no NATURAL IIl.STfJR^' IJILLETIN. 



These all were affected b}' the species in question. The only 

 specimen upon Almis rubra that I have seen was kindh' given 

 me by Prof. H. W. Harkness and collected in California. 

 The distortion occasioned bv the parasite seems here a little 

 more severe than upon the other hosts. These all corre- 

 spond well with Exoascus ahii De Bary on catkins of AInus 

 glittinosa. distributed as No. 1366 Mycotheca Universalis cura 

 F. de Thiimen. 



II. TxVPHHIXA. 



Tai'Ukina aurka [Pcrsuoji] Fries. Plate II. Fig. 4. 



Earlv American botanists considered this to be the cause of 

 a disease common upon the fertile aments of Popiilus species; 

 that is now accounted for elsewhere, and Johanson and Sade- 

 beck unite in naming this as found upon Popiihis leaves onlv. 



I have examined several cultivated species of Populiis from 

 Ames. Iowa, collected by L. H. PammeP and F. C. Stewart, 

 which bear a fungus agreeing in the main with the descrip- 

 tion of the European species. Upon Popnliis />clii//foIia occur 

 yellow^ spots, changing to dark brown. 2 lomm. in size, which 

 become blisters bearing asci on their concave side, which is 

 gensrally upon the under surface, but sometmies upon the 

 upper. 



P. pctrovsky had the diseased areas larger, and patches 

 conrtuent. P. ccrtiiiensis was still more largelv affected, and 

 P. fiiilio-iala had the smallest spots of any, 2-iomm. 



Prof. H. W. Harkness has sent me. from California, leaves 

 of P. dilatata having blisters 20mm. in diameter. 



The principal points of departure from the descriptions of 

 the authors before mentioned lie in the location and the size 

 of the asci. They are described as hypophyllous. I find in 

 every instance some epiph3dlous. My asci are 18-25x55- 

 70//. This brings them within the minimum limits of the spe- 

 cies. The mvcelium arising between the cuticle and epi- 



' See Pammel, "93. This reference had been inad vertentlv overlooked, 

 in a former statement. See Bot. Gaz., Sept., 1894. 



