174 PASSALCECUS CORNIGERA. 



Diodontus gracilis, Curtis, Brit. Ent. xi. 496. 

 Passaloecus gracilis, Shuck. Foss. Hym. 190. 2. 



Dahlb. Hym. Europ. 242. 142. 



Wesm. Hym. Foss. Belg. 121. 1. 



Female. Length 2| lines. Black and shining ; the head deli- 

 cately punctured; the clypeus marginate and obsoletely tri- 

 dentate ; the scape in front, and a broad stripe on the mandibles, 

 yellow ; palpi pale. Thorax : the mesothorax closely punctured ; 

 the scutellum very delicately so ; the metathorax rugose and 

 shining ; the wings hyaline and iridescent ; the tegulae piceous ; 

 the anterior tarsi, and the knees and tarsi of the intermediate pair, 

 pale ferruginous ; the base of the posterior tibiae pale yellow. 



The Male only differs in having the face silvery, and the pale 

 parts of the legs yellow. 



3. Passalcecus cornigera. 



P. atra ; corniculo inter antennas porrecto ( $ ), obsolete ( $ ). 



Passaloecus cornigera, Shuck. Foss. Hym. 191. 3. 

 Dahlb. Hym. Europ. i. 245. 145. 



Female. Length 2-3 lines. Black ; the head, and thorax on 

 the disk, very delicately punctured ; the metathorax coarsely 

 rugose; the abdomen smooth, shining, and impunctate. An 

 erect acute spine in the centre of the face, and an impressed 

 line above it, extending to the anterior stemma ; the clypeus 

 tridentate, the central tooth largest; the scape in front and 

 the tips of the mandibles rufescent ; sometimes only the base 

 and apex of the scape rufescent. Thorax : the epaulets of the 

 tegulae consute, a slight scratch parallel with their middle, and 

 a consute line on each side near the middle, extending from 

 the base to the apex, within which, at the base, there are two 

 slight, abbreviated, slightly elevated lines. The tubercles white ; 

 the wings hyaline and iridescent ; the tegulae rufo-testaceous ; 

 the anterior and intermediate tibiae and tarsi, the tips of their 

 femora, and the base of the posterior tibiae, fulvous ; the apex 

 of the posterior tibiae sometimes also fulvous ; a dark stain in 

 the middle of the intermediate tibiae. Abdomen : the margins of 

 the three basal segments slightly constricted. 



The Male has the spine on the face obsolete ; the clypeus with 

 a silvery pubescence ; those parts of the legs which are fulvous 

 in the female are luteous. 



This and the preceding species are plentiful in the London 

 district, and apparently widely distributed. 



