Cer 418.°°"’) 
CLASS X. ECHINODERMA. 
Remarks. The organic structure of the ani- 
mals of this class is more complicated than that of 
any other class of this division. They have an 
organized covering, often sustained upon some- 
thing resembling a skeleton, which supports sharp 
processes or spines sometimes moveable. They 
have animperfect vascular system, and their res- 
piratory organs are often very distinct. Some 
species have fibres, which seem to supply the of- 
fice of nerves. 
ORDER 1. PEDICEKLLATA., 
Having stem-like moveable processes which per- 
form the office of feet. | 
ASTERIAS, (sea-star,) body depressed, covered 
with a coriaceous crust, muricate with tentacula, 
and grooved beneath; mouth central, five-rayed. 
In sea. 
Encrinus, (stone-lily,) a stem divided into nu- 
mereus articulations ; its branches are like the 
stem, and subdivided dichetomously. Its fossil 
remains have been. called entrochites, which are 
pieces of the stems and branches of this genus. 
Ecuinus, (sea-urchin, sea-hedghog,) body 
roundish, cevered with a bony sutured crust, and 
generally furnished with moveable spines; mouth 
placed beneath, and mostly five-valved. In sea. 
HoLornuria, body detached, cylindric, thick, 
naked, and open at the extremity ; mouth sur- 
ems by fieshy branches, tentacula or feelers. 
n 6ea, 
