496 



INVEETEBEATA 



CHAP. 



stomodaeum, as homologous with the adult mouth of an Ophiuroid, 

 then we might say that in the Ophiuroid this point is displaced hy 



growth towards the left side, whereas in the Asteroid it disappears and 

 is replaced iya new growth farther to the left. Therefore the Asteroid in 

 this respect obviously exhibits a more modified course of events, and 



