WHIP-SCORPIONS AND OTHERS 125 



is composed mostly of smaller, cavernicolous forms having a dis- 

 tribution in southern and eastern Asia and the Pacific islands, 

 while the latter contains three sub-families: the Phrynicinae which 

 are found in Africa, India and Ceylon, the Damoninae which 

 occur in Africa and South America, and the Tarantulinae which 

 are entirely American. 



Biology 



As already mentioned, most of the Phrynichida live in humid 

 regions under logs and stones, or in crevices among rocks, where 

 they can move freely. Unlike the Thelyphonida which rest on the 

 ground if the object under which they are sheltering is lifted up, 

 they are usually to be found clinging to its under surface. They 

 will dart round the stone beneath which they were hiding in order 

 to evade capture, but seldom try to escape to other stones. The 

 tailless whip-scorpions are again nocturnal carnivores and spend 

 the day hiding in their dark retreats. When suddenly exposed to 

 the light, they do not at once flee, but freeze into immobility. If 

 touched, however, they can run with surprising speed. Their 

 movements are somewhat unpredictable; they usually move side- 

 ways like crab spiders, walking with the six posterior legs ex- 

 tended sideways while the first pair are waved like antennae and 

 explore the surface over which the animals are travelling. When, 

 the creatures are at rest, however, these legs may be slowly rotated, 

 one forwards and the other backwards, so as to sweep a large area 

 round the body. They resemble the writhing of tentacles rather 

 than the more typical movements of arthropod antennae. The 

 extreme tip is used to touch the surface which is being invest- 

 igated and this is done with tapping movements of extreme deli- 

 cacy. 



Thanks to their tarsal pulvilli, the Charontidae can climb 

 vertical surfaces and run about underneath the ceilings of caves. 

 Charinides bengalensis^ for example, can climb a vertical sheet of 

 polished glass and even walk across the lower surface of a horiz- 

 ontal sheet while the Tarantulidae, lacking pulvilli, cannot do 

 this. 



A number of species have become domesticated and live in dark 

 corners of houses in tropical regions. Examples are aflforded by 



