238 Illinois State Lahoratory of Natural History. 



colored, the affected cotyledons soon yellow; eecidia not numer- 

 ous, irregularly clustered, short-cylindrical, becoming coarsel}^ 

 divided and widely spreading, pseudoperidium thin but firm; 

 spores irregular, mostly elliptical, epispore rather thick, tuber- 

 culate, 12-15 by 15-18 m-', spermagonia very few, scattered, 

 above. 



On Crotonopsis linearis: Johnson, May 12, 4648, May 13, 

 4662, May 16, 4701. 



M. urticse, Schum. 



Hypophyllous. Spots distinct, brown, border yellow; aecidia 

 densely clustered, short, the narrow border abruptly turned, 

 finely divided; spores subglobose, epispore rather thin, sparsely 

 tuberculate, 15-21 n,; spermagonia minute, scattered, on the 

 upper side of spot, reddish brown. 



On Urtica: Warsaw, 111., June 27, coll. C. A. Hart. 



M. smilacis, Schw. 



Hypophyllous. Spots large, circular, somewhat effused, 

 pale yellowish, somewhat thickened; eecidia irregularly scat- 

 tered or crowded, short, recurved border wide and rather 

 coarsely divided; spores irregular, mostly angular, elliptical to 

 oblong, epispore thick, conspicuously tuberculate, 15-18 by 

 18-22 /*; spermagonia rather numerous, scattered, mostly 

 above, honey-yellow. 



On Smilax herbacea : Ravenswood, near Chicago, June 29 

 (1883), J. C. Arthur. 



M. trillii, Burrill. 



Hypophyllous. Spots distinct or somewhat confluent, cir- 

 cular, effused, yellowish; secidia densely aggregated around a 

 free central circular space, sometimes with a more or less dis- 

 tinct outer circle later in development, short, pseudoperidium 

 thin, fragile, soon after opening becoming pulverulent; spores 

 subglobose, epispore very thin, smooth, 19-24 fi; spermagonia 

 very numerous, rather prominent, scattered, central, on both 

 sides of leaf. 



On Trillium recurvatum : Union, April 24, 4251. 



Differs from ^. convallarice in the more fragile and fuga- 

 cious fficidia, and in the smooth, very much thinner epispore. 



