SPHEGIDJE. 17d 



thorax together, subpetiolate, cylindrical, abruptly tapering at 

 apex. Head and thorax black, covered with a dense hoary silvery 

 pile, particularly dense ou the clypeus, on the apex of the median 

 segment, and legs ; abdomen pale red, the apical segment fuscous ; 

 wings hyaline and iridescent, the fore wing fuscous at apex, 

 the 1st recurrent nervure received just before the middle, and 

 the 2nd recurrent nervure close to the apex of the 2ud cubital 

 cell ; nerviu'es and tegulse testaceous brown. 



Hah. Barrackpore, Bengal ; Ahmedabad, Western India. 

 2 . Lem/th 9 ; e^ty. 17 mm. d" unknown. Type in collection 

 Rothney. 



Family SPHEGID^. 



The pronotum transverse, its lateral angles not prolonged back 

 to the base of the wiugs. 



The above is the sole constant character that separates this 

 rather heterogeneous family from the other families of the Fossorial 

 Hymenoptera. 



In a limited fauna as that of G-reat Britain, for instance, it is 

 possible to divide the Fossores into fairly well-marked groups, 

 which can be conveniently regarded as forming families or sub- 

 families ; but all such limitations break down when exotic species 

 are taken into consideration. It is therefore now generally held 

 that the burrowing wasps with short prothoraces form only one 

 family, containing genera, many of which have a tendency to form 

 natural groups, while others stand more or less isolated. 



Key to the Genera. 



A . Fore wing with one cubital cell. 



a. Cubital cell confluent with 2nd discoidal 



cell OXYBELUS, p. 314. 



b. Cubital cell not confluent with 2nd discoidal 



cell Crabro, p. 321. 



B. Fore wing with two or three cubital cells. 



a. Abdomen pseudosessile, or if petiolate, petiole 

 formed by the narrowing of both ventral and 

 dorsal plates of first segment. 

 a'. Radial cell of fore wing appendiculate. 

 «^. Prothorax very long, with posterior 

 portion raised in the middle, leaving 

 sides beneath narrowly projecting .... Ampulex, p. 253. 

 P. Prothorax not so raised, pronotum short 

 and transverse. 

 a^. Mandibles incised on their outermargins. 

 a^. Fore wing with three cubital cells. 

 a'. Posterior femora with a hook or 



spine or tubercle at base Pri\GETiA, p. 210. 



n2 



