Plate 60. 



Showing some Features of the Internal Anatomy of 

 Echinothrix diadema Loven. 



1. Interior view, showing arrangement of alimentary canal ; actinal half of test and lan- 



tern removed. 



2. Interior view, showing part of reproductive organs, alimentary canal and perignathic 



girdle; one side of test removed. 

 .3. Alimentary canal, removed from test; natural position, seen from below, 

 4. Lantern and perignathic girdle in position, seen from the side, showing the rudimen- 

 tary Stewart's organ just below the forked end of the compass. 



All figures natural size. 



