CRUSTACEA IN RELATION TO MAN 255 



numerous the burrows are driven so close together 

 that the surface of the wood is reduced to a spongy- 

 mass which is rapidly washed away by the waves 

 (Plate XXXII.). The Gribble is often accompanied 

 by another Crustacean of similar habits, the Amphi- 

 pod Chelura terebrans. The latter is about one-fifth 

 of an inch in length, and differs from most Amphi- 

 pods in having the body somewhat flattened from 

 above downwards instead of from side to side. The 

 burrows made by Chelura are shallower than those of 

 the Gribble, and generally run more or less parallel 

 to the surface of the wood. 



