420 THE INHABITANTS OF THE SEA. 
floss silk round a little yellow mat; and the lovely Euplectella, 
whuse 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 molluses are by no means deficient in colour, though as a 
rule they are paler than those from shallow water. 
Dacrydium 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 larvee and young of deep-sea 
animals.” 
Thus many of the creatures dredged in the Northern Atlantic, 
off the west coast of Ireland,t in depths varying from 557 to 584 
* The Depths of the Sea, p. 73. 
{ lbid., Chapter III. Cruise of the “ Poreupine,” pp. 98-149, 
