14 COMMON BRITISH INSECTS. 



in the tarsus of Beetles, but in many families one or 

 two of the joints are so small as scarcely to be 

 visible, and only to be detected by a practised eye 

 with the aid of a lens. Next comes the tibia, or 

 shank, which is shown at b. Then follows the femur, 

 or thigh, as seen at c. This is attached to a small 

 joint called the trochanter, which is drawn at d\ and 

 last comes the coxa, or the joint which connects 

 the limb with the thorax. The action of the coxa is 

 very curious, it being a kind of ball-and-socket joint, 

 but with a limited range of movement, so that the 

 legs cannot be spread too far. The same divisions of 

 the joints are found in the three sets of legs. 



We next come to the wings. The upper pair, or 

 elytra, are shown at Fig. 14. For convenience of 

 description they are marked into several divisions. 

 Fig. 14*2 is the suture, or line of junction between the 

 two elytra. The apex is shown at c, and the base at 

 d. The middle, or disc, is marked e, and the lateral 

 margin is at b. Fig. 17 shows one of the wings ex- 

 panded, as if for flight ; Fig. 18 is the opposite wing, 

 represented as folded, and at Fig. 16 are shown 

 both wings as they appear when the elytra are 

 removed. 



At first sight some of these terms may appear to 

 be harsh, repulsive, and difficult to master. In reality 

 they are not so, and a knowledge of them is absolutely 

 necessary to anyone who wishes to understand the 

 description of an insect, and himself to describe 

 insects intelligibly. They form a kind of shorthand 

 by which knowledge can be rapidly communicated, 

 and the trouble taken in learning them is amply 



