ON THE COMMON OAK 163 



Connold, Oak Galls, pi. 23; Platit Galls, fig. 188. 

 Houard, No. 1283. Adler and Straton, Alternating 

 Generations, pi. 2, fig. 12. 

 Hymen- On the male catkin. Gall minute, pyriform, about 

 optera 2 mm. high, inserted in the axis of the catkin between two 

 stamens ; green at first, becoming brown, covered with 

 erect white hairs. Usually solitary. Imago, June, I. 

 (Text, Fig. 3.) 



Andricus pilosus Adler 232 

 Connold, Oak Galls, pi. 13; Plant Galls, fig. 223. 

 Houard, No. 1189. Adler and Straton, Alternating 

 Generations, pi. i, fig. 10a. 



„ Bud greatly enlarged, resembling a hop-cone. The 



scales are imbricated and enlarged ; there is a cavity be- 

 tween the central ones, at the bottom of which lies a 

 small, hard, ovoid gall, containing the larva. Imago, 

 spring. III., IV. (Text, Fig. 2.) 



Andricus pilotus, form fecundator 233 



Syn. Andriaisfecutidafrix Cam. ; Aphilothrix fecuitda- 

 trix Hartig. 



Connold, Oak Galls, pi. 22 ; Plant Galls, fig. 186. 

 Houard, No. 12 14. Adler and Straton, Alternating 

 Generations, pi. I, fig. 10. 



I, On the male catkin. Gall ovoid, brown, minute, about 



2 mm. high, fixed to the base of the catkin, and covered 

 with hairs 6 to 8 mm. long. The galls are often massed 

 together on the catkin, and form a rounded or ovoid 

 swelling about the size of a pea, entirely concealed in a 

 covering of white or yellowish hairs. 



Andricus ramuli Linn. 234 

 Connold, Oak Galls, pL 14 ; Plant Galls, fig. 224. 

 Houard, No. 1186. Adler and Straton, Alternating 

 Generations, pi. 2, fig. x-^a. 



In a bud, an ovoid gall, about 5 mm. high, terminating 

 in a point. It is glabrous, greenish, with a reddish 

 tint on the ujjper part, which shows above the bud ; the 

 broad base is buried in the iDud. Within the fleshy 

 covering there is a woody internal gall marked with 

 longitudinal striae. In September or October the gall 

 becomes detached ; the external part dries up and ex- 

 poses the internal gall. Imago, spring, HI. 



Andricus ramuli, form autumnalis 235 



Syn. Andricus autumnalis Hartig j Aphilothrix autum- 

 nalis Hartig. 



Connold, Oak Galls, pi. 23 ; Plant Galls, fig. 183. 

 Houard, No. 1219. Adler and Straton, Alternating 

 Generations, pi. 2, fig. 13. 



