130 TUBIPORA. PART m. 



do not touch one another, but they are united at inter- 

 vals by horizontal plates, formed of an extension of 

 their bases, dividing their mass into stages. In the 



Tubipora musica, a native 

 of the Indian Ocean, there 

 are several superincumbent 

 series of equal and parallel 

 tubes, exactly like the pipes 

 of an organ. The whole 

 compound fragile mass is of 

 the richest crimson, and the 

 Fig. 128. Tubipora musica. polypes spread their white 



tentacles like stars over the 



mouths of the uppermost pipes, or retreat into them. 

 Buds spring from the upper part of the tubes, and the 

 result is the death of the parents, which are succeeded 

 by a young living race a stage above them. The Tubi- 

 pora purpurea lives in the Mediterranean and Eed Seas. 

 The polypes of a species found by Professor Dana, at the 

 Feejee Islands, have their centre and mouth of a brownish 

 red, and their tentacles yellow, edged by a double fringe 

 of violet-coloured pinnules. 



Actinian Zoophytes. 



The great family of the Actinian zoophytes abounds 

 in genera and species. The common Sea Anemone, or 

 Actinia, of which there are more than seventy species on 

 the British coasts, is the model of the minute polypes 

 which inhabit the stony corals, and build the coral reefs 

 and atolls of the tropical Pacific. 



The Sea Anemone has a cylindrical body, attached at 

 one end by a sucker to rocks or stones at no great depth, 

 and a flat circular disk at the other, with the mouth 

 in its centre : the mouth, which is surrounded by a 

 series of tubular, smooth-edged, radiating tentacles, re- 



