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attached loosely to the substratum. The apothecia are large and are borne 

 on the produced lobes of the under side of the thallus ; disk chestnut with a 

 thin, pale margin. 



This is an alpine or subalpine species growing on the ground, on rocks 

 and trunks of trees, usually fertile. In some specimens the elongated, 

 turned over lobes with the large apothecia almost obscure the upper surface 

 of the thallus. 



Nephroma Helveticum Ach. Thallus small with narrow, deeply cut, 

 undulate lobes, with wavy margins which are edged with tooth like nodules. 

 The color is a tawny brown when pressed, a grayish brown when fresh. 

 Usually the thallus is smooth but in some specimens there are little groups 

 of spine like nodules. The under .surface is dark brown, almost black at the 

 center, is irregular and somewhat tomentose. Apothecia smaller than those 

 of N. tomentosum, the disk light reddish brown turning darker with age; the 

 margin is finely crenate. 



A^. Helveticum is found on rocks and trees, usually with mosses. On 

 rocks the specimens are well developed, usually fertile, on trees the thallus 

 is smaller and more appressed, apothecia not so frequent. This is a com- 

 mon species both in the Northern and Southern States. 



Nephroma laevigatum Ach. The thallus in this species is medium 

 and smooth, with rounded lobes which are wrinkled and rolled over. The 

 color is greenish brown soon turning to a chestnut. The lower side is pale, 

 growing darker toward the center, is wrinkled but has no rhizoids. The 

 apothecia are small, the disk is a dull, red brown. 



A^. laevigatum is found on trees and rocks in subalpine forests, usually 

 growing on moss to which it clings closely. 



Nephroma laevigatum Ach. var. parile Nyl. The variety is more 

 common than the species, TV. laevigatum. The thallus is thinner and not 

 so crisp, the lobes are broader and are usually covered on or near the crenate 

 margins with soredia of a lighter shade. The under side is pale at the mar- 

 gin, soon turning a dark brown. Habitat the same as of A^. laevigatutn. 



Nephroma Lusitanicum Schaer. In this species the thallus is much 

 wrinkled, especially toward the center, the lobes are deeply cut with crenate 

 margins. In color it is a dark russet, the outer layer of the thallus fre- 

 quently breaks, showing the dull yellow of the inner part; this is particu- 

 larly conspicuous on the under side, which is darker than the upper surface. 

 The apothecia vary in size, some are small, some are quite large, they differ 

 on the same specimen. 



A". Lusitanicujn is found on rocks and trees in alpine districts ; is also 

 found in the Western States and in the tropics. 



Solorina. This genus is a small one and may be considered the con- 

 necting link between Sticta and Peltigera. It is represented in the arctic and 

 alpine regions by the species 5. crocea, in the temperate by .S". saccata, the 

 former being found on granitic rock^, the latter on calcareous rocks or 

 soil. The thallus is medium, smooth, foliaceous, rather rigid, it adheres rather 

 closely, with short rhizoids to the rock, moss or soil on which it may be grow- 



