NEUROPTERA. 579 



The wings are large, and in the Libellulidce they are in 

 constant use. The legs are generally of simple structure, 

 these insects neither walking nor leaping much. Rarely, as in 

 Mantispa, are they adapted for seizing their pre}^, as they are 

 in many Hemiptera and Orthoptera. 



The abdomen of the Neuroptera is composed, according to 

 Lacaze-Duthiers, of eleven segments (artliromeres), and the 

 ovipositor is constructed on the same plan as in the Hymen- 

 optera, Hemiptera and Orthoptera, though .in the different 

 families the characters vary much more than in the higher sub- 

 orders, in this respect perfectly' according with the anatomy 

 of the other parts of the body in the different groups. He 

 states, however, as observation has taught us, that in its 

 structure the ovipositer is simpler than in other insects, and 

 the farthest removed from that of the Hymenoptera. 



Lacaze-Duthiers, whose work is necessarily incomplete from 

 treating of the female ovipositor alone, not regarding the 

 analogous parts in the other sex, considers the Neuropterous 

 ovipositor (tariere) as having three types of structure. The 

 simplest is found in Libellula, in the abdomen of which there 

 are ten segments much alike ; "the eleventh is more complex 

 than the others ; it has the same structure as in xEschna. It 

 is especially in the division of [the family- containing] Libellula 

 and its allies that the two appendages take the form and the 

 function of pincers, and that the special word ' forcipate,' has 

 been used. These forceps serve, as is well known, for clasping 

 organs, and to enable them to perform the A'ery long prelimi- 

 naries to fecundation." The outlet of the oviduct lies between 

 the eighth and ninth segments. 



The nervous sj^stem of the Neuroptera consists of the cere- 

 brelhim, with its lateral productions, the optic nerves, forming 

 a cylinder extending between the ej-es and presenting four 

 swellings. (Leid}'.) There are three thoracic and eight ab- 

 dominal ganglia which are of very uniform size, and connected 

 by double commissures. (See Fig. 43.) The nervous cord is 

 very equably developed and the brain portion is relatively 

 smaller than in the higher suborders. 



Professor Leidy has described the digestive organs of Cory- 

 dalus cornutus, which may serve as a type for the rest of the 



