74 LICHENES OF THE NORTHERN STATES 



12. U. Muhlenbergii, Ach. (sub Gyroph.). Th. coriaceous-cartila- 

 gineous, somewhat tacunose-reticulate, olivaceous-fuscous ; on the un- 

 der side papillose-granulate, lacerate in anastomosing ridges, fuscous- 

 cinerascent ; apolh. somewhat sunk, originally lirellseform, at length 

 composite, stellate-multiform, crowded finally into a convex, immargi- 

 nate tubercle. Gyrophora, Ach. Lichenogr. p. 227. Syn. p. 67. Hook, 

 in Rich. I. c. p. 758. — (3. alpina, Tuckerm. ; smaller, thickened, and 

 complicated. Lich. N. E. I. c. 



Rocks. Lancaster, Pennsylvania, Muhl. .' New York, Halsey. 

 New England, common and luxuriant on the coast. Northward to 

 Newfoundland, Bory in herb. Kunth ! and Arctic America, Rich. — 

 (?, alpine rocks, White Mountains. The descriptions by Sprengel (Syst. 

 IV. pp. 262, 263) of this species and of U. Pennsylvanica seem to 

 have been transposed. 



13. U. angulata, Tuckerm. Th. coriaceous-cartilagineous, very 

 rigid, smooth, and somewhat polished, becoming dark-fuscous and ni- 

 grescent ; on the under side very black, papillose-granulate, lacerate 

 at the centre, with paler fibres ; apoth. somewhat impressed, originally 

 sublirellaeform, becoming angulate-patellate, lirellate, and at length 

 convex, with an obtuse margin. 



Eocks. (California, Menzies!) Northwest Coast, Herb. Hook. ! 

 Perhaps nearest to U. DiUenii, the apothecia at length resembling those 

 of that species. 



XVIII. OPEGRAPHA, Humboldt. 



Apothecia somewhat lirellteform, elongated, margined by a free, 

 carbonaceous, proper e.xciple. Disk canaliculate, at first closed by 

 the inflexed-connivent margin, becoming open, indurated, and horny. 

 Thallus crustaceous. 



The Graphidece proper, excluding Umbilicaria, constitute a peculiar 

 subtribe, which attains to its full development only in the tropics ; passing 

 there into several genera not found elsewhere. Eschweiler (Systema, 

 & Lich. Brasil. in Mart. Fl. Bras.), Chevallier (Histoire des Graphi- 

 dees), and Fee (Essai sur les Cryptogames des Ecorces Exotiques Of- 

 ficinales) have illustrated these genera, which are probably represented 

 in our Southern States, where also several remarkable species of the 

 present genus, inhabiting the South of Europe and extending north as far 

 as the warmer parts of England (Borrer), may be expected to occur. 



