PLATE 4. 



UPPER AND LOWER TEETH OF M WHIP PUS FROM SOUTH DAKOTA AND OREGON. 



Teeth natural size. Skulls and jaws one-half natural size. 



Left column. 



Pine Ridge, So. Dak. Lower Miocene 1. Miohippus gemmarosce, Osborn, paratype, Am. Mus. 12928. 



" " " " " " 2. M. gemmarosm Osborn, paratype, Am: Mus. 13809. 



" " " " " ■ 3. M. gemmaroscB Osborn, paratype, 12917c. 



" " " " " " 4. M. gemmarosce Osborn, paratype, 12917a. 



Right column. 



John Day River, Ore. 5. M. primus Osborn, type, Am. Mus. 7291 (partly reversed in 



drawing). 



" " " " " 6. M. quart us Osborn, paratype, Am. Mus. 7285 (partly reversed in 



drawing). 



7. M. acutidens Sinclair, type, Univ. Cal. Pal. Col. 376. 

 " Upper 8. M. quartus Osborn, type, Am. Mus. 7267 (reconstructed in drawing). 



Pine Ridge, So. Dak. Lower 9. M. gemmarosm Osborn, type, Am. Mus. 13808. 



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