THE EYES OF ECHINODERM AT A 95 



The small elevation on the " ocular plate," although it was at one time 

 thought to be a rudimentary eye, has, however, been shown to be a 

 vestigial tentacle. This vestigial tentacle, however, corresponds to the 

 " terminal tentacle " of the star-fish at the base of which the " optic 

 ganglion " is developed. 



