52 



THE VOYAGE OF H.M.S. CHALLENGER. 



the young Erichthus are bordered with spines as in Alima, and the general structure of 

 the larva is very ^ ^ma-like ; a resemblance which totally disappears in the older larvae. 

 Habitat. — Common below low water mark on sandy beaches at Beaufort, N.C., 



U.S.A. 



