BRITISH LICHENS

332 PYRENOCARPEA!: POL YBLASTIA
effuse, somewhat gelatinous, _ dark-brownish or blackish. Perithecia
moderate in size, semi-immersed, somewhat prominent, the
ostiole slightly depressed; perithecial wall entire; paraphyses
m.ucilaginous, disappearing, ostiolar filaments numerous, distinct;
asci saccate-clavate; spores 8 in the ascus, oblong-ellipsoid, palebrownish
or almost colourless, muriform, 30-45 !-L long, 12-24 !-L
thick.-Verrucaria gelatinosa Ach. Lich. Univ. 283 (1810) (non
Nyl. in Maine et Loire Mem. Soc. Acad. iv. 21 (1858)). V. nigrata
NyI. in Act. Soc. Linn. Bord. ser. 3, i. 430 (1856); Cromb. Lich.
Brit. llO; Leight. Lich. FI. 456; ed. 3, 489. Sphmromphale
nigrata Mudd Man. 282 (1861).
Leighton has described the spores as dark-brown, but Nylander
includes the species in a section with colourless spores. In the specimens
examined they are colourless or slightly brownish. Nylander's
Verrltcaria gelatinosa is Polyblastia helvetica, not recorded in Britain.
Hab. On mossy earth in alpine places.-B. M. Ben Luwers (the
only British locality).
12. P. mortensis Wats. in Journ. Bot. Iv. 108, fig. B. (1917).­
Thallus thin, crustaceous, minutely granulose, effuse, continuous,
greyish or greenish-grey or olivaceous, sometimes darker or
evanescent, not gelatinous when moist. Perithecia small or
moderate, semi-immersed with the upper third emergent, convex,
shining; perithecial wall black, thin and brown at the base;
ostiole slightly depressed; penphyses few.or none; asci clavate,
somewhat inflated; paraphyses few or none, mucilaginous; spores
oblong, colourless, becoming brownish, muriform, with 7-14
transverse rows of small cells, 40-50 !-L long, 16-20 !-L thick.-
A. L. Sm. Monogr. i. 483 (1918).
Near to P. gelatinosa, but differs in the lighter-coloured non-gelatinous
thallus.
Hab. On soil of walls or on mortar, often on decaying mosses such as
Tortula muralis.-D!str. Near the sea.-B. M. Morte, Devon (Dec.
1!H3).
Spores becoming darle-brown.
13. P. theleodes Th. Fr. in KgI. Svensk. Vetensk.-Akad.
Handl. vii. n. 2, 48 (1867).-Thallus greyish-white, thickish,
wrinkled-areolatc, with thicker wart-like protuberances, sometimes
almost disappearing. Perithecia partly enclosed in the
warts or superficial, large, hemispherical with a slight depression
round the ostiole; perithecial wall black, entire, thicker over the
top; paraphyses disappearing; spores 8 in the ascus, broadly
ellipsoid, very large, colourless, then dark-brown, munform,
variable, 60-84 !-L long, 24-45 !-L thick; hymenial gelatine wine-red
with iodine.-Verrucaria theleodes Sommerf. SuppI. Fl. Lapp.
140 (1826); Cromb. Lich. Brit. llO; Leight. Lich. Fl. 457; ed.
3, 489 (incI. f. verrucoso-areolata). V. verrucoso-areolata NyI. in
Act. Soc. Linn. Bord. ser. 3, i. 438 (1856) & in Maine et Loire