INTRODUCTION. 3 



vary much in form and structure, and are consequently 

 of use in classifying the insects. 



The mouth org-ans are situated beneath the head, 

 and are used to seize, and divide, the food. They 

 consist of the labrum, or upper lip ; the labium, or 

 lower lip ; mandibles, or upper jaws, which are hard 

 and sharp, and often very large (as in the Stag 

 Beetle) ; and maxillae, or lower jaws. Two jointed 

 organs, called the labial palpi, are attached to the 

 labium, and two similar organs, the maxillary palpi, 

 belong to the maxillae. 



The thorax is the part lying between the head 



and abdomen. It carries the legs and wings, and 



is divided into three principal portions — the pro-, 

 meso-, and meta-thorax. The upper portion of the 



thorax is divided into pro-, meso-, and meta-notum, 

 and the under surface is divided into pro-, meso-, and 

 meta-sternum. The pronotum is the broad part seen 

 above in front of the elytra ; and behind it, and 

 inserted between the base of the elytra, is a small 

 triangular plate, belonging to the meso-notum, called 

 the scutellum. Each segment of the sternum bears 

 a pair of legs. 



Each of the legs consist of five parts — the coxa, 

 or hinge-plate ; the trochanter (a small joint between 

 the coxa and femur) ; the femur, or thigh ; the tibia, 

 or shank ; and the tarsus, or foot, which has normally 

 iive joints, the last bearing a pair of claws. 



B 



