316 PATAGONIAN EXPEDITIONS: PALAEONTOLOGY. 



of Hapalops and the shaft is more slender and more regularly curved, the 

 posterior border being continuously convex. 



Metacarpals IV and V, the only part of the manus preserved, are sur- 

 prisingly small and indicate either that the whole manus was very small, 

 or, more probably, that the ulnar side was greatly reduced. Metacarpal 

 IV is of nearly the same length as the corresponding metatarsal, but 

 much more slender, and considerably exceeds in length metacarpal IV of 

 Schismotherium fractum , the proximal end has a very complex facet for 

 the unciform and on the ulnar side is a deep pit which receives the head 

 of V ; in Hapalops this facet is much more nearly plane ; the distal 

 trochlea is narrow, but has a very prominent carina. The fifth meta- 

 carpal also is longer and much more slender than in Schismotherium, and 

 the narrow proximal end is occupied by the saddle-shaped facet for the 

 unciform ; the shaft is very slender and the distal trochlea is imperfect, 



with almost obsolete carina. 



MEASUREMENTS. 



Humerus, length 136 Metacarpal IV, distal width 007 



" thickness of proximal end .. .032 " " " thickness 012 



" width of trochlea 028 Metacarpal V, length 021 



" " distal end over epi- " " proximal width 0055 



condyle 060 " " thickness 0075 



Metacarpal IV, length 028 " " distal width 005 



" " proximal width 009 " " thickness 007 



" thickness oil 



The fragment of pelvis merely indicates the likeness of the ilium to that 

 of Hapalops. 



The femur (Plate LIII, fig. 5) lacks the proximal epiphysis, except 

 a portion of the head, which is directed more proximally and less 

 internally than in Hapalops; the second trochanter is very prominent, 

 but the third is more reduced than in any other Santa Cruz genus of the 

 order. The shaft is to some extent intermediate between the form seen 

 in Analcimorphus and the more usual type seen in Hapalops, being shorter 

 and broader than in the former, less flattened and with more convex sur- 

 faces than in the latter. 



The tibia (Plate LIII, fig. 6) is considerably shorter than the femur; 

 the spine is low, blunt and feebly grooved, and the cnemial process is 

 rugose ; the shaft has a very strong anterior curvature and, on the inner 

 side above the middle, is a prominent tubercle ; the great projection from 



