COLEOPTERA.—(Beetles). 
The first pair of wings (elytra) thickened, accurately adapted to the body 
and completely covering the lower wings, which fold longitudinally 
and transversely in repose. Many species are wingless, and in many 
the elytra are abbreviated, not covering the abdomen. Mouthparts 
of the predaceous or herbivorous biting type. Antennae of varied 
forms never setaceous, usually eleven-jointed. Simple eyes usually 
absent. The integument is hard ; the parts accurately co-adapted to 
form a rigid outer skeleton. 
Metamorphosis complex ; the larva a grub with complete or reduced legs, 
without suckerfeet and without tubercles bearing hairs Silk is not 
utilised in the formation of the cocoon, but anal secretion takes its 
place; after emergence from the cocoon the imago usually passes 
through a resting period during which the integument hardens. 
The order includes minute to large insects, of varied habits, including 
herbivores, predators, scavengers, both aquatic and terrestrial, with 
no social and scarcely any parasitic forms. 
No order is so easy to recognise as this, and only in rare cases, where 
the elytra are much reduced or are soldered together, will a beetle appear 
different. Looking at a beetle from above, the antennae, the large pro¬ 
thorax, the scutellum, the elytra and the pygidium (plate over the anus) 
are seen, except where the last is covered by the elytra. The large wings 
are folded below the elytra. Looking from below, the antennae can be seen, 
inserted below the head, the large mandibles and the labium, with usually 
two pairs of palpi ; the legs, with the coxa embedded in the sternum, the 
trochanter, femur, tibia, tarsus. The antennae assume different forms 
as shown in figure 137; in 1, the basal joint is elongate and forms a scape, 
the apical three joints form a club and the remainder form a funicle, 
the whole antenna being elbowed (Rhynchophora) ; in 2, the antenna 
is simple, filiform (Phytophaga) ; in 3, it is moniliform, each seg¬ 
ment a little expanded ( Cantharidce) ; in 4, it is serrate on one side 
( Sternoxi ); in 5, it is clubbed, the three apical segments expanded on both 
sides (Clavicornia) ; in 6, it is filiform (Adephaga); in 7, it is clubbed, 
the club formed of leaflets closely folded together (Melolonthidce) ; in 8, 
