274 LICHEXACEI. [STICTA. 



exotic variety, cannot be retained for our British form, — Brit. Exs. : 

 Cromb. n. 38. 



Differs from the type chiefly in having the lobes more broadly dilated, 

 and approaches var. Canariemis Ach. It is a very interesting British 

 form of an exotic lichen, which has not been found eUewhere in Europe. 

 In fertile specimens the apothecia are numerous, chiefly marginal, but 

 sometimes also sparingly scattered. 



Hah. On shadv rocks in maritime and upland districts. — iJistr. Very 

 local, though somewhat plentiful in 8.W. Ireland. — B. M. : Turk Cascade, 

 Killarne}' Woods, Cromaglown, co. Kerry ; near Bautry, co. Curk. 



Subgenus PARMOSTICTA Xyl. Flora, 1875, pp. 303, 363.— 

 Thallus beneath with pulverulent sorediiform ])seudocyphell8e ; 

 apothecia truly parmeleine (with gonidia present throughout, even 

 to the extreme margin of the receptacle). 



2. S. aurata Acb. Meth. (1803) p. 277.— Thallus expanded, 

 opaque, or but slightly shining, lobato-divided, reddish-brown or 

 red ; beneath shortly tomentose, brownish-black in the centre, 

 brownish at the circumference ; lobes sinuato-incised, crenato-undu- 

 late, and generally citrino-pulverulent at the margins. Apothecia 

 large, subpedicellate when young, marginal or submarginal, dark 

 brown, the margin thin, usually inflexed ; spores 3-?eptate, fusi- 

 form, brownish, 0,024-28 mm. long, 0,007-8 mm. thick.— Gray, 

 Nat. Arr. i. p. 430 ; Sm. Eiig. Fl. v.^ p. 205 ; Mudd, Man. p. 90 ; 

 Cromb. Lich. Brit. p. 31 ; Leight. Lich. Fl. p. 119, ed. 3, p. 112.— 

 Lichen auratus Eng. Bot. t. 2359. Lichenoides lacunosum rutiliim, 

 marf/ini'>u.s favis Dill. Muse. 549, t. 84. f. 12. — Brit. Exs. : Cromb. 

 n. 39 ; Leight. n. 261 ; Larb. Caesar, n, 16. 



The thallus with us is smooth and usually little expanded. The 

 pseudocyphellte and the medullary layer are citrine. In this country 

 neither apothecia nor spermogones have been detected. 



Hob. On trees, rocks, and heather in maritime localities. — Distr. Local 

 and scarce in S. W. England, chiefly in the Channel and Scilly Islands. 

 — B. M. : Near the Eperquerie, Island of Sark ; Jerbouro-, Island of 

 Guernsev. Near Shauklin, Ryde, and Ventnor, Isle of Wiglit; coasts 

 of Devonshire and Cornwall ; Fresco Island and Bryer Island, Scilh'. 



Form subglaucescens Cromb. GreviUea, xv. (1887) p. 76. — Thallus 

 pale brownish-glaucous, bright-green when moist ; otherwise as in 

 the type. 



Though differing merely in the peculiar colour of the thallus both in a 

 dry and wet condition, this must rank as a well-marked form. 



Hub. On the branches of old apple-trees in maritime districts. — Distr. 

 Very rare in one locality of S.W. England. — B. M. : The Undercliff, 

 Lyme Regis, Dorsetshire. 



48. RICASOLIA De Not. Giorn. Bot. Ital. i. (1846) p. 178 ; NyL 

 Syn . i. ( 1 860) p. 355. — Thallus frondose, lobed or laciniate, very rarely 



