40 LECANO-LECIDEEI [lECIDEA 



pits (foveolate), plane, blackisli, ca^sio-pruinose or naked, within 

 greyish in the middle, the margin thin, evanescent ; paraphyses 

 concrete ; epithecium and hypotheeiuin more or less brownish ; 

 spores ellipsoid or subellipsoid, 0,012-18 mm. long, 0,007-9 mm. 

 thick ; hymenial gelatine bluish then wine-red with iodine. — 

 S. F. Gray Nat. Arr. i. p. 467 ; Hook, in Sm. Engl. Fl. v. p. 

 179 ; Tayl. in Mackay Fl. Hib. ii. p. 125. L. calcivora Nyl. in 

 Ach. Soc. Linn. Bord. ser. 3, i. p. 381 (1856); Mudd Man. p. 

 203 ; Cromb. Lich. Brit. p. 81 ; Leight. Lich. Fl. p. 300 ; 

 ed. 3, p. 310. Lichen immersun Web. Spicil. Fl. Goett. p. 188 

 (1778) pro parte; Engl. Bot. t. 193; With. Arr. ed. 3, iv. 

 p. 6 pro parte. L. calcivorus Ehrh. Crypt. Exs. n. 244 (1793). 

 Exsicc. Leight. n. 94 ; Cromb. n. 184. 



The thallus is but very rarely visible, being almost always confused 

 with the substratum. When obsolete, it is indicated by more or less 

 scattered gonidia immersed in the rock. The immersed apothecia 

 when young resemble those of Verrucaria immersa, with which it is 

 then apt to be confounded. Under the apothecia, the pits (fossulae), 

 as stated by Nylander, present minute confused colourless thalline 

 cellules. 



Hab. On calcareous rocks and cretaceous stones in maritime and 

 upland tracts.— Distr. Here and there in England and N. Wales, rare 

 in the Highlands of Scotland and in S.E. Ireland. — B. M. Shiere^ 

 Surrey ; above Anstey's Cove, Torquay, and Elburton, near Plymouth, 

 Devon ; Weston-super-Mare and Bathampton, Somerset ; Cunning 

 Dale, near Buxton, Derbyshire ; Eglwyseg rocks, near Llangollen, 

 Denbighshire; Great Orme's Head, Carnarvonshire; Craig-y-Ehiw, 

 Oswestry, Shropshire ; near Thirsk, Yorkshire ; Teesdale, Durham ; 

 Lamplugh, Cumberland ; Island of Lismore, Argyll ; Ben Lawers, 

 Perthshire ; Middleton, Cork. 



51. L. Metzleri Th. Fr. Lich. Scand. p. 478 (1874).— Thallus 

 effuse, thin, whitish or greyish- white, usually obliterated (K — , 

 CaCl — ). Apothecia small, innate in pits (foveolate), becoming 

 slightly prominent, blackish, naked, plane and thinly margined, 

 at length convex, immarginate ; paraphyses conglutinate, dark- 

 brown at the apices ; hypothecium pale-brownish ; spores broadly 

 oblong, 0,018-28 mm. long, 0,006-12 mm. thick ; hymenial 

 gelatine bluish then tawny-wine-red with iodine. — Leight, Lich. 

 Fl. ed. 3, p. 311. Biatora Metzleri Koerb. Par. Lich. p. 162 (1860). 



Very similar to the preceding, for which it might readily be taken. 

 It differs, however, externally in the apothecia being smaller, less 

 deeply imbedded, dark-purplish when moistened, constantly epruinose ; 

 and internally bj^ the much larger spores. A closely allied plant is 

 L. cliondrodes (Massal.) Nyl., recorded as British by Leighton (Lich. 

 Fl. ed. 3, p. 253), but Leighton's specimen belongs to the present 

 species. 



Hah. On cretaceous stones and calcareous rocks in maritime and 

 upland tracts. — Distr, Only a very few localities in S. England and 

 S. Wales. — B. M. The Downs, Lewes, Sussex ; Shiere, Surrey ; Yatton, 

 Somerset ; Giltar Point, Tenby, Pembrokeshire. 



