8o Cameron, Hymenoptera Orientalia. 



Chaoilta, gen. nov. 



Head large, nearly as long as broad ; largely developed 

 behind the eyes ; the front not depressed ; immediately 

 beneath and between the antennae is a large obliquely pro- 

 jecting, somewhat semicircular, plate with raised margins ; 

 between the antennae, and extending half way into the 

 middle of the projection, where it is obliquely narrowed, is a 

 large flattened plate. Prothorax above bilobate, the basal 

 lobe the larger, and roundly and deeply incised in the 

 middle. Petiole broad ; the sides depressed ; the second 

 segment is triangularly keeled down the middle at the 

 base ; on the sides of the second and third segments at 

 the base are oblique depressions ; the securiform articula- 

 tion is very deep in the middle, where it is longitudinally 

 striated. The presternum is widely and deeply furrowed, 

 the furrow triangularly widened at the apex ; the meso- 

 sternum is more narrowly furrowed. The second cubital 

 cellule is large, as long as the third, and twice the length 

 of the first ; the recurrent nervure is received shortly in 

 front of the first transverse cubital; the probrachial nervure 

 is interstitial. The antennae originate from stout tuber- 

 cles; the scape stout, dilated before the apex into a tooth; 

 the third joint is slightly larger than the fourth. Mandi- 

 bles thick, with one blunt tooth at the apex. Eyes small, 

 oval, placed on the top of the head and widely separated 

 from the base of the mandibles. Legs short and thick; 

 the hinder coxae large, broad ; the hinder femora not much 

 more than one half of the length of the tibiae. 



The oblique depressions on the abdomen would refer 

 this species to Foerster's genus Ipiaulax. The head is much 

 larger and more cubital than usual. The plate and keel 

 on the front are very noteworthy, although we find a spine 

 there in some neotropical species, ^.^., in Ipiaulax nigriceps 

 Brulle. 



