MONOGRAPH OF THE EXISTING CKIXOIDS. 



163 



new plate formed will develop along the same lines as the plates already present 

 in that zone. 



The zones of similar skeletal potency of the ocliinoderm are not entirely radial 

 as has commoidy been assumed, but are chiefly concentric about the dorsal pole as 



FIG. 101. 



FIG. 102. 

 Fios. 101-102. 101, DORSAL VIEW OF A SPECIMEN or STROTOMEIRA ORNATKSIMA FROM CELEBES, SHOWING THE ENORMOUS 



EVERSION OF THE DISTAL ENDS OF THE EARLIER BRACIIIALS. 102, LATERAL VIEW OF A SPECIMEN OF STROTOMETRA ORXA- 

 TISSIMA FROM CELEBES, SHOWING THE ENORMOUS EVERSION OF THE DISTAL ENDS OF THE EARLIER BRACUIALS. 



a center, a circumstance which is at once explained when we remember the homology 

 between the sides of a crinoid from the dorsal aspect to the ventral perisome with 

 the sides of an insect or crustacean. 



