arthopyrenia] pyrenulace^ 327 



Differs from A. leptotera in the thinner thallus, distinct para- 

 physes, and smaller spores. 



Hah. On maritime rocks. — Distr. Kare on the coast of S.W. 

 England and Wales, and E. Scotland. — B. M. Clevedon, Somerset ; 

 Manorbeer Bay, North Cliff and Giltar Points, Tenby, Pembrokeshire. 



26. A. viridula A. L. Sm. — Thallus effuse, thin, greenish- 

 olive, tartareous, smooth or slightly cracked. Perithecia immersed, 

 hemispherical, emerging, the ostiole umbilicate ; perithecial wall 

 dimidiate, spreading and incurved at the base ; spores colourless, 

 linear-oblong, 1-septate, 0,017-19 mm. long, 0,006-7 mm. thick. 

 — Lichen viridulus Sm. Engl. Bot. t. 2455 (1812) pro parte. 

 Verrucaria elseina Borr. in Sm. Engl. Bot. under t. 2455, fig. 2 

 (1812) ; Hook, in Sm. Engl. Fl. v. p. 152 ; Leight. Angioc. Lich. 

 p. 63, t. 27, fig. 2 & Lich. Fl. p. 436 ; ed. 3, p. 462. Thelidium 

 eleeinum Mudd Man. p. 296 (1861). Specimen not seen. 



Perhaps identical with A. halizoa, to which the drawing in English 

 Botany bears a strong resemblance. 



Hab. On maritime slaty rocks. — Distr. Rare on the W. coast of 

 Wales and W. Ireland. 



27. A. marina A. L. Sm. — Thallus dark-olive-green, sub- 

 gelatinous, smooth, determinate with a black line at the circum- 

 ference. Perithecia minute, black, immersed in the thallus, the 

 ostiole rather flat or slightly depressed ; perithecial wall entire, 

 black ; paraphyses none ; spores 8 in the ascus, minute, ellipsoid- 

 oblong, colourless, 1-septate, becoming 3-septate at maturity, 

 0,009-14 mm. long, 0,003-5 mm. thick. — Sagedia marina Deakin 

 in Ann. & Mag. Nat. Hist. ser. 2, xiii. p. 40, t. 4, fig. 13 (1854). 

 Verrucaria marina Leight. Lich. Fl. p. 446 (1871) ; ed. 3, p. 477 ; 

 Massee in Journ. Bot. xxx. p. 193, t. 324, fig. 8 (1892). 



Similar to A. leptotera in appearance of thallus and perithecia, 

 but differing in the structure and size of the spores. Weddell's 

 Verrucaria leptotera var. r}iarniorans (Mem. Soc. Sci. Nat. Cherb. xix. 

 p. 809 (1875) ) is probably identical with A. marina. 



Hah. On maritime rocks below high tide. — Distr. Rare in the 

 Channel Islands, S. England and E. and W. Scotland. — B. M. Greve- 

 au-Lan9on, Jersey ; Torquay, Devon. 



Growing on trees ; spores 3-septate. 



28. A. rhyponta Massal. Ric. Lich. p. 166 (1852).— Thallus 

 thin, subeffuse, dark-brown or blackish, forming dark-coloured 

 spots on the bark. Perithecia minute, hemispherical, semi- 

 immersed, black ; perithecial wall dimidiate ; paraphyses almost 

 obsolete ; spores colourless or becoming slightly brownish, linear- 

 oblong, 3-septate, 0,01 8-22 mm. long, 0,004-5 mm. thick ; hymenial 

 gelatine red or yellow-brown with iodine. — Verrucaria rhyponta 



