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ZEL ENY. 



[VOL. II. 



ABBREVIATIONS USED IN CONNECTION WITH THE FIGURES. 



Ao. Aortic arch. 



Cm. Cardiac mesoderm. 



Ect. Epiblast. 



End. i " Primary hypoblast." 



End.z " Secondary hypoblast." 



Ep. Epiphysis. 



F. B. Fore-brain. 



F. G. Fore-gut. 



H. B. Hind-brain. 



H. C. Canal connecting the two pre- 



mandibular head cavities. 



Ht. Heart. 



Hyp. Hypophysis. 



Hyp. S. Stalk of hypophysis. 



/. Infundibulum. 



M. Mouth opening. 



M. B. 

 Md. 



Nc. N. 

 Pa. 

 P. G. 

 P. M. 



Mid brain. 



Floor of medullary groove. 



Notochord. 



Proamnion. 



Preoral gut. 



Pharyngeal membrane. 



Dotted line above Md. in Fig. 



i represents the height to 



which the medullary folds 



have risen. 

 Position and direction of the 



hypophysial evagination. 

 Pharyngeal membrane and 



position of future mouth 



opening. 



