226 XIPHOSURI. 



parent as glass, swim or rather glide through the water with their 

 backs downwards, whilst the undulating play of their numerous legs 

 causes currents that bring nutritive particles towards their mouth 

 in a continuous stream. 



The Salt-water Shrimps (Artemia scdina) are met with in the 

 salt-pans at Lymington, where they live in a brine sufficiently strong 

 to pickle a round of beef. 



THE SEVENTH ORDER OF CRUSTACEANS. 

 SWORD-TAILS (Xiphosuri)* 



This order contains bnt a single genus, namely 

 The King-Crabs (Limulus), a most extraordinary 

 race of creatures, commonly met with on the shores 



of tropical climates, both 

 of the old and new world. 

 In these animals the tail 

 is consolidated into a single 

 piece, forming a long, 

 pointed, and extremely 

 hard spine furnished with 

 jagged edges, and a point 

 so sharp, that in the hands 

 of savages, it forms a 

 weapon of most formid- 

 able character. The K ing- 

 Crab has no distinct head, 

 but its body is covered 

 with a broad, thin shell, 

 somewhat resembling in its 

 shape the hoof of a horse 

 hence they have obtained 

 the name of " Horse-foots " 

 from the inhabitants of the 

 coasts where they are found. 

 On turning over this sin- 

 gular creature we find that 



it possesses six pairs of well-formed feet, the thighs 

 or basal joints of which, armed with teeth and spines, 



* t<os, xiphos, a sivord ; ovpd, oura, a tail. 



