CATALOGUE OF BRITISH PLANT-GALLS 177 
Diptera 
Homop- 
tera 
Fungi 
Homop- 
tera 
ULMACEAE 
Ulmus glabra Huds. (montana Stokes). 99. YVych 
Elm. 
Midrib of the leaf much swollen. The gall usually 
appears as a rounded, hard, yellowish green swelling on 
the under surface, and a cylindrical projection on the 
upper one, with the aperture at its apex ; but not infre¬ 
quently the aperture is on the lower surface at right angles 
to the swollen midrib. When young shoots are attacked 
the leaves are much distorted. Larva solitary, greenish- 
yellow. M. E. Imago, April, II. (Plate XXI 11 .) 
Oligotrophus Lemeei Kieffer 300 
Swanton, Knowledge, June, 1910. Houard, No. 2061. 
Ovoid swelling on the midrib just above the petiole, 
10 to 14 mm. high 7 to 10 mm. in diameter, covered with 
serrated white hairs, yellowish. The leaf is more or less 
deformed, and the midiib is incurved below the point of 
attack. July and August. Aphis white or pale yellow. 
Pemphigus pallidus Halliday 301 
Syn. Pemphigus tilmi Halliday. 
Connold, Plant Galls, fig. 108. Buckton, ii., 127. 
Houard, No. 2062. 
Leaf margin swollen, puckered, and rolled loosely in¬ 
wards ; very rarely both halves of the blade are attacked 
and incurved. Greenish-yellow, tinted with red. June to 
October. Aphis covered with cotton-like fibres. 
Schizoneura ULMI Linn. 302 
Connold, Veg. Galls, pi. 107; Plant Galls, fig. 109. 
Houard, No. 2067. 
Blisters or swollen patches on the leaves. The patches 
are dark green at first, then blackish-brown, and often 
cover a large area of the leaf. 
Taphrina ulmi Johans. 303 
Massee, Textbook of Plant Diseases, p. 92. 
Elmus campestris Linn, (surculosa Stokes). 60. 
Common Elm. 
On the upper surface of the leaf. An elongated or subglo- 
bose glabrous gall, 10 to 12 mm. high ; pale green, purple 
or reddish above, with an apical opening, which, together 
with the neck of the gall, is surrounded with white hairs. 
The leaf is discoloured and somewhat thickened around 
the gall. Solitary or gregarious. June to September. 
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