168 



sp. a (PI. XXIV, Fig. .3) the vibratile band is seen to pass directly across 

 liie body, below the (levclo|)iiiq Ophiurid, so as to continue directly from 

 one posterolateral arm lo liie other. .\ (Uslinct anterior band is re])resenled 

 by the former preoral band of the larva, and moreover in this specimen 

 disliiul (races of other vibratile bands are seen. Ihc accordance wilh the 

 pupa-stage of llic I lololluirians being thus slill more emphasized. There 

 can then be no douhl, that we have really in these Ophiurid larva; a true 

 pu|)a-stage. .Viso in the metanujrphosis-slage of (). jonnosus there are 



A. 



Fifi. 03. Ophiophilciis piisillus, species c. A. body skeleton : B. outer part of postoral rod. '"°/,. 



very slight indications of small parts of vibratile bands in the median part 

 of the body. Most probably I hey will prove to exist in all forms having 

 a distinct pupa-stage. 



This species was found in the (iulf of Panama, at the island of Taboga, 

 in December 1915; 12 specimens. 



Species c. (PI. XXIX, Fig. 1). The present species dilTers markedly 

 from the two preceding species in the character of the posterolateral rods, 

 which are provided with long thorns along the inner side, but entirely 

 smooth on the outer side. The body skeleton (Fig. 93, A) forms a pair of 

 rather small, oval meshes, and there is a long often somewhat thorny pro- 

 cess from the recurrent rod; this process is directed venlrally or dorsally, 

 and it is therefore generally broken in the preparations, as also seen in 

 the figure. This thorn may, however, sometimes be lacking. The end rods 

 are rather long, gracefully curved, with a small side branch at some 



