OF ARTS AND SCIENCES. • 281 



*^* Appendix to the Lichenes, Sec. 



COLLEMACE^. 



Filamentous, or foHaceous gelatinous-conglutinate plants without dis- 

 crete layers. Sporidia included in asci, and immersed in a thalamium, 

 which is contained either in a thalline exciple or a proper exciple. 



Several genera are included here formerly referred to Lichenes, but 

 separated by Fries, and with other genera constituted a distinct family, 

 intermediate between Lichenes and aquatic Algse. CoUema and Lep- 

 togium may be said to have the thallus of Phyceae with the apothecia 

 of Lichenes, and Ephebe is considered by Fries nearly related to the 

 By ssi . 



Synopsis. 



Tribe L COLLEME^, Fr. — Thallus gelatinous-conglutinate, 

 caulescent or foliaceous. 



1. CoLLEMA. Apothecia scutelliform, with a thalline exciple. 



2. Leptogium. Apothecia scutelliform, with a proper exciple. 



Tribe IL EPHEBIDEiE. — Thallus filamentous, not gelatinous. 



3. Ephebe. Apothecia scutelliform, with a thalline exciple. 



Tribe I. COLLEMEiE, Fr. 



I. COLLEMA, HofFm. 



Apothecia at first subglobose, becoming at length discoid-open and 

 scutelliform, with a thalline exciple. Thallus corneous-gelatinous, 

 somewhat pulpy, of a moniliform-filamentous texture, variously lobed. 



* Thallus imbricate-plicate, becoming thick and turgid when wet. 



1. C. pulposum, Ach. Thallus thick, suborbicular, very compact, 

 blackish-green,of numerous, somewhat imbricate, plicate, rather entire 

 or repand-crenate, erectish lobes, those of the circumference larger, 

 somewhat appressed ; apothecia somewhat crowded, slightly concave, 

 rufous, with an elevated, irregular margin. Ach. Syn. p. 311. Schcer. ! 

 Spicil. 2, p. 538 {sub Parmelia). C. cristatum.; Borr. in Hook. Br. Fl. 

 2, p. 208. Icon, Wulf. in Jacq. Coll. 3, p. 139, t. 12, /. 1. 



Upon rocks, among mosses. Pennsylvania, Muhl. I have not ob- 

 served this species in the granite region of New England. 



2. C. plicatile, Ach. Th. thick, orbicular, black-green ; lobes ru- 

 gose-plicate, ascending, laciniate ; apoth. concave, of nearly the same 



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