470 



INVEKTEBEATA 



CHAP. 



future star-fish and are termed collectively the aboral disc. As 

 the ventral horn of the left posterior coelom extends further and 



Tn.d.a / I, i).; 



Fig. 362. — Lateral views of the brachio- 

 larjan phase of the larva of A sterias 

 vulgaris in various stages of fixation 

 and metamorphosis. (After Goto.) 



A, earliest stage: temporary fixation by 

 means of the brachiolarian arms : prae-oral 

 lobe undiminished. Bj later stage : permanent 

 fixation by means of the fixing disc: the 

 prae-oral lobe is much shrunk. C, still later 

 stage ; the prae-oral lobe has almost dis- 

 appeared : metamorphosis almost complete. 

 Lettering as in Fig. 360. In addition, 

 Jix, the disc by which the larva fixes itself; 

 roman numerals I-V, the rudiments of 

 the five arms. 



further round to the rights and grows in size, the right posterior 

 coelom and the disc covering it become displaced backwards, and 



