656 THE AMERICAN NA TURALIST. [Vol. XXXVII. 



opening more nearly over the epiglottis, and along with this in 

 the Cetacea is found an intranarial epiglottis 1 formed by the 

 prolongation upward of the epiglottis and the arytenoid cartilage 

 into the nostril, forming an independent continuous passage from 

 the exterior to the lungs. These are undoubtedly adaptations 

 to the capture of food in connection with conditions of respiration 

 at the surface of the water and permit of food being held in the 

 mouth or even of being swallowed without interfering with 

 respiration. In the Cetacea, naturally, the process is carried 

 farthest, and here the extreme is found in such forms as Globi- 

 ocephalus in which the postnarial opening is secondarily bridged 

 over by the pterygoids and the palatines are entirely excluded 

 from the anterior border. In Delphinapterus the palatines take 

 part for a small space in the formation of the anterior border of 



that found in the less modified forms, as the Pinnipedia, where 

 the whole border is formed by the palatines. The palatines are 

 posteriorly elongated as the first step in the backward shifting of 

 the internal nares, as shown by the Pinnipedia, Ornithorhynchus, 

 etc. The reduction of the salivary glands is also to be noted. 

 As the function of the saliva is chiefly a mechanical one con- 

 nected with deglutition the reduction of the glands in forms tak- 



The loss of the external ears I another noticeable result of 



ear is lost entirely, and among the eared seals, Otariidrc, it is 

 found in various stages of reduction. The opening of the ear is 

 often valvular so that it can be closed when in the water, and 



