124 HYMENOPTERA ACULEATA. 



— Easily distinguished from either of the preceding by the 

 tine pointed propodeal spine, aad the glittering silvery 

 pubescence with which the entire insect is more or less 

 covered ; the spots on the abdomen are of a bright yellow, 

 they occur on the first five segments of both sexes, those 

 of the fourth and fifth in the ? being united so as to form 

 a transverse band ; tibiae and tarsi, and in the ? nearly 

 the whole of the femora, except of the anterior pair, yellowish 

 testaceous. 



L. 7-9 mm. 



Rare. Sandhills, Hayling Island. Bristol ; Liverpool ; 

 Deal; {Smith). Braunton, Devon ; (Dale). Cheshire, sand- 

 hills; {B. Cooke). 



CRABRO, Fab. 



Differs from all the other genera of the Sphegidse, except 

 Entomognathus , which may be known by its hairy eyes, iu 

 the neuration of the wings, the anterior pair having each 

 one marginal, one submarginal, and two discoidal cells, the 

 third indicated by very fine hyaline nervures; in the pos- 

 terior wings the median nerve is bent forward towards the 

 anterior nerve, meeting it about the middle of the front 

 margin ; the posterior nerve is quite short, and is united to 

 the median by a transverse nervure. In form and colora- 

 tion the species vary much, but as a rule the head is large 

 and the vertex sub-quadrate, the clypeus wide, and the 

 mandibles often inserted behind the anterior margin of the 

 eyes; eyes very large, approximate near the base of the 

 clypeus, being separated by the antennal cavities. The 

 position of the ocelli, and the shape of the antennce, which 

 in the sub-genera Clytochrysus, SoleniiiSj Crabro, and 

 Thyreus, are only twelve-jointed in the c?, are often useful 

 for specific characters. The propodeum has usually a well- 

 defined basal area ; the abdomen is oval or elliptic, some- 

 times petiolated, narrower in the <S than in the ? , ? with 

 a distinct pygidial area ; the armature of the c? is most 



