198 PROCEEDINGS OF THE AMERICAN ACADEMY 



disk contained in an open proper exciple, which it finally cov- 

 ers, and becomes convex, cephaloid, and immarginate. 



12. Stereocaulon. Apothecia turbinate, at length cephaloid ; pode- 



tia mostly solid. 



13. Cladonia. Apothecia at length cephaloid, inflated ; podetia fistu- 



lous. 



14. BjEomyces. Apothecia capitate, globose, immarginate, velate. 



15. BiATORA. Apothecia disciform, solid, with a waxy (originally 



paler) exciple. 



16. Lecidea. Apothecia disciform, solid, with a carbonaceous, black 



proper exciple. 



Tribe III. GR APHID ACE^, Fr. — Apothecia of various form, 

 an altered thalline carbonaceous proper exciple, or an originally 

 proper exciple margining a gyrose and proliferous-papillate, or - 

 canaliculate disk. 



17. Umbilicaria. Apothecia orbiculate or lirellisform ; thallus folia- 



ceous. 



18. Opegrapha. Apothecia lirellssform ; thallus crustaceous. 



19. Lecanactis. Apothecia irregular, at first open, with a pruinose 



thalline veil. 



Tribe IV. CALICIACE^, Fr. — Apothecia orbiculate or globose, 

 always open, margined by a proper exciple, the disk collaps- 

 ing into naked sporidia ; or without an exciple, the sporidia ca- 

 pituliform-compact, 



20. Trachylia. The carbonaceous exciple innate, with an asciger- 



ous disk. 



21. Calicium. The carbonaceous exciple free ; disk compacted of 



naked sporidia. 



22. CoNiocYBE. Exciple wanting ; sporidia capituliform-compact. 



Div. II. ANGIOCARPI, Schrader, Fries, 



Apothecia closed, nucleiferous, pertuse and with an ostiole, or irreg- 

 ularly dehiscent ; the nucleus included, subglobose, ascigerous. 



Tribe I. SPH^ROPHORACEtE, Fr. — Apothecia formed of the 

 intumescent apices of the thallus, closed, at length irregularly 

 lacerate-dehiscent. Nucleus subglobose. Thallus vertical, fru- 

 ticulose. 



