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character of the encrinus, the separation into a pentapetalous form, 
begins to be displayed. In this body, the inferior surface, like that 
of the vertebrae, possesses a regular concavity ; but its superior sur- 
face is formed of five nearly triangular depressions, separated by 
as many linear projections, passing from the centre to the circum- 
ference. 
From the form and situation of this body, it may be considered as 
analogous with those parts which, in the preceding encrinites, I have 
considered as clavicles ; the only difference being, that here they are 
united in one piece, whereas in the former species they exist in five 
separate pieces. This body, or clavicle, is represented separate, 
Plate XVI. Fig. 4, united with the vertebrae at Fig. 7, and with the other 
parts of the animal, Fig. 8, a. 
That formation of the solid parts, or of the skeleton of the animal, 
next takes place, which we have already seen adopted, in the preced- 
ing species, as preparatory to the formation of the limbs of the animal. 
Five separate bodies, externally of a rhomboidal form, with inferior 
surfaces fitted to the superior surfaces of the bodies which have been 
just mentioned, and with superior surfaces exactly resembling their 
inferior, form the next series of solid parts, and which appear to answ'er 
to those parts which in the preceding species we have considered as 
scapulae. These are represented, Plate XVI. Fig. 8, b. where it will be 
also seen that, in the centre of the side of one of these, a foramen, and in 
that of another, a projection is observable, showing that from these parts 
articulated processes had been given off, in the same manner as from 
some of the trochitae already noticed. 
On the superior surfaces of these last-described bodies are placed 
five others, which are the first series of those which may be considered 
as forming the arms of the animal. The inferior surface of each of 
these bodies forms an obtuse angle exactly agreeing with the angle 
formed at the union of the preceding bodies, and in which angle 
these bodies are disposed, whilst the superior surface is regularly 
