224 8POLIA ZEYLAMCA. 



preserved specimens it often happens that most of the setae are 

 lost : they are deciduoTis, those of the dorsal tuft being provided 

 with recurved barbs by which they remain attached to foreign 

 bodies when touched or handled. The function of the setse is 

 therefore partly defensive, but during what may be called the 

 swarming period the tufts of setae act as paddles or swimmerets, 

 working to and fro in succession like the legs of a centipede, 

 accompanying the swaying movements of the body when swim- 

 ming. It is not common to obtain full-sized specimens of this 

 worm, and the three which the Museum has acquired in recent 

 years have been kindly sent by Mr. A. D. Prouse from the 

 Harbour Works, one in March, 1904, another in January, 1905, 

 and a third in January, 1906. 



The small crab which I have called the Boxing Crab was taken 

 by me last November at Weligama from under a rock close 

 to the shore at the northern end of the bay. It affords a singular 

 and by no means widely known example of symbiosis or com- 

 mensalism between a crab and sea-anemones or Actinians. In 

 each claw the crab holds a small white sea-anemone in full 



activity, tentacles expanded, which it presents with great science 

 in true boxing attitude to the observer, when alarmed. It is 

 impossible to exaggerate the singularity of the action. The 

 ground colour of the crab is whitish with a delicate roseate flush 

 in the anterior half of the carapace, and a characteristic pattern 

 formed by blackish lines ; there are tufts of bristles behind 

 the frontal margin and on the surface of the carapace. 



I forwarded a sketch of the living crab and its two guests to the 

 Indian Museum, Calcutta, and was favoured by Major A. Alcock, 

 F.R.S., with the name of the crab and references to the literature 

 dealing with it. It is not mentioned in Dr. J. G. de Man's 

 Crustacea of the Mergui Archipelago (Journ. Linn. Soc, London, 



