otected by small firm sclerites. Such larvae, and also many with
soft cuticle and swollen abdomen--those of the notorious "Colorado
beetle," for example--feed openly on foliage. Others, with soft,
white, cylindrical bodies, which recall the caterpillars of moths,
burrow in the leaves or stems of plants. The larvae of the
tortoise-beetles have the curious habit of forming an umbrella-like
shield out of their own excrement, held in position by the upturned
tail-process. The larvae of the beautiful, elongate, metallic
_Donaciae_ live in the roots and stems of aquatic plants, obtaining
thence both food and air. The larva pierces the vessels of the plant
with sharp processes at the hinder end of its body. In this way it is
believed that the sub-aqueous cocoon in which the pupal stage is
passed becomes filled with air.

The _Cerambycidae_, or longhorn beetles, are recognizable by their
slender, elongate feelers, which are never clubbed and rarely serrate.
The foot has apparently four segments, as in the _Chrysomelidae_. The
beetles are usually elongate and elegant in form, often adorned with
bright bands of colour, and some of the tropical species attain a very
large size (figs. 36, 37). The feelers are usually longer in the male
than in the female, exceeding in some cases by many times the length
of the body. The larvae have soft, fleshy bodies, with the head and
prothorax large and broad, and the legs very much reduced. They live
and feed in the wood of trees. Consequently, beetles of this family
are most abundant in forest regions, and reach their highest
development in the dense virgin forests of tropical countries, South
America being particularly rich in peculiar genera.

[Illustration: FIG. 37.--_Phryneta aurocincta_. West Africa.]

The _Bruchidae_, or seed-beetles, agree with the two preceding
families in tarsal structure; the head is largely hidden by the
pronotum, and the elytra are short enough to leave the end of the
abdomen exposed (fig. 38). The development of the pea and bean-beetles
has been carefully studied by C. V. Riley, who finds that the young
larva, hatched from the egg laid on the pod, has three pairs of legs,
and that these are lost after the moult that occurs when the grub has
bored its way into the seed. In Great Britain the beetle, after
completing its development, winters in the seed, waiting to emerge and
lay its eggs on th