PLATE XXI. 



MANDIBLES OP CAMELS, ONE-HALF NATURAL SIZE. 



Figure 1. Pliauchenia spatula, Cope; left mandibular ramus, external view; 



Mont Blanco. 

 Figure 2. Same, from above. 

 Figure 3. Holomeniscus hesternus, Leidy; left ramus mandibuli, external view; 



Austin county. 

 Figure 4. Same, from above^ 



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I 



