282 PALEONTOLOGY OF NEW-YORK. 
There is some difficulty in making out the entire structure, since the plates usually adhere 
very closely, and some of the pectoral and interbrachial plates are very small. The 
important parts, however, and the plates proceeding to the arms, are readily and clearly 
determined. 
This fossil is usually found destitute of the column; and I have not been able to decide 
satisfactorily whether all the fragments found with it are parts of the same, or belong to 
two species. The first, which evidently belong to this species, and form the upper part 
of the column, consist of joints, having a small base resting upon the broader disc of 
the next one below, giving more freedom of motion. Other portions have the upper sur- 
face of the disc excavated, and the column appears to be composed of a series of cups, 
alternating in size and placed one within the other, having the upper edges either smooth 
or fimbriated (figs. 1 a and 1 8, pl. 78). These columns have usually a distinct round 
alimentary canal, with the upper and lower surface marked by fine rays, more deeply 
impressed near the edge. In other parts of the column, where the plates are more nearly 
equal in size, the upper and lower surfaces have a pentapetalous impression or elevation 
radiating from the alimentary canal. This character, in fine, becomes the prominent and 
characteristic one of the greater proportion of the fragments of columns which we find ; 
and they present all the variety of broad equal smooth joints with even surfaces, or of 
similar joints with a thin plate interposed, and of columns composed of moniliform joints 
with smaller ones between ; or of distant rounded joints, sometimes deviating slightly from 
a cylindrical form. All the important varieties are illustrated by figures. 
Pirate LXXVIL. 
Fig. 1 a. A fragment of stone with two small specimens, preserving the tentaculated fingers. 
Fig. 1 4. Figure of a larger specimen, showing the character of the plates and their arrangement 
more distinctly. The bases of the fingers, with about five or six joints, are preserved in this 
specimen. 
Fig. 1 c. The upper extremity or crown of the last specimen, showing the capital plates. 
Fig. 1 d. The same enlarged. 
Fig. 1 e. A portion of the surface enlarged, showing the form and character of the plates, and the strong 
radiating ridges. 
Fig. 1 f. An enlarged figure, showing the structure and arrangement of the plates as described. A 
small portion only of the plates of the fingers are represented, but there are no subdivisions 
beyond this point. 
Pirate LXXVIII. 
Fig. 1 a. A figure of a specimen, preserving a small portion of the column and the entire length of 
the fingers. 
Fig. 1 b. Fragments of columns, composed of alternating larger and smaller dises with angular edges. 
suggesting that it may be an Apiocrinite, which proves otherwise on examination. From his account, it would 
appear that the first specimen was found at Cincinnati, in 1837. This species is probably one of those named in Dr. 
Owen’s Catalogue ; but I have never seen a description of the same, nor received a specimen with the name attached. 
