XIPHYDRIID.E. XYELA. 109 



There are two genera only found in Britain, which may be thus 

 distinguished by external characters : — 



Antenrue fractas, art" 3-tio valde elongato ; tibiis posticis in medio 



spiuosis : . . . . .31. Xyela. 



baud fractas ; tibiis omnibus in medio inermibus : . 32. Xiphydria. 



Genus XXXI.— XYELA, Dalman. 



AntenncE rather long, 12-jointed, slightly elbowed beyond the 3rd joint, the 

 basal joint robust, cylindric ; 2nd short, obconic ; 3rd also robust, cylindric, 

 equal in length to the remaining joints, all of which are minute, the terminal 

 one being least: palpi unequal, maxillary very long, 4-jointed, the terminal 

 one half as long as the 3rd, flat: mandibles 3-dentate: head transverse, de- 

 pressed : ocelli 3 : collar short : wings short, broad, especially the posterior ; 

 anterior with 3 marginal areolets, the 1st small, at the base of the stigma, 

 which is large, the other 2 placed obliquely beyond the stigma ; and 3 sub- 

 marginal ones, the 1st receiving 1 recurrent nervure, the 2nd 2, and the 3rd 

 being smaller, and extending nearly to the apex ; disc and posterior wings 

 distinctly areolated : abdomen short, subcylindric, elongate at the apex in 

 the males, rather acute, and furnished with a long sword-shaped ovipositor 

 in the females : legs simple, placed far behind : tibice with a spur at the 

 apex, the 4 posterior ones with a spur in the middle, and the hinder pair 

 with 2 bristles on the outer edge. 



The very singular structure of the antennae of this genus is amply 

 sufficient to distinguish it from Xiphydria, from which it also greatly 

 differs in its ample wings, all of which have numerous areolets, the 

 anterior with 3 marginal and 3 submarginal ones ; the maxillary 

 palpi are long and slender ; the tibiae armed with spurs ; the ovipo- 

 sitor in the females very different, &c. 



Sp. 1. pusilla. Nigro-fusca, capite ihoraceque luteo maculatis, abdominis seg- 

 mentorum marginibus anoque pallide luteis, pedibus pallidis. (Long. corp. 

 1^— 1| lin.; Exp. Alar. 3—4 lin.) 



Xy. pusilla. Dalman.— Curtis, v. i. pi 30 — Steph. Catul. 341. N'o. 3993. 



Head and thorax brown-black ; clypeus and orbits luteous ; the disc of the 

 thorax with 2 luteous spots ; abdomen with a yellow dot on the back of the 

 2 basal segments, the remainder with the margins pale, except the last, 

 which is entirely pale luteous ; legs pale, with the femora dusky; antennae 

 fuscous, testaceous beneath ; wings hyaline, rather tawny, with the nervures 

 and stigma darker. Ovipositor as long as the abdomen, and pale ochreous. 

 Found at the end of June near Hertford, in the vicinity of a fir 



grove ; also taken in Norfolk upon umbelliferous plants in July, and 



in Worcestershire and in the south of Scotland. 



