ANNULOSA : INSECTA. 29 I 



or labium,with two jointed labial palpi. The four wings are 

 usually present, and the anterior pair are not adapted for flight, 

 but are hardened by chitine, so as to form protective cases (ely- 

 tra) for the posterior wings (fig. 119). The inner margins of the 

 elytra are generally straight, and when in contact they form a 

 longitudinal suture. The posterior wings are membranous, 

 and when not in use, are folded transversely beneath the 

 elytra. (Amongst deviations from this state of parts may be 

 mentioned the occasional absence or rudimentary condition 

 of the hinder wings, the soldering together of the elytra, the 

 soft and yielding condition of the elytra, or the absence of 

 both elytra and wings.) The eyes are always compound, 



Fig. 119. Coleoptera. Common Cockchafer (Melolonthavulgaris). 



generally circular, oval, or reniform, but sometimes completely 

 divided. The antennae are extremely variable in form, gene- 

 rally of eleven joints, sometimes of fewer, rarely of twelve. 

 The thorax is composed of a pro- meso- and meta-thorax, but 

 when the elytra are closed, only the pro-thorax and a little 

 plate (" scutellum") belonging to the meso-thorax are visible. 

 The tarsus is generally composed of five joints, sometimes 

 fewer, never more, and its last joint is usually furnished with 

 two hooked claws. 



The larvae of Coleoptera are generally composed of thirteen 

 segments, including the head. The body is generally soft and 

 fleshy, the head horny, and the mouth adapted for mastication. 

 The antennae are small, usually of three or four joints, with 

 ocelli at their base. They have three pairs of legs attached to 

 the thorax, and sometimes anal pro-legs or fleshy tubercles. 

 The pupa is sometimes enclosed in a cocoon, and the parts 

 of the perfect insect are always distinctly recognisable in the 

 pupa. 



The order Coleoptera includes all those insects commonly 



