340 PTEEXOCAEPEI [tHRLOPSIS 



1. Th. rubella Nyl. torn. cit. pp. 194 & 202.— Thallus 

 indistinct, greyish, or obsolete. Perithecia pale-reddish, spherical, 

 prominent, vrith a distinct poriform ostiole ; perithecial wall 

 colourless in lower portion; asci with 100 or more spores; 

 paraphyses slender, septate ; spores ellipsoid, 3-septate, 0,010— 

 17 mm. long, 0,005—8 mm. thick; hymenial gelatine wine-red 

 ■with iodine. — Carroll in Journ. Bot. "d. p. 101 (1868) ; Cromb. 

 Lich. Brit. p. 123. Verrucaria rubella Leight. Lich. Fl. p. 442 

 (1871); ed. 3, p. 472. 



Hdb. On the bark of trees. — Distr. Bare in Central Scotland and 

 S.W. Ireland. — B. M. Lanrick Castle, near Domie, Perthshire. 



2. Th. melathelia ^yl. in Flora xlvii. p. 358 (1864).— 

 Thallus almost obsolete. Perithecia black, prominent, somewhat 

 wrinkled and irregular ; perithecial wall blackish or reddish, 

 entire ; paraphyses slender, distinct ; spores many in the ascus, 

 ellipsoid or oblong, 3-septate, 0,014-18 mm. long, 0,004-7 mm. 

 thick ; hymenial gelatine blue, then dark-violet, with iodine. — 

 CarroU in Journ. Bot. iii. p. 293 (1866) ; Cromb. Lich. Brit. 

 p. 123. Verrtbcaria melathelia Leight. Lich. Fl. p. 447; ed. 3, 

 p. 478. 



Hab. Incrusting mosses on the ground. — Distr. Bare in moun- 

 tainous regions.— B. M. Above Loch-na-gat, Ben Lawers and Craig 

 Calliach, Perthshire. 



118. PYRENULA Ach. Lich. Univ. p. 64 (1810) : emend. 

 Massal. Eic. Lich. p. 162 (1852) ; Mudd Man. p. 298. (PI. 54.) 



Thallus crustaceous, superficial or developed within the 

 substratum, not corticated. Perithecia simple, variously globose, 

 with poriform or slightly beaked ostiole; paraphyses slender, 

 distinct; asci 8-spored; spores elongate, 2-5-septate, the cells 

 variously lentiform or angular in shape, brown. Spermogones 

 with branched sterigmata and slender bent terminal spermatia. 



Distinguished from Microthelia, which also has brown septate 

 spores, not only by the unbranched paraphyses, but also by the form 

 of the spores. It is largely a tropical or subtropical genus, and only a 

 few species occur in Europe. 



1. P. nitida Ach. Syn. Lich. p. 125 (1814).— Thallus 

 yeUowish-oUve or greyish-brown, waxy, continuous, smooth, some- 

 what shining, sometimes traversed and intersected by blackish 

 lines. Perithecia rather large, black, globose-hemispherical, 

 immersed in or veiled by the thallus, the ostiole more or less pro- 

 truding, depressed and umbilicate ; perithecial wall entire, black ; 

 paraphyses distinct ; spores ellipsoid-oblong, 3-septate, brown, each 

 cell with an angular oil-drop, 0,020-27 mm. long, 0,007-10 mm. 

 thick ; hymenial gelatine not tinged with iodine. — Mudd Man. 

 p. 298. Sphseria nitida Weigel Obs. Bot. p. 45, t. 2, fig. 14 

 (1772) ; Dicks. Plant. Crypt. Brit. 1, p. 23 : With. Arr. ed. 3, 

 iv. p. 393 ; Sow. Engl. Fungi, n. 275. Verrucaria nitida Schrad. 



