British BraconidcB. 161 



sticticus, Fab., and Leiophron falcatus, Nees (which 

 Wesmael had regarded as Blaci) to another subgenus 

 Pygostolus, arranged under Leiophron. The step is to a 

 great extent justified by the transitional characters of the 

 two species, though they are unquestionably better 

 placed in the present group. Ruthe's paper on Blacus 

 contained in the Berl. ent. Zeit. for 1861, confirms 

 Wesmael's views as to the affinities of Pygostolus. 

 Haliday's Ganychorus must be abandoned, for reasons 

 which will shortly appear ; so also Gonioconnus, Forst. ; 

 there remain, then, the two following genera, easily 

 distinguished : — 



Prsediscoidal areolet petiolated, not touching the para- 

 stigma ; 1st joint of the flagellum shorter than the 

 2d . . . , . . . . . . . . . . i. Pygostolus. 



Prsediscoidal areolet not petiolated, touching the para- 

 stigma ; 1st joint of the flagellum almost always 

 longer than the 2d . . . . . . . . . . ii. Blacus, 



i. Pygostolus, Hal. 



Hal., Ent. Mag., ii., 459; Euthe, Berl. ent. Zeit., 

 1861, p. 157. 



Head transverse ; face subquadrate ; clypeus gibbous ; mandibles 

 projecting, armed with 2 unequal teeth ; maxillary palpi 5-, labial 

 4-jointed (at first sight 3-jointed, the penultimate joint being very 

 minute). Occiput margined on its lower edge only. Mesothorax 

 trilobate, with distinct sutures. Metathorax well-developed, regu- 

 larly convex, not areated. Recurrent nervure interstitial, or nearly 

 so ; cubital nervure springing from the praebrachial transverse. 



Of this very natural genus there are 3 known European species, 

 but only 2 have been found in the British Isles. Their ground 

 colour is testaceous, with a few blackish portions, which are 

 variable, but usually include the metathorax ; there exists also a 

 dusky variety of P. falcatus. Head somewhat narrower than the 

 thorax ; antennae longer than the body, setaceous rather than 

 filiform, 1st joint of the flagellum always a trifle shorter than the 

 2d ; lower tooth of the mandibles shorter than the upper one, and 

 more inclined inwards. Mesothorax gibbous, its lobes separated 

 by deep sutures. Furrow of the mesopleurse wide, shallow, faintly 

 rugose or crenate, and somewhat curved. Ante-scutellar fovea 

 wide and deep, geminated by a carina. Metathorax elongate, not 

 much depressed below the mesothorax, regularly convex, without 

 the horizontal and vertical portions seen in Blacus. Wings ample, 



