CLASSIFICATION AND CREATION. 47 
the centre to the periphery. Cutting it across 
transversely, or looking through its transparent 
mass, the same radiation of the internal structure 
is seen again; only that in this instance the radi- 
ating lines are not produced by vertical partition- 
walls, with open spaces between, as in the Polyps, 
but by radiating tubes passing through the ge- 
latinous mass of the body. At the periphery is a 
Melicertum seen from above, with the tentacles spreading: 0 0, radiating tubes 
with ovaries ; m, mouth; ¢¢tt, tentacles. 
circular tube connecting them all, and the tenta- 
cles, which hang down when the animal is in its 
natural position, connect at their base with the 
radiating tubes, while numerous smaller tentacles 
may form a kind of fringe all round the margin. 
The third and highest class includes the Star- 
Fishes, Sea-Urchins, and Holothurians or Beches- 
de-Mer. The radiation is equally distinct in each 
of these; but here again the mode of execu- 
tion differs from that of the two other classes. 
