182 ON A CASE OF COMMENSALISM. 



figures concerning the commensalism of species of Amplii- 

 prion and Discosomidae. This naturalist found the giant 

 Discosoma (Stoichactis Hadd.) Kenti almost invariably lodging 

 two or more specimens of A. percula; »on thrusting a stick 

 into the oral orifice of the Anemone the fishes swim out, but 

 return immediately to their residence within the gastric cavity 

 of their host on the removal of the disturbing missile". Again 

 the allied Anemone, Discosoma (Stoichactis Hadd.) Hadcloni, he 

 saw always associated with individuals of another species 

 of Amphiprion^ A. hicinctus. In Western Australian waters '), 

 where he also met with the above-named Anemones, he 

 found D. Kenti accompanied by an other Amphiprion- 

 species, that had the orange ground-colour of the body of 

 A. percula and hicinctus substituted by a scarlet or black 

 hue as in A. Clarkii. Speaking about the meaning of this 

 commensalism for the Anemone, Mr. Saville-Kent makes 

 the suggestion that the fish fulfills for it at once »the 

 role of lures, attracting by its brilliant colours the notice 

 of other predatory fishes, which, hastening to seize an 

 apparently easy prey, are themselves entrapped within the 

 outspread tentacles of the passively expectant Sea-Anemones". 

 Mr, Sluiter, though not doubting that Anemones can seize 

 living fishes, says that he himself never observed it. How- 

 ever he believes that the moving to and fro of the fishes 

 causes a refreshing of the water which is of advantage for 

 the Anemone, and also that the fishes should draw near 

 some spoil, that is too far removed to be seized by the 

 Anemone itself. 



1) The Naturalist in Australia, 1897, p. 219. 



Leyden Museum, June 1902. 



Notes from the Leyden M.useiim, Vol. XXHI. 



