CARNIVOROUS CRUSTACEA AND KING-CRABS 145 



given up, though the outward resemblance to a leg is still more 

 or less apparent. King- Crabs are found where the sea-bottom 

 is composed of mud, upon the surface of which they crawl, aided 

 by the shoving action of the tail-spine, which is further used 

 to right them if accidentally turned over. They also burrow 

 into the mud, largely aided by the last pair of legs, the ends of 

 which are peculiarly modified, and by the tail -spine, which is 

 employed as a prop. The food consists of bivalve molluscs 

 and marine worms, which are chewed between the bases of the 

 legs. 



VOL. II. 42 



