No. 2.] THE RELATIONS OF PROTOCERAS. 363 



cessive genera of these two series show that these resem- 

 blances are not due to a common ancestry, since there can 

 hardly have been an ancestor common to both series later than 

 Dichobnne, or some similar form. Even more remote is the 

 connection between the true ruminants and the true swine 

 {Suid(z), yet the latter have acquired several of those very 

 characters which give such a strong pecoran stamp to the 

 skull of ProtoceraSy for example, the backward shifting of the 

 orbits and the depression of the face upon the basicranial 

 axis. In the loss of the sagittal crest the swine-skull is more 

 modernized than that of Protoceras. Among the oreodonts, 

 Merycochcerus has the face bent down upon the cranial axis, 

 and the orbits are shifted much farther back than in any other 

 member of that family. Such resemblances are obviously, 

 therefore, not sufficient in themselves to create any strong 

 presumption of affinity. The foot-structure, by keeping on 

 such a primitive plane, reveals the true nature of these skull- 

 characters. As Osborn has said, we know of no case where 

 teeth, skull, and feet have converged to a common type from 

 different starting-points, but that one of these may display 

 such convergence or parallelism in several different respects is 

 not at all uncommon. 



(3) Even should we go so far as altogether to exclude Gelo- 

 cus from the pecoran ancestry, the difficulty of accounting for 

 the peculiar assemblage of characters found in the skull of 

 Protoceras on any other hypothesis than that of the independ- 

 ent acquisition of the pecoran features, is not at all dimin- 

 ished. For it must be remembered that these likenesses are 

 to the higher members of the group, and on the same grounds 

 such typical members of the series as Prodremotherium, 

 Dreniotheriiim, AmpJiitragidits and Palcsomeryx would have 

 to be excluded from the line. 



It is altogether probable, then, that Protoceras has but a 

 remote connection with the Pecora, and consequently that the 

 affinities with different families in that group which have been 

 suggested, are illusory. Nor can it properly be called a con- 

 necting link between the tragulines and the deer, for, having 

 more primitive feet than the former group, it cannot well be 



