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HARDWICKE'S SCIENCE-GOSSIT. 



with grey hairs. Its shape is similar, but it is 

 smaller, varying from \ inch to S inch in length. It 

 is rather a " horrid " creature, having the strength 

 and fierceness of A. crabroniformis without its 

 beauty. Its antennae and maxillary palpi are black, 

 and are furnished with long black hairs. The veins 

 of the wings are black, and the membrane trans- 

 parent and colourless, except along the hind border, 



Fig. 85. Asilus crabroniformis, female, x 2 diam. 



where each areolet is slightly shaded with grey as 

 in A. crabroniformis. A. cestivus chooses the same 

 kind of localities as the previous species, but is 



Fig. 86. Foot of Asilus crahroniformis, x 40 diam. 



said to be less frequent : we, however, have found 

 it in larger numbers, especially on the Mendip 

 Hills. 



There are several other species, none of them at 

 all common. One, which is now and then found in 

 company with A. eestivus, and may be confounded 

 with it, is called A. cristatus. It is somewhat simi- 

 lar in colour, but browner; also shorter, thicker, 

 and perhaps one may say uglier. The feature which 

 distinguishes it from all the other species, and to 

 which its name refers, is that the thorax is covered 

 with long hair from front to back, whereas 

 in the other species the bristles are on the 

 hind part only. The wings are different, 

 being smaller in proportion, much weaker, of 

 a faint brown tinge, and very transparent, 

 with light brown veins. .Fig. 87 is a drawing 

 of one. 



It will be seen from the mouth of A. 

 cestivus (fig. 88) that the mouths of the 

 Asllidce are very different from those of the 

 other flies which we have described ; indeed 

 they have no parallel among our other 

 diptera. Their chief peculiarities are an ex- 

 tremely large lingua or tongue (/, fig. 88), 

 and a curious metamorphosis of the labium 

 or lower lip (la, fig. 88) into an organ which 

 strongly reminds one of the labium of a 

 hemipterous insect, .even to its possessing two 

 little pads of hairs at the tip, one on each side, 

 which are commonly called "organs of taste" 

 in bugs. These pads of hairs are the sole repre- 

 sentatives of the lobes, which in all other flies 

 have the wonderful capillary channels on their 



Fig. 87. Wing of Asilus cristatus, x 7 diam. Names of 

 veins: co, costal; sc, sub-costal; m, mediastinal; r, radial; 

 cu cu, cubital ; pr pr, praebrachial (the end part is sometimes 

 called "sub-apical"); em, externo-medial (two veins); 

 po po, postbrachial ; an, anal ; d, the discoidal areolet ; axl, 

 axillary lobe; at, alula. 



inner surfaces. The lingua is triangular, like the 

 modern bayonet, having one edge downwards. The 

 other two edges are each furnished with a row 

 of stiff hairs, which are set in a backward 

 direction. It ends in a sharp, firm point. The 

 labrum (Ibr) is short, and not unlike the labrum of 

 a hemipteron. The maxilla; are long, and much 

 stouter than is usual among diptera, but, except 

 for this, they and their palpi are of the ordinary 

 dipterous type, and not at all like the corresponding 

 organs in the mouth of a bug. The mouths of the 

 other Asllidce are formed on the same pattern, but 

 of course they have generic and specific differences. 

 But the resemblances are greater than the differ- 

 ences, and the general form is so striking that by the 



