C A T A L O G U E 



BRITISH LICHENS. 



Family I. EPHEBACEI Xyl. Flora, 1S79, p. 223. 



Thallus fruticulose, grauulose, rarely subsquamulose, slightly 

 turgid and gelatinous when moist, dark in colour, cellular in 

 texture (without any medullary filaments), cells minute; gonimia 

 somewhat large, gonidioid, tunicated, subglobose. glaucous, variously 

 arranged, not moniliform. Apothecia biatorine, lecideiiic, lecanorine 

 or pyrenocarpous ; paraphyses various, sometimes wanting : spores 

 8nae, rarely numerous, usually ellipsoid or suboblong, simjjle, rarely 

 1-septate, colourless. Spermogones immersed in the thallus or 

 enclosed in thalliue tubercules, sterigmata generally simple or 

 simplish, spermatia usually very minute, oblong. 



Nylander, in origin ally distinguishing this family in Flora 1875, p. 103, 

 named it Byssacei Fr. ; but as the old genus Bysms in the Michehaa 

 acceptation referred to Chroolepa, which have gonidic thalli, this has 

 been named Ephebacei. 



The family (the diagnosis of which I owe to Nylander) is well cha- 

 racterized by the absence of medullary filaments, and by the nature of 

 the gonimia. which are tunicated or involved in a gelatinous cellular 

 stratum. On the tunic being ruptured, the gonimia, each of which has 

 a very thin parietal membrane (more especially visible when suffused 

 with ammonia, Xyl. Pyr. Or. p. 48), become free. Various genera re- 

 cently separated from Algae belong to this family ; and no doubt, with 

 fm-ther knowledge, others will be transferred to it. 



Tribe I. SIROSIPHEI Xyl. e:c Stiz. St. GaU. Xat. Ges. 

 (1876), p. 192 ; cfr. Cromb. Grevillea, v. p. 76. 



Thallus minute, byssoid, filamentoso-frutieulose, gonimia (siro- 

 gonimia) tunicated, variously connate ; medullary filaments none. 

 Apothecia minute, biatorine or lecideine ; para[i"hyse3 thickish or 

 slender ; spores Snce, ellipsoid, simple or rarely l-septate, colour- 

 less. Spermogones innate ; sterigmata simple, rarely articulate. 



The various genera composing this tribe (of which Xylander has sup- 



J)lied the diagnosis) consist of minute algoid plants," whose true re- 

 ations have for the most part, until recently, been but little imderstood. 

 In addition to those here described there are others which, occunincr 

 only in a sterile or imperfectly developed condition, do not admit of a 



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