INTEODUCTION. 



Fig. 13. 

 Hylotoma, sp. 



II. Suborder PETIOLATA. 



Median segment (1st true abdominal segment) completely amal- 

 gamated with the thorax ; joint between the 

 thorax (iucluding the median segment) and the 

 abdomen slender, highly mobile. 



A good representative form belonging to ilie 

 Suborder Sessihvenires is shown at fig. 13. 

 This is an undeseribed species, from Sikhim, of 

 the genus Hylotoma belonging to the family 

 Tentkrediaidcc or Sawflies. 



The Suborder Petiolaia, containing by far the 

 larger number of the famihes in the Order, can 

 be subdivided into the 



(1) Paeasitica. — Trochanters of the legs in two portions with 

 an articulation between : female furnished wdth an ovipositor. 



(2) AcuLEATA. — Trochanters undivided ; female furnished with 

 a sting. 



The character derived from the trochanters is liable to exceptions. 

 Some of the Jchneumonidce, which belong to the division Paeasitica, 

 have undivided trochanters ; while on the other hand some of the 

 Sphegidce {e. g., the genus Nysson), true aculeates, are markedly 

 ditrochous. 



The wing-neuration in the IchneumonidcB, however, is generally 

 so marked that, ^vith a little care, confusion between the forms in 

 the different divisions can be avoided. 



Fig. \^.—Ichnnimon s^.?, J. \. 



Fig. 15. — Bracon decepfor, Sm., J , 



Figures 14 and 15 show representative Indian examples of the 

 Parasitica belonging to the families Ichneumonidce and Braconidiv. 



