1802.] 'J51 



1ki« the same shape as those of ('. (^. (■ciitrirold and ((ricii/ofd, it is proba- 

 ble that C q. tiihicola has a generic afiSnity with tlieui, the more so as 

 all these galls are autumnal and produce only females. 



To No. n. CYNIPS QUERCUS PALUSTRIS 0. S. (1. c. p. M). 



(rails perfectly similar to those described as occuring on the pin-oak, 

 were ob.'^erved by me this spring on Qiierrus fdlcata., tbu-torla and cocci- 

 nca. I succeeded in rearing the gall-flies from the two former and could 

 not discover any perceptible difference between them and that of Q. paliis- 

 fris, so that my description applies to all. Still, I do not consider my in- 

 ability to distinguish them as a proof of their specific identity. 



My description stated erroneously that the antennae are 15-jointed in 

 both sexes. In reality they are, as they ought to be, 14-jointed in the fe- 

 males. The last joint, however, is, in most specimens, distinctly divided 

 in two by a slight annular incision. As this incision is more distinct in 

 dry specimens, this was the cause of the error in my description, which 1 

 became aware of, as soon as I obtained fresh specimens. In the same way 

 female gall-flies with 13-jointed antennae generally have an indication of 

 fico subdivisions on their last, elongated joint. 



Mr. Walsh, in Rock Island, writes me that he also discovered the gall 

 on Q. tinctoria. He became likewise aware of my error as to the number 

 of joints of the 9 antennae. 



IV. Oak-Galls not mentioned in the paper: On the 



CYNIPID^ etc. 



The following galls have been partly observed by myself, partly com- 

 municated to me by other persons since the publication of my paper on 

 the Ci/nrpidse. About some of them, as will be seen below, I am not 

 (|uite sure, whether they are really the produce of this class of insects. 



QuERCUS PALUSTRIS. Pin Oak. Wofnit/ liiiot^ un the limits, emittiiuj 

 pale yellmo, conical., hrittle prnjerfiouii. Cynips quercus cornigera 

 n. sp. (as yet unknown). 



Of all excrescences on oaks in general, the present one, wherever it oc- 

 curs, is perhaps the most conspicuous, as by its abundance it deforms the 

 tree and seems to cause considerable injury. (It has already been alluded 

 to 1. c. p. 55, foot-note.) It consists of woody knots on the limbs, looking 

 usually as if many of them were closely packed together and thus forming 



