Of the femur I have only the distal end, which, however, corresponds completely with the one figured by Gaudry. It is a long bone, slightly shorter than the humerus, with a small head, set on a short and poorly outlined neck. The greater trochanter is wide and rugose, rising to about the same height as the head. The lesser trochanter is not distinguishable. About the middle of the shaft there is a powerful third trochanter, which continues as a narrow ridge upward to the greater trochanter, and downward in a similar narrow ridge almost to the outer condyle. At the proximal end the shaft is greatly flattened, but in the central and lower parts becomes almost circular in section. The two condyles are set wide apart, project considerably behind the posterior face of the shaft, and are only slightly convex. The trochlea is of moderate width, short, and shallow. Gaudry outlines a short, heavy, rugose calcaneum which has but a short tuber; a flat navicular; a small cuboid; and an astragulus with only a slight convexity of the trochlea, and with the navicular facet directed obliquely forward, making an angle of 127° with the plane of the trochlea, which, as he says, would indicate a semidigitigrade position of the pes. The following species are distinguished by Ameghino as coming from the Deseado beds: _P. holmbergi_, _P. troussarti_, _P. lemoinei_, _P. ephebicum_, _P. martiale_, _P. superabile_, _P. insuperabile_. The various species are known from the same parts in but a few cases. Their relative sizes are indicated from the following compilation of the measurements given by Ameghino: