xxxii INTRODUCTION. 



A great number of fossil forms, presumed to be distinct species, have 

 been distinguished by many specific and some generic names. But we 

 must exclude their consideration from the present work as not coming 

 within its professed scope. Moreover, without any disrespect to the 

 distinguished palaeontologists who have described them, we must also 

 confess to a good deal of scepticism with respect to various fossil species. 

 The examination of many skulls belonging to one existing kind has con- 

 vinced us that though the form of the teeth is about the most constant 

 character, it is nevertheless so subject to individual variation that 

 definitions reposing upon almost any single, more or less imperfectly 

 preserved, skull have little value in our eyes. But we by no means 

 intend by this remark to slight or undervalue the labours of Palaeonto- 

 logists. They must work, with the relatively poor materials they have, 

 in the only way possible to them, i. e. by most careful discrimination 

 between all the fossil specimens they can procure. Palaeontology and the 

 Zoology of living forms seem to us such very distinct, though closely 

 allied, sciences, that the mental attitude of the student of the one must 

 necessarily diverge from that of the other, in spite of the single aim 

 common to them both. 



A genus of Mammals named Cynodiclis (in which the genera Gale- 

 cynus of Cope * and Cynodon of Eilhol should probably be included) is 

 found in the Lower Miocene and Upper Eocene of Europe, and in the 

 Miocene strata of North America. This genus, however, cannot be 

 affirmed to belong to the Canidte, as it seems to be intermediate between 

 the Dogs and the Civets. 



The genus Ampliicyon\, the dentition of which has much resemblance 

 to that of the Dogs, differs greatly from them in the structure of its feet, 

 which approach those of the Bears and are plantigrade. 



The interest of the Palaeontology of the group largely reposes upon 

 any light which may thence be thrown upon the origin and evolution of 

 the CanidcK. 



We have ever affirmed our conviction in the truth of Evolution, and 



* The Galecynus of Owen is merely Canis. It is the well-known fossil Fox of (Eningen. 

 t See below, Bibliography. 



