OF THE TONGUES OF THE MAMMALIA. 655 



The essential differences between the Cetacea, Sirenia, 

 Artiodactyla, and Perissodactyla are : — 



Cetacea — Mobility slight. No gustatory organs. Glands 

 numei'ous. An intermolar eminence is only present in some 

 Mystacoceti. Few or no mechanical papilla3. 



Sirenia — Mobility greater. Slight gustatory organs. Glands 

 fewer. Small intei-molar eminence. Mechanical papillae present. 



Artiodactyla and Perissodactyla — Mobility great. Well-marked 

 gustatory organs. Glands variable, being numerous in the latter 

 and few in the former, Intermolar eminence well-marked, but 

 variable in size. Mechanical papillae well-marked. 



3. The characters of the tongue have several points in common 

 in the Artiodactyla and Perissodactyla, but those of the 

 Hyracoidea and Proboscidea are such as to separate them into- 

 groups by themselves. Of these the Hyracoidea have some resem- 

 blance to the Sirenia. 



4. The Cetacea are the only mammals in which the tongues 

 may lie far back in the mouth. 



5. The tongues of the Mystacoceti differ from those of the 

 Odontoceti. 



6. The tongues of the Mystacoceti contain large quantities of 

 oil, but this is absent in all other mammals. 



7. The excessive development of cuticular spines on the 

 anterior part of the tongue in the Sirenia allows great use to be 

 made of the moderate mobility. 



8. The Perissodactyla differ from the Artiodactyla in the 

 characters of the glands on the base of the tongue. 



9. Sublingual combs are only present in the Camelidfe, 

 Tragulidse, Cervidae, and Bovidse. 



10. It is impossible to distinguish the genera of the Cervid^ 

 from one another by the characters of the tongue. 



11. The distribution of the fungiform papillae is a good means- 

 of telling the Cervidae from the Bovidfe, 



12. The Hyrax and Cetacea are the only mammals in which I 

 was unable to detect vallate papillae. 



13. The sheep {Ovis aries) is the only mammal below the 

 Primates which possesses the apical gland of IsTuhn. 



14. The characters of the fungiform papillae distinguish the 

 deer from the antelopes. 



Bibliography. 



1. Anderson, J, — Zoological and Anatomical Researches of the 



two Expeditions to Western Yunnan. London, 1868-75. 



2. Barclay, J. — " On the Beluga Whale." Wernerian Trans- 



actions, vol. iii. 



3. Baur, C. J. — " Ueber den Bau der Zunge." Deutsch. Arch. 



f. d. Physiol, hrsg. von J, F. Meckel, 1822, pp. 350-358. 



4. Beddard, F. E. — '• Notes on the Anatomy of a Manatee." 



Proc. Zool, Soc. 1895, pp. 47-53. 



