1864.] 687 



of the gall, which will only apply to the galls long after the true gall- 

 flies have left them. 



2nd. My galls gathered from young white oaks, and which answer 

 perfectly to his figure and description of C. q. tuber, produced females 

 with l3-jointed antenna?, while his have but 12 antennal joints. 



3rd. I have gathered several hundreds of these galls in the autumn, 

 winter and early spring within the last two or three years, but have 

 never reared from them one true gall-fly, though they have produced 

 large numbers of male and female guest-flies — the male answering per- 

 fectly to Dr. Fitch's description of C. q. arbos. The female he had not 

 seen. 



4th. The galls I collected in June have not yet produced any guest- 

 flies, but cutting open several to-day I found in one a large living 

 larva — the others were empty or contained dead gall-flies that had not 

 been able to eat their way out of the dried gall. 



From the above facts I am forced to believe that the galls C. q. tuber 

 and arbos Fitch are both produced by the same fly, and that it is the 

 same species that I have described above and for which I retain Dr. 

 Fitch's name, 0. q. tuber. Dr. Fitch has, no doubt, described two dis- 

 tinct flies, for Mr. Walsh, who has devoted much attention to the 

 guest-flies of the oak galls, finds that not only do some species live in 

 several different species of galls, but that the same kind of gall may 

 produce more than one species of guest-fly. (Proc. Ent. Soc. Philad. 

 Vol. 2d, p. 465.) 



Mr. Walsh, in the article referred to, mentions other of Dr. Fitch's , 

 species which he is satisfied are^nquilinae, and not the producers of the 

 galls from which they were reared. (See pp. 464-5, 484 and 494.) 

 Hia remark that " G. q. tuber Fitch is in all probability a guest-fly," 

 escaped my notice till this moment. 



QuERCUS MONTANA. Hard, round (jails, .25 of an inch in diame- 

 ter with a Jinrh/ papillose surface and a solid radiated cellular struc- 

 ture ; growiny sometimes on the upper, but as often on the under side 

 of the leaf; attached to the larger veins by a very short pedicel. 



These galls are rarely met with, and I have seldom found more than 

 one on a leaf. In a single instance there were three on the same leaf, 

 two on the under side and one on the upper. My specimens were found 

 in October and contained perfect insects. Through the gall of several. 



