INSECTS. 
i6 
Insects are divided by Linnceiis into seven 
orders or distributions. The first order is entitled 
Coleoptera, and contains all those insects whose 
wings are guarded by 'a pair of strong, horny, 
exterior cases or coverings, under which the 
wings are folded up when at rest. These insects, 
in common language, are called Beetles, though 
in reality that term, as we shall soon find, is to 
be restricted in science to one particular genus. 
The wing-sheaths or horny coverings are some- 
times called coleoptra, but more generally elytra. 
The Coleopterous Insects form a very large or 
extensive order. 
The second division of Insects is termed Hemip- 
tera or half-winged. That is, tlie upper part of 
the wing-sheaths in this tribe is of a tough or 
leathery texture, and the lower part membranace- 
ous. Sometimes almost the whole wing-cover is 
leathery, but of a softer texture than in the 
Coleoptera. The insects contained in this divi- 
sion are very various; all the Locusts or Grass- 
hoppers, the Cicaclee, and a great many others. 
It is to be observed that the wing-covers in this 
order cross each other when closed, instead of 
meeting in a direct line. 
The third order is termed Lepidoptei'a or scaly- 
winged. It consists of the insects commonly 
termed Butterflies and Moths. The powder on 
the wings of these insects has been generally de- 
scribed by microscopical writers as consisting of 
small feathers; but in reality it consists rather of 
