In the EUSCORPIINAE the upper surface of the hand is divided into two surfaces almost at right angles by a strong finger-keel. This is a small group of about six species found in the Mediterranean region. The two genera are _Euscorpius_ and _Belisarius_. The CHACTINAE are without any marked keel on the hand. The scorpions of this sub-family are found in equatorial South America and the West Indies, where there are more than twenty species divided about equally between the four genera _Chactas_, _Broteas_, _Broteochactas_, and _Teuthraustes_. =Fam. 5. Vejovidae.=—_No tibial, but two pedal spurs. A single row of hairs or papillae under the tarsus. Sternum generally broader than long. Elongate stigmata, and three lateral eyes._ Seven of the eight genera of this family include only American forms, the principal genus being _Vejovis_, with about ten species. The genus _Scorpiops_, however, belongs to the Indian region and numbers more than ten species.[248] =Fam. 6. Bothriuridae.=—_Sternum much reduced and sometimes hardly visible, consisting of two slight, nearly transverse bars._ Of the seven genera of this family one, _Cercophonius_, is Australian. The other six genera include some dozen South American forms, _Bothriurus_ having four species. =Order II. Pedipalpi.= _Arachnids with non-chelate, two-jointed chelicerae, powerful pedipalpi, and four pairs of legs, of which only the last three are ambulatory, the first being used as tactile organs. The cephalothorax is usually covered by an undivided carapace, but the pedunculated abdomen is segmented. Respiration is by lung-books._ The Pedipalpi are a little-known group of animals of nocturnal habits. Though rarely seen they are widely distributed, being found in India, Arabia, the greater part of Africa, and Central and South America. They are of ancient origin, a fossil genus, _Graeophonus_, of the Tarantulidae (Phrynidae, see p. 312), occurring in the Carboniferous strata in North America. They live under stones and bark, and in caves, where, when disturbed, they seek safety in crannies in the rock. Little is known of their habits, but they are believed to feed chiefly upon insects. The female _Tarantula_ carries the developing eggs, somewhat after the manner of the Chernetidea (see p. 434), in a bag beneath the abdomen, the under surface of which becomes concave and dome-like during the period of gestation.[249] [Illustration: FIG. 171.—_Thelyphonus_, diagrammatic ventral view; about natural size. _c_, Coxal joint of pedipalp; _g_, generative opening; _p_, pedipalp; _sp_, spiracles; _st_, sternal plates; 1, 2, 3, 4, ambulatory legs. (After Pickard-Cambridge.) ]