452 ., CLASS ECHINODERMATA. 
de Stok., 1767. The feet of its central disk are on three 
series. 
Others have the inferior face altogether flat and soft, fur- 
nished with an infinity of feet, and the superior face gibbous, 
supported frequently by osseous scales, and pierced on the 
front, with a star-like orifice, which is the mouth, and from 
which the tentacula issue; and on the back part with a round 
hole, which is the anus. 
We have a small one, Hol. squamata, Miill., Zool., Dan. 
x. 1,2,3,; but there are some of these of a tolerable size in 
the warmer seas. 
Others have the body cartilaginous, flatted horizontally ; 
trenchant at the edges; the mouth and feet at the inferior 
face, and the anus at the posterior extremity. 
Such is in the Mediterranean, 
Pudendum regale, Fab., Column, Aquat. xxvi. 1. Hol. 
regalis, Nob., a species more than a foot in length, three or 
four inches broad, and crenulated all round. 
Others, again, have the body cylindrical, susceptible of 
enlargement in every direction by the absorption of water ; 
all the under part furnished with feet, and the rest of the 
surface variously bristled. 
Our seas, especially the Mediterranean, produce in great 
abundance one of blackish colour, which is more than a foot 
long in its greatest extension. Its back is bristled with 
conical and soft points; its mouth is furnished with twenty 
branched tentacula; it is the Holothuria tremula, Gm., 
Bohatch., Anim. mar. vi. and vii. 
Some are found in which the feet are distributed in five 
series, which extend like the ribs of a melon, from the 
mouth to the anus, which has caused them to be called sea- 
cucumbers. 
Such is in our seas. 
Hol. frondosa, L. Gunner, Mem. de Stok. 1767. pl. iv. f. 1, 
