brine its oral surface- away from the larval organ or 



vrliicfi 



preoral lobe it fairly represents $hat A takes place- 

 in the metamorphosis of Antedon, but if we think of 

 it as rotating in the opposite way bringing the ab- 

 oral surface away fror. the preoral lobe* then it more 

 nearly illustrates the star-fish metamorphosis. 



In Antedon ? as metamorphosis proceeds , the stem 

 is carried on to the aboral surface; while in the 

 star-fish the preoral lobe finally disappears on the 

 oral surface. In O.brevispina the place of disappear- 

 ance of the- larval organ more nearly recoils the 

 crinoid than any other echinoderm,the larval organ 

 being found in eorr.e of my oldest specimens as a 

 small knob near the edge of the aborsl surface be- 

 t-re on arms (I) and (V). 



