Pedipalpi

Pedipalpi, an order of air-breathing Arachnida (q.v.) closely allied to the Scorpions, which used to be included in it. The members of this order differ from the Scorpions in that the head and thorax are fused into a mass and separated from the abdomen by a definite constriction. They thus in some ways resemble the Spiders. They further differ from the Scorpions by having no sting on the end of the abdomen.. They differ from the Spiders by the presence of a jointed abdomen, and the absence of the web-spinning organ, or spinnerets. The two principal genera are Thelyphonus, which has the "pedipalpi" or "foot-palps," chelate or pincer-like; and Phrynus, in which they are only clawed. Both are land-dwellers, and live in tropical regions.