352 LICHENACEI. [LECANORA. 
shire; Rhyl, Flintshire ; Beaumaris and Puffin Island, Anglesea; Llan- 
ellen, Denbighshire; Dovedale, Derbyshire; Oswestry, Shropshire ; 
glestone, Durham ; Whitbarrow, Westmoreland. Arthur's Seat, Edin- 
burgh ; Black Isle and Island of Lismore, Appin, Argyleshire. Morning- 
ton, co. Meath; Killarney, co, Kerry. 
Form melaloma Ach. Lich. Univ. (1810) p. 414.—Thallus with 
the squamules rounded and subentire, here and there blackish at the 
margins.—Cromb. Grevillea, xviii. p. 44.—Brit. Exs.: Mudd, n. 91. 
Differs in the squamules being less crenate and more or less blackish at 
the margins. It is often, however, confluent with the type, from which it 
is scarcely to be distinguished unless as a state. 
Hab. On calcareous rocks in upland situations.—Distr. Apparently 
only in W. and Central England—B. M.: Near Buxton, Derbyshire ; 
Durdham Downs, near Bristol, Gloucestershire. 
3. L. lentigera Ach. Lich. Univ. (1810) p. 423.—Thallus orbi- 
cular, crustaceo-foliaceous, moderate, loosely appressed, areolato- 
squamose in the centre, radiato-lobed at the circumference, whitish 
or pale-whitish, subpruinose; lobes plane or somewhat concave, un- 
dulato-crenate(K —). Apothecia adnate, pale-testaceous, the thal- 
line margin thin, entire; spores ellipsoid or oblong, 0,009-12 mm. 
long, 0,045-0,005 mm. thick.—Cromb. Grevillea, xii. p. 61.—Squa- 
maria lentigera Sm. Eng. Fl. v. p. 195; Mudd, Man. p. 128, t. ii. 
f. 40; Cromb. Lich. Brit. p. 44; Leight. Lich. Fl. p. 172, ed. 3, 
p- 159. Placodium lentigerumGray, Nat. Arr. i. p. 447, Lichen lenti- 
gerus Weber, Spicil. (1778) p.192; Dicks. Crypt. fase. i. p. 11; Eng. 
Bot. t.871; With. Arr. iv. p. 27. 
Closely allied to Z. crassa, into which, as observed by Nylander (Lich. 
Scand. p. 131), it seems to pass in the South of France. It is, however, 
distinguished by the thallus being smaller (at least twice as small), thin- 
ner, and differently coloured ; while it is also effigurato-radiating at the 
circumference. The apothecia are numerous, submoderate, at length sub- 
biatorine, with the thalline margin excluded. 
Hab. On cretaceous soil in maritime and upland tracts.—Dist». Found 
only sparingly in S. and E. Central England ; now almost extinct.—B. M.: 
Isle of Wight, Hampshire ; Newhaven, Sussex ; Gogmagog Hills and New- 
market Heath, Cambridgeshire. 
4, L. chrysoleuca Ach. Lich. Univ. (1810) p. 411.—Thallus 
lobato-squamose, peltato-affixed, ochroleucous or whitish-straw- 
coloured ; beneath sordid-pale, broadly blackish towards the circum- 
ference ; squamules firm, imbricate, lobed, plane, crenate or crenato- 
incised at the circumference (K —). Apothecia moderate, generally 
crowded, concave or plane, reddish-flesh-coloured, the thalline margin 
thin, flexuose ; spores ellipsoid, 0,009-12 mm. long, 0,0045-65 mm. 
thick.—Cromb. Grevillea, xviii. p. 44—Squamaria chrysoleuca 
Leight. Lich. Fl. ed. 3, p. 158. Lichen chrysoleucus Sm. Trans. 
Linn. Soe. i. (1791) p. 82, t. 4. f. 5. 
