176 
BRITISH GALLS 
Horn op- 
tera 
Acari 
* > 
Leaves folded and bent along the lateral nervures, 
blistered on the upper surface, the depression below con¬ 
taining the woolly Aphides. Aphis bright green or 
yellowish green with large red eyes ; the cornicles are 
mere tubercles. 
Phyllaphis fagi Linn. 293 
Connold, Plant Galls, fig. 346. Buckton, iii., p. 38. 
Houard, No. 1161. 
Densely tufted mass of short twigs on the branches and 
on the trunk. Those on the branches sometimes resemble 
a “ witch’s broom.” (Plate XIV.) 
? Eriophyes 294 
Swanton, Haslemere Mus. Gaz., i., p. 534. 
Tufts of short thick hairs, forming more or less rounded 
spots on the lower surface of the leaf. White at first, then 
rosy, finally brown. Erineum fagineum Persoon. 
Eriophyes nervisequus Can., Aar. maculifer Trotter 295 
Greville, 1827, pi. 250, vol. v. Houard, No. 1164. 
Leaf margin more or less rolled upwards, the interior 
of the roll lined with hairs. Sometimes the lateral veins 
are swollen, the leaf folded, covered with abnormal hairs, 
and tinted with red. Legnon circumscriptum Bremi. 
Eriophyes stenaspis Nalepa 296 
Connold, Plant Galls, fig. 50. Houard, Nos. 1159, 1160. 297 
Leaf folded longitudinally, with a mass of abnormal 
hairs in the axils of the nervures on the lower surface. A 
discoloured swelling on the upper surface. 
Monochetus sulcatus Nalepa 298 
Connold, Veg. Galls, pi. 72 ; Plant Galls, fig. 53. 
Houard, No. 1163. 
Branches much cankered and hypertrophied; the swell¬ 
ings are often tumour-like and large. 
299 
Connold, Plant Galls, figs. 48, 49. Massee, Textbook 
of Plant Diseases, p. 127. At one time supposed to have 
been caused by Nectria ditissima ; it is probable that it is 
induced by Aphides. 
