"A genus of insects, the type of a very numerous family, which forms the order Parasita or Auoplura. The body is flattened, almost transparent; the segments both of the thorax and abdomen very distinct; the mouth is small and tubular, enclosing a sucker; there are no wings; the legs are short, and are terminated by a claw adapted for taking hold of hairs or feathers. The eyes are simple, one or two on each side of the head. All the species are small, and live parasitically, on human beings, terrestrial mammalia, and birds." — Chambers, 1881

Magnified Louse

"A genus of insects, the type of a very numerous family, which forms the order Parasita or Auoplura.…