420 THE INHABITANTS OF THE SEA. 



floss silk round a little yellow mat ; and the lovely Euplectella, 

 whose beauty is imbedded up to its fretted lid in the grey mud 

 of the seas of the Philippines, is supported by a frill of spicules 

 standing up round it like Queen Elizabeth's ruff."* 



The stalked sea-stars, which, as the fossil pentacrinites and 

 encrinites testify, abounded in the past periods of the earth's 

 history, were, until now, supposed to be on the verge of extinc- 

 tion ; but when we consider that the first few scrapes of the 

 dredge at great depths have brought new species to light, we 

 are entitled to believe that they constitute an important element 

 in the abyssal fauna, and probably pave large tracts of the sea- 

 bottom with a carpet of animated flowers. Freely-moving sea- 

 stars and sea-urchins have likewise been hauled up in great 

 numbers from abyssal depths ; crustaceans have not been found 

 wanting, and the captured shell-fish have shown that the deep- 

 sea molluscs are by no means deficient in colour, though as a 

 rule they are paler than those from shallow water. 



DacryMum vitreum, dredged from 2,435 fathoms, a curious 

 little mytiloid shell-fish, which makes and inhabits a delicate 

 flask-shaped tube of foraminifera and other foreign bodies 

 cemented together by organic matter and lined by a delicate 

 membrane, is of a fine reddish-brown colour dashed with green, 

 and the animals of one or two species of Lima from extreme 

 depths are of the usual vivid orange scarlet. 



Some of the abyssal molluscs have even been found provided 

 with organs of sight. A new species of Pleurotoma, from 

 2,090 fathoms, had a pair of well-developed eyes on short foot- 

 stalks, and a Fusus from 1,207 fathoms was similarly provided! 

 The presence of organs of sight at these great depths leaves 

 little room to doubt that light must reach even these abysses 

 from some source, and as from many considerations it can 

 scarcely be sunlight, Professor Wyville Thomson throws out 

 the suggestion " that the whole of the light beyond a certain 

 depth may be due to phosphorescence, which is certainly very 

 general, particularly among the larvse and young of deep-sea 

 animals." 



Thus many of the creatures dredged in the Northern Atlantic, 

 off the west coast of Ireland,! m depths varying from 557 to 584 



* The Depths of the Sea, p. 73. 



t Ibid., Chapter III. Cruise of the " Porcupine," pp. 98-149. 



