262 SPHEGID.'E. 



Dark metallic blue ; the head, thorax, and abdomen covered with 

 a thin hoary pubescence, long and somewhat stiff on the clypeus ; 

 antennae and the tarsi piceous black ; wings hyaline, nervures and 

 tegulae piceous. 



(^ very similar, more slenderly made, the lateral tubercles on the 

 pronotum more prominent, and the scutellum more or less gibbous. 



Hah. Throughout India, Burma, and Tenasserim, but not 

 common. $ . Length 15-21 ; exy. 26-30 mm. 6 . Length 

 11-14 ; e.qh 20-24 mm. 



484. Trirhogma prisma tica. Smith, Jour. Linn. Soc. 1858, p. 99, c?; 

 Kohl, Ann. Katurhist. Hofinus. Wien, viii, 1893, p. 513. 



J . Closely allied to and resembling T. cferulea, Westw. ; differs 

 from the same sex in T. ccendea in the mandibles being white at 

 base, the antennje longer and more filiform, in the mesonotum 

 having two transverse carinse posteriorly, the space between 

 rugose, the scutellum with an elevated tubercle anteriorly, the 

 wings slightly fuscescent, the abdomen punctured and with violet 

 and purple tints in certain lights. 



Hah. Borneo; Tenasserim. S - Length 12-13; exp. 18 mm. 

 ^ unknown. 



Genus PSEN. 



Psen, Latr. Precis Caract. Gen, Ins. p. 122 (1793). 



Sphex, pt., Fabr. Ent. Syst. Suppl. p. 243 (1798). 



Pelopceus, pt., Fabr. Syst. Piez. p. 202 (1804). 



Trypoxylon, pt., Fabr. Syst. Piez. p. 182 (1804). 



Mi'mesa, pt., JDahlb. Hym. Fur. i, Tabl. Spheg. (1843). 



Mesopora, Wesm. Bull. Akad. Brux. xix, pt. i, p. 279 (1852). 



Type, P. ater, Panz. 

 Range. Both hemispheres. 



Head transverse, as wide as the thorax ; antennae inserted in 

 the middle or a little below the middle oi the face, the flagellum 



subclavate ; labrum concealed ; man- 

 dibles acute, the apex bideutate, the 

 inner tooth shorter than the outer ; 

 thorax very broad, subovate ; pro- 

 notum transverse. Wings broad, 

 ample ; fore wing with the radial 

 cell long, acuminate at apex ; three 

 cubital cells, measured on the cubital 

 nervure the 1st about one-fourth 

 longer than the 3rd, the second about 

 -pv -J, half the length of the 3rd ; the 2nd 



Psen jmkhS^imus, $. \. cubital cell narrowed towards the 



radial cell, receiving the 1st recurrent 

 nervure before the middle ; the 3rd cubital cell at apex abotit twice 

 as broad as it is at base, receiving the 2nd recurrent nervure near its 

 base. Abdomen very long, petiolate, the petiole about the length 

 of the remaining segments ; male with an upcurved spine at apex 

 of abdomen ; female posterior tibiae serrated in the Indian species. 



