NEUROrXERA. 581 



pi dee ; 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 trachea ; these generally consist of 

 slender filaments situated on the sides of the abdominal seg- 

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

 which take up the oxygen from the water. In the larva? of the 

 Phryganeidce these false gills are simple, "rarel}^ 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 

 Ephemeridce 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 Ephemeridm these organs have 

 movements which are sometimes slow and rhythmical, and 

 sometimes rapid and oscillator3\ . . . The trachean branchire 

 of ^schna, Libellula and the other Lihellulidm are formed 

 upon a wholly difierent 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. 62, x.) The rectum is, moreover, 

 invested by a very highly developed muscular tunic, and its 

 orifice has three P3'ramidal valves Avhich 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 sj^stera, two on each side, and much less com- 

 plicated than in other insects. 



There are generally six or eight long, fiexuous urinary or 

 Malpighian vessels. In the Neuroptera the ovaries "consist 

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

 Peril dee, Ep heme r i el ee and Libellulielee, composed of " a 

 multitude of round follicles, disposed botryoidally around 

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

 With Panorpa the two testicles are very simple and ovoid ; 

 but with the other species thej^ consist of two tufts of long or 

 round follicles. With M^-rmeleon and Hemerobius they are 

 oval and surrounded by a distinct envelope. The two deferent 



