538 SUPPLEMENT 
The ASTERIZ, or STAR-FISH, whose species are greatly 
multiplied in all known seas, are remarkable for their stellated 
form. Their body is invested with a coriaceous substance, 
bristling with tubercles or spines, or covered with scales. In 
some species it has the figure of a flatted pentagon. In others, 
the angles of the disk extend in lobes, or are elongated into 
radii, most frequently five in number, sometimes more numer- 
ous, and simple, or divided into ramifications. 
~The mouth, armed with five teeth, of a calcareous sub- 
stance, is placed at the central part of the animal underneath. 
No tentaculum is remarked there. It leads into a membra- 
naceous sac, of small extent, which serves as a stomach, and 
from which the excrements are rejected, and issue through the 
same aperture. O. Fabricius, and Bosc, are, indeed, of opi- 
nion, that the excrements are filtrated through an osseous 
tubercle, which is observable in the back of the asterie, a 
little on one side. But this opinion cannot be well founded, 
inasmuch as this tubercle is not existent in all the species of 
the genus. It seems to be generally wanting in the ophiuri. 
Besides, we are not acquainted, as it would seem, with any 
other animal, in which it is necessary that the excrements 
should pass through a filter, to issue forth from the sac, or 
alimentary canal. Some short, cylindrical, retractile tenta- 
cula, very numerous, ranged in pairs underneath, or on the 
sides of the divisions of the animal, are developed on the in- 
stant, in which it is desirous to hook itself, or to walk. We 
see on its upper part, but only while it isin the water, an in- 
finity of small conical tubes. The mouth is a sort of respira- 
tory organ, which constitutes with the stomach, and the ovary 
divided into as many pairs of branches as there are arms, all 
the apparent organs of the asteriz. Some osseous articulated 
stems form the skeleton of each branch. A net-work of the 
same nature strengthens the rest of the envelope. 
The asteria are very voracious; they walk with difficulty, 
