PALAEONTOLOGY OF NEW-YORK. 
138 
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CRINOIDEiE OF THE ORISKANY SANDSTONE*. 
Ilomocriiius proboscidalis (n. s.). 
Plate LXXXIY. Fig. 24 & 25. 
Body subturbinate : base large. Basal plates wider than long, hexagonal. 
Radial plates about as long as wide : brachial plates resting- upon the 
truncated upper edges of the radial plates. 
Arms bifurcating upon the third brachial plate, and again upon the third 
and fifth or sixth plate above the first bifurcation : bifurcations ap¬ 
parently equal. 
Proboscis long, fusiform, very slender below, and acquiring its greatest 
diameter at about two-thirds the distance from base of body to summit 
of proboscis. 
Column unknown. 
This little species resembles the H. scoparius of the Lower Helderberg group, but 
differs somewhat in the arrangement of the plates of the body and in the bifurcation 
of the arms. The arm-plates are not as broad as in that species, and they are’more 
incurved at the margins. It differs more conspicuously in the form of the proboscis, 
which is composed of plates as in the other species; but being entirely silicified, the 
structure cannot well be made out. 
Fig. 24. The specimen, natural size. 
Fig. 25. Enlargement of the body and bases of the arms. 
Geological position and locality. In the Oriskany sandstone : Cumberland, Md. 
* I am indebted to Mr. WilpiAm Andrews of Cumberland, Maryland, for the valuable and interesting 
collection of specimens of crinoids of the Oriskany sandstone, as well as for other fossils of the same rock 
and of the Lower Helderberg limestones. 
