1 8a ORDER V. Sirex, 



thofe infects, however, differ very much in their 

 external appearance, formation, and manners ; 

 the abdomen of the Sirex is as broad as the 

 thorax, and clofely connected with, or joined to> 

 that part : the abdomen of the Ichneumon, on 

 the contrary, is either joined to the thorax by a 

 petiolum or flalk, or grows much larger to- 

 wards its extremity than at its bafe •, the 

 fling of the female Ichneumon terminates 

 the abdomen, and is of a cylindrical form ; 

 that of the female Sirex projects from the 

 under fide of the abdomen, is denta- 

 ted like a faw, and the abdomen itfelf is ter- 

 minated by a kind of horn or fpine. The fe- 

 male of the Ichneumon lays her eggs in the bo- 

 dies of other infects (which (he pierces for that 

 purpofe with her fling) and particularly in the bo- 

 dies of caterpillars of Lepidopterous infects, upon 

 which the lame feed, and where they remain 

 till prepared for the chryfalis ftate ; the female 

 Sirex lays her eggs in the interior of decayed 

 trees ; the larva mod probably feeds upon the 

 wood, and always undergoes its lad metamor- 

 phofis in the place where it had lived while in 

 the caterpillar ftate. From all thefe circum- 

 flances, we may I prefume fafely conclude, that 

 the Sirex differs generically from the Ich- 

 neumon. 



Geoffroy 



