ON THE COMMON OAK 167 



Hymen- A rounded pustule about 3 mm. in diameter, showing 



optera on both surfaces of the leaf, but a little less pronounced 



below ; solitary, glabrous, pale green or brownish, marked 



with striae radiating from the central papilla. There is no 



internal gall. Imago, June, I. (Plate V. 8, c.) 



Neuroterus vesicator Schl. 249 

 Syn. Spathegaster vesicatrix Schl. 

 Connold, Oak Galls, pi. 55 ; Plant Galls, fig. 218. 

 Houard, No. 1353. Adlerand Straton, Alternating Gener- 

 ations, pi. I, fig. 3a. 



„ On the under surface of the leaf, gall resembling a 



minute silk button, 2 to 3 mm. in diameter and about i mm. 

 high. There is a well-defined depression on the upper 

 part of the gall, which is brownish, veined with red, and 

 covered with filiform silky hairs radiating from the depres- 

 sion to the margin. Often densely gregarious. Imago, 

 March, II. (Plate V. 9, «.) 



Neuroterus vesicator, form numismatis 350 



Syn. Neuroterus numismatis Oliv. 



Connold, Oak Galls, pi. 40 ; Plant Galls, fig. 212. 

 Houard, No. 1340. Adlerand Straton, Alternating Gener- 

 ations, pi. I, fig. 3. 



,, In the axillary and terminal buds and on the leaf mar- 



gin. Gall cylindrical, about 4 mm. long, greenish-yellow, 

 becoming tinted with red ; the surface covered with little 

 vesicular hairs, which give it a finely granulated appear- 

 ance. Imago, May, I. (Plate XXII. 9.) 



Dryophanta verrucosa Schl. 251 



Syn. Spathegaster verrucosus Schl. 



Connold, Oak Galls, pi. 42 ; Plant Galls, figs. 194, 217. 

 Houard, No. 1349. Adler and Straton, Alternating Gener- 

 ations, pi. 2, fig. 160:. 



,, On the midrib and lateral veins on the lower surface 



of the leaf, attached by a vejy short stalk. Gall 

 spherical, markedly flattened at the poles, diameter 

 7 mm., height 5 mm. ; green or brownish, shining, 

 often tinted red, becoming hard. Scattered. Imago, 

 October or November, I. (Plate XXII. 12.) 



Dryophanta verrucosa, form divisa 252 



Syn. Dryophanta divisa Hartig. 



Connold, Oak Galls, pi. 42; Plant Galls, fig. 204. 

 Houard, No. 1328. Adler and Straton, Alternating 

 Generations, pi. 2, fig. 16. 



» In dormant adventitious buds of the trunk and branches. 



Gall very minute, about 2 mm. long, greenish-grey, pointed, 



