94 



THE GENESIS OF SPECIES. 



[ClIAI' 



head of a bird, with an upper and lower heak, the wliole 

 supported on a slender neck. The beak opens and shxits 

 at intervals, like the jaws of the pedicellaria3 of the echi- 

 nus, and there is altogether, in general principle, a remark. 



A POLTZOON WITH OIBD's-HEAD I'BOCESSES. 



able similarity between the structures. Yet the echiiuis 

 can have, at the best, none but the most distant genetic 

 relationship with the Polyzoa. We have here again. 



