624 
RADIATA. 
separate ; the reproduction is attended with very curious transformations. They generally live 
on moUusca and other animals found in the sea. 
The animals of this class are divided into four orders, Holothurida, Schinida, Stelle-rida^ and 
Orinoidea. 
THE COMMON SEA-CtJCUMBEK. 
ORDER 1. HOLOTHURIDA. 
The animals of this order, called Sea-Cucumbers, are covered with a very elastic, leathery skin, 
kept moist by mucus that exudes through the pores ; they have a somewhat worm-like appear- 
ance, the radiate structure being only visible in the tentacles which usually surround the mouth. The 
ambulacra, though short, resemble those of the other Echinodermata in their number and action. 
The Sea-Cucumbers are of various forms, some of the species being found in nearly all seas. 
They generally live among sea-weed or in mud, and are supposed to seize their prey by their 
tentacles. They have the power of 
elongating and contracting their forms 
so as at one time to appear like 
worms, and at another to assume the 
shape of an hour-glass. One of the 
largest species, the Great Sea-Cucum- 
ber, Cucumaria frondosa, found in Eu- 
ropean seas, is a foot long. The Angu- 
lar Sea-Cucumber, C. pentactes, is 
also a European species, with double 
rows of warty suckers. There are 
many other species, common in the At- 
lantic and other seas, some of which 
are eaten ; the Trepang, liolothuria 
edulis, is an article of luxury ..rnong 
the Chinese. It is very abundant on 
the north coast of New Holland, and 
is collected there by the Malays in 
THE ANGULAR sEA-cucuMBEK. j^rge quautitlcs, drlcd, and packed up 
in bags for the Chinese market. The 
Malays and Chinese meet at the Island of Macassar, where the principal trade in this delicacy is 
carried on ; and the quantity annually brought to that place by the fishermen is said to amount to 
upwards of four hundred tons. The price varies according to quality, from eight dollars to one 
hundred and fifteen dollars per pecul of one hundred and thirty-three pounds. 
ORDER 2. ECHINIDA. 
The animals of this order are covered with calcareous plates, forming a convex shell, more or 
less globular, with an opening at each end. The division into five parts is as distinct here 
as in the star-fishes, notwithstanding the total absence of arms, the holes through w^hich the 
