110 MANDIBULATA. — HYMENOPTERA. 



Ge^us XXXII.— XIPHYDRIA, Latreille. 



AntenncE setaceous, consisting of about 17 joints, of which the basal one is 

 longest and slightly thickened, the 2nd minute subglobose, 3rd nearly as 

 long as the 1st, but slender, remainder gradually decreasing in length, and 

 the terminal ones very indistinctly articulated : palpi short, maxillary 

 slender, the 3 terminal joints of equal length, the last obliquely truncate and 

 acuminate : mandibles bidentate : head large, orbiculate, petiolated, Jbre/teatZ 

 elevated : ocelli 3 : thorax broader than the head : collar elongate : ivings 

 rather long ; anterior with 2 subequal marginal areolets, and 4 submarginal 

 ones, the 1st subquadrate, 3 following gradually increashig in width, the 2nd 

 receiving 1, and the 3rd 2, recurrent nervures : abdomen somewhat cyiindric, 

 flat and rounded at the apex in the males, convex above and subulated in 

 the females, and furnished with an exserted, compressed, subserrated ovi- 

 positor: legs slender, compressed; anterior tibise shortest, all armed with 2 

 spurs at the apex, but without any in the middle. 



Compared with the foregoing genus, these insects are gigantic, 

 but, like all xylophagous species, they are subject to very great 

 variations in size : without noticing other characters of distinction 

 between them, they may be known from the Xyelse by having 2 

 distinct marginal, and 4 complete submarginal areolets in the anterior 

 wings : they are generally found in the vicinity of willows, flying by 

 day. 



Sp. 1. Camelus. Niger, abdominis lateribus alba maculatis, pedibus testaceis, 

 tarsis apice fuscis. (Long. corp. $ 3—6 lin.; 9 7 — 9 lin.; Exp. Alar. $ 

 4|— 8 lin.; 9 11— 14 lin.) 



Si. Camelus. Linne. — Xi. Camelus. Steph. Catal. 342. No. 3994. 



Black, shining: head glabrous, forehead rough, with an oblong white streak 

 on each side of the crown, a small one behind each eye, and a smaller one at 

 the base of each mandible ; thorax rough, with a minute white dot at the 

 insertion of the wings on each side ; abdomen with the 2 basal segments 

 finely punctured, the 6 following glabrous and shining, each with a triangular 

 white dot on both sides, the 1st and 3rd being smallest, terminal segment 

 rough and immaculate ; legs testaceous, with the apex of the tarsi black ; 

 wings hyaline, slightly clouded towards the apes ; antennae sometimes with 

 the basal joints ferruginous. 



Male with the white dots on the abdomen smaller and equal ; but they vary in 

 number in both sexes, and the insects also vary greatly in size. 

 Less abundant than the next, and I believe not found in the southern 



part of the kingdom : it appears to be plentiful near Newcastle-on- 



Tyne, as I am informed by Mr. Wailes, who first kindly supplied me 



with specimens; and also taken in the south of Scotland, about the 



end of June, 



