348 



ZOOLOGY. 



found a male (king) living with thirty-one complemental 

 females. 



Order 5. Odonata. Here belong the dragon-flies, in 

 which the prothorax is remarkably small, the thorax nota- 

 ble for the great development of the side-pieces, the dorsal 

 pieces being rudimentary. The wings of both 

 pairs are' large, of nearly equal size, and finely 

 net-veined. The larvae are all aquatic, some of 

 them having gills (Fig. 323, a) at the end of the 

 body. 



Order 6. Plecloptera.The May-flies have 

 rudimentary mouth-parts; while the hind-wings 

 are small, sometimes wanting, and the hind-body 

 ends in three long filaments. The larvae are 

 aquatic and breathe by gills placed on the sides. 

 of the hind-bodv.* 



Fig. 324. May-fly and larva, the latter enlarged. 



Fig. &5.-Thrips. 



Order 7. TJiysanoptera. This group is represented by 

 Thrips, and belongs nearer to the Hemiptera than any other 

 order. The mouth-parts are united to form a short conical 

 sucker. The mandibles are bristle-like, bulbous at the base, 

 and situated inside of the maxillae, which are flat, triangular, 

 with palpi shorter than those of the labium. The wings are 

 narrow and fringed, sometimes wanting; the pronotum is 

 large, and the two-jointed feet are swollen at the ends, being 

 without claws. The metamorphosis is incomplete; the pr.pa 

 is active, its limbs and wings encased by a membrane, and the 

 antennae are turned back on the head. 



Order 8. Hemiptera. Insects of this group are called 

 * See Ealoii, Monograph of Epliemeridse. 



