496 



INVERTEBRATA 



CHAP. 



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

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



o ,= 



"H 3 



2 

 o 



g 

 o 



& 



o 



2'C 

 30, 



o 

 o . 



-3-3 



g s 



-M 5 SO 



O S 



01 >> OT 



CD 



01 OJ ^- 



P := g 



^ 

 *- c 

 o 



C g 



^ 3 



o - 



CO 



rt 



o ^d t^ 



n -P 2 2 



OJ 



co 

 d 



CD S '~ 



?> ^ 



- rS OJ Ol 



I'S g 



- ^3 

 'S S 2 



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

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

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



