COLEOPTERA. 147 



chitinous sterna move but slightly. On the sides of 

 the abdomen the spiracles are distinctly seen. 



The jointed antennas (PI. VI., Fig. 86, at) are ter- 

 minated by three leaf-like plates, and this peculiar form 

 has given the name of Lamellicorns to all the beetles 

 belonging to the family Scarab?eidae. These appen- 

 dages assume many remarkable and unique forms 

 among beetles, as will be seen by reference to any 

 illustrated work on Coleoptera. The mouth parts are 

 formed according to the Orthopterous type, consisting 

 of a pair of mandibles (Fig. ?>6, nid), and two pairs 

 of maxillae (Fig. 86, )nx\ mx"). They are strong 

 organs, although much smaller than those of the 

 locust. The three pairs of legs (Fig. 86, /', /", /'") are 

 stout, and so well fitted for running that the beetle 

 takes the same position among runners that the locust 

 holds among leapers, or the dragon-fly among fliers. 

 The two legs of the last pair are placed far back on 

 the thorax, and at some distance from each other. 

 Scholars should be encouraged to find out how these 

 insects use their legs in running. A figure by Graber ^ 

 shows one in the act ; the fore and hind legs on one 

 side of the body, and the middle leg on the other, are 

 put out first, and afterward the other three legs, so 

 that the two sets act alternately. 



The hard wing-covers, or elytra (PI. VL, Fig. 86, 

 w' ; Figs. 84, 85, 7c>'), stiffened by chitine, bend down- 

 ward at the sides and back so as to enclose the true 

 wings (Fig. 86, w"). This peculiar structure is used 

 to distinguish the order, Coleoptera (Kokeo<;, sheath ; 



1 Die hisekten. Part I., p. 161 ; copied by Packard, Manual 

 of Zoology, fifth ed., 1886, p. 327. 



