CHAPTER V. 



Jointed Animals, — continued. 



Insects, — concluded. 



Orders Neuroptera, Orthoptera, Rhynchota, etc. 



Characters of The Neuroptera form the last order of insects which undergo a 

 the Neuroptera. complete metamorphosis in the course of their development. In this 

 order it was formerly usual to include certain groups of insects, such as the dragon- 

 flies, May-flies, white ants, etc., none of which pass through a period of prolonged 

 inactivity, or pupal-stage, before reaching the perfect condition. But although it 

 is largely a matter of convenience whether these groups be placed, as they are in 

 this work, in the order Orthoptera, or arranged in a series of separate orders, no 

 one, taking into consideration the great difference in their mode of development, 

 would now think of associating them in the same order with the true Neuroptera. 

 The adult insects of the present order have their mouth-organs, when fully 

 developed, adapted to biting and grinding, and never formed for piercing or suck- 

 ing ; in which respect they differ from three of the other orders of the metabolous 

 insects, namely, the Hymenoptera, Diptera, and Lepidoptera. From the Coleoptera 

 they are easily distinguished by the structure of their fore-wings, which are never 

 hard and horny like the wing-cases or elytra of the latter. Both pairs of wings 

 are membranous, and usually traversed by numerous, more or less closely reticu- 

 lating, veins ; whence the name of Neuroptera given to the order. The hind-wings 

 are often very similar to the fore-wings, but sometimes differ considerably in size 

 and shape. In one section — the caddis-flies — they are capable of being folded like 

 a fan, but in the other section (Planipennia) they always remain flat, and are 

 spread horizontally or obliquely in repose. 



Caddis-Flies, — Suborder Trichoptera. 



The caddis-flies, forming the first of the two great divisions of the order, are in 

 general appearance rather like some of the smaller kinds of moths ; and since they 

 differ a good deal from the typical Neuroptera, they are often treated as a distinct 

 order. In their adult state they have two pairs of wings, in which the neuration 

 is comparatively simple, with few transverse nervures. The wings are generally 

 clothed with hairs, and the hind-wings usually shorter, broader, and less hairy than 

 the front pair. When at rest, the hind-wings are folded fan-wise, with the fore- 

 wings covering them over like a roof. The caddis-flies have a rather small head, 

 which bears two long, tapering, and many-jointed antennas. They have round and 



