544 SUPPLEMENT 
is performed by turning, although the animal, never- 
theless, finishes by arriving at the end which it desired to 
attain. 
The echini are said to be eminently carnivorous. It is even 
admitted that they feed upon crustacea and bivalves, but 
this is probably rather a conjecture deduced from the strength 
of their jaws, than a fact ascertained by observation. M. de 
Blainville has opened many, either taken alive, or preserved 
in spirits of wine, and never found any thing but sand in 
their stomach. M. Bosc, however, was a witness of the 
mode in which an echinus got possession of a crustaceum ; 
and it appears, that as soon as the latter was caught by some 
of the tentacular suckers, it was speedily masticated, and 
swallowed. 
We are yet ignorant of the mode of reproduction in the 
echini. We only know that it is in spring that they deposit 
their spawn, which appears to contain an almost countless 
number of eggs; and it is probable, that it is rejected in a 
mass all at once. But it does not appear that any naturalist 
has witnessed this. 
Genuine echini are known in all the quarters of the globe. 
The largest and most numerous, however, belong to the seas 
of warmer latitudes. 
The HOLOTHURIE were placed by Linnzus and Bruguiéres 
among their molluscous worms; and subsequently ranged 
by Pallas, Cuvier, and Lamarck, who better studied their re- 
lations near the asteriz and echini. We shall not repeat the 
characters of this genus here. 
Many authors, such as Hill, Brown, and Baster, have 
given the name of actinia to this genus. Linneus, for some 
time, gave it that of priapus. Gcertner preferred the deno- 
mination of hydra, and confounded these animals with the 
actiniz proper. This wasimitated by Bohatsch. Pallas re- 
turned to the name of actinia, which he divided into two sec- 
