Leaf Curl and Plum Pockets. 345 



Robinson* calls attention to the fact that the asci on the fruit 

 of P. domestica are much more slender than the measurements 

 given by Sadebeck would indicate. In a later contribution Sade- 

 beckt himself indirectly gives some ground for considering this a 

 distinct species from the E. pruni on P. domestica. In this com- 

 munication he thinks it possible that a careful examination of the 

 fungus on the fruit of Primus padus, which he previously studied 

 and placed in E. pruni, % may prove to be a distinct species. The 

 hypertrophied fruits of P. padus agree in external appearance 

 more nearly with those of P. virginiana than with those of P. 

 domestica, and the floral organs of P. padus are also hypertrophied. 

 Prunus padus and P. virginiana both belong to the same type of 

 the genus Prunus and to a different type from that to which P. 

 doinestica belongs. 



I should consider the fungus on P. virginiana much more 

 nearly related to the E. farlowii on P. serotina than to E. pruni. 



The relative size of the asci and stalk cells as well as the pro- 

 portionate length of the same, suggest this, as can be seen by 

 comparing the illustrations of the two. Figs. 34-36 being those 

 oi E. farlowii and 37-39 being those of the species on the fruit of 

 P. virginiana. There are, it seems to me, however, good specific 

 differences between these two, the base of the stalk cells in E. 

 farloivii being frequently narrower and running to a point which 

 intrudes somewhat between the cells of the epidermis. The asci 

 of E. farloii'ii are also much shorter, and the stalk cells are pro- 

 portionately a little broader. I therefore propose for the fungus 

 on the fruit of P. virginiana, the name, Exoascus confusics. 



Exoascus cecidomophilus n. sp. 



This is a very interesting species which I have found upon the 

 fruits o{ Primus virginiana which were deformed by a species of 

 Cecidomyia. The species was discovered too late in the season to 

 say whether the larvae attacked the fruit before or after the attack 

 by the fungus. I believe at this time, however, that the cecid- 

 omid larvae attack and deform fruits which are not affected by the 



* Notes on the genus Paphrina. Ann. Bot. I, p. 168, 1887-8. 



t Die parasitischen Exoasceen. Ab. a. d. Jahrb. etc. X, 2, p. 45, 1893. 



jKritische Unters. etc. Ibid. VIII, p. 29, 1891. 



