Marsh Collection, Peabody Museum. 423 



The arrangement of the metacarpals, like those of the dog, 

 is on the paraxonic plan ; the third projects a trifle beyond the 

 fourth, but the difference is so slight as not to affect materially 

 this order. In like manner, the distal ends of the second and 

 fifth reach about the same level. The actual length of the 

 third is greater than the fourth, in the same way that the 

 second is longer than the fifth, but these differences are coun- 

 terbalanced by the overlapping of their proximal articular 

 extremities. The overlapping and consequent interlocking of 

 the second with the third, and the third with the fourth, are 

 almost as great as in the metacarpals of the felines and dogs, 

 but the fifth articulates with the fourth by means of a nearly 

 plane, flat face, with little or no interlocking. In size, the 

 second metacarpal is much the largest, having a more or less 

 flattened shaft. The third and fourth have about an equal 

 degree of stoutness, the shaft of the third being a trifle the 

 thicker of the two. The sides of these two bones are consid- 

 erably flattened laterally, especially in the proximal half of 

 their extent, where they are more closely approximated, but 

 the amount of this compression is much less than in the dog. 

 The fifth is the shortest bone of the four. In the matter of 

 the stoutness of the shaft, however, it is intermediate between 

 the second and third. The distal extremities resemble those 

 of the dog, having well-developed keels confined to the palmar 

 surface. The metacarpal of the pollex is missing and there is 

 no certain means of determining the degree of reduction 

 which it had reached, unless we judge by the size of its articu- 

 lation with the trapezium. This would seem to indicate that 

 it was small and more or less vestigial, so that the fore foot 

 was essentially tetrad actyle. 



The phalanges of the proximal row are shorter, broader, 

 and heavier than those of the hind foot. That of the second 

 digit is notably shorter and stouter than the others. .The 

 fourth is the most slender, after which follow the third and 

 second. The phalanges of the second row are relatively short 

 and heavy, and exhibit a considerable degree of distal asym- 

 metry. The unguals are rather short and depressed ; they are 

 deeply fissured at their extremities and the subungual processes 

 are of moderate size. The ungual foramen is present in all, 

 and is of good size. 



Hind Limh. — The pelvis, figure 50, is much damaged and 

 many parts are missing, but enough remains to furnish some 

 of the more important points of its structure. Of the ilium, 

 the region of the sacro-iliac synchondrosis is present with that 

 of the acetabulum. A considerable portion of the ischium, 

 together with important parts of the pubis, sufficient to give a 

 clear idea of the pelvic outlet, are also preserved. From these 



