Fig. 20. Ventral View of the Skull of the 

 Alligator (^1. Mississippiensis). 



14. basioccipital. a, anterior 

 palatine vacuity; en, 

 opening of the median 

 Eustachian canal; pn, 

 posterior nares; pv, 

 poster! or palatine 

 vacuity. 



