104 NATURAL HISTORY OF INSECTS. 



thin margin which sometimes projects over the head; the 

 abdomen has seven or eight segments ; the color is commonly 

 black or brown, and some kinds have the thorax margined 

 with red or yellow. Many of these Beetles are luminous, both 

 as larvae and as perfect insects. The Common Fire-fly (Fig. 

 263) belongs to this Family. 



CLASS II. HETEROMERA. 



The insects belonging to this Section have uniformly only four 

 joints in the posterior feet; upon the whole they are not very 

 injurious. They may be divided into three Tribes, as follows: 



TRIBE I Parasitic Beetles. In these insects the head is 

 as wide as the thorax, and attached to it by a visible neck ; 

 the body is rather soft, the wing-cases flexible and the anterior 

 coxae are contiguous. The two principal Families are as fol- 

 lows: 



BLISTER-BEETLES (Meloidae). These insects have the thorax 

 rounded at the sides; the abdomen is not distinctly pointed 

 behind; and the claws at the end of each foot are forked. 



The larvae are usually provided with six legs, and live in the 

 nests of Bees, or in the egg-masses of such Grasshoppers or 

 Locusts as deposit their eggs in the ground ; the perfect 

 insects feed upon the leaves or flowers of plants. 



The insects belonging to the genus Meloe are destitute of 

 hind wings. 



Several species belonging to the genera Lytta, Cantharis, 

 Epicauta, etc., posess a blistering (vesicating) property, and 

 to this group belongs the common Spanish-fly. The 

 Striped Blister-beetle (Fig. 19) and the Ash-colored Blister- 

 beetle (Fig. 86), belong to this Family. 



Fig. 264 . NOTOXUS-BEETLES (Anthicidse). These are 



small insects, a little over two lines long, with 

 filiform antenna?; the claws are not forked; 

 the thorax is sometimes prolonged in the 

 form of a horn (Fig. 264), which projects 

 over the head; the neck is usually slender, " 



