522 



DEPTHS OF THE OCEAN 



Hydroids are little in evidence ; the vast thickets of these 

 animals found on the plateaus are absent.^ Alcyonaria are 

 chiefly represented by the genus Paraspongodes, with its 

 cauliflower-like colonies, numbers of which also flourish in 



tsf;^:?^^ 



Fig. 365. 

 Sclerocrangon ferox, G. O. Sars. (After G. O. Sars. ) 



warmer waters ; apparently the same species occur in both 

 areas, the most widely distributed being P. fritticosa. 



The commonest molluscs are shelled snails of the genera 



Fig. 366. 

 Amat/iillopsis spinigera, Heller. Slightly magnified. (After G. O. Sars.) 



Nephmea and Sipko. There are cuttlefishes of the genus 

 Octopus, though never in any great quantity, and another very 

 remarkable form is the rare Cirroteuthis miti/eri, one of the 

 eight-armed group, whose members diff"er from the other in 



' The most characteristic representatives of this group, belonging to the family Myriotiielicla- 

 (genus Lampra), are rare. 



