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CENTIPEDE,
common name for the members of the class Chilopoda of the
phylum Arthropoda, which also includes crustaceans, insects, and
spiders. The centipedes are long, segmented animals with jointed
appendages and a poisonous “bite.”
The centipede body is divided into well-marked segments, the
number of which varies from 12 to more than 100. The head, which
is covered by a flat shield above, bears a pair of antennae, usually
of considerable length and consisting of from 12 to more than 100
joints; a pair of small, strong, toothed, and bristly mandibles;
and a pair of underjaws, usually with palps. The first body segment bears
a modified pair of legs, the strong joints of which terminate in
a sharp claw into which a poison gland opens, for seizing and killing
prey. The two legs on each of the other segments are usually seven-jointed, sometimes
bearing spurs and glands, and generally clawed. The relatively large
brain is connected with a ventral chain of ganglia. Compound eyes
occur in one family, and simple eyes or none at all in many. The feelers,
certain bristles, and portions of the skin are also sensory. The
heart is a chambered dorsal vessel. Tracheae, or air tubes, open
on the sides of the body. Most centipedes are 2.5 to 5 cm (1 to
2 in) long, but some tropical species grow to 30 cm (12 in).
Centipedes are nocturnal and remain under stones or wood during
the day. They are all carnivorous. Scolopendra bears
live young; the others lay eggs.
Of the four principal families, the family Scutigeridae, to
which the common house centipede belongs, includes forms with compound
eyes, long feelers, 8 shields along the back, and 15 pairs of very
long legs. Lithobiidae have simple eyes, 15 pairs of legs, antennae
measuring a third or more of the body length, and 15 dorsal shields.
The Scolopendridae have more than 20 pairs of legs; short, many-jointed
antennae; and simple eyes or none at all. The poisonous bite of
some of the larger forms is dangerous to humans. The Geophilidae
are long, wormlike centipedes, of sluggish habit, with 31 to 173 pairs
of legs, short feelers, and no eyes. Well-developed spinning glands
are seen in this family, and their secretion cements together ova
and spermatozoa.