IV THE COLOURS AND PIGMENTS OF CCELENTERA 83 



Although descriptions of coloured organisms do 

 not as a rule convey much idea of their beauty, it may 

 illustrate the problem before us if we give details of 

 some of the corals studied by Mr. Saville Kent during 

 his sojourn at the Barrier Reef It is perhaps not 

 unnecessary to repeat that one must read into the 

 list of tints something of that purity of colour, that 

 varying light and shade, which have made the glories 

 of spring and autumn a never - failing source of 

 artistic inspiration. 



The Colours of Corals and Sea-Anemones 



Among the masses of coral which go to form the 

 reef, the different species of Madrepora, or stag's 

 horn coral, are usually very conspicuous. In this 

 country specimens of Madrepora are quite familiar 

 as slender branching stems studded with tiny 

 openings, but they reach us always in the white or 

 bleached condition ; in their natural condition almost 

 all are brightly coloured. Thus in one species 

 [M. prostratd) the whole colony is usually bronze- 

 green with yellow tips, but it may be bright green 

 with yellow tips, or more rarely shrimp-pink with 

 yellow tips. Again, another species is remarkable 

 in having the ends of its branches crowned by 

 larger cells than those which constitute the branches 

 themselves. In this case the branches are pale 

 yellow to white, the polypes being light brown to 

 greenish -yellow ; the large terminal cells are a 

 delicate china or bright turquoise blue, their con- 

 tained polypes being of an emerald - green tint. 

 Another species, M. hebes, shows a large amount of 



