234 THE NATURALIST IN AUSTRALIA. 
area of their growing surfaces is thickly studded with the expanded polyps. These, 
when fully extended, are about three quarters of an inch in diameter, possess twenty- 
four almost uniformly even subulate tentacles, and are coloured a still lighter 
yellowish green. 
W., Saville-Kent, Photo. 
REVOLUTE CUP CORAL, Turbinaria revoluta, S.-H. SHARK’S BAY, WESTERN AUSTRALIA, ONE-THIRD NATURAL SIZE. 
An extensive reef area of Turbinaria conspicua, viewed through the clear water, 
while drifting over it in a boat, presents, on account both of the colour and contour: of 
its component coralla, a most remarkable resemblance to subaqueous plantations of 
Brobdingnagian, crinkled-leaved, savoy cabbages. As has been previously remarked 
in Chapter V., the genus Turbinaria is a coral group that would appear to attain to 
the zenith of its development in the somewhat cooler waters on the outskirts of the 
tropics, and has been observed by the writer to flourish under such conditions, to 
the exclusion of other species, in the Gulf of Carpentaria and in South Queensland 
waters. Nowhere, however, has it been found by him to attain to such a plenitude 
of development, with regard both to the number of varieties and the magnitude of 
their individual coralla, as in Shark’s Bay, Western Australia. 
A final example of this very characteristic generic group is photographically 
portrayed on this page. It represents a specimen also gathered by the writer at 
Shark’s Bay, which has been retained in his collection as a sort of “ewe lamb” 
out of the flock of its comrades donated to the National Museum, which it will 
probably rejoin later on. This specimen takes the form of a shallow cup, between 
