424 LICHENACEI. [LECANORA. 



hymenial gelatine bluish, then tawny-wine-coloured or violet with 

 iodine. Carroll, Journ. Bot. 1867, p. 255 ; Cromb. Grevillea, xviii. 

 p. 68 ; Lich. Brit. p. 51, pro parte ; Loight. Lich. Fl. p. 207, ed. 3, 

 p. 191. Lichen umbrinus Ehrh. Crypt. (1793) n. 245. 



Easily recognized in this subsection by the colour of the apothecia. 

 The thallus, which is usually indeterminate, vanes somewhat in thickness 

 according to the habitat. Rarely it is more or less scattered over the 

 substratum and little developed (olive-brownish hypothalline), when it 

 is forma subdistans Nyl. ex Cromb. Journ. Bot. 1870, p. 97. The apo- 

 thecia are at times subbiatorine. The spermogones have the spermatia 

 semicircular, 0,015-22 mm. long, 0,0005 mm. thick. 



Hab. On rocks, occasionally on old pales, rarely on the ground in 

 maritime and upland districts. Distr, Only here and there in Great 

 Britain, Ireland, and the Channel Islands. B. M. : La Moye, Island of 

 Jersey. Lamorna Cliff, Penzauce, Cornwall ; Lydd, Kent ; Aberdovey, 

 Merionethshire: Ayton, Cleveland, Yorkshire. Barcaldine, Argyleshire; 

 Blair Athole, Perthshire ; Portlethen and Bay of Nigg, Kincardineshire. 

 Cliffs of Moher, co. Clare ; Killery Bay, Conuemara, co. Galway. 



104. L. crenulata Nyl. Not. Sallsk. pro F. et Fl. Fenn. Fdrh. 

 n. s. v. (1866)p. 181 ; Flora, 1872,p. 250. Thallus effuse, very thin, 

 often scarcely visible, greyish- white (K , CaCl ). Apothecia 

 small, scattered, brownish-grey, at times caesio-suffused ; the thai- 

 line margin whitish, deeply crenulate ; paraphyses thickish, jointed, 

 brownish at the apices; spores 0,010-16 mm. long, 0,005-7 mm. 

 thick ; hymenial gelatine bluish, then wine-coloured with iodine 

 Sm. Eng. Fl. v. p. 190 pro parte. L. umbrina subsp. crenulata 

 Cromb. Grevillea, xii. p. 59, form crenulata Cromb. Lich. Brit. p. 51, 

 Leight. Lich. Fl. p. 207, ed. 3, p. 191. L. albella . crenulata 

 Mudd, Man. p. 148. Lichen crenulatus Dicks. Crypt, fasc. iii. 

 (1793) p. 14, t. 9. f. 1; Eng. Bot. t. 930; With. Arr. ed. 3, iv. 

 p. 17. According to a specimen from his own Herb, this is also 

 L. c/alactina ft. disperso-areolata (non Schaer), Mudd, Man. p. 149. 

 Brit. Exs. : Larb. Lich. Hb. n. 258. 



Frequently confounded with subsp. dispersa of L. galactina, but distinct 

 in the character of the paraphyses and in the smaller spores, as pointed 

 out by Nylander, who first definitely discriminated between them. From 

 the preceding species it is distinguished by the tessellato-crenate margin 

 of the apothecia, the erenulations being deeply divided and separated 

 by a furrow, though in abraded specimens this character is scarcely 

 apparent. It differs also from it in the size of the spermatia, which (fide 

 Nyl. in lift.) are 0,011-15 mm. long, 0,0005 mm. thick. 



Hab. On calcareous, rarely sandstone, rocks in maritime and upland 

 situations. Distr. Seen only from a few localities in S.W. arid N. England, 

 the Grampians, Scotland, and N.W. Ireland. B. M. : Watcombe Bay, 

 S. Devon ; Alfrick, Worcestershire ; near Ayton and Carlton Bank, 

 Cleveland, Yorkshire; Eglestone, Durham; Lamplugh, Cumberland; 

 Teesdale, Durham. Craig Tulloch, Blair Athole, Perthshire; Craig 

 Guie, Braemar, Aberdeenshire. Oughterarde, co. Galway. 



