A LICHEN. 



Physcia sp. or Parmelia sp. 



THALLOPHYTES. 



PRELIMINARY. 



THESE plants may be found growing upon the trunks 

 and branches of trees, upon wooden fences and some- 

 times upon the ground. Parmelia is more common upon 

 hickory- trees. Physcia is quite widely distributed. The 

 body of the latter adheres closely to its support. Par- 

 melia has a body that is thicker, more extended, and 

 without the prominent radiating lines seen in Physcia. 

 The fruiting-cups in Physcia are small, with distinct and 

 regular cup margins, those in Parmelia being much 

 larger and more irregular. Other Lichens are common 

 to the locations given above. 



Species of Cladonia, as well as numerous other genera 

 of Lichens, will serve quite well for this study, and should 

 there be time enough, a general study of various forms 

 should be made. 



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