82 THE FAUNA OF THE DEEP SEA 



of the disc, now along one arm, now along another, 

 and sometimes vividly illuminating the w^hole out- 

 line of the star-fish.' 



According to Filhol many of the abysmal Annelid 

 worms are in the habit of emitting a vivid phosphor- 

 escent light, and capable thereby of illuminating the 

 medium in which they live. 



We have now considered all those characters ex- 

 hibited by deep-sea animals that may be associated 

 with the absence of direct sunlight. To run through 

 them again briefly we may say : that the deep-sea 

 species, belonging to classes of animals that usually 

 possess eyes, show some modification in the size of their 

 eyes, in that they are either very large, very small, 

 or altogether wanting. That deep-sea animals are 

 nearly always uniformly coloured. Very frequently 

 they are black or grey or white, less frequently 

 bright red, purple, or blue. But whatever the 

 colour may be, spots, stripes, bands, and other 

 markings of the body are very rarely seen. That 

 deep-sea animals are brilliantly phosphorescent, the 

 light being emitted either by special organs locally 

 situated on the head, body, or appendages, or by the 

 general surface of the body. 



But there are some other characters that cannot 

 be thus associated with the absence of sunlight. 



