ARTICULATA. 287 
wings. In some species, the fore-wings are opaque at the 
base, and transparent at the apex, whence the name of 
the order. Some feed on the juices of animals, others on 
plants. Here belong the wingless Bed-bug (Cemex) and 
Louse (Pediculus), the Squash-bug (Corews), Water-boat- 
man (Votonecta), Seventeen-year Locust (Cicada), Cochi- 
neal (Coccus), and Plant-lice (Aphis). 
4. Coleopters, or “ Beetles.” This is the largest of the 
orders, the species numbering about 90,000. They are 
easily recognized by the e/ytra, or thickened horny fore- 
wings, which are not used for flight, but serve to cover 
the hind pair. When in repose, these elytra are always 
united by a straight edge along the whole length. The 
hind wings, when not in use, are folded transversely. The 
mandibles are well developed, and the integument general- 
ly is hard. The legs are strong, for the Beetles are among 
Fie. 259.—a, imego, and 8, larva, of the Goldsmith Beetle (Cotalpa lanigera); ¢, 
pupa of June-bug (Lachnosterna fusca). 
the most powerful running Insects. The larvee are worm- 
like, and the pupa is motionless. The highest tribes are 
carnivorous. The most prominent forms are the savage 
but beautiful Tiger Beetles (Cicindela); the common 
Ground Beetles (Carabus), whose hind wings are often 
absent; the Diving Beetles (Dytiscus), with boat-shaped 
body, and hind legs changed into oars; the Carrion Bee- 
tles (S7/pha), distinguished by their black, flat bodies and 
