54 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



is now some fifty times as large as the original embryo. It is 

 now ready for the metamorphosis. 



FIG. 4. Free-swimming 

 larva (Brachiolaria) of 

 starfish. (After Weysse.) 



The waw disk-like area 

 at tie lleT end of figure 

 represents the portion of 



FlG> 5 ' Free-swimming larva (Brachio- 

 Iaria > f starfish ' 



The stippled areas in the central and 



the body which will remain lower parts of the figure indicate the posi- 



after the transformation to tion of the digestive tract, the mouth be- 



the adult stage. Compare ing shown at the left-hand edge of the 



Figs. 5 and 6. figure, with the intestinal opening below. 



The external changes by which the metamorphosis is ac- 

 complished, and the habits of the young starfish, are described by 

 Mead* as follows: 



"Already the rudiment of the resulting starfish can be seen 

 within the brachiolarian. The five crenate lobes on the margin 

 of the disk are the beginning of the five arms. The disk itself 

 at this time is already somewhat opaque. 



1 When the larva is about to ' set/ it attaches itself to some 

 object, like a spear of eelgrass, by the suckers, shown at the 

 top of the figure (Figs. 4 and 5), and then a rapid transformation 



* Bull. U. S. Fish Commission for 1899. 



