266 CLASSIFICATION OF INSECTS. 



Hemiptera. The metamorphosis of the Hemiptera is 

 isomorphous, resembling that of the Orthoptera. Imago 

 with the parts of the mouth only partially developed ; the 

 mandibles are without any horizontal motion, but elongate 

 and slender, and, together with the maxillae and tongue, 

 are inclosed in a sticker, which is composed of the labium 

 principally, but protected above by the labrum ; this sucker 

 is bent beneath the head and breast, excepting when in 

 use, when it is usually thrust perpendicularly into the rind 

 of vegetables or skin of animals, to extract the sap or blood, 

 which, in this class, constitute the food ; the feelers are 

 obsolete. 



Plant-bugs or Cimicites. Antennas elongate, conspicuous, 

 four- or five-jointed ; fore wings with the basal portion co- 

 riaceous, the apical portions which cross each other mem- 

 branaceous ; the legs are of uniform structure, not formed 

 for leaping ; the tarsi are three-jointed : terrestrial ; run 

 fast ; fly rapidly, but not far at a time ; feed generally on 

 the sap of vegetables, sometimes on other insects, and oc- 

 casionally, but apparently unnaturally, on the blood of 

 vertebrate animals. Cimex, Pentatoma, Acantkosoma, re- 

 presented at page 199, (fig. 6). 



Water-bugs or Hydrometrites. Antennas elongate, con- 

 spicuous, four- or five-jointed; fore wings co- 

 riaceous, of uniform substance ; hind wings 

 membranaceous ; all the wings linear ; legs 

 of uniform structure, very long, not formed 

 for leaping ; tarsi three-jointed; body elon- 

 gate, linear : aquatic, running with ease and 

 Hydrometra. rapidity on the surface of water. Hy drome- 

 tra, Gerris, Velia. 



Water-scorpions or Nepites. Antennas very short, con- 

 cealed below the head ; fore wings coriaceous, crossed at 

 the apex; hind wings membranaceous, completely concealed 



