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XV. New British Lichens. By the Rev. W. А. LEIGHTON, B.A. Camè., 
F.L.S., F.B.S.Ed., $c. 
(Plate XXXII.) 
Read December 7th, 1876. 
LECIDEA. тмрквкззїтА, Leight. Albido-cinerascent, thin, filmy, rimulose, nigro- 
limitate. (K yellow, then red.) Apothecia black, minute, punctiform, numerous, 
crowded into small groups of 3 or 4 or more, impressed or sunken in the thallus, 
each apothecium circumscissed so as to appear surrounded by a thin thalline margin ; 
hypothecium thin, nigro-fuscous; paraphyses indistinct, apices colourless; hyme- 
nium tinged with brown; spores 8, fuscous, rotundo-oblong, 1-septate, more or less 
constricted in the middle. 
On bluish-grey slates, rare, 1876. | 
Gelatina hymenea I dirty blue. Spores :014—0145 mm. long, "009 mm. broad. Several 
plants grow on the same stone, and by the union of their dark hypothalli map out the 
surface as in 7. geographica. Allied to L. stellulata, Tayl, but distinct by the thin 
filmy thallus, larger spores (one third larger), and the singularly impressed apothecia. 
Llanachar bridge! and Fort Hill!, near Fishguard, Pembrokeshire (1876); Festiniog 
road, near Dolgelley !, North Wales. Moel-y-gest! near Tremadoc. 
LECIDEA rEPHRIZANS, Leight. Thallus nearly obliterated, only a few whitish depressed 
scattered areole remaining; (К — C — ;) hypothallus cinerascent, predominating ; 
apothecia black, numerous, plane or slightly concave, prominent, sessile, moderate ; 
margin thickish, eventually obliterated; hypotheciwm nigro-fuscous, subtended by а 
pale greyish-blue hyaline excipulum ; hymenium thin, pale greyish-blue ; paraphyses 
distinct but cohzerent, apices nigro-fuscous ; spores 8, colourless, narrowly ellipsoid, 
simple, minute. 
On hard slaty rocks, rare, 1876. 
Spores ‘009-01 mm. long, -004—005 mm. broad. Spermatia minute, shortly cylin- 
drical, straight. Gelatina hymenea I dirty blue. 
Llanachar bridge! near Fishguard, Pembrokeshire (Sept. 1876). 
LECIDEA RYSSOLEA, Leight. Albido-cinerascent, thick, tartareous, diffracto-areolate ; 
areole plane or subplano-convex, irregularly wrinkled, nigro-limitate. (K yellow, 
then red.) Apothecia nigro-fuscous, opake, somewhat rusty, large, very prominent 
and sessile, numerous, margin thick, paler, entire or flexuose ; hypothecium very 
thick, fusco-nigricant; hymenium thin, brownish; paraphyses indistinct, apices . 
thick, nigro-fuscous ; spores 8, JSuscous, oblong, 1-septate, small. 
On Caradoc sandstone rocks, rare, 1876. 
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SECOND SERIES.—BOTANY, VOL. 1. 2M 
E. 7 
