148 



absorbed (liiiiiif; iiu'tamorpliosis, bul arc kept iiitacl as a lloaliii^ appa- 

 ratus and Iheii dropped, when the young Opliiurid has completed meta- 

 morphosis and is ready to give up pelagic life. Tlic long posterolateral aims 

 remain in connection, after the Ophiurid has gone, their ciliated hand 

 being intact and in the |)resenl case, moreover, joining in the middle, 

 below the Ophiurid (this takes place before IheOiihiniid leaves the "larva"). 

 While in the case of Ophiolhiix tiie abandoned jjosterolateral arms must 

 evidently soon perish, this appears not to be the case with the present 



Fig. 7.">. Skeleton of Ophiopluteus opulenlus, s|)ecies c. ^,. 



Fig. 76. Basal part of posterolateral roil of the saino species. '•""/,. 



larva. As stated above (p. 124) it seems fairly certain that a new larval 

 body regenerates in the place of the former larval body. How far 

 the process of regeneration goes cannot be ascertained; but in any case 

 PI. XX, Fig. 5 shows that it may go on so far as till the formation of a 

 new mouth and esophagus; it is also evident from the numerous nuclei 

 seen in the anterior part of the new body that a vigorous growth is going 

 on here, so that it would seem most probable that the process may continue 

 the short while, until the new digestive organs are able to assume normal 

 function — and then there seems to be no reason to doubt that a new 

 complete and ultimately metamorphosing larva may be the result. Thus 

 we would here have a true case of metagenesis, otherwise totally un- 

 known in I^Lchinoderms. — As explained above (p. 124) the suggestion that 



