ARACHNIDA — EMBOLOBRANCHIATA 



Fossil scorpions are rarely found. The earliest examples 

 known occur in the Silurian rocks, and belong to the genus 

 Palaeophonus. In the Carboniferous Hoscoiyius is found, and 

 in the Oligocene 'Tityus. 



Much remains to be discovered with regard to the habits of 

 scorpions, and most of the isolated observations which have been 

 recorded lose much of their value through the uncertainty as to 

 the species concerned. The brief accounts given by Lankester 

 and by Pocock,^ and the more recent and elaborate studies of 

 Fabre," are free from this defect and contain almost the only trust- 

 worthy information we possess. 



All are viviparous, and the females carry the newly-hatched 

 young on their backs. They are predaceous, feeding for the most 

 part on insects and spiders. These are seized by the chelate 

 pedipalps, and, if small, are simply picked to pieces by the chelicerae 

 and devoured, but if large the tail-sting is brought into play and 

 the victim quickly paralysed. The process of eating is a slow 

 one, and a Cape scorpion in captivity took two hours to devour a 

 cockroach. 



In walking, scorpions carry their pedipalps horizontally in 

 front, using them partly as feelers and partly as raptorial organs. 

 As regards the body the attitude varies considerably. In some 

 cases {Parccbidhus, Prionurus, etc.) it is raised high upon the legs, 

 and the " tail " or metasoma is curved forward over the back, but in 

 others (JSuscorpius) the body is held low, and the " tail " is dragged 

 along behind, the end only being slightly curled. In the day- 

 time they hide away under wood or stone, or in pits which they 

 dig in the sand. Parabuthus capensis was observed to dig a 

 shallow pit by means of its second and third ambulatory legs, 

 resting on its first and fourth legs aided by the chelae and the 

 metasoma. Those that hide under wood are usually found 

 clinging to their shelter ventral side uppermost. In captivity 

 the creatures, though supplied with water, were never observed to 

 drink ; indeed, they are characteristic inhabitants of arid steppes 

 and parched wastes. Like most Arachnids they can endure 

 prolonged abstinence from food. 



The only sense well developed seems to be that of touch. 

 Notwithstanding the possession, of Several eyes their sight is 



' Nature, xlviii., 189.3, p. 104. 

 ^ Souvenirs entomologiques, Ser. 9, 1907, p. 229. 



