236 
as not, I believe, to show its original surface ; and hence it is impos- 
sible to determine at present any thing respecting the substance with 
which it was connected at this part, or the kind of articulation which 
was here employed. It, however, very nearly resembles the smaller 
modiolus, from Ireland, which is represented in Plate XVIL 
Among the enigmas which must be left to be solved by the indus- 
try of future inquirers, into the original nature of the various species 
of encrinites, there is no one which appears to me to be more difficult 
than the determining the original properties and mode of existence 
of the animal, of which a part of its vertebral remains, in the state of 
hme-stone, is represented Plate XVI. Fig. 16. Two remarkable cir- 
cumstances in this fossil must attract your admiration, and, of course, 
excite your curiosity : the contorted forms in which the vertebral column 
IS disposed, and the remarkable processes which appear to have issued 
from the sides of the vertebree. 
The first inquiry which naturally arises, on viewing the parts of 
an animal disposed in a form entirely different from that which 
any other species of that kind of animal assumes, is, whether or 
no that position is the effect of accident ? To this question I ac- 
knowledge that, on the first view of this specimen, I was much in- 
clined to anticipate an affirmative answer. A careful examination 
into the structure of these fossil remains, soon, however, convinced me 
that these contortions were natural to this part of the animal, and 
that the construction here adopted displayed the most admirable in- 
stance of tbe wise adaptation of means to the accomplishment of a 
proposed end. In the examination of most of the preceding species 
of encrinites, we discovered that, for the purpose of securing a 
greater degree of freedom of motion, in that part of the vertebral co- 
lumn which was nearest to the superior extremity of the animal, a 
peculiar structure was employed the vertebrae were alternately 
wider and narrower, and the narrower were received into the perpendi- 
cularly lengthened margin of the wider ; the outer crenulated edge of 
