xxiv INTRODUCTION. 



Dentition. The Canidcs, in common with almost all Carnivora, have 

 six incisors and two canines* above and below. They have also four 

 premolars on either side of either jaw. One true molar f, at least, is 

 present in the upper jaw, and at least two in the lower. There may be 

 no more, as is normally the case in Icticyon. In Cyon we find two 

 true molars, both above and below ; while in Otocyon there are three, 

 or even four, true molars above and four below. In all the rest (that is, 

 the overwhelming majority of the Odnida) there are two true molars 

 above and three below, so that their dentition may be thus expressed : 



T 3 n * T> 4 -\/r 2 10 



I. 3, C. if Pm. 4, M. 5 = n . 



In the dentition, however, as in every part of the body, abnormalities 

 are occasionally to be met with. Thus we have found a specimen of 



Fig. 



Abnormal denticles in C. cancrivorus. (Twice the size of nature.) 



Cyon javanicus to be destitute of the second upper molar on each side ; 

 a C. lateralis with five premolars on one side ; and both a C. magel- 

 lanicus and a C. cancrivorus with one extra molar on each side of the 

 lower jaw. 



* For an explanation of all terms used in describing the dentition, see * The Cat,' 

 pp. 27-33, and figs. 12-15. 



t A true molar is a tooth which has no milk predecessor, but is behind other teeth, 

 the premolars, which (except the first) have milk predecessors; A " true molar " is 

 often called a " molar" simply. 



