EXPLANATION OF PLATE 20. 



.1/? figures are reproduced one-half natural size. 



Fig. 1. Euceratlierium collinum. Left pes. Several dissociated elements 

 are combined in the drawing. 



Fig. 2. Euceratlierium collinum. Left anterior cannon-bone. 



Figs. 3, 4. Aplocerus montanus. Portions of anterior cannon-bones. The 

 proximal three-fourths of the right cannon-bone is repre- 

 sented in figure 3, while 4 shows the distal half of the same 

 element of the opposite side. 



Figs. 5, 6. Megalonyx sierrensis, n. sp. Views of the proximal and dis- 

 tal surfaces, respectively, of the right navicular. 



Figs. 7, 8. M. sierrensis. Views of the dorsal and distal aspects of the 

 left scapho-trapezius (s-t), trapezoid (t), and magnum (m). 

 One of the facets for articulation between the scapho- 

 trapezius and lunar is seen at (1). 



