182 
PALEONTOLOGY OF NEW-YORK. 
JOINTS OF UNDETERMINED CRINOIDEA. 
Pl. A XLT. Figs. 7o-e. 
These bodies, from their structure, are apparently the joints of crinoidal columns, which have 
been worn smooth, and the marginal angles worn down to a rounded edge : the canal is also 
rounded and enlarged, and the whole presents a flattened globular appearance with a depression 
in the centre. When these bodies are separated from the stone, the two sides are precisely 
similar. They vary in thickness from half an inch to the fiftieth part of an inch. The thicker 
ones are mostly found in the iron ore, and appear not so much worn as macerated and dissolved. 
They present in fact the same peculiar oolitic aspect with the materials of the iron ore, where 
all the little fragments of fossils, of whatever kind, have lost their angular character. In the 
shale at Sodus and other places there are many thin joints of this kind, which are clearly worn 
or dissolved away on the prominent edges and angles, and they all present the smooth uniform 
character peculiar to the thicker ones in the iron ore. Some of these appear to be composed of 
more than one joint or articulation, but so closely united that there is no line of separation except 
upon the edge. All these are crystalline in structure, and those in ore are replaced by crystallized 
carbonate of iron. 
In their external aspect the rings have lost all the characteristic features of the Crinoidea, 
but their crystalline structure is a clearly distinctive character on which we can rely. 
Fig. 7 a. One of these rings, presenting a smooth globular surface, with a smooth opening in the 
centre. The thickness of this one is nearly a quarter of an inch. 
Fig. 7 b. The impression left in the iron ore by a larger individual, the thickness of which was 
more than a quarter of an inch. 
Fig. 7 c. A very thick one, with a small opening in the centre. 
Fig. 7 d. A small specimen of the same character. 
Fig. 7 e. View of the edge of a very thin specimen. 
Position and locality. All the specimens figured are from the iron ores south of Mohawk 
village, on Steele’s creek. Similar specimens, but smaller and thinner, occur in the shales of the 
lower part of the group in Wayne county. ( state Collection.) 
576. 1. CARYOCRINUS ORNATUS. 
Pl. A XLI. Fig. 1. 
For description, see this species under Niagara group. 
The only specimen known in the Clinton group, presents the anomalous structure shown in 
the figure referred to. The difference between this structure and the structure usually found 
in this species is clearly shown by a comparison with the figure on Plate 49. The difference in 
this one appears to result from the modification or imperfect development of the second series 
of plates, and the absence in part of the third series or scapular plates, allowing the arms to 
