TEETH OF UNGULATA. 



349 



278 



Dentition of Camel (Camehta boctrianus) . 



in the periodically hornless deer, and by their larger size in the 

 absolutely hornless Musks, is further illustrated by the presence 

 not only of canines, but of a pair of laniariform incisors, fig. 278, i, 

 in the upper jaw of the Camelidce. 



In the Camel and Dromedary the upper canines, fig. 278, c, 

 are formidable for their size and shape, but do not project beyond 

 the lips like the tusks of 

 the Musk-deer ; they are 

 more feeble in the Lla- 

 mas and Vicugnas, and 

 are always of smaller size 

 in the females than in the 

 males. The inferior ca- 

 nines, 0, moreover, retain 

 their laniariform shape 

 in the Camelidce, and are 

 more erect in position 

 than in the ordinary Ru- 

 minants. They are separated by a short diastema from the inci- 

 sors in the Auchenice. 



The true nature of the corresponding canines in the ordinary 

 Ruminants, in which they are procumbent, and form part of the 

 same series with the incisors, is always indicated by the lateness 

 of their development, and often by some peculiarity of form. Thus 

 in the Moschus, fig. 277, c, they are smaller and more pointed 

 than the incisors ; in the Giraffe they have a much larger crown, 

 which is bilobed. The laniariform tooth in the premaxillary 

 bone of the Camelidce, fig. 278, i, which represents the upper and 

 outer incisor, 2, is smaller than the true canine, c, which is placed 

 behind it in the Camel and Dromedary ; but in the Vicugna it is 

 as large as, or larger than, the true canine. 



Most of the deciduous molars of the Ruminants resemble in 

 form the true molars ; the 

 last milk-molar, for example, 

 fig. 279, d 4, in the lower 

 jaw, has three lobes like the 

 last lower true molar, m 3. 

 The deciduous molars in 

 existing true Ruminants are 



, . , i n Deciduous arid permanent teeth of a Sheep. 



three in number on each side, 



and, being succeeded by as many premolars, the ordinary perma- 

 nent molar formula is 



3.3 3.3 



279 



d c 3 



'II 



