In the trap-door species of Lycosidae, like, for instance, Lycosa opifex of the Russian steppes, the hinge is weak and the lid of the burrow is kept normally shut by being very much thicker and heavier at its free margin opposite the hinge so that it readily falls by its own weight.
As instances of procryptic or celative coloration may be mentioned that of the species of the genus Dolomedes, one of the Lycosidae, which lives amongst reeds and is marked with a pair of longitudinal yellow lines which harmonize with the upright stalks of the vegetation, and Lycosa pitta, which lives on the sand, can scarcely be seen on account of its mottled pattern: Sparassus smargdulus and the species of Pecucetia, which are found amongst grass or low green herbage, are mostly green in colour, and Salticus scenicus is banded with white and black to match the grey tint of the rocks and stone walls on which it hunts its prey.
TARANTULA, strictly speaking, a large spider (Lycosa tarantula), which takes its name from the town of Taranto, (Tarentum) in Apulia, near which it occurs and where it was formerly believed to be the cause of the malady known as "tarantism."
This spider belongs to the family Lycosidae, and has numerous allies, equalling or surpassing it in size, in various parts of the world, the genus Lycosa being almost cosmopolitan in distribution.
In recent times the term tarantula has been applied indiscriminately to many different kinds of large spiders in no way related to Lycosa tarantula; and to at least one Arachnid belonging to a distinct order.