EOCCELLA.] EOCCELLEI. 183 



p. 81, ed. 3, p. 74. Lichen Roccella Eng. Bot. t. 211, is true Roccella 

 tinctoria DC. (minor), but the figure is drawn from an exotic speci- 

 men. Brit. Exs. : Mudd, n. 48; Larb. Csesar. n. 11 ; Lich. Hb. 

 n. 122 ; Cromb. n. 14. 



States with the branches more elongate and scarcely sorediiferous have 

 been confounded with It. tinctoria, whose range, however, does not extend 

 so far north as our islands. It differs in its smaller size (1-3 inches in 

 height), the less opaque thallus, which is more thinly branched and sore- 

 diiferous (not farinaceous) on the surface, as also in the smaller lecideine 

 apothecia. It is very rarely fertile in Great Britain. The spermogones, 

 which are occasionally present in our specimens, have the sterigmata 

 slender and the spermatia arcuate, 0,013-10 mm. long, scarcely 0,001 mm. 

 thick. Our fig. 37 shows that the globulose or ellipsoid gonidia are 

 simple, or two or more concatenate. The papillseform cells of the cortex 

 are sprinkled with the powder (granulations) of the pigmentary matter. 



Hal>. On rocks, rarely on walls in maritime localities. Distr. Not un- 

 common in the Channel Islands and in S.England; extremely rare in 

 S.W. Scotland. B. M. : St. Brelade's Bay, La Moye and Noirmont, 

 Island of Jersey ; Petit- Bot Bay, Island of Guernsey. Godshill Church 

 and Bembridge, Isle of Wight ; 'Portland Island, Dorsetshire ; Bolt Head, 

 Lynmouth, and Valley of Kocks, Lynton, Devonshire ; Tintagel Castle, 

 Lamorna Cove, Fenfire and St. Minver, Cornwall ; St. Mary's, Scilly 

 Islands. Millport, Cuuibrae Island, Frith of Clyde. 



Form tenuior Nyl. ex Leight. Lich. Fl. ed. 3 (1879) p. 74. 

 Thallus somewhat elongate, very slender, much branched towards 

 the apices. Apothecia not seen. Roccella fuciformis (errore) f. 

 tenuior Cromb. Grevillea, xv. p. 47. 



Differs from the type in the more slender, elongate, and apically 

 branched thallus. It is plentifully sorediate, but apparently never fertile. 



Hab. On rocks in maritime situations. Distr. Local and scarce in the 

 Channel Islands. B. M. : La Moye, Island of Jersey. 



2. R. fuciformis DC. Fl. Fr. ii. (1805) p. 335. Thallus com- 

 pressed, much branched, glaucous-white or glaucous-brown, often 

 sorediiferous ; branches dichotomously laciniate (CaCl , soredia 

 -(-reddish, medulla I -(-bluish). Apothecia moderate, superficial, 

 lecanorine, black, pruinose, the thalline margin at length nearly 

 excluded ; spores fusiform or oblon go-fusiform, 0,020-30 mm. long, 

 0,004-6 mm. thick. Gray, Nat. Arr. i. p. 426 : Sm. Eng. Fl. v. 

 p. 222 ; Tayl. in Mack. Fl. Hib. ii. p. 83 ; Mudd, Man. p. 76, t. 1. 

 f. 18; Cromb. Lich. Brit. p. 23; Leight. Lich. Fl. p. 82, ed. 3, 

 p. 74. Lichen fuciformis Linn. Sp. PI. (1753) p. 1614; Dicks. 

 Crypt, fasc. iii. p. 17 ; With. Arr. ed. 3, iv. p. 51 ; Eiig. Bot. t. 728. 

 Lichenoides fact forme tinctoriutn, corniculis lonyioribus et acutioribus 

 Dill. Muse.' 168, t. 23. f. Ql.Brit. Exs. : Leight. u. 171 ; Larb. 

 Cresar. n. 12; Lich. Hb. n. 123; Cromb. nos. 15, 125. 



From It. phycopsis, with which in this country it is usually found asso- 

 ciated, this differs in its compressed, broader/ generally longer thallus, 

 and in the fructification. It varies considerably in size, occasionally 



