88 MODERN CLASSIFICATION OF INSECTS. 
alone, is as completely artificial as any arrangement resting upon any 
other single character. Thus the Eumenides and Mutillariz amongst 
the Parasitica are strictly raptatorial ; and, if the parasitic Psithyrus, 
&c., be admitted into the A&dificatoria, there is no ground for excluding 
the Nomadini. In this respect the views of Dahlbom are not so 
precise as those of Saint Fargeau, which are based, not only upon the 
natural habits but also upon the precise structure of those individual 
organs which are employed in performing such habits. 
Dr. Theodore Hartig, in a memoir published in Wregmann’s Archiv. 
1837, No. 2., and in his Die Aderflugler Deutchslands, has proposed 
an arrangement founded upon the external characters of the imago, 
and originating in a dichotomy, nearly agreeing with that of La- 
treille, well characterised by the structure of the trochanters, a pe- 
culiarity not previously adopted for this purpose. 
tibiis anticis spinis apicalibus H. Phyllophaga. 
Hymenoptera : 
) P abdomine duabus = es 
Diiree sonnato } tibiis anticis spina apicali | 
(Trochanteribus 3 Aree Sack ees H. Xylophaga. 
DERI TS) abdomine vel sessili vel petiolato —- - H, Parasitica. 
a emeuoptera Tarsorum postic. articul. 1 mus. simplex H. Rapientia. 
WhO MeeeEg Tars. post. articul. 1 mus. plerumque 
(Trochanteribus or Ee ee ; saat 4 Hi. Anthophila. 
; . : dilatatus - - - - 
inarticulatis) 
The Phyllophaga comprises the family of the saw-flies ; the Xylophaga 
that of the Uroceride ; the Parasitica, those of the Evaniidz, Ichneu- 
monide, Chalcididee, Proctotrupidaee and Cynipidee?; the Rapientia 
consists of the Sand-wasps, Wasps, Ants, and Chrysidide; and he 
Anthophila, the solitary, social, and parasite Bees. 

The TEREBRANTIA, or first general and aberrant section of the 
Hymenoptera, is distinguished by having the posterior trochanters 
2-jointed, and the abdomen in the females furnished with a lamellate 
or filiform, auger-like, and generally more or less exserted instrument, 
employed for the purpose of depositing the eggs in the various bodies 
destined for their reception. This instrument is connected with glands 
which do not secrete a highly concentrated poison, although it is 
evident that, in some species (as the Gall-flies, and some Tenthre- 
dinide ), the act of oviposition is accompanied by the emission of an 
irritating and analogous fluid.* The antenne are very variable in the 
* 'The Ichneumonide, when alarmed, endeavour to use the ovipositor as an organ 
of defence, and certainly emit a fluid. (See E. W. Lewis, on Pimpla stereorator ; 
and my additional observations, Mag. Nat. Hist. vol. vi. p. 414.) 
