2 • IXTROPUCTION. 



tlioracic portion of the imago; to each of them is usually 

 (hut not always) attached a pair of le«^s. Tlie larva, like 

 the imago, does not hreathe through the mouth, l»ut hy 

 means of air carried through the hody in numerous tuhes 

 (tracJicae), comnninicating with the external air hy holes 

 in the sides of the Ijody (sjnrades), of which there is 

 usually one on each side of every segment after the head, 

 except the second, third, and last. Tlie larva when fully 

 oTOwn hecomes a. ■i)ui)a, which is soft, often enclosed in a 

 case or a cell underground, and in which the parts of the 

 future beetle are visiljle through the skin. After a longer 

 or shorter time passed inactively in this state, the fully 

 formed 1)eetle emerges, being at first soft and light in 

 colour (immature), but becoming gradually harder and 

 darker l)y exposure to the air. The head of the beetle 



Fio. 2. 



Head aii<l Tliorax of Lcistvs 



..-d 



Labium of Khtphrus ri2Mrius. 



exhibits on its ui)per-side the lahruvi (fig. 1, ((), the chfprus 

 (fig. 1, h), the forehead (fig. 1, c), the vertex (tig. 1, d), the 

 ci/cs (fig. l,e), and the antennae (fig. 1,/); the under-sich; of 

 the mouth is composed of the menturn (hg. 2, a), the lujida 

 (fig. 2, h), and the laUal j'alpi (fig. 2, c, fig. 1, h), with 

 their bases (fig. 2, d), these together forming the lahinm. 

 The part of the head supporting the mentum is called the 

 suh7nent'um. 



I'etween the labrum and labium lie the jaws, of which 

 there are two pairs, working horizontally, viz.: an upper 



