THE SEASHORE 



181 



with acorn-shells, so that the movement of the curled legs may be 

 studied in a shallow dish ; everywhere under stones there are crowds 

 of amphipods (such as Gammarus 

 locusta\ scavengers of the shore ; 

 the protectively coloured shrimps 

 must be looked for in a sandy 



FIG. 99. Brittle star (Ophiopholis]. 



FIG. 98. Horse starfish (Hippasterias 

 phrygiana). M, the madrepore. 



pool ; and the higher Crustacea 

 are familiarly illustrated by the 

 common shore-crab (Carcinus 

 mcenas), so variable in its color- 

 ation when it is young, by the 

 swimming - crabs (Portunus\ 

 and the perennially interesting 

 hermit-crabs. 



To watch the action of the 

 baler in the common crab, to 

 search for one that has just 

 moulted, to distinguish (by the 

 clean-cut line of breakage) be- 

 tween a crab's moult and the 



shell of a dead crab, to look for FlG " I00 - Brittle star (Qpti 



a sand-crab (Hyas araneus) with a garden of sea- weed on its back, 

 or for a shore-crab with the remarkable crustacean parasite 



