348 PYRKNOCARPKI [mELANOTHKCA 



form'is var. oUvaeca Ach.), 358 (as 0. ptnictiformiH var. (jalactina) ; 

 Larb. Lich. lib. n. 40. 



Similar in outward appearance to M. arthonioidcs MassuJ., a 

 continental plant, but differing in the lif];litcr coloured walls of the 

 perithecia, the less distinct paraphyses and larger spores. The latter 

 are at first colourless and 1-septate, becoming brownish and 3-septate. 



Hah. On the smooth bark of trees. — Disfr. Frequent throughout 

 Great Britain and Ireland, rare in the Channel Islands. — JJ. M. 

 Withiel, Cornwall ; near Becky Falls, Torquay and Cornwood, Devon ; 

 near Handcross, near Balcombe. Newtimber, Tilgatc and Tonbridge 

 Wells, Sussex ; Hailey Wood and Chedwortli Wood, Gloucestershire ; 

 Stableford and Church Stretton, Shropshire ; Dolgelly, Merioneth ; 

 Dolbadarn Castle, Llanberis and Conway Falls, Carnarvonshire ; 

 Baysdale and near Ayton, Cleveland, Yorkshire ; Appin, Argyll ; Glen 

 Lochay, Killin and Blair Athole, Perthshire ; Glen Cluny, Braemar, 

 Aberdeenshire; Glen Nevis, Invernessshire ; IJallyedniondand Rivers- 

 town, Cork ; by Glenmore Lake, Kerry ; Glenstale. Tipperary ; Kyle- 

 more, Connemara, Galway ; Deer Park, Glenarm, Antrim. 



2. M. diffusa Leight. Lich. Fl. p. 467 (1871).~-Thallus 

 forming eff"use greyish spots. Perithecia several in irregularly 

 round or oblong stromata ; perithecial walls colourless ; para- 

 physes stoutish rather crushed ; spores linear-oblong, smoky- 

 brown, 1-septate, slightly constricted, 0,022-26 mm. long, 

 0,005 mm. thick. — Cromb. in Journ. Bot. ix. p. 179 (1871); 

 Leight. op. cit. ed. 3, p. 498. 



Hah. On the bark of young trees. — Distr. Pi,are in N. Wales. — 

 B. M. Nant Gwynant, Snowdon, Carnarvonshire. 



3. M. ischnobela Nyl. in Flora lix. p. 238 (1876).~-Thallus 

 whitish, forming rather large effuse spots. Stromata small, 

 scattered, somewhat convex ; perithecia 2-4 in each stroma, 

 perithecial walls dimidiate, black ; paraphyses slender, numerous ; 

 asci cylindrical ; spores 8 in the ascus, acicular, multi-guttulate 

 and 1 -multi-pseudo-septate, 0,060-115 mm. long, 0,001-2 mm. 

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

 Fl. ed. 3, p. 499. Verrucaria myriospora Leight. in Trans. Linn 

 Soc. ser. 2, i. p. 145, t. 22, figs. 1-3 (1876). 



Exsicc. Larb. Lich. Hb. n. 80. 



Distinguished by the smaller stromata and by the acicular, colour- 

 less spores. 



Hah. On holly. — B. M. K^demore, Connemara, Galway (the ojdy 

 locality). 



MYCOPORACEJK, 



Thallus crustaceous not corticated, superficial or developed 

 within the bark (hypophloeodal). Algal cells Palmella or 

 TrentepoJilia. Perithecia compound, several united in a common 



