ARTICULATA. ; 169 
a case with bits of gravel, sticks, or grass, which they generally drag with 
them, but some of these cases are affixed permanently to stones. A few 
species form their cases in the shape of turbinated shells, and these have 
been described as Mollusca. In most cases their food is vegetable. ‘The 
adults inhabit damp places near the water; they run with tolerable ease, 
but do not fly well. Zydropsyche (pl. 79, fig. 65), Limnophilus ( fig. 68), 
Phryganea (figs. 66, 69). . 
Orvrer 7. Hymenoprera (pl. 79, jigs. 1-53). In this order the body is 
generally of a hard consistence, divided into three distinct portions. The 
wings are four in number (although sometimes absent) with few nervures ; 
in repose the tips cross each other horizontally; and the posterior pair is 
the smallest, and attached to the anterior pair during flight by a row of 
minute hooks. They have a pair of biting mandibles, membranous maxilla, 
with palpi, and a labium or tongue. The feet are well developed, and the 
tarsi are generally pentamerous. The female has an ovipositor or sting. 
The head and eyes are generally large, and the stemmata rarely absent. The 
antenne are variable, but generally slender, and with thirteen articulations 
in the male, and twelve in the female. The prothorax is much reduced, 
and the mesothorax well developed for the insertion of the anterior wings. 
The larve are with or without feet, and the pupa. is incomplete and 
incapable of locomotion. The habits of this order excite more interest, 
and their instincts are more striking than those of any other. The nervures 
or veins of the wings (at least the anterior pair) are extensively used in 
classification, each longitudinal or transverse part, and each intermediate 
area or cell having its peculiar name. 
The larvee of the Zenthredinide (the only ones which have feet) bear a 
considerable resemblance to those of the Lepidoptera. These feed upon 
leaves, others feed upon the juices of living plants and animals in which 
the eggs have been inserted by the mother. Some larve feed upon animal 
food placed near them by the adult, whilst others, like those of ants and 
bees, are regularly fed by the neuters. The limbs of the pupe are free, but 
inclosed in a filament. Adult Hymenoptera are mostly found upon flowers 
and fruits, the mouth being adapted for taking fluids. In general they do 
not feed much, and in a few cases they are without a mouth. 
These insects fly and run well, and some leap with facility. A few 
simulate death when taken, bringing the abdomen in contact with the 
thorax at such times. Some defend themselves by biting, and others by a 
poisonous sting at the extremity of the abdomen, which can be extended or 
retracted at will. They are of medium size, the largest species (as 
Pompilus formusus, Say) being much smaller than the large Coleoptera, 
Lepidoptera, or Orthoptera, whilst the small species rival in minuteness 
those of other orders. 
Blanchard divides the Hymenoptera into thirteen tribes, with French 
names, corresponding to the family names: 1, Apidw; 2, Vespide, 3, 
Humenide ; 4, Crabronide ; 5, Sphegide ; 6, Formicidae ; 7, Chrysidide ; 
8, Chalerdide ; 9, Proctotrupide ; 10, Ichnewmonide ; 11, Cynipide ; 12, 
Suricide ; 13, Tenthredinide. 
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