OF THE TONGUES OF THE MAMMALIA. 653 



surface of the tongue. The following arrangements have been 

 observed : — 



1. Combs absent — Perissbdactyla, Suina, Hyracoidea. 



2. Edges divided into triangles — Tylopoda, Tragulid^e. 



3. Long, more or less separate processes^ — Bovidee and 



Cervidce. 



Some forms are shown in text-fig. 30. 



The fi-enicvi is always present, and permits the tongue to be 

 very mobile. But there is no trace of a frenal lamella. 



There is no trace of a foramen ctecum, sublingua or plicte 

 fimbriatse, and the apical gland of Nuhn is present only in 

 Ovis aries. 



It has been the object of the above summary of the characters 

 of the tongues of the Ungulata to show their value for purposes- 

 of classification. And they have been arranged schematically as 

 follows. From that system it will be seen that the characters of 

 the tongue are a usefxil addition to the external and skeletal 

 characters at present in use. 



Classification.-— T1\\Q following characters are valuable for 

 purposes of classification : — 1. Character of the orifices of glands 

 on the base. 2. Nature of the intermolar eminence and its 

 papillfe. 3. Arrangement of the vallate papilla?. 4. Lateral 

 organs. 5. Sublingual combs. 6. Distribution of conical and 

 fungiform papillfe. 



Suborder Perissodactyla. 



Numerous orifices of glands on base. No combs. Conical 

 papillse silky and closely-set. Ventral pa,pillary zone very small 

 or absent. 



A. Intermolar eminence cleft. Vallate papillas in fields. No 



lateral organs Rhinoceros. 



B. Eminence low, flat, and entire. 



a. Apair of vallate papillffi. No lateral organs. No fungifoi-m 



papilloe on eminence Eqtms. 



b. Vallate papillas form a row or V. Lateral organs present. 



Large fungiforms on eminence Tapirus. 



Suborder Artiodactyla. 



Few or no orifices of glands on base. Combs variable. Conical 

 papillfe hard and not so closely set. Ventral papillary zone 

 well-marked. 



A. No sublingual combs. Two vallate papillie. 



0, Edges of tongue tave long processes Bus. 



b. No long processes present. 



i. Papillse on base immense Fotamochcertis, 



ii. Papillffi on base not immense. 



a'. Lateral organs present Fhacochcerus.. 



V . No lateral organs Dicotyles. 



