48 



Mycologia 



the fruits. The aecia of G. Juniperi-virginianae were found only 

 on the fruit and leaves of Mains glaucescens. 



Specimens of these rusts have been collected at different times 

 within this area by Dr. F. D. Kern, Prof. C. R. Orton and the 

 writer. The different species of Crataegus have been kindly 

 identified by Prof. W. W. Eggleston. The following list includes 



Fig. 4. An intimate association between cedar and hawthorn favorable for 

 the development of the rusts. 



those species of hawthorns not previously reported as hosts in 

 North American Flora for G. germinale and G. globosum. 

 There «are ten additional species reported for G. germinale and 

 six for G. globosum. The remaining species of hawthorns listed 

 includes those not previously reported for Pennsylvania. 



