80 STAR-FISHES, SEA-URCHINS, ETC. 
Synapta takes in large quantities of fine pebbles, 
sand, and shell, from which it doubtless extracts 
considerable nourishment. These objects are dis- 
tinctly visible through the walls of the body and 
intestine. 
A much stouter form of the sands is the Caudina, 
Fy 
J 
4 
é 
’ 
i 
rey 
tel 
sal 
st 
ro 
rm 
e 
ot 
Gy 
e 
Y, 
", 
CAUDINA ARENABIA. 
which is sometimes thrown up in considerable num- 
bers after a storm. Its color is light yellowish, the 
texture is tough, and in a distant way the animal 
might be likened to a cucumber greatly attenuated 
at one extremity. 
