EXPLANATIONS OF PLATES 

 Blastoidocrinus carchariaedens Billings (sp.) 



Page g7 



The upper figure shows the oral surface with its star-shaped apical piece. 

 The wing plates were lost from ray IV exposing several of the covering 

 pieces. Six of these and the outer boundaries of the double row were 

 partly outlined with ink on the original photograph. Although the 

 figures have been reduced to less than half the diameter of the originals, 

 additional boundaries can still be detected. The upper boundaries of 

 the deltoids were also marked. 



The lower figure shows the aboral surface of the same specimen. A few of 

 the sutures were lined with ink on the photograph. Pencil marks used 

 in finding the center were allowed to remain and two circles drawn from 

 this center. On the outer of these, small portions of extended radii were 

 marked to show the slight displacement of the rays. With the exceptions 

 mentioned there has been no retouching of the photographs. 



The original is from a yet undetermined horizon of the Chazy limestone of 

 Valcour island, Lake Champlain, but the position is probably near the 

 upper portion of the middle beds. 



The specimen is in the possession of E. M. Hudson. 



