lbcidea] lbcidbaoeje gTT 



113. L. contigua Fr. Lich. Eur. p. 298 (1831) pro parte.— 

 Thallus greyish-white or sometimes ashy-grey, usually rather 

 thin, continuous, finely cracked granular or areolate, the areote 

 continuous and flat or sometimes convex and somewhat tumid (K — , 

 CaCl — ); hypothallus black. Apothecia seated on the thallus, 

 varying in size, plane or convex, somewhat rough, the margin 

 thick, obtuse, prominent, or sometimes almost obliterated ; hypo- 

 thecium thick, blackish-brown ; paraphyses slender, subcoherent, 

 dark- or olivaceous-brown at the apices ; spores ellipsoid, large, 

 0,016-27 mm. long, 0,008-13 mm. thick ; hymenial gelatine blue 

 then wine-red with iodine. — Mudd Man. p. 209 (excl. syn. ; spore 

 measurements too small) ; Cromb. Lich. Brit. p. 80 (excl. vars. 

 crustulata and speirea) ; Leight. Lich. Fl. p. 292 ; ed. 3, p. 299 

 (excl. forms meiospora and aggerata). Verrucaria contigua Hoffm. 

 Deutschl. Fl. ii. p. 184 (1795). 



The thallus and apothecia of this lichen vary considerably in 

 appearance, giving rise to a large number of varieties which have been 

 described by Leighton" as forms. They are all distinguished by the 

 characters of the apotheoium, its thick dark-coloured hypothecivmi 

 and somewhat large ellipsoid spores. When the thallus is limited 

 and intersected by the hypothallus, it is f. Umitata Leight. (Lich. Fl. 

 p. 292 ; ed. 3, p. 299) ; when it occurs in round somewhat furfuraoeous 

 patches with rather small apothecia, it is f. leprosa Leight. (l. c. 

 p. 293). Another series of forms have a thick well-developed thallus 

 and occasionally very large apothecia; var. nohiUs Fr. (Z. c. p. 301, 

 f. nobilis Leight. I. c. p. 293) is characterized by having the thallus 

 thick, tartareous, areolate and turgid ; while f. Hoffmoffini Leight. 

 (I. c.) is lighter in colour and less turgid with larger apothecia. 

 In var. notabiUs Nyl. (in Not. Sallsk. Faun. & Fl. Fenn n. ser. i. 

 p. 241 (1859)), (f. notabiUs Leight. I. c. ed. 3, p. 302), the thallus is 

 whitish and unequally minutely grauulose, the granules dispersed or 

 sometimes in small clusters (acervulate), resembhng the thallus of 

 Stereocaulon condensatum. Leighton describes a further evidently 

 rare form as i. pustulata {I. c. p. 302), which is yellowish-grey, 

 limited by the black hypothallus, and areolate, the areolae plane with 

 central sorediate protuberances ; some of these are enlarged into 

 orbicular, rather flat tubercles, in which are embedded a conglomera- 

 tion of minute marginate black apothecia. 



Hab. On rocks in maritime or hilly regions. — Distr. Common 

 throughout Great Britain and Ireland. — B. M. Endellion, Cornwall 

 (f . Umitata) ; Crown, East Down, Dartmoor, Devon ; Leith Hill, 

 Surrey ; Chamwood Forest, Leicester ; near Malvern, Worcester ; 

 Caercaradoc, Haughmond Hill (f. leprosa), and near Ludlow, Shrop- 

 shire ; near Monmouth ; Aran Mawddwy, Llyn Aran, Cader Idris, 

 and Dolgelly, Merioneth ; Camedd Dafydd, Nant Ffrancon and 

 Capel Curig, Carnarvon ; Eougbton, Lincoln ; Ayton, Cleveland, 

 YorkAire; Westwater, Forfar; Loch-na-gat, Ben Lawers, Killin, 

 Glen Lochay, Craig Calliach, and Ben-y-gloe, Perthshire ; Barcaldine, 

 Lome, Achosragan Hill, Appin and Island of Lismore, Argyll ; 

 Morrone, Braemar, Aberdeenshire. 



Form calcarea Leight. Lich. Fl. p. 292 (1871).— Thallus 

 creamy-white, tartareous, smooth, areolate, the areolae plane or 



F 2 



