242 CLADOISTIA. 



last preceding one, is seen to have a distinct development ; and 

 this to "be well-marked by the diversity in the epidermis. There 

 is little difference of opinion as to the three forms determined 

 by Fries ; but the second of these (f. tub&formis) may most 

 readily be extended to include another lichen, which, unrecog- 

 nized in Europe, fills a considerable place in the Lichen-Floras 

 of both northern and equinoctial America. The interest of the 

 study of Lichens lies in the resolution rather than the over- 

 estimation of differences. C. adspersa, Mont. & V. d. Bosch 

 1. c. (C. fimbriata, v. adspersa, Tuckerm. II. cc.) possesses, in 

 the two cited diagnoses, no single character that should exclude 

 it from the form we are now considering : the specimens in 

 Wright Lick. Cub. n. 32 (though referred by Mr. Leighton to 

 his C. pyxidata, v. decorticata) being inseparable from Mon- 

 tagne's lichen, and agreeing equally, as a subulate state, with 

 the scyphiferpus n. 31 (taken by Leighton for his C. pyxidata, 

 v. pityrea) which is manifestly only an extension of Cuban spec- 

 imens (unpublished) of what should as clearly be a. 



10. C. degenerans, Floerk. ; thallus squamulose, much as in 

 the next, infrequent at the base and now wanting; podetia 

 longish; cartilagineous - corticate ; irregularly but at length 

 luxuriantly proliferous-ramose ; for the most part smooth but 

 beset more or less with squamules ; and now at length granu- 

 late-furfuraceous ; glaucous-greenish, ash-coloured, and brown ; 

 but blackening, with white spots, at the base ; cups irregular, 



cristate-lacerate ; apothecia brown. Fl. Clad. p. 41. Fr. L. 



E.p. 221 (b. excl.) Tuckerm. Lich. exs. n. 95. Nyl. Scand. p. 53. 



On the earth. Northern and middle States, Muhleriberg 

 Gated. 1818; Halsey. Canada, Agassiz. Arctic America, Rich- 

 ardson-, Wright. Southward, Virginia, Dillenius. 



11. C. gracilis (L.) Nyl.; thallus squamulose, middling- 

 sized to now ample, but infrequent for the most part at the 

 base, and now scarcely any ; podetia soon elongated, and from 

 slender very robust ; cartilagineous- corticate ; polished ; from 

 pale-greenish becoming pale- to finally dark-brown ; cups rather 



flattened ; apothecia brown. Nyl. Syn. p. 196. C. gracilis, 



max. p., Fr. L. E. p. 218. C. gracilis, & verticittata, Floerk. 

 Clad. p. 26, 30. C. ecmocyna, Ach. 



a. verticillata, Fr. ; podetia from shortish now rather elon- 

 gated; all cup-bearing; the cups dilated and flattish, soon 



