242 THE GREAT BARRIER REEF. 



gaily-decorated, bright yellow and rose-coloured type, was dredged from a depth of six or seven 

 fathoms, in the centre of the most prolific pearl-shelling ground at the Western end of Torres 

 Strait. The tentacles in this form differ essentially from those of the typical reef-feeding varieties. 

 In the latter they are mop-like, and specially adapted for sweeping food particles off the rock or 

 mud-surfaces on which the animals feed. In Colochirus, as in the British genera Psolus and 

 Cucumaria, the tentacles are subdivided into minute filamentous ramifications, and are utilised 

 more after the manner of a set-net, to intercept floating organisms in the surrounding water. 

 In both instances, and also in Synapta, the process of food ingestion is identical, the pabulum 

 being transported to the gullet by the complete inversion of the food-laden tentacles, in consecu- 

 tive and almost rhythmical succession. 



