c. Class Chilopoda. The class Chilopoda consists of the centipedes. The
centipede has a distinct head and a flattened, worm-like, segmented body with one pair
of legs on each segment (see figure 1-4). Some centipedes are up to 10 inches long
and can inflict painful bites.
Figure 1-4. Centipede, class Chilopoda. (Note: One pair of legs per
body segment.)
d. Class Diplopoda. The class Diplopoda consists of the miIIipedes, which are
worm-like arthropods with many legs; hence, the name "thousand legger." The head is
distinct and the remaining segments form a continuous trunk or body. Each of the body
segments bears two pairs of legs, except the first three segments that have one pair
each (see figure 1-5). MiIIipedes have repugnatorial glands, which open through pores
along each side of the body. The secretions from these pores are offensive and repel
other insects. They can also cause skin irritation to humans.
Figure 1-5. MiIIipede, class Diplopoda. (Note: Two pairs of legs per body
segment except for first 3 segments.)
e. Class Crustacea. The class Crustacea is comprised of crabs, lobsters,
shrimp, sow bugs, barnacles, and water fleas. A member of this class has two pairs of
antennae and five or more pairs of legs (see figure 1-6). The anterior body region, as
with some arachnids, is the cephalothorax.
Figure 1-6. Lobster and crab, examples of class Crustacea.
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