78 NATURAL HISTORY. [n. ZOOL. GAL. 
they assume this perfect state. These insects are di¬ 
vided into two great groups, according to the form 
of their mouth, some being provided with jaws ( Mandi - 
bulata ) for gnawing their food, while others have only a 
trunk or proboscis, ( Haustellata ,) and live by suction. 
The Jaw-bearing Insects (Mandibulata, Cases 1 to 4) 
are divided into orders, according to the form and struc¬ 
ture of their wings. 
The Coleoptera , or Beetles, (Cases 1 to 3,) have ge¬ 
nerally two hard horny wing-cases, or shards, united by 
a straight line, and covering two folded transparent wings, 
with which they fly. This order contains some of the most 
brilliant insects, as the Diamond-beetle, Buprestis, &c. 
The Orthoptera , (Cases 3 and 4,) the upper wings 
of which are generally like parchment, and fold over 
each other at the edge, as the Cockroaches, the Pray¬ 
ing Insects ( Mantis ), Walking Sticks ( Phasma ), Crickets 
and Locusts. In the latter Case are also exhibited the 
Neuropterous Insects, which have usually two pairs of 
similar netted wings, as the Dragon-flies, Ant-Lion, &c., 
and the Hymenopterous Insects, which have four wings, 
with fewer nervures than in the preceding order, and all 
taking their origin from the base of the wings ; the 
body of the female ends in an egg-depositor, or sting, as 
the Ichneumon, Ant, Wasp, Bee, &c. 
The Suctorial Insects (Haustellata, Cases 5 to 10) 
have only a trunk or proboscis. 
The Lepidopterous Insects (Cases 5 to 9) have their 
wings for the most part covered with series of minute 
scales, which are very finely and microscopically striated, 
and reflect most beautiful colours. Some, as the Butterflies, 
( 'Papilionidce ,) fly by day, and have club-shaped antennae. 
(Cases 5, 6.) Others, having prismatic antennae, generally 
fly just before sunset, as the Sphinges or Hawkmoths. 
(Case 8.) Those which chiefly fly in the evening, and have 
pectinate, or filiform antennae, as the Moths, are in Cases 
8 and 9. 
The Dipterous Insects , (Case 10,) which have only 
two transparent wings with radiating ribs, the under 
pair of wings being replaced with halteres, or balancers, 
as the Crane-fly, Bluebottle, &c. 
The Hemipterous insects, so called because in some the 
