1-septate constricted, brown 0,025-35 mm. long, 0,010-12 mm.
thick.
Apt to be confused with Arthopyrenia saxicola on account of the
minute shining perithecia. The specimens in the British Museum
were collected by AV. Joshua and labelled by him A. saxicola var.
Hah. On calcareous rooks.—Distr. Eare in AV. England.—'
B. M. Sapperton, Gloucestershire.
4. M. exerrans A. L. Sm.—Thallus thin, blackish, scattered.
Perithecia minute, black ; peritheciai wall entire ; spores 8 in
the ascus, blackish, oblong, 1-septate, 0,010—15 mm. long,
0,003-5 mm. thick ; hymenial gelatine wine-red with iodine.—
Endococcus exerrans Nyl. in Flora Ixii. p. 360 (1879) ; Cromb. in
Grevillea viii. p. 114 (1880). Specimen not seen.
Distinguished by the narrow spores. Nylander notes the rather
thick colourless chroolepoid gonidia with cells 0,018—23 mm. thick.
Hai). On quartzose stones, Ben-y-Gloe, Blair Athole, Perthshire.
5. M. dissepta A. L. Sm .-T h a llu s whitish-grey, sometimes
faintly yellowish, tartareous, thin, slightly cracked-areolate, sub-
determinate. Perithecia black, numerous, somewhat prominent,
the upper p a rt convex, the ostiole a minute pore ; peritheciai
wall entire, paraphyses in d istin c t; spores 8 in the ascus, ellipsoid,
brown, 3-septate, 0,018-22 mm. long, 0,007-010 mm. thick ;
hymenial gelatine not tinged with iodine.— Verrucaria dissepta
Nyl. in Flora lix. p. 576 (1876) ; Cromb. in Grevillea v. p. 107 ;
Leight. Lich. Fl. ed. 3, p. 480. Specimen not seen.
Nylander (1. c.) suggests that possibly the perithecia may be
parasitic on the thallus of some other lichen.
Hab. On mica-schist rocks, Doughruagh Mts., Connemara, Galway
(the only locality).
116. PORINA Ach. Lich. Univ. p. 60 (1810) pro p a rte ;
emend. Muell.-Arg. in Plora Ixvi. p. 320 (1883).—Segestrella Fr.
Lich. Fur. p. 460 (1831) (Segestria tom. cit. p. 429); Mudd Man.
p. 283. (PI. 52.)
Thallus variously crustaceous, not corticated, sometimes
developed within the substratum. Perithecia simple, superficial
or semi-immersed; peritheciai wall light-coloured, becoming
darker towards the ostiole, entirely dark-coloured or dimidiate;
paraphyses persistent, simple; asci elongate, 6-8-spored; spores
elongate-fusiform or clavate, colourless, 2- multi-septate. Spermogones
small, globose with simple or branched sterigmata and
rod-like or elongate-fusiform spermatia.
Distinguished from Arthopyrenia by the character of the paraphyses.
The texture of the peritheciai wall is also more variable; it
is usually softer in texture, and in some species waxy and light-
coloured {Segestrella).
Perithecia brightly coloured, waxy ; spores 3-7-septate.
1. P. lectissima A. Zahlbr. in Fngler & Pran tl Pfianzenf.
i. 1*’, p. 66 (1903).—Thallus pale-olivaceous or reddish-yellow,
thin, continuous, subtartareous, effuse. Perithecia small, pale-
reddish, semi-immersed, with a ra th e r large ostiole ; peritheciai
wall reddish, dimidiate ; paraphyses slender, distinct, longer than
the asci; spores 8 in the ascus, fusiform, colourless, 3-septate,
0.022-32 mm. long, 0,004-7 mm. thick ; hymenial gelatine not
tinged with iodine.—Segestria lectissima Fr. Syst. Orb. Veg. i.
p. 287 (1825). Verrucaria irrigua Tayl. in Mackay PI. Hib. ii.
p. 94 (18361 Leight. Angioc. Lich. p. 56, t. 24, fig. 4. V.
rubiginosa Tayl. I. c. ? V. erysiboda Tayl. tom. cit. p. 98 ; Leight.
1. c. t. 24, fig. 6. V. lectissima Nyl. in Bot. Not. 1853, p. 181
pro p a rte ; Cromb. Lich. Brit. p. 117 (excl. syn. Segestria
umbonata); Leight. Lich. Fl. p. 4 4 3 ; ed. 3, p. 4/5. V. holo-
chrodes Nyl. in Flora lix. p. 311 (1876) ; Cromb. in Grevillea v.
p. 29 ; Leight. Lich. Fl. ed. 3, p. 476. Segestrella lectissima
Mudd Man. p. 284 (1861). ,
Exsicc. Larb. Lich. Cæsar. n. 49, n. 120 (as Verrucaria holo-
chrodes) ; Leight. n. 32 (as V. irrigua var. erysiboda pro parte).
Easily distinguished by the numerous brightly coloured perithecia,
it has been confused with Lichen thelostomus Sm., but the latter has
much larger perithecia and simple spores.
Hah. On moist rocks.—Distr. Eare in the Channel Islands and
S.AV. England, more frequent in AVales and in S. and AV. Ireland,
rare in Scotland.—B. M. La Coupe and Eozel, Jersey ; DolgMly,
Merioneth ; Breiddow, Montgomeryshire ; Cwm Idwyll, Cwm t.ywion,
Bettws-y-Coed and Ffridd-du, near Aber, Carnarvonshire; Ballaghbeama
Gap, Crogham, Killarney and Carig, Kerry; Doughruagh Mts.,
Killery Bay, Connemara, Galway.
2. P. humicolor A. L. Sm.—Thallus thin, brownish. Perithecia
scattered or crowded, globose, reddish-brown or blackish,
prominent with a slightly beaked ostiole ; peritheciai wall entire,
reddish-yellow in th in sections ; paraphyses distinct ; spores 8 in
the ascus, elongate-fusiform, 3-septate, 0,024-33 mm. long,
0,004-5 mm. thick.—Verrucaria humicolor Nyl. in Flora Ix. p.
462 (1877); Cromb. in Grevillea vi. p. 114; Leight. Lich. Fl.
ed. 3, p. 478.
Exsicc. Larb. Lich. Hb. without number.
Hab. On peaty earth and on rooks among liverworts.—R. M.
Mwellan, Connemara, Galway (the only locality).
3. P. leptalea A, L. Sm.—Thallus thin, greyish, efiuse or
brownish and subdeterminate. Perithecia minute, hemispherical,
almost superficial, reddish, shining, becoming darker especially
round the ostiole ; peritheciai wall dimidiate ; paraphyses slender,
d istin c t; spores 8 in the ascus, colourless, 3-septate, 0,016-23