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,| 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, ie. 19 C+ Pm+# M 3. 
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, Amer. Journ. Sci. 1897, p. 165. 
