FALSE SPIDERS. 235 



watching the while its everjr movement, the spider gradually stalks nearer, until 

 within reach of a leap ; then, with a well-judged spring, launches itself on to its 

 prey, and, in spite of vehement struggles, tenaciously retains its hold until the 

 victim succumbs to the paralysing effects of the poison. An Australian species 

 (Attus volans) has acquired the power of prolonging its leaps into short flights, 

 by elevating flaps of skin which arise from the abdomen. 



The False Spiders, — Order Solifug^e. 



The members of this group bear such a strong superficial resemblance to the 

 true spiders that they are usually called by that name. The structural distinctions 

 between the two orders are, however, so great and so easily ascertainable, that an 

 example of the one may be without difficulty distinguished from an example of the 

 other. In the first place, the abdomen is composed of ten distinct segments, and 

 is not supplied with spinning-glands, while the breathing-organs, which are in the 

 form of long tracheal tubes, open upon its second, third, and sometimes on its 

 fourth sterna. The cephalothorax is distinctly jointed, its last two segments 

 having separate tergal plates, while its front part is covered by a head-shield 

 bearing a pair of large eyes near the middle of its front border, and merely traces 

 of the lateral eyes at the sides. The mandibles, which form a powerful pair of 

 toothed nippers, are articulated to the sides of the head-plate. The appendages of 

 the second pair are palpiform and tipped with a sensory organ ; but their basal 

 segments, like those of the legs, are united together on the lower surface of the 

 cephalothorax, which has no sternum. The three posterior pairs of legs are 

 tipped with two claws each, but those of the first pair have only a single minute 

 claw. On the basal segments of the last pair are certain racket-shaped organs, 

 termed malleoli ; and behind those of the second pair open a couple of large stigmata, 

 leading into additional breathing-tubes. The mouth is situated at the tip of a 

 long horny beak, projecting forwards between the mandibles. The males are 

 smaller and lighter than the females, but have more powerful and longer legs and 

 palpi. Their mandibles, however, are much weaker, and are furnished above with 

 a sensory organ called the flagellum. In both sexes the mandibles are supplied 

 on their inner adjacent surface with a set of ridges, which give rise to a grating 

 sound when rubbed together. Both in Europe, Africa, and America, the Solifugm 

 closely follow the scorpions in their distribution, ranging in America from the 

 Southern States of the Union southwards into Chili, and being found over the whole 

 of Africa ; none, however, have been recorded from Madagascar. In Europe they 

 occur in Spain, Greece, and South Russia, being abundant and of large size in the 

 steppes of the latter country. Thence they spread southwards and eastwards over 

 the desert countries of South- Western Asia and India ; but to the east of this 

 point they become gradually scarcer, and although species have been discovered 

 in Siam and the Moluccas, the group appears to be unrepresented in Australia and 

 New Zealand. No extinct members have been described. 



The order contains but a single family Soljiugidce, divisible into several well- 

 marked genera, differing from each other in a number of structural characters. 

 The largest members of the group belong to the genus Solpuga, confined to South 



