352 ' Bulletin 73. 



Explanation of the Plates. 



All the illustrations in Plates X-XIX inclusive were drawn 

 with the aid of the camera lucida to the same scale. One milli- 

 meter of the eye piece micrometer scale of this combination is 

 drawn in each plate. The figures are magnified 30 times more 

 than this scale. 



Plate I. Exoascus deformans (Berk.) Fuck el, on leaves of 

 Prunus persica (ly.), peach. Fig. i from Ithaca, N. Y, The 

 petioles and a portion of the stem are here also affected. Fig. 2 

 from Auburn, Ala. 



Plate II. Fig. 3, Exoascus longipes Atkinson, in fruits of 

 Prunus americana Marshall. One young plum at the right is 

 sound and serves for comparison with the hypertrophied fruits. 

 From N. Y. 



Fig. 4, Exoascus rhizipes Atkinson, on fruit and bud of Prunus 

 trifiora Roxburgh, Japan plum. From Auburn, Ala. 



Plate III. Figs. 5 and 6 Exoascus decipiens Atkinson in the 

 leaves of Prunus americana Marshall. In 6 the shoot is deformed. 

 In 5 the fruits are deformed by E- longipes Atkinson. From 

 N. Y. 



Fig. 7, Exoascus decipiens var. cecidomophilus Atkinson in 

 half grown fruits of Prunus americana Marshall. The plum at 

 the left shows but a few warty excrescences, while the one at the 

 right is affected over a large part of the surface. From Aetna, 

 N. Y., on the same tree on which E. decipiens was collected. 

 Fig. 17 in Plate VIII is E- decipiens Atkinson from the same 

 tree, on which the plums in fig. 7 were collected. 



Plate IV. Exoascus mirabilis Atkinson var. tortilis Atkinson, 

 in fruits of Prunus angustifolia Marshall (P. chicasa Michz.). 

 Only one side of the fruit is attacked. In each figure one healthy 

 and one afiected fruit is shown. From Auburn, Ala. 



Plate V. Exoascus mirabilis Atkinson in buds of Prunus 

 angustifolia Marshall. In figure 10 several of the leaves were 

 fully expanded before the bud was severely attacked. Fig. 12 

 Exoascus mirabilis var. tortilis Atkinson on fruits of P. angusti- 

 folia Marshall. All from Auburn, Ala. 



