OX SOME PELMATOZOA FROM CHAZY LIMESTONE OF NEW YORK 99 



Fig. 1 Analysis of the theca of Blastoidocrinus carchariaedens. The bra- 

 chioles have been drawn for one side of one of the deltoids and all their external ossicles out- 

 lined save a portion of those between the 1st and the 10th and the tips of the nth to the i8th. 

 The 6th external ossicles have been shaded as have also the 10th, 14th and 22d ossicles of the 

 uniserial brachioles. At a 7 the lower ossicles of the 7th brachiole have been drawn to a 

 larger scale. The wing plates of but two of the radii are shown. The piece marked "central 

 plate" is the apical piece. 



