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In several trochitee, projecting points are observable on their sides: 
some of these appear to have been intended chiefly for ornament : such 
appear to be the five regularly disposed processes on the trochites at 
Fig. 27, which, from their regular position, almost give to the trochites 
a pentagonal form. The entrochus, Fig. 7, is of a very peculiar form. 
It is composed of plain trochitae, alternating with sharp-i-idged and with 
knobbed trochitae of a larger diameter. This specimen is not in that 
state of perfection to allow of its being determined, whether or not the 
knobbed processes have served the purpose of articulation with any 
Other bodies, which have gone off laterally ; a circumstance which is 
rendered very probable, by the regularity of their form and disposition. 
It is to trochitae of this species that Mons. Davila gives the name of 
Trochites epmeuses, and to the minuter points of which Rosinus applies 
the term Aculei minimi. 
The entrochi, Fig. 4, 9, 45, 46, have also lateral processes. In 
these sufficient marks are discoverable by which it may be determined 
that these have been certainly for the purpose of articulation. Thus, 
for instance, by the aid of the lens, it is discovered that the lateral 
process of the trochites. Fig. 4, is not only a regular concavity, with a 
crenated margin, but that there is also, in the middle of the cavity, 
a small canal, which pierces through the body of the trochites, and 
passes into the common central cavity of the chain of trochites, or spinal 
canal. By this is shewn, not merely that this was an articulating surface, 
but that a due communication was here also preserved with the general 
organ of sense and of motion. 
Fig. 45 represents an entrochus which is very interesting. On the 
uppermost of the trochitae which compose it, three of these articulating 
processes are observable : a minute trochites is also discoverable on 
two of these processes, being the first of the new or second series of 
trochitae. 
The distorted column, Fig. 9, presents us with a set of trochitae 
which are ornamented by small projections on their sides. These 
