302 THE MEDALS OF CREATION. ” Gwar. Vile 
t 
cula are protruded. The mouth is situated in the centre of 
the under surface. Now if we imagine a Star-fish placed with 
its mouth upwards, and the five rays fringed with long arti- 
culated tentacula, as in the Comatula, and fixed by the centre 
of its dorsal surface upon a jointed stem, we shall have the 
essential characters of a crinoidean ; and the animals of one 
recent tribe of Astercade are actually in this condition in 
the earlier stage of their existence: these are the Comatule, 
or Feather-stars, in some of which (the Zuryaie), the arms 
are as numerously subdivided as in the Pentacrinites.* © 
From the importance of the Crinoidea in the economy of 
the ancient world, the history of the only type at present. 
inhabiting Europe, the ancient seas of which swarmed with — 
numerous forms of these beautiful creatures, presents many — 
points of interest. The receptacle of the soft body of the 
Comatula, like that of the “Crinoideans, consists of a cup- 
shaped calcareous base, which sends off from its margin five 
arms, that quickly subdivide, and are beset on each side with 
rows of articulated pinne; on the convexity there are also 
numerous slender, jointed, simple, tentacula. The mouth 
is situated in the centre of the area surrounded by the arms, 
and is capable of being elongated into a proboscis. In the 
young state, the Comatule are attached by a jointed stem — 
to other bodies, as shown in Lign. 91, jig. 1, which repre-— 
sents several of the natural size; jig. 1% is an enlarged view — 
of an individual, and closely resembles an expanded Crinoi-— 
dean. The stem is composed of about eighteen joints, which — 
are pentangular ; after a few weeks the Feather-star becomes — 
detached from its peduncle, and ranges the sea in free- 
dom.t 
* The reader interested in this subject should peruse the charming 
volume on British Star-fishes and other Echinoderms, by Professor 
Edward Forbes. 1 vol. 8vo. John Van Voorst. 1841. 
+ The researches of J. V. Thompson, Esq. first brought to light 
these interesting facts in the Natural History of the Comatula; this 
