CRUSTACEANS 5 5 



independent, only visiting its bulky but helpless partner 

 during the breeding season. Various exotic forms similarly 

 quarter themselves upon sea squirts, sea urchins, or the 

 cavities in corals. 



A very large number of insects and spiders have their 

 being in a maritime zone, a few entering the salt waters. 

 For the purpose of this book, however, the only remaining 

 groups to be discussed are creatures standing midway 

 between the true crustaceans and the spiders and their 

 allies. 



The King Crab (Lz/nu/us) is an arachnid-like animal 

 of ancient lineage, which enjoyed its heyday during the 

 Jurassic Period many millions of years ago. Its nearest 

 kin are certain marine scorpion-like creatures, some of 

 enormous size, which disappeared with the dawn of 

 terrestrial vegetation. Few species of King Crab survive 

 to-day, and they are confined to coastal areas of moderate 

 depth on the eastern coast of South and Central America 

 and in the East from the Bay of Bengal to China, Japan, 

 the Torres Straits, etc. 



As shown in the text-figure, the King Crab has a seg- 

 mented body with paired limbs entirely covered by a 

 large dome-shaped carapace suggestive of the teutonic 

 military " tin hat." The sexes are distinguished by 

 differences in the fore limbs and in both the upper surface 

 of the carapace bears a median eye in addition to the 

 lateral organs of vision, the third eye being more apparent 

 in young specimens than in old ones. The long tail spine 

 is of sendee in righting the animal when, as frequently 

 happens, it turns turtle. 



