340 Bulletin 73. 



Exoascus viirabilis Atkinson. 



To this species I refer the form on the buds of P. americana 

 Marshall, from Iowa, specimens communicated by Prof. Pammel, 

 and by Prof. Seymour. The asci, stalk cells and spores are 

 shown in figs. 68 and 69. 



Specimens of probably this same species on the buds of the 

 Maquoketa* plum were reported from Iowa in 1888, the Maquo- 

 keta being here inadvertently referred to the Chickasaw plum. 



Exoascus decipiens n. sp. 



This species distorts the leaves and young shoots of Primus 

 americana Marshall. Specimens have been collected at Danby, 

 N. Y., by T. A. Mandeville, and at Aetna, N. Y., by the writer. 

 A photograph of two of the specimens from Danby are reproduced 

 in figs. 5 and 6, Plate III. The young shoot is somewhat 

 enlarged, though there are developed no asci on any of the shoots 

 which I have seen. In fig. 5 some of the leaves can be seen to be 

 finely wrinkled near the base. The affected part of the leaf is 

 usuall}^ thrown into a series of very fine folds or wrinkles, and the 

 under surface, which at the time of the maturity of the asci is fre- 

 quently farther injured, presenting a scurvy appearahce, is covered 

 by scattered groups of rather loosely associated asci. No asci 

 have as yet been found upon the upper surface, and from careful 

 examination I have not been able to detect any development cor- 

 responding to the "witches brooms," so that the species seems to 

 be well differentiated from E. msititiae Sadeb. The asci are also 

 much larger and diflferent in other respects than those of that 

 species. They are nearly cylindrical and rounded or rarely trun- 

 cate at the free ends, and measure 20-40 long by 7-10 in diameter. 

 The stalk cells are quite broad, frequently broader than the asci, 

 and measure 6-13 high by 7-12 in diameter. They are usually 

 rounded below, but sometimes are pointed much as in E. defor- 

 vians on the peach. The spores are oval or broadly elliptical, 

 measuring 3-4 in diameter. Quite frequently conidia are devel- 

 oped by budding while still within the ascus. 



* Report Dept. Agr. p. 36S, 1S88. 



