86 Guide to Arachnida. 



Table- has been introduced into all the warmer regions of the world, and 

 cases Nos. ]g found in oceanic islands. 

 ' " ' Scorpions are carnivorous, feeding chiefly on insects. As is 



well-known, they are poisonous; the poison glands, which are 

 paired, are situated in the terminal bulb of the tail. The larger 

 species mostly construct deep burrows with their pincers, others 

 live in shallow excavations under stones or under the hark of 

 fallen trees. 



A representation of the burrows of the common Egyptian 

 scorpion [ButJiits quinquestriatiis) is placed in Wall-case 7. 



The young of scorpions are born fully formed, but in some 

 species at least they are still enclosed within the egg-shell at birth 

 and are liberated by their mother or by their own efforts. Until 

 they are able to shift for themselves they are carried about on the 

 back of the mother; a female example of a South American 

 scorpion (Centrurus margaritatus.), carrying its family on its back, 

 is exhibited in Table-case 19. 



The classification of the scorpions is still in an unsettled state ; 

 the recent species are an'anged by Mr. Pocock in four families : 



1. PaNDINIDAE. 2. BOTHRIURIDAE. 3. VeJOVIDAE. 4. BUTHIDAE. 



A representative series of scorpions is displayed in Taiile- 

 case 20. 



Fam. 1. — I'aiidhiidac. 



This family, which contains the largest of the existing 

 scorpions, is found in Africa, South Asia, Australia, and South 

 America. It is characterised by having the sternum of the 

 cephalothorax pentagonal in shape, and by the presence of only 

 a single pedal spur upon the feet. (Genera : Pandinus, Opidhoph- 

 thahniis, Urodacus, etc.) 



Fam. 2. — Botliriuridac. 



This family is confined to South America and Australia. It is 

 characterised by having the sternum strongly compressed antero- 

 posteriorly, and reduced to a short but wide transversely-lying 

 plate. There are two pedal spurs on the feet. (Genera : Botliri- 

 urus, CcrcophoniiiH, etc.). 



Fam. 3. — Vejovidac. 



The representatives of this family are found in South Europe, 

 Asia, and North and South America, Imt are entirely unknown in 



