so deep a yellow or orange. Apothecia are not common, but soredia are 

 frequent, covering the curled over margins of the lobes so that they are very 

 granular. Found on rocks, but more frequently on living trees, especially 

 on old elms. 



Theloschistes concolor (Dicks.) Tuckm. Thallus foliaceous with very 

 narrow, finely dissected, branching lobes of uniform width, adhering closely- 

 to the substratum. Greenish-yellow in color, white on the underside, with 

 short, white rhizoids. The apothecia are small, sessile and not very numer- 

 ous, occasionally fibrillose; disk the same color as the thallus, with an entire 

 margin. This is a very common species, found in all parts of North America 

 on trees and rocks. 



Theloschistes concolor (Dicks.) Tuckm., var. effuse Tuckm. This 

 species is a reduced form of T. concolor. The thallus is more squamulose 

 and scattered, with powdery margins, appearing very much like a very small 

 form of T. lychneus. It is found on trees, usually in little scattered yellow 

 patches. 



PYXINE resembles Physcia in general appearance, as well as Parmelia, 

 but the thallus is much thinner and clings more] closely to the substratum. 

 There are only a few species of Pyxine, and many lichenists do not con- 

 sider it a separate genus. We have only two species which are common in 

 North America. The apothecia are small and sessile, with a pruinose or 

 black disk whose margin is wavy. 



Pyxine picta (Sw.) Tuckm. 

 (Fig. 6.) Thallus closely adnate to 

 the substratum, with thin, confluent, 

 flattened lobes, the older portion 

 wrinkled and warty ; gray or green- 

 ish-white on the upperside, and 

 black underneath. The apothecia 

 are small and sessile, with a pruinose 

 or black disk, and thick thalline bor- 

 der, which is crenate. Found on 

 trees and dead wood in the Southern 

 States. 



Fig. 6. Pyxine picta. 



Fig. 7. 

 within. 



Pyxine sorediata X^. 



Pyxine sorediata Fr. (Fig. 7.) This 

 species resembles closely Physcia speciosa, 

 but has two well defined differences in ap 

 pearance. In P. speciosa the cilia are 

 white, in P. sorediata they are black. In 

 the former the underside of the thallus is 

 white with grayish fibrils, in the latter the 

 under part is black, with a thick mat of 

 black fibrils. If the thallus of P. sorediata 

 is broken it will be found to be yellow 



The lobes of the thallus are many cleft, round and regular, with 



