246 HANDBOOK OF INVERTEBRATE ZOOLOGY. 



(ii.) Arching over the tongue and forming the anterior 

 boundary of the mouth are the black tips of the ^naxillcBy 

 meeting upon the median Hne. Each maxilla (Fig. 

 131, (7) is made up of: — 



(a.) A basal joint or cardo (cd), which is directed trans- 

 versely to the long axis of the head, and articulates with 

 the lower posterior edge of the gena. 



(b.) The second joint, or stipes (st), runs forward at 

 right angles to the cardo, and parallel to the long axis of 

 the head. It is movable towards and away from the 

 median line. 



(c. ) The maxillary palpus (mp) is carried upon the outer 

 angle of the stipes, and is made up of three short and 

 three long joints. 



(d.) The lacinia, the toothed, black-tipped, cutting por- 

 tion (la) of the maxilla, is carried upon the inner margin 

 of the distal end of the stipes. 



(e.) The galea (ga), or soft brown spoon-shaped portion 

 of the maxilla is carried upon the outer angle of the stipes 

 and bends around in front of the lacinia. 



(iii.) Make a sketch of the maxilla, indicating all the 

 joints. 



7. The Thorax. 



Remove the legrs and wino^s in order to examine the 

 structure of the thorax and abdomen. The thorax is made 

 up of three segments, each of which carries a pair of legs. 

 These three segments are known as the prothoi'ax, meso- 

 thorax and metathorax. 



a. The prof horax. 



The sides and dorsal surface of this segment are covered 

 by a large sunbonnet-shaped piece, the pronotum (Fig. 

 130, 2'), which bears a slight resemblance to the carapace 

 of a crustacean, but does not, as in the latter, extend over 

 the head. 



