Parasitic Fmuji of' [llinois. 151 



species. It has not been considered wise to try to give a full 

 list of synonyms, yet such references are made in the notes as 

 are needed to justify any departure from common usage in the 

 selection of names. In a few instances changes have been 

 made with much regret, since the current names are well es- 

 tablished; but in these cases the law of priority clearly demands 

 the substitutions made. For instance, the rust on the leaves 

 of the common sunflower, and other allied plants, has long 

 been known as Puccinia helianthi, Schweinitz. Probably no 

 species of Puccinia is more commonly found or better recog- 

 nized in the herbaria of our country, and nearly or quite uni- 

 formly under the name cjuoted. But Schweinitz published this 

 name in 1822 ( Syn. Fungi Carol, p. 73), seven years after De 

 Candolle had published the description of a species of Puccinia 

 under the name of P. tanacefi (Flore Franc. II. p. 222). Now 

 it is found that no specific difference can be maintained between 

 these, and therefore the latter name must be adopted for the 

 collections made in America as well as for those of Europe. 



T. J. BURRILL. 



Illinois Industrial University, 

 December 29, I8S4. 



12 



