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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 59. 



in the limb bones the epiphyses are not yet ankylosed to the shafts. 

 However, in a skeleton of M. monax at hand, the bones are in about 

 the same stage and the molar teeth are worn down nearly as much as 

 in the jaw of M. arrodens. The writer is inclined to believe that the 

 limb bones belong with the jaw. They are here to be compared with 

 a skeleton of M. monax (Cat. No. 20765) found near Washington, 

 District of Columbia. These bones are illustrated alongside those of 

 the fossil. On the plate cited the humerus of M. arrodens is shown by 

 figure 5; that of M. monax by figure 6. 



Measurements oj humeri of Marmota. 



M. arro- 

 dens. 



M. 



monax. 



Total length 



Side-to-side diameter of head 



Side-to-side diameter at middle of length 

 Width across d istal condyles 



74 

 15.2 

 7 

 20 



74.8 

 14 



IS. 5 



Figures 7 and 8 of plate 117 show, of the natural size, the right ulna 

 of the fossil and that of M. monax; while figures 9 and 1 present views 

 of the right radii of the same individuals, respectively. The ulna of 

 the fossil has lost its distal epiphysis. Of the left femur supposed to 

 belong with the bones of the fore-limb there is present only the 

 upper half (pi. 118, fig. 1). It will be seen at once that the fossil 

 femur is a far stouter bone than that of M. monax (pi. 1 1 8, fig. 2) ; 

 and it was probably little, if any, longer than the other femur. 



Three tibia, one of the right side of M. nlonax and both right and 

 left of the fossil, are shown on plate 118; figures 3 and 4 are those of 

 the fossil bones; figure 5 that of the recent skeleton. The right tibia 

 of the fossil is 81 mm. in total length; that of M. monax only one-half 

 millimeter longer. Here again the recent bone is seen to be much 

 slenderer. In the fossil the upper half of the hinder face is much more 

 deeply excavated than in the eastern woodchuck. 



From Dr. Joseph Grinnell, of the University of California, the 

 writer has received important materials belonging to Marmota van- 

 couverensis, M. jiaviventer jiaviventer and M. f. sierrae. M. van- 

 couverensis is a very large species, one humerus measuring in length 

 93 mm., the ulna 94 mm. The humerus of M. arrodens, 74 mm. long, 

 is a relatively stouter bone than that of M. vancouverensis, especially 

 proximally. On comparison with a humerus 82 mm. long of M. van- 

 couverensis, it is found that the side-to-side diameter just above the 

 insertion of the latissimus muscle is 9.5 mm.; in M. arrodens, 11 mm. 

 Where the bones are narrowest below the deltoid ridge the diameters 

 are little different, that of M. arrodens being slightly less. The 



