PLATE 12 



NEOTYPE SKULL OF MERYCHIPPUS SPHENODUS COPE. 

 One-half natural size. 



Merychippus sphenodus Cope, neotype, Princeton Mus. 12291 (partly reversed in drawing). This finely preserved 

 skull in the Princeton collection was found by Dr. W. J. Sinclair in Logan County, Colorado, about a mile west of Sand 

 Canon, in the Middle or Upper Miocene. In the structure of its superior molar teeth it agrees much more closely with 

 the type of M. sphenodus than the specimens which Cope selected as the cotype of that species. The molars are distin- 

 guished by the duplication of the pli caballin as well as of the pli prefossette and pli postfossette. 



The geologic age is almost certainly typical Pawnee Creek. All referred specimens of M. sphenodus come from this 

 level (W. D. M. 1918). The type of M. sphenodus Cope is recorded as "Pawnee Creek," but the exact locality is not 

 known. 



The author is indebted to Dr. W. J. Sinclair for the opportunity of figuring this skull. 



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