92 



DINETUS. 



tured ; the front with an impressed line running from the an- 

 terior stemma to the insertion of the antennae. Thorax : an 

 impressed line in the middle of the collar continued on the 

 mesothorax faintly, nearly to the middle of its disk ; the meta- 

 thorax black, and having a central longitudinal impressed line, 

 which runs into a deep fossulet at the verge of the truncation, 

 which is coarsely striated transversely, the base of the meta- 

 thorax with some oblique irregular striae; the wings fusco- 

 hyaline, with their apical margins clouded. Abdomen shining, 

 very delicately punctured, the apical margins of the first and 

 second segments slightly depressed. 



Male. Length 2-2^ lines. Differs from the female only in 

 having a little silvery pubescence on the face, and the meta- 

 thorax with cinereous scattered pubescence ; the thorax some- 

 times more brassy. 



This insect I at first thought might be the M. spurius of 

 Dahlbom, but on more mature consideration I think it is cer- 

 tainly undescribed : the conspicuous brassy tinge on the head and 

 thorax at once distinguishes it. Independent of the difference of 

 colour, it differs from M. bicolor in having the metathorax pro- 

 portionably longer, and it is also a larger insect : all Dahlbom's 

 black species, M. niger, concolor, and spurius, are even smaller 

 than M. bicolor. I discovered this species in 1856, in the begin- 

 ning of August, on the sand-hills at Sandown near Deal ; the 

 following season I again met with it in the same locality, having 

 taken a dozen examples, all agreeing in size and colouring : I 

 may add, that I do not consider size alone of much specific value. 



Genus 3. DINETUS. 



Crabro, pt., Fabr. Ent. Syst. ii. 293 (1793). 

 Sphex, pt., Fabr. Ent. Syst. ii. 198 (1793). 

 Pompilus, pt., Fabr. Syst. Piez. 187 (1804). 

 Larra, pt., Latr. Hist. Nat. Ins. xiii. 206 (1805). 

 Dinetus, Jurine, Hym. 209 (1807). 



Head transverse, as wide as the thorax ; eyes ovate, conver- 

 ging at the vertex ; stemmata in a triangle ; antennae filiform 

 in the female, the scape incrassate, with a deep lateral impres- 

 sion ; the apical joints convolute and covered with silvery pubes- 

 cence; the clypeus convex, transverse, and rounded in front; 

 mandibles tridentate, emarginate on the exterior towards their 

 base. Thorax ovate ; the collar and scutellum transverse ; the 



