mycopokum] MYCopoEACBa: 349 



outer dark-coloured wall (peridium), but with separate ostioles ; 

 spores 6-8 in the ascus, variously septate, colourless or coloured. 



A small Order represented in Great Britain by four species in 

 two genera : — 



Algal cells PaZmeZZa 122. Mycoporum. 



Algal cells Trentejoohlia 123. Mycoporellum. 



122. MYCOPORUM Flot. ex Nyl. in Mem. Soc. Soi. Nat. 

 Cherb. iii. p. 186 (1855). (PI. 58.) 



Thallus thin or obsolete. Algal cells Palmella. Perithecia 

 compound with a dark-coloured outer wall (peridium), the 

 different hymenia not distinctly separated ; asci elongate or 

 pyriform- ellipsoid ; paraphyses entangled or disappearing ; spores 

 6-8 in the ascus, colourless or becoming dark-coloured, variously 

 septate or muriform. 



1. M. miserrimum Nyl. in Mem. Soc. Sci. Nat. Cherb. v. 

 p. 145 (1857). — Thallus very thin, indicated by a pale spot, or 

 obsolete. Perithecia 2-6-compound ; the outer peridium small, 

 black, nodulose with the ostioles of the enclosed perithecia ; 

 perithecial walls dark below, indistinct laterally ; paraphyses 

 crushed, almost disappearing ; asci broadly ellipsoid ; spores 8 in 

 the ascus, oblong, 3— 5-^eptate with 1 or 2 longitudinal divisions, 

 colourless, , becoming brownish, 0,015-18 mm. long, 0,005-8 mm. 

 thick. — Carroll in Journ. Bot. iii. p. 292 (1865) ; Oromb. Lioh. 

 Brit. p. 106 ; Leight. Lich. F\. pp. 406, 485 ; ed. 3, p. 438. 



Exsicc. Mudd n. 231 (a& Arthonia punctiformis). 



Hah. On smooth bark of trees. — Distr. Not uncommon in England 

 and Wales. — B.M. Ullacombe, Devon; Polegate, Sussex; Chedworth 

 Wood and Hailey Wood near Cirencester, Gloucestershire ; Pontesford, 

 Shropshire ; Nannau, Dolgelly, Merioneth ; Hoggart's Wood, Ingleby 

 and near Guisboro, Cleveland, Yorkshire. 



2. M. ptelEeodes Nyl. Lioh. Scand. App. p. 291 (1861).— 

 Thallus forming pallid spots or obsolete. Perithecia united in 

 small scattered peridia, the upper wall black, the basal wall 

 scarcely developed ; paraphyses scanty, disappearing ; spores 8 in 

 the ascus, ovoid-ellipsoid, 3-septate, usually with one longitudinal 

 septum, colourless, 0,012-16 mm. long, 0,006-8 mm. thick. — 

 Cromb. in Journ. Bot. xiv. p. 363 (1876); Leight. Lich. Fl. 

 ed. 3, p. 438. 



Closely allied to the preceding, but with a less developed basal 

 wall and shorter spores. 



Hab. On trees (alder). — Distr. Bare in W. Engljmd. — B. M. Cleve 

 Hill, Cheltenham, Gloucestershire. 



123 MYCOPORELLUM A. Zahlbr. in Engler & Prantl 

 Pflanzenf. i. 1*, p. 78 ^1903). (PI. 59.) 



