284 EXTINCT TRAGULIDS CHAP. 



by rudiments at the upper and at the lower end only ; they are 

 deficient in the middle. The middle large metacarpals, though 

 closely applied, are not fused. The metatarsals, on the other 

 hand, are, or are not fused, according to the species. A later form is 

 the genus Leptomeryx from the Miocene of North America. This 

 genus departs from the typical Traguline structure in more than 

 one point. The tympanic bulla is hollow instead of being filled 

 with cancellated bone ; the cuneiform is not fused with the cuboid 

 and navicular, though the latter are with each other ; the lateral 

 digits of the hind-feet are rudimentary. The magnum and 

 trapezoid, however, are fused. In the fore-feet the middle meta- 

 carpals are separate, and the lateral less perfect metacarpals have 

 toes. The metatarsals are fused. 



Not definitely referable to the Tragulidae, but coming near 

 to them, are the Protoceratidae. Of this family there is but 

 one well-known genus, Protoceras, 1 from the Miocene of North 

 America. 



The skull is singularly reminiscent of Dinoceras, with which 

 this quite Artiodactyle genus has, of course, nothing to do. It 

 merely exemplifies the phenomenon of " parallelism." In general 

 form it is peculiarly long and low. There are three pairs of bony 

 protuberances : one, the largest, pair are situated on the maxillae 

 rising up just behind the implantation of the canine teeth ; the 

 parietals have a second pair ; and a third much more diminutive 

 pair of bosses are upon the frontals, near their junction with 

 the nasals. This description refers to the male ; the female has 

 only traces of the parietal bosses. These were all possibly tipped 

 or sheathed with horn or roughened skin. The dentition of this 

 genus is precisely that of the Tragulidae, i.e. I C |- Pm -| M |- . 

 The orbit is completely encircled by bone ; the auditory bulla is 

 not swollen ; the premaxillae are small. 



The nasal cavity is very large and open, the end of the nasal 

 bones anteriorly being situated at about the middle of the 

 skull ; this would seem to indicate at least a flexible and long 

 nose like that of the Saiga Antelope, if not a trunk. 



The brain was of good size, and quite well convoluted. 



The limbs are constituted on the Traguline plan ; in the fore- 

 limbs the middle metacarpals are quite free from each other, 

 and the more diminutive lateral digits are complete. The meta- 



1 Marsh, Amcr. Journ. Sci. 1897, p. 16f>. 



