BACIDIA] LECIDEACEiE 157 



Characterized by tlie colour of the apotheoia and the thinner 

 longer acicular spores. Spermatia as in the species. 



Hah. On siliceous rocks in a maritime district. — Distr. Extremely 

 local and scarce in W. Ireland (near Kylemore, Galway). 



16. B. caligans A. L. Sm. — Thallus indeterminate, thiniiish, 

 rugose, diffract, fuliginous-black (K-|-, CaCl). Apotheoia small, 

 plane, obtusely margined, blackish, pale within ; hypothecium 

 colourless (the perithecium somewhat brownish above) ; para- 

 physes concrete, colourless at the apices ; spores thinly acicular, 

 indistinctly septate, 0,030-35 mm. long, 0,0015 mm. thick ; 

 hymenial gelatine wine-reddish with iodine. — Lecidea caligans 

 Nyl. in Flora Ivii. p. 10 (1874); Cromb. in Grevillea ii. p. 140 

 & xxii. p. 58; Leight. Lich. ed. 3, pp. 283, 371. 



Resembling in some respects B. inundata, but very distinct in the 

 dark colour of the thallus, and in the rather larger apothecia. 

 The thallus is overrun by a thin Scytonema. 



Sab. On rocks in a maritime district. — B. M. Island of Alderney 

 (the only locality). 



17. B. egenula Th. Fi-. Lich. Scand. p. 363 (1874).— Thallus 

 very thinly granulose, greyish (Kf -|- yellowish), nearly obsolete. 

 Apothecia small, plane, obtusely margined, blackish or dark- 

 brown, the margin thickish, at length evanescent, within pale- 

 whitish (brownish in the centre) ; paraphyses coherent, clavate 

 at the apices ; epithecium colourless or faintly coloured ; hypo- 

 thecium yellow-brown or reddish in thin section ; spores acicular, 

 simple or indistinctly septate, 0,020-38 mm. long, 0,0015-20 mm. 

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

 Lecidea egenula Nyl. in Flora xlviii. p. 147 (1865). L. Leigh- 

 toniana Larb. ex Leight. Lich. Fl. ed. 3, p. 368 (1879) ; Cromb. 

 in Grevillea xxii. p. 59. 



Exsicc. Larb. Lich. Hb. n. 144. 



Allied to B. arceutina, but differs in the much smaller plane 

 darker apothecia, the usually shorter spores, and the colour of the 

 hypothecium. The apothecia are somewhat scattered. 



Hab. On schistose rooks in an upland tract. — B. M. Doughruagh 

 Mt. and Lough Peagh, Connemara, Galway. 



18. B. arceutina Branth & Rostr. in Bot. Tidsskr. iii. p. 233 

 /1869).— Thallus effuse, very thin, smoothish or subgranulose- 

 verrucose whitish or greyish, often evanescent. Apotheoia 

 small, sessile, at first plane with darker margin, then convex, 

 immarginate, dark-red or blackish and shining, colourless within ; 

 epithecium brown or brownish ; hypothecium yellowish ; spores 

 narrowly acicular, straight or slightly curved, 3-15-septate, 

 0,044-54 mm. long, 0,0015-25 mm. thick ; hymenial gelatine 

 bluish then wine-red or sordid with iodine. — Lecidea luteola var. 

 y arceutina Aoh. Meth. p. 61 (1803) & Lioh. Univ. p. 197 ; var. 

 fuscella Fr. Summa p. 112 (1846). L. arceutina Nyl. in Flora 



