Blastoidocrinus carchariaedens Billings (sp.) 

 Page 97 



Figures a-f are of radials of different ages viewed from their bases and showing 



radiating grooves and marginal growth lines. 

 Figures g-h are of exterior surfaces of radials viewed in an inverted position. 



It is this surface that forms the inside of the craterlike hollow at the base. 

 Figure i shows the interior surface of a radial, the thick sutures where it 



meets the bibrachials and the larger interradials, and the narrowing at the 



suture to meet the smallest of the lower interradials. 

 Figures j-k are of radials seen from their edges ; j has a vertical ridge on the 



interior surface for the attachment of viscera, this ridge is not present in 



i and k. 

 Figures 1-n are of bibrachials; 1 shows two as they join each other, m shows 



the interior surface and the remarkable widening of the face of the suture, 



n shows the exterior surface, and a deltoid suture with its transverse 



respiratory grooves. The last plate is of a less common form, i. e. is more 



acute at the apex. 

 The plates figured show some marked variation but all are from the same 



locality as the more complete specimen. They are now in the New York 



State Museum. 



