128 THE LIFE OF CRUSTACEA 



accident, a by-product of physiological processes 

 directed to other ends, not a character of protective 

 or warning value, as in animals that hunt and are 

 hunted in the light of day. It is a curious fact, 

 which may have some bearing on this problem, that 

 in many cases, while the adults are coloured in some 

 shade of red, the eggs carried by the female are 

 bright blue or green. 



Some of the peculiarities of structure observed in 

 deep-sea Crustacea seem to be correlated with the 

 difficulties of resting or moving about with security 

 on the soft ooze of the sea-floor. Among the Crabs 

 we find a preponderance of long-legged species, not 

 only among the true Spider Crabs (Oxyrhyncha), but 

 also in other groups (Dromiacea like Latreillia^ 

 figured on Plate XIX., and Oxystomata), the 

 members of which assume the same spider-like form. 

 In some cases the legs are fringed with long stiff 

 hairs, which may help to prevent the animal from 

 sinking in the ooze, and the spines on the body and 

 legs of many species may have the same effect. 

 Among the deep-sea Prawns, the species of the 

 family Nematocarcinidae (Plate XVII.) have ex- 

 tremely long and slender legs, which we may assume 

 to be used like stilts for walking over the soft ooze. 



Not much is known regarding the food of deep- 

 sea animals. In the absence of plant-life they must 

 of necessity be all carnivorous, and all ultimately 

 dependent on the food-supply falling from above. 



