548 



HEMIPTEEA. 



bears much the same relation to the Cor i sice as the lice do to 

 the Membranacei (Cimex), or Podura and Lepisma to the 

 Neuropterous families above them. A comparison with the 

 3fallophaga is still better, for in Thrips (Fig. 552) we find, 

 as in the last named group, free, biting mouth-parts, accom- 

 panied by a general degradation of the bodj". Though the spe- 

 cies are winged, yet the wings are partially aborted ; they are 

 long, narrow, linear, both pairs of equal size, as in the typical 

 Neuroptera, and b}'^ the frequent absence of any veins, either 

 longitudinal or transverse, and the long delicate silky fringe, 

 remind us strikingly of some minute degraded hymenopterous 

 Froctrotrypidai^ Pteratomus (Plate 3, fig. 8), for example. 

 The mandibles are bristle-lilve ; the maxillae are flat, triangular, 

 bearing two to three-jointed palpi, and the labial palpi are 

 f ,,,„„„ present, but ver}^ short, 



or three joints. 



Chiefly on account of 

 these characters these in- 

 sects were placed in a dis- 

 tinct order, termed Thy- 

 sanoptera by Haliday, and 

 by many recent authors 

 they have been widel}' 

 separated from what seem to us their nearest allies. Latreille, 

 however, recognized their affinities to the Homoptera, while 

 stating that in their free biting mouth-parts they resembled 

 the Orthoptera, to wliicli Geoftroy referred them. To us they 

 appear to be, as it were, degraded Lygaeids, and to preserve 

 the general form of that group, in the long liead, the stout, 

 thickened fore limbs, and the large, square prothorax. They 

 have both compound and simple eyes, the latter three in 

 iuimber. 



The antennae are long and slender, with from fiAe to nine 

 joints. In some species the fore wings are comparatively 

 well developed, or, as Haliday states, they are "transformed 

 into broadish elytra, ciliated only behind, and with longitudinal 

 and transverse nerves. In some species the wings are want- 

 ing, at least in the males." (Westwood.) "The abdomen is 



