124 PANNAKIA. 



throughout; cells rounded; the goniinia (diam. 5-6 mic., but 

 now larger) being mostly solitary. Spermatia ellipsoid; on 

 sub-simple sterigmas. The place of the lichen to be further 

 determined by the fruit, as yet unknown. 



15. P. crossophylla, Tuckerm. ; thallus effuse, membrana- 

 ceous, terete-compressed, dichotomously much-branched, de- 

 cumbent; leaden -gray; the outer portions plume-like, ^the 

 inner ones densely imbricated, and crowded into a squamaceous- 

 verrucose crust ; beneath blackening at the centre ; apothecia 

 small, biatorine, immixt ; the disk from flesh-coloured becom- 

 ing chestnut-brown, soon convex and excluding the thin, pale 



margin. Spores ellipsoid, simple, decolorate, ^ mic. Obs. 



Lick. 1. c. 4, p. 404. 



Rocks, Vermont (Russell), Tuckerman I. c. 1861. New 

 York, Peck. Pennsylvania, Eau. Ohio, Lesquereux. Alabama, 

 Peters. 



***** Coccocarpia. Thallus foliaceous, sub-mono- 

 phyllous. Medullary layer compact, with the habit of that of 

 Peltigerei. Gonimous system constituted of gonimia; also com- 

 parable with those of the last family. Apothecia biatorine. 



Spores simple. In this group Pannaria may be said to look 



back, so far as thalline structure is considered, to the preced- 

 ing and higher, rather than forward to the next following fam- 

 ily, but, as regards the fruit, to be less typical than Pannaria 

 proper. 



16. P. plumbea (Lightf.) Delis.; thallus smallish, orbicular, 

 coriaceous-membranaceous ; from yellowish-brown becoming 

 livid-lead-coloured ; the more or less connate lobes dilated out- 

 wardly, radiately wrinkled, and, with age, concentrically zoned, 

 with rounded and round-crenate tips ; the centre passing into 

 imbricate lobules ; upon a dense, spongy, at length bluish-black 

 hypothallus ; apothecia smallish, biatorine ; with flat, or swell- 

 ing, from rusty- at length sanguineous-red disk ; and thin, paler 

 margin ; finally confluent. Spores ellipsoid, simple, decolorate, 

 ~ mic. Parmelia, Ach. L. U. p. 466. Fr. L. E. p. 87. 



On an old oak, Newport mountain, Island of Mt. Desert, 

 Maine, Tuckerman Gen. 1872. On a Birch stump, and on ex- 

 posed rocks, Island of Grand Menan, Willey. 



17. P. molyMcea (Pers.) Tuckerm.; thallus small to ample, 

 orbicular, with the texture of the last, and the radiately plaited, 



