190 NATURAL ARRANGEMENT OF INSECTS. 



enormous heads, and beautifully coloured bodies. Prox 

 imate to this group, — but where is doubtful, — should 

 be placed the interesting but perplexing genus Xyela 

 Dalm. The abnormal structure in the neuration of its 

 wings, its singular antennae, with their third joint very 

 much elongated, and its lengthy exserted ovipositor, 

 tend in combination to perplex us, but it appears to be 

 probably the transition from the securiform ovipositor 

 to the valvular one. Having thus finished our rapid 

 survey of the Hymenoptera, Ave can only regret that 

 we could not spare more room for the investigation of 

 so interesting an order. All that we have been able to 

 do in this limited space has been to notice the most 

 remarkable forms, and loosely generalise their most 

 striking peculiarities ; and, in doing so, we have pre- 

 ferred dwelling upon those groups which offered the 

 most extensive interest. [(142 — 163.) W. E. Sh.] 



CHAP. V. 



THE COLEOPTERA. 

 ON THE COLEOPTERA GENERALLY. 



(164.) The coleopterous order of insects is composed 

 entirely of those which, in popular language, are called 

 Beetles ; that is, of insects covered by a hard crust or 

 shell analogous to that of the tortoise, and which, m 

 both, protects the soft parts of the body from external 

 injury. This is manifestly a wise and a merciful pro- 

 vision for their safety, because these insects are not only 

 the most terrestrial of all others of the Ptilota, but 

 they are also the most imperfect fliers. From these 

 circumstances, it follows that the Coleoptera are more 

 exposed to injury than are any of this class; but, to 

 counterbalance these disadvantages, and to give them a 

 defence which no others enjoy. Nature has clothed them 



