644 ASILIDt^ 



parts whicli appear the lightest when viewed from in front appear the darkest 

 when viewed from behind and vice versa ; as a rule the most definite markings are 

 seen when the specimen is viewed from behind ; sloping lights also give different 

 patterns of colour. Each segment has a skin-like bare hem on its hindmargin which 

 is the membrane uniting it with the next segment. 



Legs strong, and normally provided with strong bristles which are probably 

 useful in catching and holding prey. The tibiae always bear rows of bristles and 

 a circlet of bristles at the tip, while each of the four basal joints of the tarsi is pro- 

 vided with an apical circlet ; other bristles also occur on the basal joints of the tarsi 

 away from the tips, while the femora usually bear scattered bristles. Besides the 

 bristles there is often considerable long soft pubescence behind and beneath the 

 anterior femora and to a smaller extent on the hind femora. Another form of 

 clothing exists in the minute adpressed short usually whitish hairs which cover 

 almost all parts of the legs, and which may even modify the ground colour, and 

 dense orange or reddish felt covers considerable spaces on the inside of the front 

 and hind tibiae and on the soles of the tarsi. Some long thin postero-ventral bristles 

 always occur on the front tibiae. The bristles are by no means invariable in position 

 or colour, but yet in conjunction with the long bristly hairs they afford useful 

 specific characters. 



Wings usually conforming to one type of coloring, and only distinguished notably 

 amongst British species in Asilus crahroniformis and Pamponerus germanicus ; there 

 is however a peculiar but indistinctly margined grey clouding or gloominess on the 

 outer part of the wing which may afford specific distinctions, as its extent may vary 

 in its limitations to grey kernels in the cells or to its leaving the veins with hyaline 

 borders or to its greater connection between the posterior cells and the wingmargin. 

 The intensity of brownish coloring about the veins may vary within the limits of 

 individual species according to the age of the specimen, and the general tint of the 

 wing may vary according to the colour and nature of the earth upon which the 

 specimens exist. Small distinctions may occur in the venation, in the shape of the 

 cubital fork, and especially in the presence or absence of the small cross-vein, but 

 this latter character must always be accepted with doubt in this genus because 

 individual specimens may differ, as in all cases the cross-vein if present is very short 

 and if absent the upper branch of the postical vein only touches the lower margin of 

 the discal cell for a short space. 



The characters now given for the extended genus are partly original 

 but mainly adopted from Loew's article in the Linnma Entomologica. 



2. ASILUS (sensu strictissimo). 



Asilus Linnc, Syst. Nat., Ed. x., T. 1., 605 (1758) pt. 



Asilus {sensu strictissimo) Loew, Linn. Ent., iv., 132 (1849). . 



Large or very large brightly colored flies ; wings orange 

 with brownish markings at the tip and spots or markings 

 near the hindmargin. 



Face broad ; facial knob forming only a rounded projection, and the unicolorous 

 bristly face-beard leaving the vipper half of the face bare ; face-beard not connected 

 with the jowl-beard ; festoon composed of only short hardly curved bristles. 

 Proboscis long and pointed. Antennae mth only short inconspicuous bristles on 

 the two basal joints. 



Thorax rather flat, with the usual dark stripes rather faintly defined. Pubescence 

 composed of minute bristles all over the disc except on a narrow middle line, and 

 these minute bristles are strongly contrasted with the strong bristles. Bristles not 

 long or strong but conspicuous ; 2-3 pr£esutural, 3-4 supra-alar or almost intra-alar, 

 3-5 postalar, 4-6 dorso-central all postsutural ; metapleural fan composed of about 

 six long bristles or bristly hairs, and the hypopleural fan of about four stift' hairs. 

 Scutellum with short bristly pubescence on the disc except down a middle stripe, 

 and with 2-6 curved marginal bristles which are neither stout nor strong. 



