26 EPHEBACEI. [PYREXOPSIS. 



are enveloped in a thickish gelatinose tunic." The apothecia are rare in 

 the few British specimens gathered, and the spores are seldom well deve- 

 loped. We have not detected any mature spermogones on our specimens, 

 though these would determine mo're definitely the place of this species, as 

 the spermatia in the PhyUiscodei (Nyl. Flora, 1887, p. 133) are elongate 

 and arcuate. 



Hab. On moist mica-schist rocks in alpine places. Distr. Very local 

 and rare, having been found only very sparingly among the S. Grampians. 

 B. M. : Summit of Ben Lawers, Perthshire. 



Tribe III. HOMOPSIDEI Nyl. ex Stiz. St. Gall. Nat. Ges. 

 1876, p. 193 ; Flora, 1887, p. 133. 



Thallus variable in form and texture, being either (1) fructi- 

 culose, with gonimia seriate, and chiefly contiguous or seriately 

 connate in the branches and branchlets, or (2) squamuliform or 

 granuloso-continuous, uniform, with gouimia (haplogonimia) some- 

 what large and subsolitary, or large and solitary, always gelatinoso- 

 involute ; medullary filaments wanting. Apothecia pyrenocarpous, 

 innate in thalline protuberances, externally more or less eminent, 

 or immersed and without any external protuberance ; spores simple 

 or rarely 1-septate ; paraphyses slender or none. Spermogones 

 inclosed in thalline protuberances, or immersed and without any 

 protuberance ; spermatia either shortly cylindrical, straight (the 

 sterigmata simple), or elongate, thin, arcuate (the sterigmata 

 simple, somewhat short). 



This tribe comprises various small brown or blackish plants, agreeing 

 in the common character of having pyreuocarpous apothecia, though in 

 other respects differing considerably in the several genera. According 

 to the form and texture of the thallus, the arrangement of the gonimia, 

 and the presence or absence of thalline protuberances enclosing the 

 fructification, it is divided into two subtribes, viz. Ephebei and Phyttis- 

 codei. To the latter, according to Nylander in lift., belongs Collcma 

 granuliforme ^y\. = Phylliscodium granuliforme Nyl., which, although 

 recorded (erroneously) by Leigh ton (Lich. Fl. ed. 3, p. 22) from Galway, 

 has not been gathered in our Islands. 



Subtribe EPHEBEI Nyl. ex Stiz. St. Gall. Nat. Ges. 1876, 



p. 193 ; Flora, 1887, p. 133. 



Thallus small, byssoid, fructiculoso-ramose ; gonimia tunicated, 

 in nodulose syngonimia. Apothecia minute, pyrenocarpous, in 

 ellipsoid or pyriform incrassations of the thallus, paraphyses distinct 

 or none : spores 8n;ie, ellipsoid, simple or 1-3-septate, colourless. 

 Spermogones innate in globular or shortly ellipsoid thalline tubercles, 

 with slender, simplish storigmata. 



The thallus in its younger and immature state is entirely Sirosiphoid 

 in structure ; so that this subtribe might briefly be defined as consisting 

 of "pyrenocarpous sirosiphoid Ephebacei." Its two genera are wefl 

 distinguished from each other by the anatomical characters of the 

 apjthecia. 



