168 SPILOMENA TROGLODYTES. 



serted on each side of the base of the elypeus ; labrum con- 

 cealed ; mandibles simple and arcuate (in the males, bidentate 

 at the apex). Thorax ovate ; the collar transverse ; the scu- 

 tellnm transverse ; the metathorax elongate and truncated ; the 

 anterior wings with the stigma large and ovate, with one mar- 

 ginal and two submarginal cells, the first submarginal cell nearly 

 twice as large as the second, which is quadrate ; the recurrent 

 nervure unites with the first transver so-cubital nervure; legs 

 simple. Abdomen subsessile, ovate-conic. 



1. Spilomena troglodytes. 

 S. niger ; pedibus piceis, tarsis posticis ferrugineis. 



Stigmus troglodytes, Van d. land. Obs. ii. 74. 2. 



St. Farg. Hym. iii. 99. 2. 

 Celia troglodytes, Shuck. Foss. Hym. 182. 1. 



Dahlb. Hym. Europ. i. 238. 139. 

 Spilomena troglodytes, JVesm. Hym. Foss. Belg. 123. I. 



Female. Length \\ line.— Black and shining; the scape and 

 basal joint of the flagellum pale ferruginous ; these are some- 

 times black ; a carina runs up the middle of the face from the 

 base of the elypeus, halfway to the vertex, where it becomes 

 an impressed "line, which extends to the anterior ocellus. 

 Thorax very delicately punctured; the collar longitudinally 

 striated; the scutellum quadrate; the superior surface of the 

 metathorax enclosed by a ridge round its margins; the en- 

 closure with two abbreviated longitudinal carina; in the centre, 

 the space between them transversely striated ; the wings hya- 

 line and iridescent, the stigma very large and black ; the ante- 

 rior tibiae, the apex of the intermediate pair, and all the tarsi, 

 ferruginous. Abdomen smooth and shining. 



Male. Length If line. — Differs from the female in having the 

 elypeus very much produced ; the elypeus, a spot on each side, 

 the mandibles, scape, and basal joint of the flagellum, yellow ; 

 the legs usually pale rufo-testaceous, with the posterior femora 

 fuscous. 



This insect is only occasionally captured, usually by sweeping 

 herbage ; it is found about London, and appears to be pretty 

 generally distributed. I once took several specimens entering 

 burrows" in a bank of very fine hard white sand, at Charlton, 

 Kent. 





