178 BRITISH GALLS 



Aphis shining, dark green or black, globular. (Text, 

 Fig. 21*.) 



Tetraneura ulmi l)e Gear 304 

 Connold, Veg. Galls, pi. 108; Plant Galls, fig. 107. 

 H Guard, No. 2048. 



Homop- Leaf margins folded upwards, midrib much swollen, 

 tera yellowish-green, aperture on the upper surface. Lateral 

 veins slightly swollen. June to October. 



Tetraneura alba Ratzeburg 305 

 Connold, Veg. Galls, pi. 108 ; Plant Galls, fig. 106. 



„ Leaf margin swollen and rolled inwards. See No. 302 



and Text, Fig. 21a. 



SCHIZONEURA ULMI Linn. 306 



Buckton, ii., 100. Houard, No. 2050. 



,, Leaf completely deformed and hypertrophied, dilated 



and contorted to form a densely hairy bladder, 60 to 80 

 mm. in diameter. Green at first, slowly becoming brown, 

 and remaining attached to the branch after the normal 

 hairs have fallen. Aphis black, clothed with cottony 

 filaments. 



SCHIZONEURA LANUGINOSA Hartig 307 



Connold, Plant Galls, fig, 105. Buckton, iii., 104. 

 Houard, No. 2051. 



Midrib of leaf swollen. See No. 301. 



Pemphigus pallidus Halliday 308 

 Buckton, lii., 127. 



Acari Minute pustule, about i mm. in diameter, on the upper 



surface of the leaf, opening on the lower surface in a 

 minute cylindrical protuberance. Green and red ; often 

 very numerous. 



Eriophyes ulmi Nalepa 309 

 Houard, No. 2053. 



Fungi Dense mass of twigs on a branch, forming a " witch's 



broom." The leaves on the abnormal twigs are atrophied. 



ExOAScys TURGiDUS Sad. 310 

 Swanton, Haslemere Mus. Gaz., i., 531. Connold, 

 Plant Galls, p. 95. 



Leaves blistered. See No. 303. 



Taphrina ULMI Johans, 311 

 Massee, Textbook of Plant Diseases, p. 92. 



