20-4 GBAPHIDEI [lECANACTIS 



p. 90 (1870). Schismatomma amylaceum var. eandidum Mudd 

 Man. p. 222, t. 4, f. 84 (1861). 



Exsicc. Mudd n. 199 ; Leight. n. 336 (as Lecklea amylacea). 



As noted above, the Lichen candidus of Engl. Bot. was quoted at 

 p. 137 on Leighton's authority as the originsil of his Lecidea Tumeri. 

 Though no spores are to be found in the British Museum specimen, it 

 seems more probable that it belongs here. Leighton had already 

 quoted it as synonvmous with his pubhshed specimen, Lecidea 

 amylacea n. 336. 



Sab. On maritime and subalpine rocks. — Distr. Bather rare in E. 

 and X. England and the Grampians, Scotland. — B. M. Ingleby Park, 

 Cleveland, Yorkshire ; Staveley, "Westmoreland ; the Trossachs, Perth- 

 shire ; Achallater, Braemar, Aberdeenshire. 



5. L. delimls A. L. Sm. — Thallus dark-greyish, warted- 

 granular or ■wrinkled, scattered (K + yellow, CaCl -|- red) ; 

 hypothallus dark brown limiting the thallus. Apothecia small, 

 black, convex, thiidy marginate or immarginate, greyish-pruinose ; 

 hypothecium thick, black ; paraphyses subdiscrete ; epithecium 

 granular, dark in thick section ; spores linear-oblong or some- 

 what fusiform, 3-septate, slightly constricted at the septa, 0,015- 

 18 mm. long, 0,004—5 mm. thick or longer and narrower, 0,021- 

 23 mm. long, 0,003 mm. thick ; hymenial gelatine tawny-wine- 

 coloured or reddish with iodine. — Lecidea delimig Xyl. in Flora 

 Ivi. p. 297 (1873); Cromb. in Journ. Bot. xii. p. 149 (1874); 

 Leight. Lich. Fl. ed. 3, p. 351. 



Hab. On rocks. — B. M. Mount Orgueil, Jersey (the only loeahty). 



82. PLATYGRAPHA Xyl. in Mem. Soc. Sci. Xat. Cherb. 

 iii. p. 188 (1855). (PI. 19.) 



Thallus scanty or evanescent. Apothecia roundish or oblong, 

 simple or rarely divided, immarginate, but with a spurious 

 thalline margin, blackish ; spores 8 in the ascus, fusiform, 

 septate, colourless ; paraphyses slender, more or less discrete. 

 Spermogones with shortly cylindrical straight or slightly arcuate 

 spermatia. 



The genus is almost entirely exotic, but of the four known 

 European species, two occur verv sparingly in Great Britain. 



1. P. periclea Xyl. I. c. & in Act. Soc. Linn. Bord. ser. 3, 

 i. p. 408 (1856). — Thallus effuse, scanty, very thin, subleprose, 

 white or whitish. Apothecia depressed, rotundate or oblong, 

 at times somewhat difform, black, opaque, concolorous within, 

 the thalline margin at length subevanescent ; spores narrowly 

 fusiform, 3-septate, often curved, 0,030-0,042 mm. long, 0,003--4r 

 mm. thick ; hymenial gelatine bluish then wine-red with iodine. — 

 Martind. in Naturalist, 1886, p. 49. Lichen perideus Ach. Lich. 

 Suec. Prodr. p. 78 (1798). 



Like other species of the genus, this might in some states readily 

 be taken for a Lecanora, aUied to L. exigua, to which species 



