152 THE WORLD OF THE SEA. 
depth of 260 fathoms! It belonged to a species generally found 
only in a fossil state, and here it was living under an enormous 
pressure, and far out of the reach of the light of day. The asterias 
are peculiar to the sea; they have no fresh water representatives. 
Certain species are extremely numerous—so numerous, indeed, that 
the sea-board population cart them away to manure the land. 
The star-fishes are variously coloured. Some are a greyish 
yellow, some an orange yellow, others a dull red, or a violet. 
Their bodies are surrounded by a calcareous envelope, com- 
posed of pieces placed side by side, united by fibres. These 
THE VIOLET ASTERIA. 
(Uraster violaceus.) 
plates are armed with tubercles and pricks; M. Gaudry found 
more than 11,000 of them on a red star-fish—that species which 
is most common in Europe. 
The asterias have a mouth at the centre of their lower sur- 
face. There are also upon this under surface globular drop-like 
protuberances, which are furnished with arm-like appendages; 
and it is from the globular projections that the organs are put 
forth, which are really the feet. of the creature. These form a 
double or quadruple row; they consist of a fleshy cylinder of a 
greyish colour, and in most cases are terminated by a little glo- 
bular vesicle filled with a watery liquid. This vessel is capable 
of great extension. When the creature wishes to push out its 
foot, it causes the globular vessel to contract; this forces the liquid 
into the cylinder, which is consequently stiffened, and can be 
