PARHELIA. 63 



14. P. stygia (L.) Ach. ; thallus sub-cartilagineous, smooth 

 and shining, from olivaceous-brown finally blackening; beneath 

 at length black, obsoletely tibrillose ; lobes linear, convex, pal- 

 mately many-cleft, finally contorted, and passing now into 

 terete branches, the tips more or less incurved ; apothecia mid- 

 dling-sized ; disk dark-chestnut, and blackening, with a sub- 

 granulate margin. Spores rounded and ellipsoid, -^ mic. - 

 Ach. Meth. p. 203. Fr. L. E. p. 67. Tuck. exs. n. 17. Nyl. 

 Syn. p. 397. 



Alpine and- sub-alpine rocks. Arctic America (Richardson], 

 Hooker I. c. 1823. Higher mountains of New Hampshire, and 

 Vermont, Tuckerman. Mfc. Monadnock, N. H., J. L. Russell. 

 Adirondack mountains, New York, C. H. Peck. 



P. lanata (L.) Wallr. ; Alectorioid, blackening, lobes 

 filiform, terete, dichotomously much-branched, intricately inter- 

 tangled, decumbent; apothecia and spores of the last. - Nyl. 

 Scand.p. 103. Th. Fr. Scancl. p. 126. P. stygia p, Fr. L. E. 

 p. 68. 



Arctic America (Richardson), Hooker 1. c. 1823. Yosemite 

 valley, California, fertile, Bolander. 



* * * Thallus stratt '-coloured. 



15. P. caperata (L.) Ach. ; thallus dilated, coriaceous-mem- 

 branaceous, undulate-plicate, conspicuously rugulose, now sore- 

 diate, or coarsely isidiophorous, pale-greenish-yellow ; beneath 

 black, rather sparingly black-fibrillose ; lobes sinuately-laciniate, 

 with rounded, somewhat entire tips ; apothecia middling to 

 large; disk chestnut, with a sub-crenulate margin often at 

 length sorediate, or isidioid-granulate. Spores ellipsoid, ^|j mic. 

 Ach. Syn. p. J96. Fr. L. E. p. 69. Tuck. exs. n. 75. Nyl. 

 Syn. \,p. 376. 



Trunks, dead wood, and stones ; not very commonly fertile. 

 Virginia, Dillenius Muse., 1741. Northern, middle, and west- 

 ern States, Muhlenberg, etc. Southern States to New Mexico, 

 Curtis; Hale, etc. Mexico, Nylander. California, Bolander. 

 Arctic America, Richardson. 



A narrower-lobed southern form (Texas, Wright; New Mex- 

 ico, Fendler) characterized not seldom by white-sorediate mar- 

 gins, and shewing smaller spores (^ mic.), differs also from the 

 common plant in giving a red reaction with chloride of lime; 



