548 



HEMIPTEEA. 



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

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

 Neuropterous families above them. A comparison with the 

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

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

 panied by a general degradation of the bod}-. Though the spe- 

 cies are winged, j^ct the wings are partiall}^ aborted ; the}' are 

 long, narrow, linear, both pairs of equal size, as in the tj-pical 

 Neuroptera, and by the frequent absence of any veins, either 

 longitudinal or transverse, and the long delicate silk}- fringe, 

 remind us striking!}^ of some minute degraded hj-menopterous 

 Proctrotrypidce, Pteratomus (Plate 3, fig. 8), for example. 

 The mandibles are bristle-like ; the maxillog are flat, triangular, 

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

 /^ present, but verj'- short, 



w////////^^'^- ^^'^ composed of but two 

 ^:;^^ or three joints 



Chiefly on account of 

 these characters these in- 

 sects were i^laced in a dis- 

 tinct order, termed Tliy- 

 sanoptera by Haliday, and 

 by many recent authors 

 rig. 552, the}' have been widely 



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 which Geoft'ro}^ referred them. To us they 

 appear to be, as it were, degraded L3'gffiids, and to preserve 

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

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

 have both compound and simple ej'es, the latter thi'ee in 

 number. 



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

 joints. In some species the fore wings are comparative^ 

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

 into broadish elj^tra, ciliated only behind, and with longitudinal 

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

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



