PATYSCTA. | PHYSCIEI. 321 
i. p. 439. Squamaria eleina Sm. Eng. Fl. v. p. 197. Lichen 
eleinus Eng. Bot. t. 2158.-—Brit. Hzs.: Cromb. n. 152; Larb. Lich. 
Hb. n. 49, 
The thallus is often leproso-pulverulent in the centre, and sometimes 
subeffuse, through the confluence of several plants. From states of P. 
obscura, of which it has frequently been considéred as a variety, it at 
once differs in the form of the spermatia. The apothecia are chiefly 
central, The spermogones, which are not uncommon, are olive-brown, 
ee spermatia long, acicular, about 0,018 mm. long, scarcely 0,001 mm. 
thick. 
Hab. On the trunks of trees, rarely on walls, in maritime and lowland 
districts. —Distr, Probably not uncommon throughout England and W. 
Ireland; rare in the Channel Islands; apparently absent from Scotland. 
—B.M.: Noirmont, Island of Jersey. Norwich, Nerfolk ; Walthamstow, 
Essex ; Glynde, Hurstpierpoint, and between Henfield and Brighton, 
Sussex; Lymington, Hants; Penzance, Cornwall; near Cirencester, 
Gloucestershire ; Gamlingay, Cambridgeshire; Cleveland, Yorkshire; 
Kendal, Westmoreland. Killarney, co. Kerry; Kylemore, co. Galway. 
Form sorediata Nyl. ew Leight. Lich. Fl. ed. 3 (1879) p. 188.— 
Thallus leproso-sorediate almost throughout, glaucous-white ; laciniee 
more dilated at the circumference and there only esorediate. Apo- 
thecia not seen.—Brit. Hvs.: Larb. Lich. Hb. n. 127. 
Apart from the paler colour and the broader lacinie this differs only 
in the much more sorediate thallus, in which respect it resembles var. 
subvirella Nyl. (Pyr. Or. p. 63), which does not occur in our Islands. 
The specimens seen are sterile. 
Hab, On walls and trees in upland districts.— Distr. Only sparingly in 
N.W. Ireland.—B. M.: Letterfrack and Letter Hill, Connemara, co. 
Galway. 
Tribe XVII. GYROPHOREI Nyl. Mém. Soc. Cherb. 
iii. (1855) p. 175; Lich. Scand. p. 112. 
Thallus membranaceo-foliaceous, monophyllous or subpolyphyllous, 
peltate, umbilicately affixed in the centre to the substratum, cor- 
ticate on both surfaces; internally with white lax filamentose 
medulla ; gonidial layer containing gonidia. Aputhecia either leca- 
noroid, or lecideine and gyrose, black; spores solitary or usually 
Sn, oblong or ellipsoid, simple or murali-divided, colourless or 
brown; paraphyses discrete. Spermogones either immersed or 
somewhat prominent, with jointed sterigmata. 
The systematic position of this tribe has been variously regarded by 
authors. There is no doubt, however, that this is its true place as indi- 
cated by the character of the vegetative and reproductive organs, though 
the structure and form of the apothecia are rather peculiar. It is a very 
natural tribe, comprising two genera, the distinctive characters of which 
have recently been definitely pointed out by Nylander. The species are 
all saxicolous, characteristic of cold regions, and for the most part very 
brittle when dry. = 
