170 



CASWELL GRAVE. 



the ciliated bands of the fully formed auricularian larvae at the 

 time when the metamorphosis into the adult form is about to take 

 place. Semon's figures of the auricularian larva and the pupa 



M 



- H 



FIG. I. Auricularian larva of Synapta digitata. After Semon. M, mouth ; ff, 

 hydroccele ; A, anus. The ciliated bands stippled. 



of Synapta digitata are reproduced in outline in Figs. I and 2. 

 During the pupal stage the mouth shifts from a ventral to a ter- 

 minal position and the tentacles and tube feet first become func- 



FIG. 2. Pupa of Synapta digitata. After Semon. A, anus; T, tentacles; I, 

 2, 3, 4 and 5, ciliated rings. 



tional. The ciliated rings of the pupa are five in number and are 

 arranged transversely to its long axis. 



