HYMENOPTERA. 
162 
retrusible ovipositor and single trochanter, the former with three to 
five visible ventral segments and an ovipositor, the latter with the 
abdomen of more than five visible ventral segments and a sting. 
Th eAculeata again fall into four series, the Anthophila with plumose 
hairs and dilated hind tarsi, the Diploptera with forewing longitudinally 
folded in repose, the Heterogyna with the basal one or two segments 
formed into nodes, and the Fossores without any of these characters. 
The classification of the order falls as in the following table :— 
Sessiliventres. 
(Cephidae). 
(Phytophaga). 
Siricidee. 
Tenthredinidae. 
Petiolata. Parasitica. 
Cynipidae. 
Proctotrypidae. 
Chalcidae. 
Dryinidae. 
Ichneumonidae. 
Braconidae. 
Stephanidae. 
(Megalyridae). 
Evaniidae. 
(Pelecinidae). 
Trigonalidae. 
Tubulifera. 
Chrysidae. 
Aculeata Fossores. 
Mutillidae. 
Thynnidae. 
Scoliidae. 
(Sapygidse). 
Pompilidae. 
Sphegidae. 
Diploptera. 
Eumenidae. 
Yespidae. 
(Masaridae). 
Anthophila. 
Colletidae. 
Apidae. 
Heterogyna. 
Formicidas, 
