ANIMALIA RADIATA. 327 
produces trunks and expansions forming all sorts of figures. It 
is to this circumstance, together with the simple nature of the 
organization in most of the species, and the radiating disposi- 
tion of their organs which reminds us of the petals of flowers, 
that they owe their name of Zoophytes or Animal-plants, by 
which we merely mean to express this apparent aflinity, for as 
Zoophytes enjoy the sense of touch and the power of volun- 
tary motion, mostly feed on matters which they have swallowed 
or sucked, and digest them in an internal cavity, they are cer- 
tainly animals in every point of view. 
The greater or less degree-of complication in Zoophytes 
has occasioned their division into classes; but as all the parts 
of their organization are not yet well known, those sections 
cannot be characterized with as much precision as those of 
the preceding divisions. 
In Asterias and Ursinus, called Ecuinoprermes by Bru- 
giere on account of their spines, we find a distinct intestine 
floating in a large cavity, and accompanied by other organs, 
for generation, respiration, and a partial circulation. The 
Holothoriz were necessarily united to them on account of the 
analogy of their internal organization, which is perhaps still 
more complex, although they have no movable spines on the 
skin. 
The Enrozoa or Intestinal Worms, which form the second 
class, have no very evident vessels in which a distinct circu- 
lation is carried on, nor separate organs of respiration. Their 
body is usually elongated or depressed, and their organs ar- 
ranged longitudinally. The difference in their system of 
digestion will hereafter probably cause them to be divided 
into two classes, a circumstance already indicated by our es- 
tablishing two orders. In some we find an alimentary canal 
suspended in a true abdominal cavity, which is wanting in 
the others. 
The third class comprises the ACALEPHA or Sea Nettles. 
They have neither true circulating vessels nor organs of res- 
piration. Their form is usually circular and radiating, and 
their mouth is almost always their anus. They only differ 
