624 ASILID^ 



Palaearctic Asiatic) genus Ommatius and its allies ; in all the British species the style 

 is slender and has only a very short indistinct basal joint. 



Thorax strong, rather contracted forwards (which causes a contrast with the wide 

 short head) and almost always with certain well defined stripes and markings, and 

 (except in some species of Malfophom) -with strong bristles of which the 

 prsesutural, supra-alar, postalar, and dorso-central are well defined, and of which 

 further details are given in the characters of the comprehensive genus Asilus. 

 Pleurae rarely with conspicuous pubescence except on the metapleurae and hypo- 

 Dleurse, and on those the metapleural and hypopleural fans are composed of either 

 ong bristly hairs or even strong bristles. Scutellum with long upturned marginal 

 gristles. 



Abdomen usually long and in European species narrow, rarely flattened broad 

 and bare on the disc {Ci-aspedia), composed of eight segments without the genitalia 

 though the eighth segment may often be very short or even quite concealed, and in 

 the female the end segments of the abdomen (even occasionally beginning with the 

 sixth segment) may appear to form part of the ovipositor. Genitalia of the male 

 conspicuous and always conforming to one type though varying very much in 

 details ; there are a pair of lateral upper lamellae which end by forming a forceps, 

 and beneath them are the usually much shorter under lamellae ; female ovipositor 

 long and often compressed laterally, also composed of upper and lower parts and 

 with a pair of terminal lamellae, though these parts are not so conspicuously 

 separated as in the male • in several genera (allied to Proctacanthus) the ovij^ositor 

 ends with a circlet of snort stubby spines, which seems to show affinity to the 

 Therevidcie and Mydaidce. Pubescence and chjetotaxy somewhat variable, but with- 

 out bristles except when the pra^hindmarginal ciliation (which crosses each segment) 

 becomes so strong as to form bristles either only near the sides or almost all across, 

 and this band of ciliation generally precedes a quite bare hindmarginal hem on 

 especially the second and usually on the succeeding segments. 



Legs strong, seldom very long or very short. Pubescence varying in amount, 

 but strong bristles always occur in circlets at the tip of all the tibiae and of the 

 four basal joints of all the tarsi, and (though the traces may sometimes be faint) in 

 sparse rows on the tibiae, while other strong bristles usually occur ; femora commonly 

 with strong spines on the underside, but not unfrequently (especially the front 

 pair) unarmed. Pulvilli two, long and narrow ; claws long and strong but otherwise 

 normal. 



Wings long ; subcostal vein very long, extended almost to the wing- tip and joined 

 just before its end by the radial vein so that the marginal cell is always distinctly 

 closed. Venation conforming very much to one type and but little modified in the 

 British species, the cubital fork being always a long simple one with a someAvhat 

 1 jell-mouthed opening, while the fourth postei'ior and anal cells are always closed ; 

 in some genera (of which there are a few Palaearctic species) the upper branch of the 

 cubital fork throws back from near its base a recurrent veinlet (fig. 350), which may 

 be short or may extend quite back to the radial vein and thereby cause the presence 

 of three submarginal cells (figs. 346-8), and in some specimens of Promackus leoninus 

 this recurrent vein (or veinlet) shows a tendency to continue onwards toward the 

 wing-base even after its junction with the radial vein; the cubital vein is longer 

 between its origin and the discal cross-vein than the praefurca, and consequently the 

 discal cross-vein is placed after the basal third of the discal cell ; the opening of the 

 cubital fork is not always bell-mouthed • the small cross-vein is often punctiform 

 and on rare occasions the upper branch oi the postical fork forms for a very short 

 distance the lower margin of the discal cell ; the first posterior cell is sometimes 

 narrowed or even closed ; veins strong ; wing-membrane ribbed or wrinkled though 

 occasionally only faintly wrinkled. Alulaj well developed, even if sometimes rather 

 small. Squamae with only the alar pair developed, not large but well defined 

 and with a thickened margin on which is a delicate but fairly abundant fringe ; 

 thoracal pair only represented by a bare frenum. Halteres normal. 



Loew in 1848 divided the Asilinm into three "super-genera" as 

 follows : — 



1. Polyi^honius nov. Gen. Antennal style bare, thick, and extremely 

 short, with its first joint much longer than the second ; middle femora 



