THE HUNTING SPIDERS 235 



a vestige of the anterior median spinnerets, and which is put to use 

 while spinning to produce distinctive threads. 



One family of this series, the Thomisoididae, consists of quite 

 large spiders that lie flat against large stones and hold their legs in 

 the laterigrade fashion of the crab spiders. Instead of running away 

 when disturbed, they rub the femora of their palpi against files on 

 the chelicerae to produce a sound much like the buzzing of a bee. 

 These curious spiders occur chiefly in Chile and adjacent regions, 

 and in South Africa. 



The species of Scytodes, sole representatives of the Scytodidae 

 in the restricted sense, are mostly very pretty creatures, with bodies 

 less than half an inch long tinted in clear white or yellow, and 

 delicately spotted and lined in black, or more boldly marked with 

 heavy dark spots or bands. The cephalothorax is oval and quite 

 elevated, sometimes nearly globose; the abdomen is oval; the legs 

 are very long and thin. The unpaired claw of the tarsi is usually 

 present and of small size, but it may be completely absent. These 

 nocturnal spiders live under stones, in rock fissures, in buildings, 

 and even on the leaves of plants, where they put down a thin, flat 

 web. The females carry the globular egg mass beneath the ster- 

 num, held in the chelicerae. A number of species occur in our 

 southern states, but they are well distributed. They have developed 

 one of the most interesting devices for capturing prey known 

 among spiders, which the following example will serve to illustrate. 



The spitting spider, Scytodes thoracica, handsome in a yellow- 

 ish coat marked with small black spots, is a cosmopolitan species 

 that occurs far north in the United States. In habit it is domestic, 

 and parades leisurely over the walls and ceilings of houses at night 

 in search of small food animals. When one is discovered, Scytodes 

 gives a convulsive jerk of its body and squirts a viscous gum from 

 its chelicerae, usually at a distance of a quarter to half an inch. The 

 victim is securely entangled and stuck to the surface by the gum, 

 which is laid down by the rapidly oscillating chelicerae in ten, 

 twenty, or more closely spaced, paraller bars. The spitting and 

 entangling is almost instantaneous; thereafter the spider moves lei- 

 surely forward to claim its prey. The viscous liquid is produced 

 in tremendously enlarged venom glands, which, although given 

 over largely to the production of viscous liquid, still produce a 

 quantity of venom. 



