316 PYRENOCARPEI [aRTHOPYRBNIA 



appearing ; asci somewhat elongate-ovate, 2-8-Hpored ; spores 

 ellipsoid or elongate, more or less constricted in the middle, 1- or 

 more-septate, grouped in the ascus, colourless. Spermogones 

 small, globose or ovoid with simple sterigmata and rod-like 

 spermatia. 



Growing on Ireen ; thallus usually light-coloured ; spores ^-septate. 



1 . A. epidermidis Mudd Man. p. 303 (1 861 ) (excl. vars. except 

 var. atomaria) (ntm Massal.). — Thallus developed below the bark, 

 forming greyish or brownish sj)ots or little visible, smooth, effuse 

 or determinate. Perithecia small, black, hemispherical, semi- 

 immersed, becoming more or less prominent and shining, some- 

 times slightly spreading at the base ; perithecial wall dimidiate ; 

 paraphyses present, more or less branched, entangled or 

 disappearing ; asci ovate-elongate ; spores oblong or clavate- 

 oblong, colourless, 1 -septate, sometimes slightly constricted, the 

 cells almost equal in length, sometimes with a mucilaginous coat 

 (halonate), 0,015-24 mm. long, 0,005-7 mm. thick.— J., nitescens 

 Mudd I. c. ; Verrucaria epidermidis Fr. Lich. Eur. p. 447 (1831) 

 pro parte (non Ach. fide Wainio in Helsingf. Faun, k Fl. Fenn. 

 Meddel. x. p. 187 (1883)); Grev. Fl. Edin. p. 353? Hook, in 

 Sm. Engl. Fl. v. p. 149 pro parte; Tayl. in Mackay Fl. Hib. 

 ii. p. 88 pro parte ; Leight. Angioc. Lich. p. 40, t. 17, fig. 3 

 (excl. var. analepta) k Lich. Fl. p. 431 ; ed. 3, p. 463 (excl. 

 vars.); Cromb. Lich. Brit. p. 119 (excl. vars.). V. nitescens 

 Salwey in Trans. Nat. Hist. Soc. Penzance, 1853, p. 140 

 (e descript.) ; Leight. Lich. Fl. p. 434 ; ed. 3, p. 467. F. epider- 

 midis var. nitescens Cromb. I. c. 



Exsicc. Carroll Lich. Hib. n. 31 ; Bohl. n. 63. 



Confused withVe7'7'ucaria epidermidis Ach. (LeptorJia^jhis), which is 

 wholly confined to birch bark and has different spores. The perithecia 

 are always small and round in outline with the base immersed in the 

 epidermis of the host. 



Hab. On the bark of birch and other trees. — Distr. Somewhat 

 common in S. and N. England, and in S. and W. Ireland; Scotland? 

 — B. M. Bodmin, Cornwall ; Torquay, Devon ; Malley Wood, New 

 Forest, Hants ; Ulting, Sussex ; Shere, Surrey ; Cowcombe Wood, 

 Kemble'inear Cirencester and Chalford, Gloucestershire ; Bath, 

 Somerset ; Capel Arthog, Merioneth ; Builth, Brecknockshire ; Tre- 

 friwand Bettws-y-Coed, Carnarvonshire ; near Ayton, Cleveland, York- 

 shire ; Kiverstown, Castlemartyr, Carrigaloe, Glanmire and White 

 Point Harbour, Cork ; Tore Mt., Croghan Mt. and Cromaglown, 

 Killarney, Loch Inchiquin and Glencar, Kerry ; Clonmel, Tipperary. 



Var. lactea Mudd Man. p. 304 (1861) pro parte.— Thallus 

 white or whitish, determinate, sometimes surrounded by a dark 

 line. Perithecia moderate in size, spreading at the base, shining- 

 black or partly covered by the thallus, otherwise as in the species. 

 — Verrucaria punctiformis var. lactea Schaer. Enum. p. 220 (1850) 



