Order III. PHACIDIACB^. 



Receptacle more or less coriaceous or carbonaceous ; disc at 

 length exposed by a fissure of the outer coat. 



This natural order, together with the Sphseriacese, forms 

 what is called the Pyrenomycetes. 



The best American literature on the subject is by J. B. Ellis, 

 of Newfield, N. J.: "Pyrenomycetes of North America." I 

 hav^e examined very few species of this natural order, but I 

 know that they are common in our Valley. 



Genus IX. PHACIDIUM. 



Perithecium bursting irregularly in the center by valvular 

 teeth. 



P. carbonaceum. Fr. 



Erumpent unequal, black, dehiscing into obtuse pits, disc 



dry and black. 



Common in spring on willow twigs. 



P. dentatum. Fr. 



Spot four parted, pallid, then black, disc ochraceous ; asci 



linear, oblong ; sporidia thread-like. 

 Found in jungle on oak leaves. 



Genus X. RHYTISMA. Fr. 



Perithecia forming a confluent mass opening by fiexuous 

 fissures. — Berkeley Outlines. 



R. Ilicis-Canadensis. Schw. 



Innate, round, costa-rugose, shining, disc black. 

 Common on leaves of Prinos verticillata all through the Valley where 

 the black alder grows. 



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