4G2 LTCHEXACET. [lECANOEA. 



Form 1. crenularia Cromb. Grevillea, xviii. (1890) p. 70. — 

 Thallus as in the type, Apothccia with, the thalline margin rugoso- 

 crenulate. 



Differs merely in the coai-sely erenulate thaUine margin of the apothecia, 

 ■which, however, is occasionally less distinctly visible in their juvenile 

 state, so that it is scarcely a variety. 



Hah. On rocks and trunks of old trees in maritime and upland 

 situations. — Distr. Only a very few localities in Great Britain and 

 Ireland. — B. M. : Xew Forest, Hants ; Hale's End, Malvern, "NVorcester- 

 sliire ; AVansbeck Valley, Xorthumberlaud, Island of Lismore, Argvle- 

 shire. Brandon mt., co. Kerry, 



Form 2, nivea Cromb. — Thallus and the thalline margin of the 

 apothecia soft, snowy-white ; otherwise as in the type. 



Apparently a well-marked form, which, if the characters given are 

 constant, would be a good variety. In the two small British specimens 

 the thallus is veiTUC(jso-rugose and the apothecia concave with thick 

 thalline margin. 



Hah. On the trunk of an old tree in an upland situation, Distr. Seen 

 only very sparingly from W. Ireland. — B. 31, : Killaloe, co. Clare, 



Tar. p. Turneri Xyl, Mem. Soc, Cherb. v. (1857) p, 113,— 

 Thallus more or less leproso-dissolved, whitish or greenish-white. 

 Apothecia submoderate, white-pruinose ; the thalline margin thick, 

 entire, white-pulverulent, — Cromb, Lich. Brit. p. 54 ; forma Turneri 

 Leight. Lich, Fl. p, 190, ed, 13, p. 203. — L. pallescens y. Turneri 

 Mudd, Man, p, 155. Rinodina Turneri Gray, Xat. Arr. i. p. 454. 

 Lecanora Torneri Sm. Eug, Fl. v. p. 191. Liclii-n Turneri Y.ng. Bot. 

 t. So'i.—Brit. Ea's. : Mudd. n. 127; Leight. n. 237. 



A good variety characterized by the white-sorediate thallus and the 

 pulverulent margin of the apothecia, The.«e are usually rather scattered, 

 with the thalhue margin rai'ely subcrenulate (form suhcrenata Cromb. 

 Grevillea, xviii, p, 70), 



Hab. On trunks of old trees in maritime and upland wooded regions. 

 — Distr. Here and there throughout England ; rare in X. AVales, the 

 S.W. Highlands and X. Grampians, Scotland, as also in S. Ireland. — 

 B, M, : Epping Forest, Essex : The Holmwood, Surrey ; Hurstpierpoint, 

 Sussex ; Carrisbrook and Bembridge, Isle of AA'ight ; Xew Forest, 

 Hampshire; Gillingham, Dorsetshire; Ugbrook Park, Chudleigb, S, 

 Devon; Savernake Forest, AViltsliire ; near Barmouth, Merionethshire; 

 near Avton, Cleveland, Yorkshire ; Egleston, Durham, By Loch Creran, 

 Barcahiine, Argvleshire ; Morrone, Braemar, Aberdeenshire, Old Deer 

 Park, Castlemartyr, co. Cork ; Mucki'uss, Killarney, co, Kerry, 



156. L. pallescens Xyl, Bull, Soc. Linn. Xormand, scr. 2, t, ii. 

 (1868) p. OS. — Thallus determinate, thiniiish, granulato-uneciual, 

 whitish or greyish-white (K — , CaCl — ); hypothallus white, limiting 

 the thallus. Apothecia submoderate, concave oi- somewhat plane, 



