646 



DR. C. F. SONNTAG ON THE COMPARATIVE ANATOMY 



2, The tongues of the Mystacoceti agree with those of the 

 Odontoceti as follows : — 1. Filiform papillae are scanty or absent. 

 2. The mucosa is more or less corrugated. 3. There is no trace 

 of foramen caecum, lytta, frenal lamella, lateral organs, and 

 apical gland of Nuhn. 



3. The tongues of the Mystacoceti and Odontoceti differ in the 

 following points : — 



Mystacoceti. 



Tongue soft. 



Intermiolar elevation present. 



Much oil in the tongue. 



Apex massive. 



Absent. 



Lateral borders ill-defined. 



Glands less numerous. 



Muscles slight. 



Mobility slight. 



Odontoceti. 



Tongue firm and hard. 



Absent. 



Absent. 



Not so. 



Marginal lobules present. 



Well-marked. 



Glands very numerous. 



Muscles well-developed.^ 



Mobility variable. 



Order SIRENIA. 



The tongues differ considerably from those of the Cetacea, 

 and their characters approximate to those of the tongues of the- 

 Ungulata. 



Text-figure 29. 



Wfl^P^' A. 

 Tongues of the Sirenia. A and B 



dorsum and lateral aspect of the tongue of 

 Salicore indicus ; C : lateral view of the tongue of Manatus american-us. 



The tongues (text-fig. 29) are firm and hard, but not very 

 mobile. That of Manatus thickens progressively from before- 



