92 THE BIOLOGY OF THE SEA-SHORE 



other similar phenomena are often just as important for 

 offensive as for defensive purposes, enabling the animal to 



Fig. 8. — Spider-crab partly masked by sponge on front of carapace. 



Stalk its prey or to lie in wait for it unseen. For instance, 

 the habit possessed by Tealia crassicornis of covering its 

 warty body with particles of shell and gravel found in shore 



