THE ZOOLOGICAL STATION AT NAPLES 215 
Among the echinoderms the methods of feeding are interesting. The 
sea-cucumber holds fast to a rock by means of the suckers at the tips 
of its tube-feet, and, with tentacles widely expanded like the branches 
of a tree, waits for minute crustaceans and the larve of all sorts of 
animals to comfortably settle themselves upon the hospitable branches. 
Then, with the least possible motion, the sea-cucumber very gradually 
bends a tentacle over and into the mouth, and, as it is again extended 
one of the two small tentacles scrapes off the resting organisms. So 
each tentacle, in rhythmical succession, takes its turn in the feeding 
process. Some species of star-fishes have large mouths and can swal- 
low snails and mussels whole, sometimes consuming as many as twenty- 
five or thirty mollusks of various kinds at one meal. Other star-fishes 
have mouths too small to receive the animals commensurate with their 
appetites and so they simply turn their stomachs inside out, covering 
over a clump of oysters, and thus forming a sort of external stomach 
into which the secretion from the digestive glands is poured. When 
the soft parts are thus dissolved and absorbed the star-fish pulls in its 
stomach and goes on in its devastating course. The sea-urchin has an 
apparatus known as Aristotle’s lantern providing five strong teeth 
worked by powerful muscles with which it catches live worms and 
crabs. The sea-crawfishes, built like lobsters except for the absence 
of the large pincers, most perfectly convey the impression of life on 
the bottom of the sea. They seem like uncanny agents of evil as they 
solemnly stalk about over the rocks, poking their great antennae into 
each other’s affairs and always having several claws out for a fight, 
yet seldom engaging with one another. Some of the veterans, however, 
have lost an antenna, or a leg, and the missing parts are being regen- 

THE PALM-LIKE RINGED WORMS. 
