NEUROPTERA. 581 



\ the males have three pairs of very long, tortuous tubes, 

 while with the females the only vestiges of this apparatus are 

 two indistinct vesicles." (Siebold.) 



In their larval state the aquatic Neuroptera breathe by 

 false gills, or branchial tracheae ; these generally consist of 

 slender filaments situated on the sides of the abdominal seg- 

 ments. These filaments are fleshy, and penetrated by tracheae, 

 which take up the oxygen from the water. In the larvae of the 

 Phryganeidce, these false gills are simple, "rarely ramified, 

 and united in groups of from two to five, which stand out to- 

 wards the back." Siebold also states that "with those of the 

 Epliemeridce each of the anterior abdominal segments has 

 a pair of these branchiae which are sometimes ramified in the 

 most varied manner, and sometimes consist of two kinds, 

 some being lamelliform and alternating with the others which 

 are fasciculate. With all the Ep hemeridce these organs have 

 movements which are sometimes slow and rhythmical, and 

 sometimes rapid and oscillatory. . . . The trachean branchiae 

 of ^Esclma, Libellula and the other Libellu'lidce are formed 

 upon a wholly different plan. They are situated in the very 

 large rectum, and consist of numerous epithelial folds which 

 are traversed by a great number of very fine branches of many 

 large trachean trunks. (Fig. G2, x.) The rectum is, moreover, 

 invested by a very highly developed muscular tunic, and its 

 orifice has three pyramidal valves which regulate the entrance 

 and the escape of the water required for respiration." 



In the larval and adult insect there are four main trunks to 

 the tracheary system, two on each side, and much less com- 

 plicated than in other insects. 



There are generally six or eight long, flexuous urinary or 

 Malpighian vessels. In the Neuroptera the ovaries "consist 

 always of multilocular tubes," and the two testes are, in the 

 Perlidce, Ephemeridce and Libellulidce, composed of "a 

 multitude of round follicles, disposed botryoidally around 

 a long dilated portion of each of the deferent canals. . . . 

 With Panorpa the two testicles are very simple and ovoid ; 

 but with the other species they consist of two tufts of long or 

 round follicles. With Myrmeleon and Hemerobius they are 

 oval and surrounded by a distinct envelope. The two deferent 



