VBRRCCARIA] VBEEUCAEIACBJE 277 



Edin. p. 353 ; Tayl. in Mackay Fl. Hib. ii. p. 93 ; Leight. Angioc. 

 Lich. p. 59, t. 25, f . 3 & Lich. Fl. p. 419 ; ed. 3, p. 449 ; Mudd 

 Man. p. 284 ; Cromb. Lich. Brit. p. 113. V. araetina Wahlenb. 

 torn. cit. p. 17; Cromb. I. e. (fide Leighton Lich. Fl. p. 419). 

 V. aspera Tayl. in Hook. Lond. Joum. Bot. vi. p. 153 (1847) ? 

 Lichen maurus Sm. Engl. Bot. t. 2456 (1812). Lithocia maura 

 S. F. Gray Nat. Arr. i. p. 498 (1821). 

 Exsicc. Leight. n. 33 pro parte. 



Easily distinguished by the maritime habitat and by the well- 

 developed polished-looking cracked thallus ; the minute areolss are 

 slightly raised at the margin. 



Hah. On maritime rocks. — Diatr. Somewhat common on the 

 coast of the British Isles. — B. M. Sark ; Gerrans, Cornwall ; Torquay, 

 Devon ; Shoreham, Sussex ; Manorbeer near Tenby, Pembrokeshire ; 

 Harlech Castle, Merioneth ; Pwllheli, Deganwy and Conway Bay, 

 Carnarvonshire ; near Dunbar, Haddingtonshire ; Pifeshire ; Wills' 

 Braes, Forfarshire ; Portlethen, Kincardineshire ; Dunkerron and 

 Kenmare River, Kerry. 



Var. memnonia Koerb. Syst. Lich. Germ. p. 340 (1855) e 

 descript. ; Wedd. in Mem. Soc. Sci. Nat. Cherb. xix. p. 301 (1875). 

 — Thallus thin, effuse, gelatinous, brownish-black with a light- 

 coloured hypothallus, cracked in places when dry, but not 

 areolate. Perithecia scarce, immersed in a swelling of the 

 thallus; spores varying in size, ellipsoid, 0,012-20 mm. long, 

 0,005-7 mm. thick, or 0,010-15 mm. long, 0,007-9 mm. thick, 

 sometimes almost round. — Y. memnonia Flot. ex Koerb. I. c. 



Eegarded as a variety by authors, but almost specifically distinct 

 owing to the continuous thallus, the superficial cracks being due 

 enthely to shrinking and occurring only on portions of the thallus. 

 It is traversed in places by the greyish lines of the hypothallus. 



Hab. On maritime rocks and growing nearer the sea than the 

 species. — B. M. Jerbourg, Guernsey. 



2. V. mucosa Wahlenb. in Ach. Meth. Suppl. p. 23 (1803).— 

 Thallus olivaceous or dark-greenish, smooth, gelatinous, opaque, 

 continuous, thin or sometimes rather thick. Perithecia minute, 

 immersed and scarcely visible above the thallus ; perithecial wall 

 dimidiate or almost entire ; spores small, ellipsoid, colourless, 

 0,007-10 mm. long, 0,005-6 mm. thick or rather larger. — Carroll 

 in Journ. Bot. iii. p. 292 (1865); Cromb. Lich. Brit. p. 113; 

 Leight. Lich. Fl. p. 413; ed. 3, p. 444. V. microsporoides Nyl. 

 in Bull. Soc. Bot. France viii. p. 759 (1861) ; Carroll in torn, 

 cit. p. 293; Cromb. Lich. Brit. p. 114; Leight. Lich. Fl. p. 414 ; 

 ed. 3, p. 445. 



Exsicc. Larb. Lich. Hb. n. 278. 



In the British specimens the spores are slightly narrower tjjan the 

 size given by Th. Fries in Lich. Arct. p. 269, measuring generally 

 about 0,004 mm. in thickness. Weddell (M6m. Soc. Soi. Nat. Cherb. 



