EMBRYOLOGY Or ECHINODEEMS. 



117 



b. 



Fig. 67. 

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

 by W. K. Brooks. ) 

 a, a', b, c, f, l,m,p, s, and w. As in Fig. 65. n. Rudiment of lateral arm. 



