OPEGKAPHa] GRAPHIDAOEaS 245 



p. U, f. 7 (1824); Fr. Lich. Eur. p. 375 (1831). Leight. in 

 Ann. Mag. Nat. Hist. ser. 2, xiii. p. 391 (1854). 



Exsicr. Leight. n. 195; Mudd n. 204; Larb. Lich. Hb. 

 n. 111. 



Easily recognized by the whitish thallus which sometimes spreads 

 over large patches of the bark, and by the grey-pruinose apothecia. 

 These are occasionally attacked by a fungus which changes them into 

 a disintegrated blackish mass. This condition {Spiloma versicolor, 

 Sm. Engl. Bot. t. 2076, S. variolosum t. 2077 (1809) ? Turn. & Borr. 

 Lich. Brit. p. 35 (1839) & 8. nigrum pro parte ?) was named by 

 Pries O. lyncea var. spilomatica (Lich. Eur. p. 376), and later by 

 Nylander Spilomium grapJiideorum (in Act. Soc. Linn. Bord. ser. 3, i, 

 p. 398 (1856) ). 



Hab. On old oaks. — Distr. Bather rare in the Channel Islands and 

 England. — B. M. Brookenhurst, New Forest, Hants ; near Glynde, 

 Danny, Hurstpierpoint ; Parham Park, Sussex ; Holmwood, Sm-rey ; 

 Thorndon Hall, Gosfield Hall, and Epping Forest, Hainault Forest, 

 Essex ; Penshurst, Kent ; Tickworth Park and Bennington Park, 

 Suffolk ; Sherwood Forest, Nottinghamshire ; Purton, Wiltshire ; 

 Donningtou Park, Leicestershire ; Haughmond Hill, Shropshire ; 

 Hoggarts Wood, Ingleby, Cleveland, Yorkshire. 



25. 0. prosodea Ach. Meth. p. 22 (1803).— Thallus 

 effuse, thickish, membranaceous, duU-pallid-brownish. Apothecia 

 prominent, stout, subcylindrical, somewhat shining, straight ; 

 disc narrow ; margins elevated, connivent ; paraphyses distinct ; 

 spores elongate-fusiform, colourless, up to 17-septate, about 

 0,050-60 mm. or more long, 0,006 mm. thick ; spermogones 

 rod-shaped 0,005-6 mm. long, 0,007 mm. thick. — Nyl. in Prodr. 

 Fl. N. Gran. p. 568 ; Cromb. Lich. Brit. p. 99 ; Leight. Lich. Fl. 

 p. 387 ; ed. 3, p. 410. 



Exsicc. Larb. Csesar. n. 92. 



Hah. On barli of trees. — Distr. Bare in Channel Islands and 

 S. England. — B. M. Ann Port and St. Peter's Valley, Jersey ; Newton 

 Bushel], Devon ; New Forest, Hants ; Shiere, Surrey. 



26. 0. viridis Pers. ex Ach. Meth. p. 22 (1803).— Thallus 

 pale-yellowish or brownish, thin, somewhat vaguely limited. 

 Apothecia innate or sessile, oblong or linear, rounded, straight 

 or curved mostly simple; disc narrow, uniform, the margins 

 rounded, inflexed ; spores elongate-acicular or narrowly fusiform, 

 up to 15-septate, colourless, 0,040-80 mm. long, 0,006-7 mm. 

 thick; spermogones with arcuate spermatia 0,014-16 mm. long, 

 0,0005 mm. thick. — Cromb. Lich. Brit. p. 100 ; Leight. Lich. Fl. 

 p. 387 ; ed. 3, p. 410. 0. siderella Leight. in Ann. Mag. Nat. 

 Hist ser. 2, xiii. p. 209, t. 6. f. 14 (1854) (non Ach.?). 0. rubella 

 Mudd Man. p. 233, t. 4, f. 90 (1861) (non Pers.?). 



Exsicc. Mudd n. 213 (as 0. rubella). 



Distinguished from the preceding by the thinner thallus and the 

 smaller and more slender apothecia. 



