DAKOTA AND NEBRASKA. 89 



pressed along the middle, and the sagittal crest is not so long, from the parietal being 

 deeply but narrowly notched to receive the triangular summit of the conjoined 

 frontals. The nasal bones are broad and unusually convex. The posterior nasal 

 triangle is sub-acute, fourteen lines long and ten lines wide. The molar teeth occupy 

 very little more space than in the preceding specimens. 



7. The greater portion of a skull nearly as robust as those last described. The 

 sagittal crest long and narrow. The anterior border of the parietal forming a wide 

 shallow notch. Orbits slightly smaller than in the preceding specimens, sulD-rotund. 

 Lachiymal fosste as deep, but narrower and more defined than in the preceding two 

 specimens. Snout Ijroad, convex above. The nasals moderately wide and convex. 

 The posterior nasal triangle obtuse, eleven lines long and eight and a half Hues wide. 



8. The greater portion of a skull nearly resembling the last, but having the poste- 

 rior nasal triangle notched at the apex. 



9. The greater portion of a skull, in which, in comparison with all other skulls of 

 Oreodon Culherisoni, the forehead is remarkable for its convexity both antero-posteri- 

 orly and transversely. The snout appears quite flat and shelving, but the depression 

 m.ay partly be due to accident. The nasal bones are comparatively flat, and mode- 

 rately wide. The posterior nasal triangle is acute, thirteen lines long and ten lines 

 wide. The skull is about as robust as in the preceding S]3ecimens generally, and, 

 excepting in the differences mentioned, exhibits no peculiarity. 



10. A skull, without the lower jaw, as robust as any of the preceding specimens, but 

 with larger canines, the other teeth being about the same as in the former. Sagittal 

 crest extended the whole length of the parietal, which presents a small compara- 

 tively narrow notch to accommodate the summit of the frontals. Orl^its rather oval; 

 lachrymal fossae broad and deep. Snout broad; nasals broad and moderately convex. 

 Posterior nasal triangle acute, fifteen Hues long, ten and a half lines wide at base. 



11. A mutilated skull without the lower jaw, more robust than any of the pre- 

 ceding ; with large canines, and the other teeth occupying slightly more space than 

 usual, though separately not larger. The sagittal crest is strong, and extends the 

 length of the parietal. The latter is deeply notched to receive the nearly equilateral 

 triangular summit of the frontals. The forehead is rather more convex than usual, 

 and less depressed along the middle. Orbits slightly oval ; lachrymal fossaj broad 

 and deep. Face much more robust than in any of the preceding specimens. Snout 

 broad, convex above. Nasals wide, convex, narrowmg a short distance in advance 

 of the frontal angular processes. Posterior nasal triangle acute, fourteen lines long 

 and thirteen and a half wide. 



12 



