70 [October 



flies are very similar. The % thus obtained had 15-joiuted autennge, which 

 agrees with O. quercus Jicus Fitch; but the males of the flies which I rear- 

 ed from the oak tumor had the same number of joints. By all means, the 

 insects which I reared from both galls are no true Ci/nipiihr, the second 

 segment of the abdomen being shorter than the third and must be refer- 

 red to the Fujitidse. (See No. 27, C. quercus tuber.) 



23. Quercus phellos. Willow Oak. Rounded, iroodij su-elliiuj at 

 the tip of the limbs. Cynips QUERCUS PHELLOS n. sp. 



Found copiously on the Virginia side of the Potomac, near Washington 

 in June. At this time they were greenish and from 0.8 to 0.35 in diam- 

 eter; numerous green leaves wei'e attached to them. The flies escaped on 

 the 29th of June. 



Cynips quercus phellos n. sp. — Reddish-brown, abdomen shining, tarsi some- 

 what paler, their tips infuscated; antennse 13-jointed; wings hyaline, very trans- 

 parent, the thick veins almost colorless, hardly yellowish, areolet none, radial and 

 cubital veins almost obsolete; the branch of the subcostal running towards the 

 margin is abbreviated, rudimentary. Four J . Length 0.1. 



The color of this species is like that of the head and thorax of C. quercus 



ni(/rse. and the wings have the same transparency. The only thick and dis- 



itnct veins of the wing are the basal vein and the subcostal vein, except its 



branch, running towards the margin, and the cross vein, running from the 



angle of the subcostal towards the place of the areolet. All the other veins, 



and consequently the area which they form, are almost obsolete. 



24. Quercus alba. White Oak. " SweUinga similar to those of 

 Cynips quercus tuber, groioing on the tips of the limbs of aged and large 

 white oak trees." (Dr. Fitch, Reports, Vol. II, No. 310.) Cynips quer- 

 cus ARBOS Fitch. 



The fly is "small, black, having all its legs and antennae of a bright pale 

 yellow color, and one more joint in the latter organs than in the preceding 

 species ( C. quercus tuber) in the males, which sex is 0.06 in length and to 

 the tip of its wings 0.1." (Fitch, 1. c.) 



Is it identical with the following gall? But according to Dr. Fitch, 

 this gall diff"ers from that of C. quercus tuber by occuring on old and large 

 trees only, whereas my gall No. 25 is found on trees of diff"erent age and 

 size. 



25. Quercus alba. White Oak. Club-shaped ., icoodij swelling at the 

 tip of the limbs. 



In June these swellings are yet green; later in the season, they become 

 brown, hard and woody; in autumn, the leaves emerging from their tip, 

 break oflF and the swellings at the tip of the limbs are easily noticed. 



