292 ZOOPHYTES, SPONGES, ETC. 



Gaudy as the zoophytes of the reefs often are, 

 those of the dark unfathomed caves of ocean, though 

 they are born to blush unseen, and to waste their 

 beauty in the pit, undeniably surpass them both in 

 richness and daintiness of colour. The Umbellulas 

 range from deep purple and puce to pink, the sea- 

 pens are arrayed in the same colours, though some 

 are of a lurid orange : among the Alcyonarians we 

 see every tint from a deep crimson to a faint rosy 

 hue or a delicate lavender. 



The branching bush-like zoophytes of the abysses, 

 no less than those of the littoral zone, afford con- 

 venient cover for many kinds of worms, echinoderms, 

 and Crustacea, and we know of several instances 

 where the guest has become specially adapted to its 

 host. Again, the simple zoophytes, such as the sea- 

 anemones, have the same tendency as their kindred 

 of the shallow-water to form those permanent partner- 

 ships with hermit-crabs, of which two or three peculi- 

 arly perfect cases have already been mentioned. 



The true stony-corals [Madreporaria) exist even 

 in the profound abysses of the ocean, though in the 

 Indian basins, 1070 fathoms is the greatest depth at 

 which, up to the present, they have been dredged. 

 Of course they are all very different from the reef- 

 building species, and with two exceptions our Indian 

 deep-sea corals belong to genera very remote from 

 those found anywhere near shore. Most of our 



