EMBRYOLOGY OF ECHINODEKMS. 



117 



1 



n. 



w. 



b. 



FIG. 67. 



FIG. 67. Dorsal view of a slightly older larva. (Drawn from nature 

 by W. K. Brooks.) 

 a, a', b, c,f, I, m,p, s, audio. As in Fig. Go. 7;. Ku liment of lateral arm. 



