HO DIDINEIS. 



shining, an ovate white spot on the lateral margins of the 

 second segment, and another in the centre of the base of the 

 fifth. 



Tlie Male is usually rather smaller, and differs in having more 

 silvery pubescence on the face ; the antenna-, except the basal 

 joint, piceous beneath; the white spot, on the fifth segment 

 forming a band a little dilated in the middle, and the sixth with 

 a longitudinal white line in the centre ; the white markings on 

 the elypeus are sometimes wanting, as well as the spot on the 

 scutellum, and sometimes the spots on the sides of the second 

 segment, and the band on the fifth also ; in some examples 

 both the band am| line on the sixth are wanting. 



The prey of this insect has not been ascertained ; it is occa- 

 sionally found in hot sandy situations, where the female has 

 been observed burrowing. I have taken it on Hampstead Heath 

 in July and August; at Erith, and also at Deal, in September: 

 and at Lowestoft in July and August*. 



Genus 4. DIDI1TEIS. 



Pompilus, pt., Fabr. Ent. Syst. Supp. 2-19. 

 Alyson, Latr. Gen. Crust, et Ins. iv. 86. 

 Didineis, Wesm. Hym. Foss: Belg. 96. 



Head subrotund ; antennae filiform, inserted at the base of 

 the elypeus, the scape slightly bent ; the elypeus transverse, 

 convex, the anterior edge with a slight margin, which is triden- 

 tate in the female and edentate in the male ; the mandibles 

 tridentate, the teeth obtuse, the labrum concealed. Thorax 

 sublinear ; the collar transverse, quadrate, considerably narrow er 

 than the thorax ; the metathorax elongate, truncated posteriorly, 

 with a spine on each side near the vertex of the truncation ; 

 the anterior icings with one marginal and three submarginal 

 cells ; the marginal cell oblong ovate j the first submarginal cell 

 longer than the tico following, receiving the first recurrent 

 nervure at its apex; the second submarginal subfriangular and 

 pctiolated, receiving the second recurrent nervure at its apex ; 

 the legs slender, moderately long, the anterior tarsi having the 



* The Harpactus l&vis is, I believe, an Italian species, erroneously 

 included in the British list. 



