MONOGRAPH OF THE EXISTING CBINOIDS. 



267 



Fig. 30S. 



Fig. 309. 



Figs. 308-309.— 30S, Dlvgram snovpiso the reuttie size and frequenct of the arms and orri in Pkntametrocrintjs 



VARIANS; THE CIRRI ARE NUMEROUS, VERY LONG, AND BUT SLIGHTLY CURVED, AND SERVE TO FORM A CIRCULAR MAT BY 

 WHICH THE ANIMAL 13 SUPPORTED ON SOFT OOZE. 309, DIAGRAM SHOWING THE REHTH'E SIZE AND FREQUENCY OF THE ARMS 

 AND CIRRI IN ASTEROUETRA MACROPODA; THE CIRRI ARE FEW, VERY LONG, STOUT, AND SPINOUS DORSALLY, ADAPTED FOR 

 CLINGING TO A VERY ROUGH HARD SURFACE. 



