94 PROCEEDINGS ENTOMOLOGICAL SOCIETY 



in the adult is equally inexplicable. This is rendered all the 

 more difficult to understand by the fact that in the prepupa the 

 ovipositor is coiled as it is in the adult, while in the pupa it 

 forms a simple loop in the thorax. 



In the male the abdomen is composed largely of eight large 

 visible tergites and nine sternites (the first being a small plate 

 concealed under the coxae) . Lying between the apices of the 8th 

 tergite and 9th sternite are two small plates connected by weakly 

 chitinized tissue with the 8th tergite ; the exact nature of these is 

 not clear; but apparently the connecting tissue is the fused 9th 

 and 10th tergites and the plates themselves are the cerci. The 

 10th sternite is apparently fused with the large ninth and the 

 appendages which make up the genitalia do not materially 

 change the appearance of the 8th and 9th sternites. 



Larval characters: The larva of only one species is known and 

 what characters are known will be found in the above description 

 of the larva of Oryssus. 



Key to suborders of Hymenopiera. 



Adults and pupae 



Larva 



1. The first abdominal segment so consolidated with the thorax as to be 



a part of the second division of the body, the posterior part of which 

 bears a spiracle; the separation between the first (propodeum) and 

 second abdominal segments marked by a distinct socket form articu- 

 lation; in short the abdomen is divided into two parts, propodeum and 



gaster. . Clistogastra Konow. 



- The first adbominal segment not forming a part of the second divi- 

 sion of the body; the first (basal plates or propodeum) and second 

 abdominal segments united by their entire width and not separated 

 by a socklet like articulation; in short the abdomen is not divided 

 into two parts 



2. Metapostnotum wanting; antennae inserted much below the lower 



margin of the eye; wings with two cubital cells and with only one 

 recurrent vein; ovipositor concealed within the body and extending 

 anteriorly so it is coiled in the mesothorax. 



Idiogastra Rohwer and Cushman. 



Metapostnotum present; antennae inserted above lower margin of 

 eye; wings with more than two cubital cells and with two recurrent 

 veins; ovipositor not concealed or extending anteriorly into the 

 thorax. Chalaslogastra Konow. 



3. Mouthpart^ more or less complex, maxillary and labial palpi distinctly 



jointed; antennae usually jointed . .ChalaStogastra. 



- Mouthparts much reduced, palpi, if present soft and papilla-like; 

 antennae like palpi; ocelli wanting 



