240 Illinois State Laboratory of Natural History. 



negative results, but served to throw doubt upon previous con- 

 clusions. In Illinois one species only of Gymnosporangium has 

 been collected (from Juniperus Virginiana), and wherever this 

 has been observed near apple orchards the latter have been 

 strikingly infested with Rcestelia. Unfortunately the specific 

 type of the latter from anatomical characteristics cannot 

 be confidently given at the time of this writing. It seems to 

 be R. lacerata. 



R. lacerata, (Sow.) Fr. 



^Ecidia hypophyllous, sometimes on the stems and young 

 fruit, seated on the yellow pulvinate thickening of the leaves, 

 slender, cylindrical or somewhat subulate, recurved, densely 

 clustered, 5-30 together; peridia yellowish white, rather deli- 

 cate, soon splitting and becoming fimbriate, the divisions not 

 extending to the base of the peridium; cells of peridium nar- 

 row, 20 /* broad by 55-72 ^ long; spores brownish, roundish- 

 oblong, surface finely granulated, 19-24 ^ in diameter. Sper- 

 magonia in yellowish spots on the upper surface of the leaves. 

 (Farlow, Gymnosporangia of the U. S., p. 30.) 



On leaves of Cratcegus tomentosa: Lee, Sept. 8, 5715; La- 

 Salle, Sept. 13, 1509; Union, Oct. 31, 2141. C. tomentosa, var. 

 mollis: Piatt, Aug. 17, 1122; LaSalle, Sept. 13, 1510, Sept. 13, 

 1528; JoDaviess, Sept. 18, 5980; Ogle, Sept. 26, 6193. C. to- 

 mentosa, var.: Piatt, Aug. 17, 1113; LaSalle, Sept. 12,1472. 

 C. coccinea: Kane, Aug. 30, 1385. 



R. penicillata, (Sow.) Fr. 



Same as R. lacerata, but aecidia smaller and frequently con- 

 centrically arranged, peridia splitting to the base, the divisions 

 very numerous, revolute, fimbriate, formed of one or more rows 

 of cells. (Farlow, Gymnosporangia of the U. S., p. 30.) 



On leaves of Pyrus coronaria: Tazewell, July 22, 2433, 

 2436; McLean, Aug. 1, 2435; Champaign, Aug. 13, i042; Piatt, 

 Aug. 16, 1082; McHenry, Aug. 20, 1161, Aug. 27, 1334; Lee, 

 Sept. 8, 5714; Stephenson, Sept. 13, 5838; LaSalle, Sept. 14, 

 1522; JoDaviess, Sept. 15, 5910; Rock Island, Sept. 23, 1631. 



