236 Illinois State Laboratory of Natural History. 



M. apocyni, Schw. ? 



Undeveloped. 



On Apocijnum cannabinum: McLean. June 14, 4977. 



2&. Jamesianum, Peck. 



Amphigenous, on the leaves more abundant beneath. 

 Spots circular, distinct, or often confluent, on the leaves some- 

 what, and on the stems much swollen; aecidia subcircinate or 

 irregularly crowded, short, pseudoperidium fragile, soon becom- 

 ing pulverulent; spores subglobose or elliptical, epispore very 

 thick, conspicuously and densely tuberculate, the tubercles 

 often united in short irregular ridges, 21-36 by 24-45 /*, usu- 

 ally about 30 bv 39 jt; spermagonia numerous, scattered or cen- 

 trally clustered above, nearly black. 



On Asdepias Cornuti: McLean, May 26, 4799, June 1, 4886 ; 

 June 19, 5264, June 23, 5277, July 14, 5535, July 17, 5582. 



Occurs on stems, petioles and midribs, forming swellings, 

 and on both sides of the leaf, being most plentiful on the lower 

 surface. It is very destructive, eating holes in leaves and 

 stems. The spores are very remarkable for size, marking and 

 thickness (5 /*) of epispore. 



There is a different ^cidium on Asdepias Cornuti, speci- 

 mens of which were received from E. W. Holway, Decorah, 

 Iowa, labeled JE,. Jamesianum. 



M. fraxini, Schw. 



Hypogenous, occurring especially along the veins and upon 

 the leaf -stalks. Spots definite, swollen, often purple; secidia 

 more or less densely clustered, few or many, elongate, cylindri- 

 cal, tardily lacerated, but ultimately deeply split and recurved; 

 spores elliptical, epispore thin, tuberculate, 21-24 by 24-32 /*; 

 spermagonia rather numerous, scarcely elevated, on the upper 

 side of leaf, scattered over central area of the spot. 



On Fraxinus viridis: Champaign, June 8, 4915, June 10, 

 4954; LaSalle, June 21, 5252; McLean, June 24, 5279, July 5, 

 2427. 



