WHIP-SCORPIONS AND OTHERS 121 



the third and fourth legs of the female, but sometimes pass be- 

 hind her back legs. Their tips are generally crossed. At the same 

 time the chelae of the male are held open and are moved slightly 

 over the dorsal surface of the abdomen of the female. 



When the female is pregnant, she seeks shelter. Thelyphonus 

 caiidatiis digs a burrow some 40 cm in depth and slightly enlarged 

 at its extremity. The entrance is concealed with leaves and other 

 debris. The female installs herself at the bottom of the burrow 

 where she lays some 20 to 35 yellowish eggs. These are retained in 

 a transparent membrane fixed beneath her genital sternite. They 

 are comparatively large, measuring about 3 mm in diameter, and 

 are protected from desiccation by a quantity of liquid produced at 

 the time of their emission. 



The female remains motionless in her retreat for several weeks. 

 The exact incubation period is not known however, as captive 

 females usually devour their eggs. The young free themselves by 

 cutting the egg-sac with special spines on their legs. They are 

 yellowish-white in colour and very different in appearance from 

 the adults. After a while they climb slowly on to their mother's 

 back and cling to her opisthosoma and the base of her back legs 

 by means of the adhesive discs with which their tarsi are furnished. 

 Here they remain until after the first moult when they acquire the 

 typical form and resemble miniature adults. Now they leave their 

 mother who has become so thin and weak as a result of her pro- 

 longed vigil that she falls into a state of lethargy from which she 

 does not recover. The development of the young is extremely slow. 

 They undergo three more moults at yearly intervals before be- 

 coming adult (Strubell, 1926). 



Order schizomida 



Classification and distribution 



Schizomida, sometimes known as Schizonotidae or Tartaridae, 

 differ from the Thelyphonida, with which they are often grouped, 

 in their small size — they measure from 5 to 7 mm in length — and 

 in having the carapace subdivided into three unequal divisions, 

 the propeltidium, mesopeltidium and metapeltidium. The last 



