780 THE CRINOIDEA CAMERATA OF NORTH AMERICA. 
rather long quadrangular pieces. Pinnules long. Anal plate in size and 
form resembling the radials. Anus and ventral disk not visible in the 
specimens. 
Column near the calyx straight, but at 5mm. from the calyx it curves 
abruptly back upon the crown, then it enlarges, and by a reverse curve coils 
upon itself and the included calyx and arms, giving off from alternate joints 
at the concave side two rows of long cirri, which sometimes completely 
envelope and conceal the crown. Near the calyx, the stem joints are short 
and circular, but they gradually grow longer and crescent-shaped, their 
width increasing from 2 to3mm. ‘The cirri are very long and stout at their 
proximal ends, but terminate in a sharp point. They are composed of about 
sixteen to eighteen joints, which are as wide as long, and radiate from the 
centre of the spiral curvature of the stem. | 
Horizon and Locality. — Keokuk group; Indian creek, Montgomery 
Co., Ind. 
Types in the collection of Wachsmuth and Springer. 
Camptocrinus cirrifer W. and Sp. (nov. spec.). 
Plate LXXVI. Figs. 18a, 6, ¢. 
In its general aspect closely resembling the preceding species, the calyx, 
however, shorter, especially the basal part, which occupies only one third 
the length of the dorsal cup, being but slightly convex at the bottom, and 
rather deeply depressed in the centre for the reception of the column. Radi- 
als once and a half as long as wide, the sides nearly parallel, the upper faces 
slightly excavated to one half their width. Costals two, very short, the 
intervening suture lines obscure; the first linear, the second subtrigonal, its 
sloping upper faces at right angles. Arms two to the ray, simple, slender, 
divergent, thread-like in the upper portions, and composed of long, quadran- 
gular joints. Pinnules of moderate length and not in contact. All plates 
perfectly smooth. Structure of ventral disk and anus unknown. 
The column is narrow in the upper portions, but gradually increases in 
width downward, until at an inch and a half from the basals it is twice as 
wide as at the top. Close to the calyx it bends abruptly upward to a level 
with the top of the radials, then reversing it curves downward, either gently 
to the end, or— more generally — forming a coil around the crown. The 
stem joints are short and circular near the calyx, but soon grow longer, and 
the section becomes oval and gradually crescent-shaped with the concave 
