212 PROCEEDINGS OF THE AMEKICAN ACADEMY 



5. P. polpdactyla, HofFm. Th. papyraceous, very smooth, shining, 

 plumbeous-virescent (and gray), on the under side almost naked, re- 

 ticulated with spongy fuscous veins; (fertile lobules often very numer- 

 ous ;) apoth. ascending, finally revolute. Fr. Lichenogr. p. 46. — /5. 

 scut.ata, Fr. ; margins often crisped (or powdery) ; apoth. at first trans- 

 versely oblong, at length erect and revolute. Fr. I. c. PeUidea scutata, 

 Ack. 



Rocks and trunks among mosses, abundant in mountain forests; 

 New England. New York, Halsey. Pennsylvania, Muhl. The va- 

 riety /5 may be taken for the next species, which has a different thallus. 

 P. reticulata, Hook. ms. (herb. Borr. !), from the Northwest Coast, is 

 near this, but apparently a distinct species. I have not seen the de- 

 scription. 



6. P. horizontalis, Hoffm. Th. coriaceous, lacunulose, smooth, fus- 

 cous-virescent ; the under side reticulated with black veins ; apoth. 

 transversely oblong, plane, horizontal. Fr. Lichenogr. p. 47. 



Rocks and trunks, among mosses, less common than the last ; New 

 England. New York, Torrey. Pennsylvania, Muhl. Margins of the 

 thallus sometimes crisped,and the under side scarcely venose (var. lo- 

 phyra, Ach.). 



7. P. venosa^ Hoffm. Th. coriaceous (small), fan-shaped, simple, 

 green (and cinereous) ; white on the under side, and variegated with 

 fuscous-black, divaricately branched veins ; apoth. adnate to the thal- 

 lus, round, horizontal. Fr. Lichenogr. p. 48. 



On the earth, in woods. Pennsylvania, Muhl. New York, Torrey ! 

 Northwest Coast, Menzies ! 



VII. SOLORINA, Ach. 



Apothecia suborbiculate, depressed, adnate to the disk of the thallus, 

 covered originally with a thin membrane, which forms at length an 

 evanescent margin, ' subgelatinous within.' Thallus coriaceous-mem- 

 branaceous, foliaceous, venose or lanuginous beneath. 



Eschweiler (Syst. p. 21, & Lich. Brasil. in Mart. Fl. Bras. 1833, p. 60) 

 considers this genus very distinct from Peltigera'jn the peculiar evolu- 

 tion of its apothecia. The apothecia of some species of Peltigera are 

 indeed velate", and this is the case with nearly all, according to Fries ; 

 but these groups differ also in their thecae, as shown by Eschweiler and 

 by Fee, and in a somewhat different habit. Montagne (Bot. Zeitung, 



