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JOU'RNAL OF MAMMALOGY 
20 mm. and it terminates below in a bluntly pointed apex. A, tubercle similar 
in shape is present in Zalophus californicus, though only a scar marks its presence 
on the radius of Eumetopias juhata. In Odobenus divergens the tubercle and 
tuberosity of the fossil are represented by a pair of flattened adjoining articular 
surfaces. 
The structure of the carpus is unknown and it is hoped that future geological 
work in this region will result in the accumulation of additional material. The 
metacarpals are relatively slender and slightly enlarged at their articulations. 
Right Metacarpal I of Pliopedia pacifica X No. C. 537, Stanford 
University 
Santa Margarita, California: fig. 7a, dorsal view; fig. 7b, proximal view 
The first metacarpal of the right fore limb (fig. 7a) differs from the others in 
its larger size and in the shape and direction of its proximal articular surface. 
Its proximal surface (fig. 7b) for articulation with the trapezium is convex from 
the dorsal to the palmar border and concave transversely. On the ulnar face is 
a concave articular surface for the corresponding facet on the head of the second. 
The shaft is sub-triangular in outline; immediately below the proximal facet and 
Left Metarcarpal III ? of Pliopedia pacifica X J, No. C. 537, Stanford 
University 
Santa Margarita, California: fig. 8a, radial view; fig. 8b, ulnar view; fig. 8c, 
dorsal view. 
