NEPHROMA. 103 



regions of the earth. All the European species are also 

 North American. 



* Gonimous layer constituted of gonidia. 



1. JV. arcticum (L.) Fr. ; thallus large to very large, coria- 

 ceous; of flexuous, rounded lobes which are smooth, and 

 greenish-straw-coloured above, and black beneath with a paler 

 margin, and a coarse, appressed nap, becoming obsolete; apo- 

 thecia large, to very large ; disk brick-red. Spores fusiform- 

 oblong, 4-locular, pale brown, ^ mic. Tuckerm. Syn. N. E. 



p. 18, & LicJi. exs. n. 62. Nyl. Syn. p. 316. 



Rocks among mosses, and on trunks, in alpine and arctic 

 regions. Greenland, Retz Fl. Scand. 1779, and elsewhere in 

 Arctic America, Richardson, etc. North West Coast, Scouler, 

 etc. White Mountains, Tuckerman, Lich. N. E. 1838. Essex 

 Mountains, N. Y., Peck. 



2. N. expattidum, Nyl. ; thallus ample, coriaceous-rnembrana- 

 ceous, lobes rounded, smooth, undulate, crenate, and finally 

 crisped; from greenish-glaucescent becoming tawny -brown; 

 beneath blackish-brown with pale margin, and a delicate nap; 

 apothecia of middling size; disk reddish-brown. Spores fusi- 

 form-ellipsoid and dactyloid; pale-brownish, ^ mic. Nyl. 



Syn. I, p. 318 (Nephromium). 



On the earth, dead wood, etc., in arctic regions. Great Bear 

 Lake (Richardson ? ), Leighton in Ann. Nat. Hist. 1870. Green 

 cells gonidia rather than gonimia ; but Nylander takes them for 

 intermediate between the two sorts gonidimia, Nyl. 



* * Gonimous layer constituted of gonimia. 



3. N. tomentosum (Hoffm.) Koerb. ; thallus ample, cartila- 

 'ineous-membranaceous ; lobes sinuately cut, rounded-crenate, 



tomentose above more or less at the circumference, the fertile 

 ones elongated ; from greenish - glaucescent becoming lead- 

 coloured or lurid-brown ; pale and tomentose beneath, where 

 they are beset commonly with minute white, confluent tubercles; 

 apothecia middling to large ; disk reddish-brown. Spores fusi- 

 form-ellipsoid and oblong, pale-brown, ?~ mic. Koerb. Syst. 



p. 56. N. resupinatum, Ach. L. U. p. 522, a. Tuckerm. Syn. 

 N. E.p. 18, & Lich. exs. n. 13. JUv^'lr. 



Trunks in mountain forests, and also on rocks. Arctic Amer- 



