PHLYCTIS. | LECANO-LECIDEEL, 513 
brook, Isle of Wight; New Forest, Hants; Ilsham Walk, Torquay, 
8. Devon; Bathampton Downs, Somersetshire ; Cirencester, Gloucester- 
shire; Harboro’ Magna, Warwickshire ; Huglith, near Church Stretton, 
and Oswestry, Shropshire; Barmouth and Aberdovey. Merionethshire ; 
<Airyholme Wood and Hoggart’s Wood, Cleveland, Yorkshire. Kits- 
boro’, Riverstone and Castlebernard Park, co, Cork; Dunkerron, 
Killarney, co. Kerry. 
2. P. argena Koerb. Syst. Lich. Germ. (1855) p. 391.—Thallus 
effuse, thin, smoothish or rugose, pulverulent, silvery-grey or 
cream-coloured (K+ yellow, then deep red). Apothecia minute, 
brownish-black, cesio-suffused ; spores solitary, oblong or cylindrico- 
oblong, very large, 0,100-0,140 mm. long, 0,027-50 mm. thick.— 
Mudd, Man. p. 280; Cromb. Lich. Brit. p. 61; Leight. Lich. FI. 
p. 246, ed. 3, p. 237.—Variolaria argena Turn. & Borr. Lich. 
Brit. p. 75; Sm. Eng. Fl. v. p. 171. Lichen argenus Ach. Prodr. 
(1798) p. 8; Eng. Bot. t, 1928. 
Subsimilar to the preceding, from which it at once differs in the non- 
apiculate spores. It usually cccurs only in a sterile condition, when it 
is‘ very apt to be overlooked. The apothecia are either scattered or 
aggregate, and in the former case are with difficulty detected by the 
naked eye. 
Hab. On the trunks of old trees in upland tracts.—Distr. Locel (at 
least in fruit) in 8S. and W. England.—B. M.: Epping Forest, Essex ; 
. Ightham, Kent; New Forest, Hants; Haslemere, Surrey ; Beckey Falls, 
S. Devon; Burnham Beeches, Bucks; Charnwood Forest, Leicester- 
shire; Barmouth, Merionethshire ; Oswestry, Shropshire. 
65. THELOTREMA Ach. Meth. (1803) p. 180 pro parte; Nyl. 
Mém. Soc. Cherb. t. ili. (1855) p.324.—Thallus thinly crustaceous, 
continuous, containing chrysogonidia. Apothecia verruceform, at 
first closed, then open, with a proper and a thalline margin ; spores 
variable in number (1-4ne or 8ne), oblong or fusiform, usually 
colourless ; paraphyses slender ; hymenial gelatine not tinged with 
iodine. Spermogones with simple sterigmata and short straight 
spermatia. 
A genus well characterized by the fructification. Nearly all the 
species are exotic and natives of warm regions. The three which occur 
in Europe, one of which is confined to our Islands, belong to the sub- 
genus Euthelotrema Nyl. 
1. T. lepadinum Ach. Meth. (1803) p. 182 pro parte; Syn. 
p. 115.—Thallus subeffuse or rarely determinate, thin, smooth or 
slightly ruguloso-unequal, protuberant around the apothecia, whitish 
or cream-coloured (K-+red,CaCl—). Apothecia submod erate, urceo- 
lato-scutelliform, dark-brown or blackish, cesio-pruinose or naked ; 
the proper margin lacerate, inflexed, the thalline margin thin, even ; 
spores (4nz) 8nz, oblongo-fusiform, colourless, 0,035-70 mm. 
long, 0,011-16 mm. thick.—Leight. Angio. Lich. p. 31, t. 12. f. 1; 
‘Lich. Fl. p. 247, ed. 3, p. 238; Cromb. Lich. Brit. p. 61 ; Mudd, 
Man. p. 278, t.5. f.116; Turn. & Borr. Lich. Brit. p. 180; Sm. 
Eng. Fl. v. p. 161; Gray, Nat. Arr. i. p. 494; Hook. Fl. Scot. ii. 
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