352 



[May 



the same relation as the gall-fly of Q. prinoides. C. petiolkola is very 

 probably an Anlricus. 



8. C. fusiformis 0. S.. Proc. etc. I, p. 61 ( 9 ; Q. alba). This 

 insect somewhat resembles C. petwlicola,and, as I possess only a single 

 specimen of it, the difference indicated in the analytical table may not 

 be a constant one ; I will try, therefore, to point out some others. Both 

 species have, between the parapsidal grooves, two lines or grooves run- 

 ning from the collare a short distance backwards; in 0. petiolkola they 

 are much more distinct, but can hardly be called grooves, as they are 

 smooth lines, easily perceptible, on account of their lustre, among the 

 sculpture of the surface of the inesoiiotum ; in 0. fusiformis they ap- 

 pear more like furrows, but not being very deep, they have less lustre 

 than those of the other species, and are therefore less perceptible; a 

 third, intermediate, impressed line is, in a certain light, perceptible be- 

 tween them. The scutellum of C. petiolkola is more deeply wrinkled 

 than that of 0. fusiformis. Both species have a short, sparse, micro- 

 scopic pubescence on the sides of the mesonotum and on the scutellum, 

 but this pubescence is more distinct in C. petiolicola. (Compare also 

 below, No. 56, about the possible relationship between this gall and 

 that of Figites chinquapin Fitch). 



9. C. FUTILIS 0. S. (% ; Q. alba). 10. C. PAPILLATA 0. S., (£ ; 



Q. prinus) Proc. etc. I, p. 63-64, Nos. 13, 14. Compare also Bassett. 

 1. c. II, p. 320. These are probably the same species, attacking two 

 different oaks and producing somewhat different galls. 



11. C. flocci Walsh 9 . Proc. etc. II, p. 482 ( 9 ; Q. alba ?). This 

 species, which I have not seen, may possibly belong to Andricus Hartig. 

 Whether the gall is identical with the gall Q. lana Fitch is not certain. 

 (Compare below, No. 45.) 



12. C. PKZOMACHOIDES O. 8.. Proc. etc. I, p. 250 ( 9 ; Q. alba?). 

 Although, at the time I described this insect, I was somewhat un- 

 certain about the kind of oak to which the galls belonged, I hardly 

 doubt now that this insect is the author of the gall called Q. pisum by 

 Fitch (Pep. II. No. 310). the Cynips q. pisum Fitch being a guest- 

 gall-fly. The gall described by Mr. Walsh as Q. erinacei ( Q. alba; 

 gall-fly unknown) Proc. etc. II, p. 483. may be the same species, as Dr. 

 Fitch also mentions prickles, occasionally occurring on his galls of Q. 

 pisum. A difference somewhat more difficult to reconcile is, that Mr. 



Walsh's gall is said to occur twice as often on the upper side of the leaf 

 as on the under side ; whereas both Dr. Fitch and myself found the 

 gall V- pisum ( which is now to be called pezomachoides) always on the 



