576 DEPTHS OF THE OCEAN 



remarkable being the larvae of starfishes, ophiuridae, and sea-urchins. In 

 the larvae of the ophiuridae (see Fig. 411) the skeleton consists of rigid 



^-- 



Fig. 410. 

 Velella spiralis, Esch. (From Steuer. ) 



Larva of Ophiothrix fragilis, O. F. Mtiller (about -\-). (From Mortensen.) 



P^lG. 412. 



Arachnactis albida, M. Sars. Nat. size. (FromSars. ) 



rays of carbonate of lime, with a belt of cells provided with whip-like 

 hairs, by the aid of which they swim ; these larvae go through wonderful 

 metamorphoses before finally attaining the adult form. 



