LF.CAXOUA.] 



LECANO-LE(irii;Kr. 



3'i' 



Subsimilar in tlio colour of tlx' tlialliis and ajjotlu'cia to subgenus 

 riatodium, but dilK-rs, among niinor marks of distinct ion, in tlie absence 

 of chrvsoplianic acid, and more essentially in the chara;ter of the sterig- 

 inata. 



1 



\ 



Fig. 02. 



(1) Lccanora (Ca)i(lelarin) laciiiiosa yyl. — a. A tlieca and parapbysis, X 350. 

 b. Three spore?, X 5lM). c. Sterigmata and spertnatia, X .')()U. (2) Ltcunora 

 medians Nyl. — d. A tbeca and paraphysis, x 35(J. e. Three spores, X oUO. 



a. Thecae poh-spored. 



22. L. crenata Xyl. Xot. Siillsk. pro F. et Fl. F. Forh, v. (1SS6) 

 p. 13tX — Thallus orbicular, closely adnate, crenato-graiiulose, 

 narrowly radiato-effigurate at the circumference, citrine-yellow, 

 opaque; radii convex, crenato-incised (K— ). Apothecia moderate, 

 somewhat plane, pale-citrine or livid-yellow (K— ), the thalline 

 margin crenate ; spores 20-40nse (or more), ellipsoid or oblong, 

 simple or obsoletely l-septate, 0,009-0,015 mm. long, 0,004-7 mm. 

 thick. — Crorab. Grevillea, xviii. p. 45 ; Leight. Lich. Fl. p. 180, 

 ed. 3, p. 166. The specific name crenulata Wablenb. Fl. Lapp, 

 p. 416, has priority, but cannot be retained, because of the previous 

 homonym of Dickson. 



Looks like a Placodium, but the absence of any reaction, the number 

 of the spores, and the nature of the sterigmata place it in this subgenus. 

 In the two British specimens seen, the thallus is not very well developed, 

 and only one is sparingly fertile. 



Hnh. On rocks in maritime districts. — Distr. Very local and rare in 

 X. AVales and N.E. Scotland. — B. M. : Aberdovey, Merionethshire. 

 Portlethen, Iviucardineshire. 



23. L. laciniosa Xyl. Flora, 18S1, p. 45 L — Thallus suborbicular 

 or effuse, minutely laciuiato-divided, greenish-yellow ; laciuite mul- 

 tifid, subimbricate, crowded, the margins crisp, more or less granu- 

 loso-pulverulent (K — ). Apothecia small, subsessile, tawny-yellow 

 (K— ), the thalline margin entire or granulate; spores (lO-lOOnae) 

 ellipsoid, simple, often subpolari-bilocular, variable in size, 0,006- 

 0,< •! 1 ram. long, 0,004-6 mm. thick. — t'romb. Grevillea, xviii. p. 45. 



