lSfi2.] 25:j 



contracted under it, so tliat its jioslcrior margin projects beyond them. The neck 

 (or first segment) of the abdomen is turgid and bmgitudinally grooved. The 

 wings are hyaline, the radial area closed; the stout veins ])ale yellow; the areo- 

 let narrow, triangular, its two' anterior sides rather indistinct, almost obsolete; 

 the origin of the cubital vein (from the first transverse vein) is obsolete. 



Numerous % and 9 specimens. 



Ct/nijis onerotus Harris is souiewliat larger than this species, it has a 

 black spot on the pectus, so that the middle coxae are inserted on a black 

 ground ; the yellow color is not strictly confined to the collare, as in C. 

 Ugnicola, but extends across the suture on both sides of the dorsum of 

 the mesothorax ; at the same time the black of this dorsum encroaches 

 anteriorly on the middle part of the collare, reaching the head ; the ab- 

 domen is more light yellow, and the black on its upper part is less extend- 

 ed. These characters belong at least to the only specimen of C. oneratus 

 in my possession. 



QuERCUS PALUSTRIS. Piu Oak. RouudcJ, icoody gull on tlie upper 

 side of the leaves, along the prhiclpal ribs. Diameter upwards to 0.4 to 

 0.5. Gall-fly unknown. 



These excrescenses, occuring frequently in autumn, vary in size from 

 0.15 to 0.4 or 0.5 ; most of them, however, are about 0.2 or 0.3 long and 

 narrower than their length. Their color is brownish, sometimes more or 

 less yellow, or reddish or with a grey efflorescence ; their surface has ir- 

 regular, more or less deep wrinkles, according to the age or size of the 

 gall; otherwise it is smooth, and has nothing of the deep and regular 

 sculpture of C q. jnsuni. They somewhat resemble the gall of Cecido. 

 myia symmetrica 0. S. (see Monographs of N. A. Diptera, p. 200), but 

 project only on one side of the leaf; besides, their outline is more regular- 

 ly rounded and less deeply cracked. When cut open they show several 

 (commonly three) cells, divided by partitions, somewhat converging to- 

 wards the middle of the base. 



I am not sure whether they are produced by a Cymps, the more so as 

 Cynijys-gaWfi usually occur on the under side of the leaves. 



QuERCUS PALUSTRIS. Pin Oak. Pound, icart-like, r usty-p>uherlent ex- 

 crescences on the upper side of tlic leaf, growing several together. Diam. 

 of single ones about 0.1. 



These galls are not unlike those of C. (j. verrucarum 0. S. (1. c. p. Gl, 

 No. 9) of the post oak and similar galls, found on the white and the swamp 



