ARTICULATA. J69 



a case with bits of gravel, sticks, or grass, which they generally drag with 

 them, but some of these cases are aflfixed 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. Tlie 

 adults inhabit damp places near the water ; tliey run with tolerable ease, 

 but do not fly well. JIydroj>8ycJie {2)1. 79, fig. 65), Lhmiojyhilus {fi(j. 6iS), 

 Phryganea {figs. QQ^ 69). 



Okder 7. Hymenopteka {jyl. 79, figs. 1-53). In this order the body is 

 generally of a hard consistence, divided into three distinct portions. The 

 wings are four in nimiber (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 maxillte, 

 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. Tiie 

 antenn£e 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 larvse 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 wrings (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 TenthredlnidcB (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 larvae 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 pupce 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 for7nusus^ Say) being much smaller than the large Coleoptera, 

 LepidopUra.^ or Orthoptera., whilst the small species rival in minuteness 

 those of other orders. 



Blanchard divides the Ilymenop/tera into thirteen tribes, Avith French 

 names, corresponding to the family names: 1, Apldce ; 2, VesptidcB ; 3, 

 Eumenidce ; 4, Cmhronidcß ; 5, SphegidcB; 6, Foi'm,icidcs, ; 7, Chrysididm ; 

 ^.^ ChalcididcB ; ^.^Proctotrupidcß ; 10^ IchneuinonidcB ; l\.,Cynipidce ; 12, 

 SiricidcB ; 13, Tenthredinidce. 



373 



