284 PROCEEDINGS OF THE AMERICAN ACADEMY 



13. C. saturninum, Ach. Th. rosulate, blackish-green, glaucous 

 and subtomentose beneath, the lobes broad, oblong, rounded, waved, 

 very entire ; apoth. scattered, somewhat plane, rufous, with a thin, en- 

 tire nnargin. Ach. Syn. p. 320. Hook. Br.Fl. 2, p. 211. Exs. Schcer. ! 

 Helv. 423. 



Trunks and stones. New England. Arctic America, l?ic/i. I have 

 omitted several species of this genus, which require more observation. 



II. LEPTOGIUM, Fr.. 



Apothecia rounded, becoming discoid-open and scutelliform, some- 

 what pedicellate, with a proper exciple. Thallus gelatinous-membra- 

 naceous, subdiaphanous, texture cellulose. 



1. L. Tremelloides, Fr. Thallus foliaceous, membranaceous, very- 

 thin and somewhat diaphanous, smooth on both sides, or powdery above, 

 lead-colored ; lobes oblong, rounded, very entire ; apothecia scattered, 

 elevated, plane, rufous-fuscous, with a paler margin. Fr. Fl. Scan. p. 

 293. Collema, Ach. Hook. Br. Fl. 2, p. 213. 



Rocks and trunks. New England. New York, Torrey. Pennsylva- 

 nia, Muhl. 



2. L. lacerum, Fr. Th. foliaceous, membranaceous, very thin and 

 somewhat diaphanous, glaucous-fuscescent, the lobes small, subimbri- 

 cate, lacerate-laciniate, denticulate-ciliate ; apoth. (small) scattered, 

 subsessile, somewhat concave, rufous, with a paler margin.. Fr. ! Fl. 

 Scan. p. 293. Collema, Ach. Hook. Br. Fl 2, p. 213. 



On the earth, and rocks, among mosses. New England. New 

 York, Halsey. Pennsylvania, Muhl. 



3. L. Burgessii., Fr. Th. membranaceous, subimbricate, glaucous- 

 fuscescent, somewhat spongy and downy beneath, the lobes rounded, 

 sinuate-laciniate, crisped and minutely lacerate-dentate at the margins ; 

 apoth. depressed ; disk somewhat concave, fuscous, with an elevated, 

 lacerate-dentate or foliose margin. Collema, Ach. Syn. p. 320. Hook. ! 

 Br. Fl. 2, p. 211. Icon, E. BoL t. 300. 



Trunks. Mountains of New England. 



Tribe II. EPHEBIDE^. 



III. EPHEBE, Fr. 



Apothecia formed from the thallus, from concave becoming plane. 



