LECIXORA.] LKCA.VO-LKCIDEri. 4u3 



section oi Lcccuiora. The tliuUns is rather scattered, green ish-g-rey when 

 moistened, usually but sparinjrly fertile; tliouj^h in one corticolous frag- 

 ment the apothecia are soniewjiat numerous. 



Ilab. On mossy and naked trunks of trees in upland situations. — Dii>tr. 

 Extremely k)cal and scarce in N. "Wales, where it has not recently been 

 met witli. — B. M. : Cwm Byclian and ("rafiiaiit, Merionethshire. 



D. Thallus placodioid. Apothecia Iccanorino ; spores Sua*, ellipsoid, 

 rarely subglobose, simple, colourles.s ; paraphyses jointed. 

 Spermogonos with .simple or shortly jointed sterigmata and 

 cylindrical, moderate, straight spermatia. 



77. L. melanaspis Ach. Lieh. I'niv. (1810) p. 427; Xyl. Flora, 

 1873, p. 18, nota. — Thallus suborbieular, adnate, thinnish, arcolate 

 or verrucoso-rugose in the centre, radiato-laciniate at the circum- 

 ference, greyish or leaden-greyish, the radii convex, multifid (K — , 

 CaCl — ). Apothecia small, appressed, plane, at length convex, the 

 thalliue margin entire ; spores ellipsoid, ••.011-13 mm. long, 

 0,008-10 mm. thick ; hymenial gelatine bluish, then wine-red with 

 iodine. — Leight. Lich. PL ed. 3, p. 201. — Lccanora a1j)hoplaca var. 

 melanaspis Stirt. Scottish Xaturalist, iv, p. 28. 



Differs from L. alphoplaca (Wahl.), the typical species of this section, 

 of which it has sometimes been made a variety, and whicli is not found 

 in Britain, in the negative reaction with K, among other distinctive cha- 

 racters of the thallus and apothecia. I have, however, seen no British 

 specimen, and regard it as of doubtful occurrence in the locality re- 

 corded. 



Hah. On rocks in a mountainous region. — Didr. Said to have been 

 found in the S.VN'. Highlands of Scotland (Ben Brecht, Argyleshire). 



78. L. circinata Ach. Lich. Univ. (1810) p. 425— Thallus orbi- 

 cular, closely adnate, verrucoso-areolate in the centre, radiato-plicate 

 at the circumference, greyish or greyish-white, the radii contiguous, 

 narrow, somewhat plane or convex (K— or -f- yellowish). Apothecia 

 small or submoderate, innate, at first suburceolate, then plane, 

 brown or dark-brown, the thalline margin thin, entire ; spores ellip- 

 soid, 0,011-15 mm. long, 0,0065-85 mm. thick; hymenial gelatine 

 bluish, then reddish with iodine. — L. circinata Cromb. Lich. Brit. 

 p. 49; Leight. Lich. FL p. 195, ed. 3, p. 179 ; Hook. Fl. Scot. ii. 

 p. 50. Sqtiamaria circinata Mudd, Man. p. 130 ; Sm. Eng. Fl. v. 

 p. 196. Flacocliwn circi nation Gray, Xat. Arr. i. p. 448. Lichen 

 circinatus Pers. in Fst. Ann. Bot. vii. (1794) p. 25, Eng. Bot. t. 

 1941, — A well-marked species, of which the type apparently does 

 not occur in Britain, but only the pccidiar form suhcircinata Xyl. in 

 lift., differing merely in the thalline reaction (K 4- yellow, then 

 saffron-red). This being but a supplementary reaction, the plant 

 is not now regarded by Xylander as constituting a distinct species as 

 in Flora, 1873, p. 18, subsp. Cromb. (frevillea, xviii.p. 47. — Liclu-n 



