BRITISH LICHENS

378 . PYRENOCARPEJE THELOCARPON
one enclosing a perithecium. Perithecia almost globose, completely
enclosed or opening abovc by a pore; perithecial wall
colourless, slightly developed; paraphyses slender, simple or
branched or wanting; asci elongate, clavate or ventricose-fusiform,
many-spored; spores minute, colourless, simple or pseudoseptate.
Spermogones unknown.
Species of Thelocarpon are evidently of raro occurrence, but owing
to their minute size they are probably overlooked. There have been
no records in recent years.
1. Th. Laureri Nyl. in Mem. Soc. Sci. Nat. Cherb. iii. 191
(1855) & in Flora xlviii. 261 (1865).-Thallus confined to minute
scattered or aggregate verrucm, yellowish-green. Perithecla
minute, enclosed in the verrucm, soft, globose, citrine- or greenishyellow,
the ostiole slightly depressed and inconspicuous; perithecial
wall colourlcss; paraphyses scanty, slender, branched,
shorter than the asci; asci flask-shaped, broad in the middle,
narrower upwards, about 100 fJ.long, 12 fJ. thick; spores minute,
colourless, oblong, obsoletely guttulate at each end, 2·5-4 fJ. long,
1,5-2 fJ. thick; hymenial gelatine scarcely tinged, the asci palebluish,
with iodine.-Leight. in Ann. Mag. Nat. Rist. ser. 3, xiv.
401, t. 9, fl. 1-5 (1864) & Lich. Fl. 407; ed. 3, 439; Cromb. Lich.
Brit. 106. Sphmrops1s Laureri Flot. in Bot. Zeit. v. 65 (1847).
Exsicc. Leight. n. 351; Larb. Lich. Rh. n. 357.
Hab. On old rails and on burnt ground.-Distr. Rare and scarce
in Central England.-B. lIf. Middletown and Arkoll Hill, Shropshire.
2. Th. intermediellum Nyl. in Flora xlviii. 261 (1865).­
Thallus forming small verrucm, yellowish-green. Perithecia
minute, globose, enclosed in the verrucm, depressed at the ostiole ;
paraphyses absent; asci broad towards the middle, tapering
upwards; spores minute, oblong, guttulate at each end, 3·5-5 fJ.
long, 2 fJ. thick; hymenial gelatine tawny-wine-red, the asci
faintly bluish, with iodine.-Phillips in Grevillea Ii. 125, t. 21
(1874); Leight. Lich. F!. ed. 3, 439.
Distinguished from J;he preceding species by the somewhat large
size of the perithecia and the absence of paraphyses. I have given
the size of the spores as recorded by PhIllips, but in the specimens
examined they are constantly small, measuring about 2-3 fJ. long, 1'5-2 fJ.
thick. Nylander calls attention to the penphyses, fasciculate filaments
which occur near the ostiole and replace the paraphyses.
Hab. On rotten wood and old leather.-B. 1II. Near Shrewsbury,
Shropshire;
3. Th. superellum Ny!. in Flora xlviIi. 261 (1865).-Thallus in
scattered verrucaJ, greemsh-yellow. Perithecia small, globose,
the ostiole subconical; paraphyses very abundant, straight,
slender and thread-lIke; asci tapering upwards; spores ellipsoid,
9-12 !I. long, 4-4·5 fJ. thick; hymenial gelatine not tinged, the