PEDIPALPI, the name of a group of the class Arachnida (q.v.), in some respects connecting the scorpions and the spiders but more nearly related to the latter. The most scorpion-like in appearance are the species of the order Uropygi which takes its name from the termination of the body by a distinct tail formed by the narrowing of the last three segments to form a jointed stalk for a post-anal horny appendage, the homologue of the scorpion's sting, which acts as a tactile organ. In the Urotricha, containing the family Thelyphonidae, this appendage is long, flexible and lash like ; and the legs of the first pair are also tactile, while the palpi, or chelae, are pincer-like and armed with powerful spikes for seiz ing and impaling prey which consists mostly of beetles and other ground insects. The whip-scorpions, as these Arachnida are some times called on account of the lash-like tail, are not poisonous but when handled they emit a pungent, acid secretion which is defen sive. They live for the most part in damp places, beneath stones or pieces of wood, in rock-crannies or termites' nests or other crevices where shelter from light and protection from the rays of the sun are obtainable. Some species excavate burrows as dwell ings for themselves and their young. The young are hatched from eggs which the female carries about enswathed in a glutinous mem brane and attached to the lower side of the abdomen. Most of the species soon die when removed from their humid haunts; but in Florida a species is found which is adapted to dry sandy locali ties. Whip-scorpions are found in the East Indies where they
range from India and Ceylon to southern Japan and the Fiji Islands and in the warmer parts of America from Brazil to the southern states of the Union. There are several genera of which the best known are Thelyphonus from India and Java, Uroproctus from north-eastern Bengal and Mistigoproctus from Brazil, the last two being the largest of the group, measuring about 4 in. in total length.
A degenerate group related to the Urotricha, and known as the Tartarides, contains several genera (Trithyreus, Schizomus, Hubbardia belonging to the family Hubbardiidae). The largest measures about a of an inch. Their habits and distribution are similar to those of the whip-scorpions but the group is found in Africa as well as in Asia and America.
The tailless Pedipalpi or Amblypygi recall spiders in appear ance, having broader, flatter bodies and longer limbs than the whip scorpions. Their habits, however, are tolerably similar. They live for the most part under loosened bark or in natural crannies in forests, but do not burrow; and in the East Indies species of the genera Stygophrynus and Catageus frequent the dark recesses of caves and Sarax has been found beneath stones between tide marks. There are many other genera ( Tarantula, Phrynichus, etc.), the largest species rivalling the whip-scorpions in size. The group is widely distributed in tropical Asia, Africa and America.
(R. I. P.)