116 CLASSIFICATION OF INSECTS. 



Order IV. NEUROPTERA (Dragon-fly, May-fly). In these, 

 too, the mouth is formed for mastication ; but the anterior pair 

 of wings, like the posterior, is membranous ; and the nerves of 

 the wings form a close reticulation or network by their inter- 

 lacement. The degree of metamorphosis is variable. 



ORDER V. HYMENOPTERA (Bee, Wasp, Saw-fly]. In these, 

 the mouth is still furnished, as in the preceding, with prehensile 

 mandibles, but the other parts are so formed as to be rather 

 fitted for suction than for mastication ; the wings are all mem- 

 branous, but the nerves do not form such a minute reticulation 

 as in the preceding order ; the metamorphosis is always complete. 



The four preceding orders, in which mandibles are always 

 distinctly present, form the group of MANDIBULATA ; the four 

 succeeding, in which the mandibles are wanting or are completely 

 changed in form, and in which the other parts are adapted for 

 suction, being converted into a more or less complete haustellium 

 or sucking-tube, are termed HAUSTELLATA. 



Order VI. LEPIDOPTERA (Butterflies and Moths}. These have 

 the mouth furnished with a long trunk, coiled in a spiral when not 

 in use ; the wings are all membranous, and are covered with minute 

 scales, having the appearance of fine dust, but arranged with the 

 most perfect regularity ; the metamorphosis is complete. 



Order VII. RHYNCHOTA (Bugs, Cicada, Lantern-fly, fyc.). 

 In which the mouth consists of a jointed rostrum enclosing four 

 bristles ; the wings are usually four in number ; and the meta- 

 morphosis is incomplete. 



Order VIII. DIPTERA (Gnats, flies, #e.). In these there 

 are but two wings ; the mouth is furnished with a sucking-tube ; 

 and the metamorphosis is complete. 



Division b. Insects undergoing metamorphosis, but destitute 

 of wings. This division includes but a single order. 



Order IX. APHANIPTERA (Flea, fyc.\ In this group, also, 

 the mouth is formed for suction ; and the insects composing it are 

 parasitic, living upon the juices of other animals. 



