232 



'^rf^" 



fa,' 



Cll' 



Figure 181: Stichopus japonicus. 



Formation of coelomic diverticula — rudiments of primary tentacles. 



he — hydrocoel; sc — somatocoel . 



The bands of cells in the perioral field are sensory. According to Semon 

 (1888), these cells are provided with cilia. Sensory cilia are also situated on 

 the anterior end of the larval body, where the aboral organ is located. 



The diverticula of the hydrocoel may be considered rudiments of the 

 definitive organs in the auricularia. The elastic spheres situated at the ends 

 of the lateral processes of the auricularia can be considered rudiments of the 

 provisional formation of the next larval state, the doliolaria. 



