. — Thallus ashy- or whitish-grey, 

 continuous, granular, following the inequalities of the substratum, 



Y 2 



