THE DKVKLOPMKNT OF Tl 



AKT IN SHAD. 

 II. D. SKNIOK. 



^^V 



Mandibular pouch 



-*^ntodermal pharynx, Entodermal pharynx, 

 SB closed ventral wall 5C 



Endocardi 



Eniodermal 

 pharynx, closed 



Ftg. 5. — Diagram of the ventral surface of a reconstnirtion of the peri- 

 cardial region of shad, stage of 22 somites lUU diams. See explanation of 

 figures, footnote on page 22(>. 



The American .Tot'unal ok Anatomy. — Vol. IX, No. 2. 



