COLLEMA.] COLLKHEI. 43 



1874, p. 333, Leight. Lich. Fl. ed. 3, p. 17, is a slightly thinner 

 state of the species. 



The thallus is memhranaceous in texture, and has rather small gonimia. 

 From the allied species it is readily distinguished by the transversely 

 rugulose lobes, and by the reaction with iodine in a thin section of the 

 thallus, which takes 'place immediately on application. In the British 

 specimens the apothecia are very rare. 



Hab. On rocks and old walls, chiefly calcareous, in upland districts. 

 Distr. Local and scarce in W., Central, and N. England, N. Wales, in 

 the S.W. Highlands and the S. Grampians, Scotland. B. M. : Paignton, 

 S. Devon ; Sherbrook and Cole Heath, Buxton, Derbyshire ; Island of 

 Anglesea; Ashgill Force, Cumberland. Appin, Argyleshire; Killin, 

 Perthshire. 



Subsp. C. granosum. Nyl. ex Cromb. Grevillea, xv. (1886) p. 11. 

 Thallus smaller, thickish, more rigid, somewhat smooth or granu- 

 late ; lobes more elongate, variously incised, imbricate in the 

 centre, crenate at the margins. Apothecia and spores as in the- 

 type. Collema dermatinum Borr. Eng. Bot. Suppl. t. 2716. f. 2 (two 

 upper figs) ; Sm. Eng. Fl. v. p. 212 ; Mudd, Man. p. 36. Leptogium 

 dermatinum Leight. Lich. Fl. p. 29, ed. 3, p. 32. Lichen granosus 

 Wulf. in Jacq. Coll. iii. (1789) p. 131, 1. 10. f. 2. Lichenoides gela- 

 tinosum atro-virens, auriculatum et granosum Dill. Muse. 140, t. 19. 

 f. 24 A. 



This is well distinguished as a subspecies by the smaller subcoriaceous 

 thallus and by the more incised, imbricate lobes. The apothecia are 

 sessile and numerous on our fertile British specimens. 



Hab. On calcareous rocks and walls in upland districts. Distr. Local 

 and scarce in W. England, N. Wales, and S.W. Ireland. B. M. : Cheddar 

 Cliffs and opposite St. Vincent's Rocks, Bristol, Somersetshire ; near 

 Cirencester, Gloucestershire; Pentragaer, Oswestry, Shropshire. Dun- 

 kerron, co. Kerry. 



8. C. furvum Ach. Lich. Univ. (1810) p. 650. Thallus roundly 

 lobed, more or less granulate on boch sides, dark greenish-brown or 

 olive-black ( I + blood-red when dry); lobes irregularly complicate, 

 usually undulate and crisp, entire. Apothecia moderate, somewhat 

 scattered, plane, brown, the margin entire : spores ovoid or ellipsoid, 

 3-septate, becoming irregularly murali-locular, 0,018-24 mm. long, 

 0,009-11 mm. thick. Hook. Fl. Scot. ii. p. 72 ; Mudd, Man. p. 36 : 

 Cromb. Lich. Brit. p. 5 ; Leight. Lich. Fl. p. 24, ed. 3, p. 17. 

 Lathayrium furvum Gray, Nat. Arr. i. p. 400. Lichen furvus Ach. 

 Prodr. (1798) p. 132. Collema granulatum Sm. Eng. Fl. v. p. 211 ; 

 Tay]. in Mack. Fl. Hib. ii. p. 110. Lichen granulatm Huds. Fl. 

 Angl. ed. 2, p. 536, pro parte ; With. Arr. ed. 3, p. 73, pro parte : 

 Eng. Bot. t. 1757. Lichenoides gelatinosum lobis crassioribus fusco- 

 viridibus Dill. Muse. 138, t. 19. f. 22. Brit. Exs. : Cromb. n. 102. 



The thallus, usually of moderate size, is either naked or more 

 frequently granulato-furfuraceous, from the presence of numerous isidia, 

 occasionally giving origin to young lobules. By our older authors 



