Art. Til.— On the JVimraTidaB and Canidse of the 



Miocene Period. 



By E. D. Cope. 



In following the general series of the Carnivora, we pass, as in other 

 orders, from the generalized to the specialized types. That we should 

 begin with the Frocyonidce and their allies is indicated by all the char- 

 acters to be especially considered in the case. They have five toes on 

 all the feet, and are plantigrade, resembling in these points all primitive 

 Mammalia.* They have the original number of molar teeth, seven on 

 each side, and of these none are distinctly developed sectorials. The 

 condyloid and carotid foramina are distinct, and there is a postglenoid 

 foramen. If, starting from this point of departure, we arrange the suc- 

 ceeding families of Carnivora according to their resemblances and differ- 

 ences in these respects, we have a tolerably consecutive series of 

 divisions. 



Passing at present over the families Mustelidce, Viverrida;, Cryptoproc- 

 tidce.) and others with five toes on all the feet, we reach those in which the 

 hind foot has lost a digit, leaving the number 5-4. These are the Fro- 

 telidce, Canidw, and Felidw. We can take but one step further in this order ; 

 that is to those species where the anterior foot has also lost a toe, which 

 constitute the family Sycenidce. The toes are therefore, here, 4-4. For 

 the well-marked characters of the three families mentioned just before, 

 I refer to another page, and proceed to define briefly the division which 

 has been heretofore termed the Felidw. In doing so I am compelled to 

 omit several of the characters generally emi)loyed to define that family, 

 since I have found them to be wanting from various extinct genera. The 

 only comprehensive definition which I can give is the followiug: 



Digits 5-4; sectorial teeth icell developed in both jaws; not more than 

 one true molar tooth in the upper nor more than tioo true molar teeth in the 

 lower jatv. Glenoid cavity grasping mandibular condyle anteriorly as 

 icell as posteriorly. 



Professor Gill, who has devoted much attention to the definition of 

 the families of the Mammalia,\ gives the followiug skeletal characters 



* See Homologies and Origin of Types of Molar Teeth of Mammalia Educabilia, 

 Journal Academy Phila. 1874, March. 



t Arrangement of the Families of Mammals,-Smithson. Misccll. Coll. 230, 1872, j). 56. 



165 



