CHI1VLEROID FISHES AND THEIR DEVELOPMENT. 



cc 



DD 



be. Body cavity. 

 ff l > flf". Evaluation of gut wall to form the 



first and second gill openings. 

 h. Heart. 



Figs. 73 T-EE-Continued. 



tiff. Neural crest. 

 sn. Subnotochordal rod. 

 y. Yolk lying free in cavity of gut. 



