HEMIPTERA. 



97 



have linear bodies. The head, which forms nearly the third of the 

 •entire length, is furnished with two long antenncT, and armed with a 

 thin, hair-like beak. The legs are long, and of equal length. The 

 reader may have often seen the Hydrometra stagnorum walking by jerks 

 on the surface of the water (Fig. 74). The body and legs ^are of a fer- 

 ruginous colour, the hem elytra 



a dull brown, and the wings 



Fig 74. — Hydrometra stagnorum. 



hyaline, or glassy, and slightly 



blackish. Geoffroy says that it 



resembles a long needle, and 



calls it the Needle Bug. 



The HydrocoriscE, or "Water 



Bugs, have the antennae shorter 



than the head, or scarcely at- 

 taining to its length, and inserted and hidden under the eyes, which 



are in general of remarkable size. All these Hemiptera are aquatic 



and carnivorous. We will mention the two principal types, the Ncpce^ 



or Water Scorpions, and the NotonedcE^ or Boatmen. 



The Nepa cmerca (Fig. 75), which Geoffroy calls the Oval-bodied 



Water Scorpion, and which he also designates by 



the name of the Water Spider, is very common in 



the stagnant waters of ponds and ditches. Its body, 



oval, very flat, of an ashy colour, with red on the 



abdomen, is four-fifths of an inch long. The 



hemelytra are horizontal, coriaceous, and of a dirty 



grey colour. Its front legs, with short haunches, 



and very broad thighs, are terminated by strong 



pincers, which give to the insect a strong resem- 

 blance to the scorpion. It is by folding back the 



leg and the tarsus under the thigh, that the animal 



holds its prey, and sucks it with its rostrum or beak. 

 t This rostrum is composed of three joints, and 

 '! contains four pointed bristles. Two present on one 



side a sort of narrow sharp blade, and have teeth 



towards their base. Of the two others, the one» 



is a thin smooth needle, the other is provided with Fig. 75.— Ncpa cinerea. 



hairs directed backwards and forwards. 

 11 It is with this rostrum, which resembles a case of surgical instru- 

 ' ments, that the Nepa pierces and sucks little aquatic insects, not even 



sparing its own species. Its wound is painful to man, but not in the 



least dangerous. With its four hind legs the Nepa swims, but at a 



very slow pace. It generally drags itself along the bottom of the 



H 



