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PETERSON: A REVISION OF THE ENTELODONTIDA 65 
is specifically to be separated from D. shoshonensis is principally the smaller size, so 
far as can be determined by comparison of the two. Sinclair states that the type of 
D. calleinsi represents a very old individual and that many of the teeth are shed and 
Fic. 19. Outline of Illustration of Skull of Dwxodon calkinsi (Sinclair). (After Sinclair. ) 
the alveoli closed. “Py... resembles the smaller premolars of the upper series. 
Anterior and posterior cingula are well developed on the lower molars. In Mg the 
hypoconulid is not differentiated from the posterior cingulum, which projects 
slightly, forming a very small heel. . . 
“The mandible is peculiar in the absence of the knob-like bosses on the chin 
The protuberances beneath Pz are small and deeply cupped. ‘The dependent angle 
slopes gradually backward without the abrupt downward curvature characterizing 
i. ingens. 
“The chief point of specific value attaching to the cranium is in the shape and 
direction of the jugal processes. These processes are plate-like with a thickened 
median rib. The free edges, especially the anterior, are thin and sharp. The 
processes are short, not extending below the lower mandibular border. The orbits 
are posterior in position, their anterior borders lying above the posterior edge of M®.” 
The unciform and tibia were kindly sent to the writer for purposes of study 
by Professor John CG. Merriam of the University of California. It is at once notice- 
able that the lunar facet of the unciform is more elevated than in Dinohyus and 
