122 HYMENOPTERA ACULEATA. 



metanotal spine are peculiar to this genus. Kohlj in 

 1884, Term. Fiiz. viii., enumerates the then known species, 

 making a total of ninety-two, of which sixty-seven are 

 Palsearctic — of these we have four species in Britain. The 

 species provision their nests with Diptera. 



(C) 1. Abdomen not clothed with silvery hairs. 



(3) 2. Mandibles black uniglumis. 



(2) 3. Mandibles flavous or testaceous. 



(5) 4. Propodeal spine entire at the apes, more 



or less pointed mandibulaiiis. 



(4) 5. Propodeal spine deeply emarginate at the 



apex NiGRiPES. 



(1) 6. Abdomen clothed with bright silvery hairs muchonatus. 



0. uniglumis, Linn. — Head, including the mandibles, 

 and thorax, black, rugosely punctured, forehead rather 

 densely clothed with erect brownish-grey hairs except on 

 the vertex, face with bright silvery hairs apically, clypeus 

 in the c? tridentate, the central tooth being the apex of a 

 strongly-raised central carina ; between these teeth the 

 surface is densely clothed with pale hairs; in the ? the 

 clypeus has a longitudinal tubercle at the base, and two 

 slightly produced points on its anterior margin, antenna) 

 fulvous beneath ; thorax with the tubercles in the ? flavous, 

 the tegula3 in both sexes testaceous, scutellum with a cen- 

 tral carina, metanotum on each side with a pale, wing-like 

 appendage, propodeum very largely clathrate, with a short, 

 slightly curved basal spine, which is rouuded at the apex ; 

 abdomen black, clothed with short grey hairs, dull in the 

 (J, shining in the ? , in the former generally with a pale 

 lateral spot on the two basal segments only, in the latter with 

 spots on all the segments except the sixth, these are of an 

 ivory white, puncturation exceedingly fine and close, that 

 of the basal segment rather less fine than of the others ; 

 legs black, with the tibiae and tarsi in both sexes, and the 

 apex of the femora in the ? fulvous ; tibiae sti'ongly 

 spinose, 



L. 6-9 mm. 



