154 



NEW YORK STATE MUSEUM 



late, and are made up of long, strongly cuneiform joints. Stem 

 consisting of circular joints pierced by a circular axial canal. 



Stephanocrinus angulatus Conrad (Fig. 48) (Hall. 1852. Pal. 

 N. Y. 2:212, pi. 48, 83) 



Distinguishing characters. Thick, equal stem joints, with crenu- 

 lated, articulating margins, and minute round canal; form of calyx 



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y^ 



\ :-V 



St"vV .V 



-^ 



Fig 48 Stephanocrinus angulatus with an enlargement of the stem and an analysis of the calyx 



reverse pyramidal, gradually spreading from a triangular base up- 

 ward; sutures scarcely visible; three basals, one pentagonal and two 

 heptagonal; radials hexagonal with short excavated upper side; in- 

 terradials broad below, contracting upward to form the coronal 

 points; strong and angular carinae, six of which alternately con- 

 verge upward and downward, while two others, somewhat stronger, 

 extend from the bases of the heptagonal basals to the summit of the 

 radials immediately succeeding; elevated tuberculated striae of the 

 plates which extend transversely, vertically or obliquely on different 

 parts of the calyx; surface sometimics merely tuberculated. 



Found in certain thin calcareous layers of the lower Rochester 

 shale at Niagara, sometimes quite abundantly. Also in the same 

 shale at Lockport (Hall). The crinoid is generally much lighter in 

 color than the inclosing rock, and is easily distinguished. Associated 



