1880.] DKNTAL CHARACTERS OF THE CANID.E. 285 



group, to the Wolves, Lycaons, Cyons, and Northern Foxes, as the 

 most tnodified forms. 



II. In the skull these modifications consist chiefly (a) in the 

 increase of absolute size; (i) in the increase of the relative dimen- 

 sions of the jaws, and particularly in the width of the palate- (c) in 

 the persistence or disappearance of the sagittal area Common to all 

 young Camdse and the correlative development or absence of a 

 sagittal crest ; (d) in the diminution of the inflexion of the an-ndar 

 process of the mandible; (e) in the disappearance of the suban|ular 



III. In the teeth, the most important modifications are the in- 

 crease in the proportional size of the sectorials, accompanied by the 

 relative diminution and, in some cases, suppression of the posterior 



™''^'''''*, 4'^" ?^°'^°"' ~ ^'''' "'"'''^'^ disappeared. In C. cancri- 

 vorus, '^ ^'-, and ^^ are most frequently suppressed ; but — often 

 remains, and — persists in one known case. In the great majority 

 of the Canidae, ^*, ^, and — are normally suppressed, while — 

 becomes relatively small, and, as a rule, disappears in Cyon. Finally' 

 in the majority of examples onctiajon, botii '^ and -- are wanting' 

 and when -^ is present it is very small. 



The gradation will be rendered more intelligible by placin- the 

 formulcc of the cheek-teeth under one another. ° 



Maxilla. Mandible. 



Otocyon : ^ , , ^ 



Fullest dentition observed... 1234 1234 1234 19^4 



^"^''^^'•y 12 34 123* 1234 1234 



C. cancrivorus : 



Fullest dentition observed... 1234 123* 1234 1234 



^"^'"'-^"•y 1234 12** 1234 123* 



Most Alopecoids and Tbooids 1234 12** 1234 1"^ 



^•^"^ 1234 12** 12 34 12* 



Icticyon : 



Fullest dentition observed... 1234 12** 1234 1^ 



^^■'^"^""^ 123 4 1*** 1234 1211 



In the individual teeth, the most important changes are the increase 

 of the length in proportion to the breadth of th" uppe s ctorhl 

 and in the lower sectorial, the change in the relative dimen 'io s a.^ 

 position ot the inner anterior cusp, which, from being on a levd v^th 

 the outer and higher than it in Otocyon, becomes smaller and shifts 

 further and farther backwards, eventually even disappearing, as in 



* 



* 



