﻿Blastoidocrinus carcharidens Billings 



Fig. i Reproduced from photomicrograph of the weathered face 

 of the type and showing the position of the stem which 

 Billings took to be a natural one. X3. 

 Shows also the outer edges of three displaced columnals at 

 lower right of stem. These were uncovered by the re- 

 moval of some of the foreign material lodged in the 

 basin formed by the infolded radials. 

 2 The proximal portion of the stem shown above as revealed 

 by a photomicrograph taken through a gum dammar 

 mounting. The broken edges of the basals are clearly 

 revealed and the beginning of the narrow stem lumen 

 shown. The displacement of the columnals due to prob- 

 able inthrust at death (the form being covered and pre- 

 served from passage through the alimentary canal of 

 some larger form with consequent plate separation) is 

 clearly manifest. 

 3 A detail of the hydrospires shown just to the right of the 

 proximal end of the stem in fig 1, xio. The rounded inner 

 edges of the water-bearing cavities of the hydrospires 

 have been weathered away in the upper portion of the 

 figure but still show just below the broken edges of the 

 sheetlike sides of these cavities. 



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