R. S. Lull — New Tertiary Artiodactyls. 125 



BLASTOMERYX MAESHI, N. SP. 



(Fig. 25). 



In searching in the Marsh Collection for material for 

 comparison, I discovered a specimen bearing the initials 

 0. C. M. and the date Jnne 27, 1873. This material 

 was collected by the Yale College expedition of 1873, 

 which worked eastward along the Niobrara River from 

 the mouth of Antelope Creek to Fort Niobrara, a distance 

 of 85 to 100 miles, between the dates of June 24 and July 

 7. "We have no record of the number of camps nor of 

 the rate of progress during these two weeks. One would 

 judge that they made about four hauls, certainly not 

 fewer, in covering the distance. The presumption is, 

 therefore, that this specimen collected on the 27th must 

 have been found within 25 miles of the locality of Aleto- 

 meryx and from an approximately equivalent geologic 

 level. 



The specimen, Cat. No. 10756, holotype, consists of a 

 skull and jaws, three dorsal and three lumbar vertebrae, 

 a femoral head, the humeral end of the right scapula, and 

 two rib fragments. 



The skull, while in fragments, was nevertheless suscep- 

 tible of repair, such portions as were absent on the one 

 side being present on the other, so that little that is essen- 

 tial is lacking. The dentition, while rather badly worn, 

 is perfect except for the two median incisors and the 

 second and third, together with the inferior canine of the 

 left side. The upper canines are missing, but their 

 alveoli are present and give indication of their size and 

 curvature. Coupled with the well developed laniary 

 tusks were rudimentary horns comparable to those of 

 the female of Aletomeryx, though somewhat larger, or 

 to those of the female prongbuck, from which they differ 

 in their position, overhanging as they do the rim of the 

 orbit, and again in being relatively larger. This creature 

 is evidently a Blastomeryx and proves beyond question 

 that Aletomeryx belongs to a separate phylum, though 

 probably a local contemporary. The two forms differ 

 very markedly in skull profile, Blastomeryx being de- 

 cidedly convex, while Aletomeryx is more nearly straight, 

 correlated with the presence or absence of the canine 

 tusk. The Blastomeryx skull, while only slightly larger 

 than that of Aletomeryx, has nevertheless a more ex- 



