HYMENOPTERA : CLASSIFICATION. 387 



of the variations and causes of variations to which not only 

 these but other essential organs, as the ovipositor, legs, &c., 

 are subject : but I have advanced sufficient to prove that 

 this branch of the subject, which may, without hesitation, be 

 laid before the reader almost as an unopened field of inquiry, 

 possesses a very great degree of interest, sufficient to repay 

 the labour devoted to its elucidation. 



The following is the classification of this order given to 

 us by Latreille, to whom, indeed, we are greatly indebted for 

 our knowledge of these insects, which were especial favourites 

 with this celebrated author. 



Section I. Terebrantia : abdomen of the females fm'- 

 nished with a saw, or borer. 



Sub-sec. 1. Securiferaj abdomen sessile, furnished 

 with a saw; larvae with feet. Families, TenthredinidcB 

 (saw-flies), Siricidce. 

 Sub-sec. 2. Pupivora j abdomen pedunculated, fur- 

 nished with a borer ; larva3 without feet. Families, 

 Evaniidce, IchneumonidcE, Cynipidce, Chalcididce, 

 ProctotrupidcB, ClirysididcB. 

 Section II. Aculeata ; abdomen of the females (and 

 neuters) armed with a sting. 



Sub-sec. I. Heterogyna ; females or neuters wing- 

 less. Families, Formicidce (social) MutilUdce (soli- 

 tary). 

 Sub-sec. 2. Fossores J females winged, wings not 

 folded, basal joint of posterior tarsi simple. Fami- 

 lies, Scoliidce, Sapygidoe, Sphegidce, Bembecidce, 

 Larridce, Nyssonidce, Crabronidoe. 

 Sub-sec. 3. Diploptera j females (and neuters) winged, 



wings folded. Families, Masaridce, Vespidce. 

 Sub-sec. 4. Mellifera ; females (and neuters) winged, 

 wings not folded, posterior tarsi with the basal 

 joint large, and compressed into a pollinigerous 

 organ. Families, Andrenidce, Apidce. 



