348 ZOOLOGY. 
found a male (king) living with thirty-one complementa} 
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 larve are all aquatic, some of 
them having gills (Fig. 323, a) at the end of the 
body. 
Order 6. Plectoptera.—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 larve are 
aquatic and breathe by gills placed on the sides 
\ of the hind-body.* 
Fig. 824.—May-fly and Jarva, the latter enlarged. Fig. 325.—Thrips. 
Order 7. Thysanoptera.—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 maxille, 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 pupa. 
is active, its limbs and wings encased by a membrane, and the 
antennz are turned back on the head. 
Order 8. Hemiptera.—Insects of this group are called 
* See Eaton, Monograph of Ephemeride. 
