IV. Diviston, 
COADUNATA ? 
Character of the Division. 
Tue joints of the pelvis anchylose to the first columnar joint. 
Observation. 
I have been induced to constitute this fourth division from the occurrence 
of a single species, in which the pieces composing the bulbous body of the 
animal, instead of being connected by articulations or sutures as in the pre- 
ceding division, are united together by a solid and continuous anchylosis; it 
will be seen, however, that some doubts may be reasonably entertained, whe- 
ther the circumstances described may not arise from the imperfect develope- 
ment of the separate pieces, in that cartilaginous state which characterises the 
early stage of growth in these animals; should this prove to be the case, the 
genus which I have formed for the reception of the only species known to me, 
and which forms the subject of the following article, would certainly fall under 
the first division, and perhaps (as will hereafter be noticed) may be only the 
younger state of a species belonging to the Genus Encrinus ; on these accounts 
I have placed this division, which can only be considered as of a temporary 
nature, at the end of the series, and marked it with a note of interrogation. 
