Opercular opening 



Opercular opening 



Mouth-cavity 



Esophagus 



Nasal cavity 



Premaxillary \ "| ,ern pi Ql nans 

 \ ., .,, \ \ Palatine 

 \ Maxillary 



\ \ Nasal 



Eustachian opening 



Tympanic membrane 



Esophagus 



Nasal cavity Nasopharynx 



Eustachian / g^, 



Premaxillary] Hard | Frontal ope ! lin 9 



\ Maxillary palate 

 \\ PalatineJ 



— Larynx 

 Esophagus 



Fig. 435. Alimentary and respiratory passages of fish (fop), reptile [renter), and 

 mammal (bottom). The solid arrows indicate alimentary and the broken arrows 

 respiratory passages. 



562 



