or SPRING TAIL, in zoology, a genus of insects of the order of aptera. Linn. Syst. Nat. p. 1013. They have six feet formed for running; two eyes composed of eight facets; a tail forked, bent under the body, elastic, and acting like a spring; the antennae are long and fetaceous. "This genus is distinguished (says Barbut) into several species. Some inhabit still waters, leaping and walking with ease on the surface of that element. They assemble in troops in the morning, on the banks of pools, fish-ponds, and reservoirs; others are found in damp places, under leaves, bark, and stones; others among heaps of rotten wood, mushrooms, and in melonbeds. In Lapland, they are seen running upon the snow, but when it begins to melt they perish. The podura, by its elasticity, eludes the eager grasp of the naturalist. Its hard forked tail is a kind of spring, by means of which the body of the animal is thrown up into the air." The podura villofa is one of the largest species found in Britain, and appears to be of a brown footy colour, though it is really of a yellow brown, interpered throughout with black-coloured spots and streaks. The head and thorax are hairy, and stick to the fingers when touched; the abdomen is smooth; the antennae, consisting of four articulations, are as long as two-thirds of the body. It is commonly found under stones.