196 GUIDE TO TFIE STUDY OP LICHENS. 



beneath and somewhat reticulate. Apothecia medium. 

 Disk reddish-brown. Spores fusiform-elliptical, brown, 

 20/x X 6/i. 



2. Nephromium Lusitanicum. Thallus medium, 

 lobes deeply cut, sinnate, margin crenate, dark-brown ; 

 the interior appears yellowish. Apothecia and spores 

 mufeh as in N. Icevigatum. 



3. Nephromium Helveticum. Thallus medium, lobes 

 rather narrowed, undulate, smooth above gray to 

 tawny ; dark beneath. Apothecia medium. Disk dark. 

 Spores as in N. Icevigatum. 



4' Nephromium tomentosum. Thallus large, lobes 

 rounded, undulate and crenate margin, gray to reddish- 

 brown above ; paler beneath. Apothecia medium. Disk 

 reddish-brown. Spores much as in N Icevigatum. 



12. Stictina. » 



Most authors combine Stictina with Sticta, but ow- 

 ing to distinct algal differences we have kept them 

 separate. 



The thallus is large, lobed, medium in thickness and 

 brittleness. It reminds one somewhat of Parmelia 

 and Physcia. The lobes usually lie flat upon the sub- 

 stratum and are rather loosely attached by rhizoids. 

 Color is generally dark-brown tinged with bluish-green. 

 The algae are blue-green and occur in colonies (as in 

 Pannaria and Peltigerd). 



There is a morphological character by means of 

 which one may recognize most of the representa- 

 tives of Stictina as well as Sticta, and that is the 

 occurrence of cyphellae upon the lower surface. (See 



