THE KING CRABS 



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sixth ending in a number of flattened plates. The basal segments of the second, 

 third, fourth, and fifth limbs are furnished with large processes, projecting into the 

 mouth and studded with numbers of slender softish spines. The mouth is thus 

 situated between the bases of these limbs, near the middle of the lower surface of 

 the cephalothorax. The males differ from the females in having the second, or sec- 

 ond and third pairs of limbs thickened and otherwise modified. In the male of the 

 round-tailed king crab (Limulus rotundicauda) the second and third pairs are con- 

 siderably swollen, and the two fingers of the nippers cross each other when closed; 

 whereas in the Moluccan king crab (Z,. moluccanus} the immovable fingers of these 

 limbs are reduced to short processes. 



In distribution, king crabs are limited to the east coast of the United States, 

 to the shores of China and Japan, and of the Indo-Pacific islands, ranging from the 

 Moluccas to Singapore and Java. In the last-named area two species, L. moluccanus 

 and L. rotundicauda, occur. The Chinese species is known as L. longispinus, on 



CHINESE KING CRAB. 



accounts! the long and strong spines projecting from the carapace and abdomen; 

 while the North- American species is L. polyphemus. The habits of the last-named 

 species are tolerably well known. It spends the greater part of the year in water 

 from two to six fathoms deep, and, being unable to swim, creeps about the bottom 

 of the sea in search of food, or even lives buried in mud, into which it scoops its 

 way. This it effects by thrusting the front edge of the carapace forward and 

 downward into the mud, the tail behind being used as a prop, while the legs are 

 engaged in raking up the mud and pushing it out sideways. The tail is also of 

 service in helping the animal to regain its proper position if turned upside down. 

 Digging the tip of the organ into the soil, the crab raises its body, and after a few 

 efforts succeeds in struggling over. In fact, were it not for the possession of a 

 long tail, the king crab would be as helpless on its back as a tortoise in the same 

 position. 



King crabs feed almost exclusively upon soft marine worms and bivalve mol- 

 lusks. The food is seized and tucked into the mouth by means of the legs, where 



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