INVERTEBRATE ZOOLOGY. lllT 



by their relationship to pairs of nerves which supply them. The 

 I^resent solution is as follows : 



Somite. Appendages. 



I Antennae. 



II Lateral ocelli. 



III Median ocelhis (^a fused pair). 



IV Eyes. 



V Labrum. 



VI Mandibles. 



VII First Maxillae. 



VIII Second Maxillae (labium). 



Thorax. This consists of three segments, termed respectivelj% pro-, 

 meso- and meta-thorax. Their tergites are termed pro-, meso- and 

 meta-notum, and their stemites, jyro-, meso- and meta-stemum. The 

 terms ending in -ite, used in defining the parts of the type, are thus 

 only employed in the abdomen. The pro-thorax is free and mova- 

 ble. It consists of a broad pro-notum. forming a sort of collar, and 

 a very narrow i)ro-sternum, bearing a .spine, the pro-thoracic tuber- 

 cle. Its appendages are the first pair of legs. The meso- and meta- 

 sternum are fused to give a firm support to the third or jumping 

 legs. They are reinforced by a portion of the first abdominal somite. 

 Dorsally they are divided up into a complex mass of small skeletal 

 elements, to give freedom of motion to the two pairs of wings which 

 are not ajjpendages, but integuniental folds which have become mov- 

 ably articulated with the rest of the skeleton. Ventrally a sternal 

 jilate is formed, the sutures of which show its composition. The 

 most anterior piece is the meso-sternnnt, into which the nieta-sterniini 

 is fitted by a joint knowaias a •' dove-tail." Theflist abdominal ster- 

 nite is again dove-tailed into it. and forms the posterior portion of 

 the sternal plate. Make an oiitline drawing of the sternal plate. 

 The vieso- and meta-thoracic legs are inserted at the posterior edges 

 of their respective segments. The pleura of the meso- and meta- 

 thorax are double, an episternum in contact with the sternal plate, 

 and an epimeron above it. There are also a few minute pieces de- 

 veloped about the bases of the legs. 



Legs. The first four are used for walking and the last pair for leap- 

 ing. They consist of the same parts, but their relative size differs 

 according to function. The two long joints are the " thigh " {femur) 



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