496 CLASS ECHINODERMATA, 
and of tentacula, and an organization pretty nearly similar to 
that of the actiniz. But they are united in a more or less 
considerable number, on a common base, sometimes in the 
form of a creeping stem. (Hydra sociata, Gm.) Sometimes 
in the form of a broad surface. (Alcyonium mamillosum, Ell.) 
LUCERNARIA, Miill. 
It would appear, should be approximated to the actiniz ; 
but their substance is softer; they fix themselves to fucus 
and other marine substances, by a slender pedicle; their 
upper part is dilated like a parasol; the mouth is in the 
middle. Numerous tentacula approximated in fasciculi, fur- 
nish the edges. Between the mouth and these same edges, 
are eight organs, in the form of cceca, which proceed from the 
stomach, and contain red and granulated matter. 
In Lucernaria quadricornis, Miill., Zool., Dan. xxxi. 1—6, 
the edge is divided into four forked branches, each supporting 
two groups of tentacula. In the Z. awricula, Ibid. clii. the 
eight groups are equally apportioned round an octagon edge. 
SECOND ORDER OF POLYPI. 
POLYPI GELATINOSI, 
ARE not, like the preceding, invested with a hard envelope, 
neither do they produce in the interior of their structure an 
axis of ligneous, fleshy, or corneous substance. Their body 
is gelatinous, of a form more or less conical ; its cavity serves 
as a stomach. 
