South Dakota 'School of iMines 113 



anterior end,, where the muzzle becomes extremely slender. The 

 cranium is capacious and well formed. The brain case is of 

 good size and indicates a brain fairly well convoluted, in fact 

 the brain development of Protoceras seems to. have been more 

 advanced than any other animals of the time. The nasals are 

 remarkable in that they indicate a long flexible nose if not a 

 true proboscis. Among recent ruminants such a proboscidiform 

 muzzle is found only in the saiga antelope and to a less extent 

 in the moose. 



The dentition for each side is : Incisors none above, three 

 below; canines, one above and one below; molars, three above 

 and three below. The upper canines of tat male are trihedral, 

 large and prominent and project outwards and backwards. 



The four toes of the front foot are functional and corres- 

 pond to the second, third, fourth, and fifth, of five-toed animals. 

 The hind foot shows only two toes, the third and fourth. Small 

 short splint-like processes disclose, however, the rudimentary 

 second and fifth. The hind limb compared with the fore limb, 

 is large and long. The tail is larger and better developed than 

 in the present day deer. 



The size of Protoceras is practically that of the sheep, but 

 the general build seems to have corresponded more nearly to that 

 of the pronghorn antelope. It is, however, not very closely re- 

 lated to either. A restoration of the complete skeleton by Prof. 

 Scott is shown on Plate 45. A reproduction of the animal in 

 life by Mr. Charles R. Knight under direction of Prof. Osborn 

 is given on Plate 47. The reproduction of Syndoceras, a rather 

 distant relative of Protoceras, found near Agate Springs, north- 

 western Nebraska, by Mr. Harold J. Cook and described by 

 Prof. E. H. Barbour, is g-iven on Plate 26. 



The Hypertragulidae identified to date in the badland for- 

 mations of the Black Hills region are as follows : 



Lower Oligocene. 



Heteromeryx dispar Matthew. 



Middle Oligocene. 



Hypertragalus calcaratas Cope. 



*For the more extended studies of Protoceras see the following: 



Osborn, H. F., and Wortman, J. L. Characters of Protoceras 

 (Marsh), the New Artiodactyl from the Lower Miocene. Am. Mus. 

 Nat. Hist., Bull. Vol. 4, 1892, p,p, 351-371. 



Scott, W. B. The Osteology and Relations of Protoceras. Journ. 

 Morph., Vol. 11, 1895, p.p. 303-374, 3 pis. 



iMiarsh, O. C. Principal characters oif the Protoceratidae. Am. 

 Journ. ScL, Vol. 4, 1897, pp. 165-176, 6 pis. 



