I2O 



H. H. NEWMAN. 



poric pores or at least double pore-canals, while the remainder of 

 the larvae were quite typical. After a prolonged search in other 

 cultures of Asierlna, I was unable to discover any other larvae 

 with double madreporic pores. 



These double-pored larvae were .carefully watched and attempts 

 were made to rear them by introducing diatoms collected from 



FIG. i. Dorsal view of largest bipennaria, viewed as a transparent object. 

 The hydroenterocoel cavities are shown stippled. Note both left and right 

 madreporic pores, opening far apart ; distinct pore-canals on both sides. 



the kelp found in the tide pools inhabited by Asterina. They fed 

 to some extent on several species of diatoms, but made no progress 

 beyond the condition in which they were when the double-pored 

 character was first noticed. Instead, they slowly retrogressed in 



