830 



CLASS V. ARACHNIDA. 



..li 



abdomen. The head or cephalothorax consists of the segments 

 bearing the chelicerae, the pedipalps and the first pair of walking 

 legs, all fused to form a trapezoid-like mass bearing two dorsal 

 simple eyes near the middle line. Ventrally there is no sternum, 

 the coxae of the legs approximating. The mouth is borne on 

 a rostrum which projects forward between the base of the powerful 



chelicerae. A pair of 

 thoracic stigmata lie be- 

 tween the coxae of the 

 second and third legs. 

 The abdomen consists of 

 ten segments with sterna 

 and terga and softer 

 pleura connecting them. 

 The first of these bears 

 the genital pore, the 

 second and third segments 

 bear a pair of abdominal 

 stigmata, and some 

 species also have a 

 median stigma on the 

 fourth segment . The 

 tenth segment bears the 

 anus. There is little 

 constriction between the 

 abdomen and thorax. 



The chelicerae are very 

 large and powerful and by 



their shearing action the Solifugae can kill small mammals and 

 birds, but as a rule they seem to live on insects. They bear a 

 series of stridulating ridges and in the male a process termed the 

 flagellum. The arrangement and size of the teeth on the claws is of 

 value in classification. The pedipalpi are six-jointed and leg-like ; 

 they end in an eversible sense-organ, probably olfactory. The 

 number of joints in the legs varies. The basal joints of the last 

 pair of legs in the adult bears five racquet-shaped projections of 

 doubtful function, the malleoli ; probably they are sensory. 



The Solifugae are animals of fair size, the smallest measuring 

 from the tip of the chelicerae to the end of the abdomen 1*5 cm., 

 the largest some 7 cm. 



FIG. 56.Galeodes araneoides, Pallas, a Chelicerae ; 

 b eyes ; c head ; d thorax ; / abdomen ; g pedi- 

 palpi ; h palpiform legs ; k digital joint (capsule) ; 

 o shear-like points of falx (end joint of chelicera) ; 

 r anus. 



