CHIM^ROID FISHES AND THEIR DEVELOPMENT. 



be. Body cavity. 

 g^t U^'^' Evagination of gut waU to form the 

 first and second giil openings. 

 h. Heart. 



EE 



Figs. 73 T-EE — Continued. 



71''. Neural crest. 

 sn. Subnolochordal rod. 

 y . Yolk lying free in cavity of gut. 



