AMERICAN HYMENOPTERA. 81 



the entire surface of the basal plate, all black. Cenchri whitish. A 

 more or less distinct black cloud on the pectus, and another on the 

 posterior disk of the pleura, the former occasionally obsolete. Abdo- 

 men with that part of the anterior edge of joint one, that borders the 

 whitish basal membrane, or rarely the basal half of joint one, black. 

 Ovipositor honey-yellow, its sheaths dusky. Cerci full as long- as the 

 last tarsal joint of the legs, honey-yellow, lightly tipped with dusky. 

 Legs honey-yellow, the tarsal claws dusky. Wiiigx hyaline; veins 

 black ; those on the costa, as well as the basal half of the stigma, 

 whitish or yellowish ; the rest of the stigma dusky. Length 9 -IT — 

 .22 inch ; front wing 9 .18 — .24 inch. 



"S Differs from the normal 9 only as follows : — 1.n7. The ground 

 color is greenish-white, not honey-yellow, 'liid. The black sput en- 

 closing the ocelli is larger, and is separated from the eyes only by a 

 narrow orbit, and occasionally touches them fur a small space ^rd. 

 The occiput, except the orbit, is distinctly black. AtJi. In the antennae 

 the pale colors are more dominant, and verge more or less on greenish- 

 white ; and the antennaj are three-fourths (not three-fifths) as long as 

 the body. bth. The thorax is black, except the teguhe, the superior 

 margin of the collare and the cenchri, which are all greenish-white. 

 Qth. The abdomen is black above, greenish-white below, the lateral 

 plates basally black, but terminally clouded with the pale color, liasal 

 membrane white. 1th. The legs are greenish-white, sometimes, espe- 

 cially the hind legs, more or less honey -yellow. In the hind legs the 

 base of the coxae, the extreme tips of the femora and the tarsi are 

 more or less fuscous, ^th. The veins on the costa are scarcely whitish, 

 and only the extreme base of the stigma is whitish. Lengh S .10 — 

 .17 inch; front wingS .11 — .19 inch. 



"Ten % . five 9 ? bred April 16 — 27. Absolutely undistinguishable 

 by any reliable character from the inquilinous Emn-a perturlxtns, n. 

 sp., u. v. Distinct at once from E. s. yemma and from E. orbitads, 

 Nort., by the abdomen 9 being honey-yellow above and below, and by 

 the abdomen S having its lateral plates partly pale, and the venter en- 

 tirely pale." 



The gall is found on Salix cordata. An oval or roundish, sessile, 

 monothalomous swelling, 0.30 — 0.50 inch long, placed lengthwise on 

 the side of small twigs, green whenever it is smooth, but mostly covered 

 with shallow longitudinal cracks and irregular rough scales, which are 

 pale opaque-brown. Particular twigs on badly infested bushes some- 



TRANS. AMER. ENT. SOC. (11) JUNE, 1867. 



