THTSCIA.] PHYSCrET. 297 



glaucous-white. Apothecia small or moderate, nearly plane, with 

 entire thaUine margin. — ^ludd, Man. p. 112; Cromb. Lich. Brit, 

 p. 37; Leight. Lich. Fl. p. 14:2, ed. 13, p. 131. — Ph>/.^Tia villosa, ya,T. 

 Dlclcieana Linds. Trans. Key. Soc. Edin. t. xxii. (1^(57) p. 254. 



Apparently but an accidental state of the type, depending upon the 

 nature of the habitat. It is distinguislied by the pale thallus and the 

 entire margin of the apotliecia, which latter character, however, some- 

 times occurs in the type itself. 



Ilah. On shady rocks in maritime districts. — Distr. \evy local and 

 rare in the Channel Islands (?) and in N.E. Ireland. — B. M. : Newcastle, 

 CO. Down. 



3. P. parietina De Xot. Mem. R. Ac. Sc. Turin, ser. 2, x. (1849) 

 p. 3S7. — Thallus suborbicular, appressed, imbricato-lobed, smooth, 

 yellow ; beneath paler or pale-whitish, sparingly fibrilloso-rhizino.sc ; 

 lobes somewhat plane or concave, rounded and crcnate at the mar- 

 gins (K]^ violet-purplish, CaCl~). Apothecia moderate, concave or 



plane, subconcolorous, the margin entire or nearly entire ; spores 

 0,012-16 mm. long, 0,007-9 mm. thick.— Mudd, Man. p. 113; 

 Cromb. Lich. Brit. p. 38 ; Leight. Lich. LI. p. 142, ed. 3, p. 131.— 

 Parmella parietina Gray, Xat. Arr. i. p. 438 ; Hook. Fl. Scot. ii. 

 p. 52 ; Sm. Eng. Fl. t. p. 2u4 ; Tayl. in Mack. Fl. Hib. ii. p. 141. 

 Lichen parietiaus Linn. Sp. PI. (1753) p. 1143: Huds. Fl. Angl. 

 p. 447 ; Lightf, Fl. Scot. ii. p. ^22 ; Eug. Bot. t. 194 ; With. Arr. 

 ed. 3, iv. p. 34. Lichenoides vulgare sinnosum foliis et scuteVis luteis 

 Dill. Muse. ISO, t. 24. f. 76. Lichenoides crusta foliosa scutellata, 

 jlavescens Dill, in Bav Svu. ed. 3, p. 72, n. 59. — Brit.Exs.: Leight. 

 n. 10 ; Mudd, n. 85 \ Larb. Lich. Hb. n. 9 ; Bohl. n. 12. 



A very common and well-known plant, easily recognized bv its bright- 

 yellow, smooth, appressed thallus. At tirst sight it looks as if it were a 

 Parmelia, but its essential characters are those of this genus. It varies 

 considerably in colour and in the character of the laciuia?, which give 

 rise to the forms and varieties described. With us, as elsewhere, it is 

 commonly fertile, the apothecia being chiefly central and crowded, with 

 the margin somewhat thickish and inflexed or thin and entire. The 

 spermogones are not very frec|uent in the type. They are usually more 

 or less concregate, inclosed in thailine protuberances, with spermatia 

 0,0025 mm^ long, 0,001o mm. thick. 



Hah. On the trunks and branches of trees, old pales, and walls, in mari- 

 time, lowland, and upland districts. — Distr. Very general and plentiful 

 throughout Great Britain and probably Ireland.' — B. M. : Bury St. Ed- 

 munds, Suffolk ; Edgeware, Middlesex; Lydd, Kent; Lewes,' Sussex; 

 Appuldurcombe, Isle of Wight ; Plymouth, Devonshire ; Cirencester, 

 Gloucestershire ; Windsor, Berkshire : Madingley Park, Cambridgeshire ; 

 near Worcester ; Harboro' Magna, A^'ar■v^■ickshire : Grimsbury Green, 

 Northamptonshire ; Matlock and Buxton, Derbyshire ; near Shrewsbury, 

 Shropshire ; Island of Anglesea ; Cleveland, Yorkshire ; Levcns, West- 

 moreland; Hexham, Xorthumberlaud. New Galloway, Kirkcudbright- 

 shire ; near Stirling ; Fiularig, Killin, Perthshire : Dundee, Forfarshire ; 

 Drum and Castleton of Braemar, Aberdeenshire ; Abernethy, Banffshire ; 



