PLATE 41 



FORE FEET OF MERYCHIPPUS. 

 COMPARISON OF THE MANUS IN FOUR SPECIES FROM THE SHEEP CREEK BEDS, NEBRASKA. 



All figures one-half natural size. 



Sheep Creek, Nebr. Middle Miocene 1. Merychippus isonesus seeundus Osborn, type, Am. Mus. 14179. a, Anterior, 



b, external, c, internal view of incomplete fore foot. The nodular vestige 

 of the fifth metacarpal and the trapezium are perfectly preserved in this 

 specimen. The trapezium in flexure of the wrist shifts to a small facet 

 on the second metacarpal, erroneously supposed by previous writers to 

 indicate a vestigial pollex. 



2. Merychippus isonesus tertins Osborn, type, Am. Mus. 14180. Anterior 

 view of manus. 



3. Merychippus isonesus quartus Osborn, type, Am. Mus. 14184 (reversed in 

 drawing). Anterior view manus. 



4. Merychippus isonesus quintus Osborn, type, Am. Mus. 14185. a, Anterior 

 and, b, external views of manus. 



» a a (i (i 



