rhizocarponJ lecideace^ 193 



areoljB discrete or crowded, K — , CaCl — , medulla I — ); hypo- 

 thallus little visible. Apothecia small, black, prominent, convex 

 and immarginate ; hypothecium blackish ; paraphyses coherent, 

 blackish at the tips ; spores fusiform-oblong or ellipsoid, 3-septate 

 and sometimes muriform, blackish, 0,018-25 mm. long, 0,009-11 

 mm. thick ; hymenial gelatine deep-blue with iodine — Rh. (jeo- 

 graphicum var. sphsericum Mudd Man. p. 221. Lecidea viri- 

 diatra Floerke Deutsch. Lich. iv. p. 4 (1819). L, geographica var. 

 sphserica Schaer. Enum. p. 106 (1850) ; f. sphserica Leight. Lich. 

 Fl. ed. 3, p. 373 (1879); var. viridiatra Leight. Lich. Fl. p. 347 

 (1871). 



Exsicc. Leight. n. 93 pro parte. 



Distinguished from the preceding by the smaller spores and by the 

 absence of medullary reaction with iodine (hyphae not amyloid). The 

 apothecia arise either from the hypothallus or from the areolae. 



Hah. On rocks and boulders in hills and mountainous districts. — 

 Distr. Seen from only a few localities in England, Wales and 

 S. Ireland ; but no doubt to be detected also in S. Scotland. — B. M. 

 Malvern Hills, Worcestershire ; Llandegl}^ Radnorshire ; Haughmond 

 Hill and Longmynd, Shropshire ; Cliffrigg, Cleveland, Yorkshire ; 

 near Bantry, Cork ; Croghan, Killarney, Kerry. 



8. Rh. calcareum Th. Fr. Lich. Arct. p. 236 (I860).— Thallus 

 thickish, white, orbicular, determinate, tartareous, cracked- 

 areolate in the centre, radiate at the circumference (K — , 

 CaCl — ) ; hypothallus wanting. Apothecia immersed or depressed, 

 concave becoming plane, black, sometimes slightly pruinose, the 

 margin thick, becoming thin and flattened ; hypothecium blackish- 

 brown ; paraphyses conglutinate, olivaceous or brownish towards 

 the apices ; spores ellipsoid or oblong-ellipsoid, obtuse, colourless, 

 then brownish or greenish-brown, large, muriform, with a distinct 

 hyaline epispore (halonate), 0,022-30 mm. long, 0,012-18 mm. 

 thick ; hymenial gelatine deep-blue with iodine, — Lichen calcarius 

 WeisPl. Crypt. Gott. p. 40 (1770). L. rimosus Dicks. Plant. 

 Crypt, i. p. 12 (1785); Engl. Bot. t. (1736)? L. speireus Ach. 

 Lich. Suec. Prodr. p. 59 (1798); Engl. Bot. t. 1864. Lecidea 

 speirea Ach. Meth. p. 52 (1803) ; S. F. Gray Nat. Arr. i. p. 468 ; 

 Hook, in Sm. Engl. Fl. v. p. 180 ; Tayl. in Mackay Fl. Hib. ii. 

 p. 125. L. contigua subsp. confluens f. calcarea Nyl. Lich. Scand. 

 p. 225 (1861) ; Cromb. Lich. Brit. p. 80. L. rimosa Leight. 

 Lich. Fl. p. 350 (1871) ; ed. 3, p. 379. Diplotomma calcareum 

 Koerb. Syst. Lich. Germ. p. 220 (1855) ; Mudd Man. p. 219. 



Exsicc. Johns, n. 397. 



Hah. On calcareous rocks. — Distr. Not uncommon in maritime or 

 upland regions of the British Isles. — B. M. Downs and Newhaven, 

 Sussex; Llanympiech, Shropshire; Beddgelert and Snowdon, Car- 

 narvonshire ; Llangollen, Denbighshire ; I. of Anglesea ; near Buxton, 

 Derbyshire ; Carlton Bank, Cleveland, Yorkshire ; Eglestone and 

 Teesdale, Durham ; Hartside Fell, Cumberland ; Achosragan Hill, 

 II. o 



