there
seem to be only four or three segments in each foot; hence the names
_Tetramera_ and _Trimera_ formerly applied to them. The larvae have
soft-skinned bodies sometimes protected by rows of spiny tubercles,
the legs being fairly developed in some families and greatly reduced
or absent in others. As might be expected, degeneration in larval
structure is correlated with a concealed habit of life.

The _Coccinellidae_, or ladybirds (fig. 32), are a large family of
beetles, well known by their rounded convex bodies, usually shining
and hairless. They have eleven segments to the feeler, which is
clubbed at the tip, and apparently three segments only in each foot.
Ladybirds are often brightly marked with spots and dashes, their
coloration being commonly regarded as an advertisement of inedibility.
The larvae have a somewhat swollen abdomen, which is protected by
bristle-bearing tubercles. Like the perfect insects, they are
predaceous, feeding on plant-lice (_Aphidae_) and scale insects
(_Coccidae_). Their role in nature is therefore beneficial to the
cultivator. The _Endomychidae_ (fig. 33), an allied family, are mostly
fungus-eaters. In the _Erotylidae_ and a few other small related
families the feet are evidently four-segmented.

[Illustration: FIG. 31.--_Goliathus giganteus_ (Goliath Beetle).]

[Illustration: FIG. 32.--_Anatio ocellata_ (Eyed Ladybird). Europe.]

[Illustration: FIG. 33.--_Endomychus coccineus_. Europe.]

[Illustration: FIG. 34.--_Sagra cyanea_. W. Africa.]

[Illustration: FIG. 35.--_Eumorphus ivguttatus_. Sumatra.]

[Illustration: FIG. 36.--_Lophonocerus barbicornis_. S. America.]

The _Chrysomelidae_, or leaf-beetles (figs. 34, 35), are a very large
family, with "tetramerous" tarsi; there seem to be only four segments
to the foot, but there are really five, the fourth being greatly
reduced. The mandibles are strong, adapted for biting the vegetable
substances on which these beetles feed, and the palps of the second
maxillae have three segments. Most of the _Chrysomelidae_ are metallic
in colour and convex in form; in some the head is concealed beneath
the prothorax, and the so-called "tortoise" beetles (_Cassidinae_)
have the elytra raised into a prominent median ridge. The most active
form of larva found in this family resembles in shape that of a
ladybird, tapering towards the tail end, and having the trunk segments
pr