90 



THE WONDER OF LIFE 



ceans have a rich representation at many levels of com- 

 plexity, and there are quaint Sea-Spiders or Pycnogonids 

 which are neither spiders nor crustaceans ; most of the 

 molluscan types are in abundant evidence ; and finally 

 there is a weird army of voracious abyssal fishes. 



Adaptations. — ^A common feature in the sedentary 

 Deep-Sea animals is the possession of long stalks on which 

 the more essential parts of the body are raised high out 



of the treacherous ooze. We 

 see this useful adaptation in 

 the surpassingly beautiful 

 Crinoids which grow some- 

 times in great beds, in 

 Alcyonarians such as Umbel- 

 Mas and Funiculinas, and in 

 some of the sponges hke the 

 Glass-Eope-Sponge. In some 

 of the Alcyonarians the sup- 

 porting stalk which bears the 

 colony of polyps on its sum- 

 mit may be over a yard in 

 length. 



A similar adaptation is seen 

 in the extraordinarily long 

 hmbs which many of the 

 Crustaceans and Sea-Spiders 

 exhibit. They illustrate an 

 extreme of lanMness and they 

 may be thought of as walking 

 on stilts. In many cases the 

 hmbs are several times longer 

 than the body. There can 



FlQ. 30. — Deep-Sea Brittle 

 Star or Ophiuroid, Astro- 

 charis virgo, showing the 

 disproportionate elonga- 

 tion of the arms — very- 

 liable to breakage — and 

 the very small central 

 disc. {After Koehler.) 



