lOi NATURAL HISTORY BULLETIN. 



scribed as •• exceeding that of any other Exoasci."' The stalk- 

 cells are 5-8x10-16". Mature spores, of which there are 

 eij^ht to an ascus, are ellipsoidal in form and measure 5-7x6- 

 C),'j : their large size is a distinguishing character of the spe- 

 cies. I understand this to include all species formerly con- 

 sidered as £xoascits Zi'icsno'i. I have examined it upon 

 leaves of Prumis scrotina collected at Cambridge, Mass., bv 

 Dr. W. G. Farlow and Economic Fungi No. 128 from Ala- 

 bama, and also upon deformed leaves of •• cultivated cherry."' 

 [PrujiHs avium? ) distributed as No. 2286 of Ellis. North 

 American Fungi. I think to this species can be referred 

 specimens of Pntnns aniericaua showing both branch and leaf 

 distortion; some were collected in Illinois by Prof. L. H. 

 Bailey, and several were sent me bv Prof. E. H. Pammel. 

 which had been found in various localities in Iowa. I am also 

 indebted to Prof. Pammel for the opportunity of examining 

 Pninus hortiilana collected at Cedar Rapids. Iowa, by A. B. 

 Dennis, and leaves of the Miner plum, a cultivated variety of 

 P. hortiilaiia. collected at Amana, Iowa, bv A. Noe. both of 

 which are doubtless affected by this species. It is also found 

 upon several specimens of Primus foiusylzauica from New 

 Hampshire. I believe it proper to refer to this species the 

 disease of Pniuus ziro-jniana leaves collected at Ute Pass. 

 Col., and sent me by Prof. Wm. Trelease: in some respects 

 it resembles Exoascns deformans, but the spores are larger, 

 being 5x7,'/. Pniiiiis dcmissa. the western choke-cherry col- 

 lected in Nebraska by Mr. T. A. Williams and sent me for 

 examination by Mr. B. T. Gallowav, shows the characteristic 

 leaf and sprout deformation and agrees microscopically with 

 the fungus upon P. virginiaiia. 



For comparison of these American forms with authentic 

 exsiccati. I have examined Kriecjer. Funn;i Saxonici, 621. 

 Exoascns deformans (Berk. ) Fckl., s}n. E. z.'icsncri, Rathay 

 on P. avium. Mycotheca Eniversalis, cura F. de Thiimen 

 2265. Exoascns vciesncri Ratha\'. on living leaves of P. 

 cerasi. and several others. 



There are upon some of the hosts here referred to this spe- 



