304 THE GREAT BARRIER REEF 



on being taken as far south as Sydney. The colours of 

 these splendid creatures were mostly pinks, oranges, 

 purples, and bright crimson, and the varieties were 

 hundreds in number. Considering that the temperature 

 of the sea a foot below the surface on the Barrier Reef 

 does not differ so much as a degree from that of the water 

 off the coast of New South Wales, it is singular that I 

 could not keep reef Anthozoa alive at the latter place, 

 especially as similar species obtained on the coast near 

 the Harbour Heads, Port Jackson, flourished well in a 

 small body of water. I suspect that it was the great 

 atmospherical change of temperature which affected them. 



In beauty of form, though not of tint, the reef 

 anemones are perhaps eclipsed by the glass-sponges, 

 which abound, especially at some considerable depth, on 

 the outer face of the Barrier. In delicacy and intricacy of 

 pattern these sponges excel the finest laces I have seen. 

 Here I found the largest sea-fans and brain-corals known 

 to me. All classes of Ccelenterates and sponges are very 

 numerous on the reef The sponges are mostly small, 

 and are found within the Barrier in water which does not 

 often exceed one hundred feet in depth. Outside the 

 reef there is as much as six hundred feet of water close 

 to its face, and in some spots quite two thousand feet. 

 This was the greatest depth I could sound, as I had no 

 more line with me ; but the chart shows that even the 

 latter depth is exceeded in a few places, though the depth 

 does not increase for a long distance to the eastward — an 

 unusual circumstance, I think, as the water a few miles, or 

 at any rate, a few hundred miles outside a coral reef is 

 usually of abysmal depth. Abysmal depths, however, are 

 not found in the immediate neighbourhood of Australia ; 

 and there seems to be evidence that the whole continent 

 is based on a coral formation of vast extent, which indicates 

 that it was, at a distant period, at least twice its present 

 area in extent. If this is really so, the tiny coral-zoophyte 

 is an even more wonderful land builder than it is univer- 

 sally known and admitted to be. 



On and about the reef nearly every sea-bird and fish 



