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POPULAR HISTORY OP LICHENS. 



Nat. Ord. VIII. LECIDJEA CEJE. 



Fam. Char. Thallus crustaceous. Ajpoihecium patellate, orbi- 

 cular, concave, flat or tumid, solid. 



Genus I. GYALECTA, AcL 



Gen. Char. Thallus uniform. Apothecium urceolate, immargi- 

 nate, at first closed and nucleiform, afterwards variously dehis- 

 cent, the excipular border being elevated, discrete, coloured. 

 (Named from yvaXos, concave, in allusion to the form of the 

 apothecia.) 



1. Gyalecta cupularis (cupa, a cup). Thallus reddish- 

 grey, becoming greyish-green when dry, leprose. Apothecia 

 superficial, concave, radiate-dehiscent, brick or flesh-co- 

 loured ; margin in younger contracted-rugose, whitish-sub- 

 pulverulent. (E. B. 739.) 



On stones and rocks, especially of a calcareous and arena- 

 ceous nature, and also sometimes on ground in various low- 

 land and subalpine districts. Its thin thallus moulds itself 

 accurately to the surface of the stones on which it grows. 

 The spermogones may be recognized as small, somewhat 

 spherical tubercles, with a broadened base, seated on and 

 scarcely in the thallus ; they are of a pale rose-colour, have 

 a dense thick capsule, and are of a horny consistence ; the 



