484 



DEPTHS OF THE OCEAN 



especially sponges, coelenterates, bryozoans, brachiopods, and 

 tube - worms, with a few unattached forms, of which the 

 crustaceans are the most important. Most of the species of 

 attached forms belong to the sponges, coelenterates, and 

 bryozoans, though the brachiopods and tube - worms exceed 

 the others in number of individuals. The sponges are nearly 



Fig. 342. 

 Thejiea muricata. Bowerbank. 



all silicious, whereas in the littoral zone they are chiefly 

 calcareous. The principal coelenterates are attached coral 

 animals, especially gorgonians,^ alcyonarians, and hydroids. 

 We commonly get, for instance, one or two species of alcyonaria 

 of the genus Paraspongodes, the larger specimens of which 

 resemble cauliflowers ; in the same way we find Alcyonium 



1 Paramuricea placomtis, Primnoa lepadifera. In the same localities we also find two sea- 

 anemones {Phellia abyssicola and Bolocera ttiedia:), of which the latter also occurs on muddy 

 bottom in the deep parts of the fjords (see p. 482). 



