CATALOGUE OF BRITISH PLANT-GALLS 197 



Acari 



Fungi 



Homop- 

 tera 



Acari 



Fungi 



Pustules about 4 by 3 mm. on the upper surface of the 

 leaf, green, reddish, or brown, often numerous and 

 coalescent, opening by a minute hairy aperture on the 

 inferior surface. (Plate XXI. i.) 



Eriophyes similis Nalepa 460 



Syn. Phytoptus similis Nal. 



Connold, Veg. Galls, pi. 65 ; Plant Galls, fig. 68. 

 Houard, No. 3294. 



Densely fasciculated twigs on the branches, forming a 

 "witch's broom." 



EXOASCUS DEFORMANS Fiickel 461 



Syn. Ascomyces deformans Berk. 

 Massee, Brit. Fung. Flora, iv., p. 15. 



Fruit much swollen and deformed, often curved and 

 flattened, about three times the normal size, without stone 

 or kernel. The whitish bloom, which appears in July on 

 these malformed fruits, is the fruit of the fungus, and 

 consists of closely packed asci. 



ExOASCUS PRUNI Fiickel 462 



Syn. Ascomyces pruni B. and Br. 



Massee, Brit. Fung. Flora, iv., p. 14. 



Fninus insititia Linn. 

 Leaf margins swollen. 



Buckton, ii., iii. 



Pustules on the leaves. 



Houard, No. 3265. 



67. BuUace. 

 See No. 457. 

 Hyalopterus pruni Fabr. 463 



See No. 460. 

 Eriophyes similis Nalepa 464 



Densely fasciated twigs. See No. 461. 



Exoascus deformans Fiickel 465 



Fruit deformed. See No. 462 and Plate XXV. 



Exoascus pruni Fckl. 466 

 Connold, Veg. Galls, pis. 126, 129; Plant Galls, fig. 79. 



Branches swollen, bark destroyed, the margin of the 

 wound surrounded by a thickened irregular mass of living 

 bark, presenting the condition known as " canker." 



Massee, Textbook of Plant Diseases, p. 127. 



At one time said to have been caused by the fungus 

 Nectria ditissima, which, however, has been shown to be 

 only a saprophyte. Probably results from the presence 

 of aphides. 



467 



