Mr. F. A. Bather on British Fossil Grinoids. 315 



prejudice,' not implying any homology between Echinozoa 

 and Pehnatozoa. In his ' Challenger ' Reports Dr. Carpen- 

 ter has spoken of B and C as Right, D and E as Left ; but 

 he agrees with me that the orientation adopted by Wachsmuth 

 and Springer, which is the one I now follow, is practically 

 the most convenient for the description of fossil Crinoids. 



In using the terms Proximal and Distal I reckon from the 

 Chambered Organ ; so that the Infrabasals and the top Stem- 

 ossicle are the proximal elements of Crown and Stem respec- 

 tively. 



Differential Characters. 



Of the many characters in which the genera of the Fistulata 

 differ from one another, the following have been with justice 

 considered as of chief importance : — ■ 



23-* 



