324 



ON THE EXTINCT MAMMALIA OF 



Lines. 



Lines. Lines. Lines. 



Lines. 



Lines. 



Greatest breadth of articular surface of 



the condyles, 

 Width of inner condyle, 

 Width of outer condyle, 

 Breadth of base. 

 Breadth of scaphoid surface, 

 Depth of the same, 



28. Six calcanea, from the same locality, agreeing in proportions with the bones 

 just described. The measurements of three of the specimens are as follow: 



Extreme length, 



Depth at middle of tuberosity. 



Width " 



Depth of extremity of tuberosity 



Thickness " " 



Depth of articular end, . 



Breadth " " .' 



29. Four bones together, of due proportions, recomposing a hind foot, of an equine 

 animal remarkable for its small size and slender form. The bones apparently be- 

 longed to different individuals, and all came from the Niobrara River except the 

 coronet bone, which was obtained at Bijou Hill. The entire foot measures ten and a 

 half inches in length. 



The metatarsal bone is longer in comparison with its thickness, or is proportion- 

 ately of more slender form than in the Horse or Ass. Its measurements are as 

 follow : 



Inches. Lines. 



Length, . . . . . . . .72 



Circumference at middle, . ...... 24 



Transverse diameter at middle, ..... 8 



Antero-posterior diameter at middle, ..... 9 



Breadth of proximal extremity, ..... 12 



Antero-posterior diameter of do., ..... 10 



Breadth of distal articulation, ...... 11 



Antero-posterior diameter of its median ridge, .... 9 



The pastern is nineteen lines long ; the breadth of its proximal extremity is eleven 

 and a half lines, and of its distal end nine and a half lines. 



