The humerus has a large head but is considerably flattened at the proximal end. The internal side is deeply excavated, the shaft is slender and light as though the wing were quite reduced, though not so much as in Pelecyornis and not nearly as much as in Phororhacus.
The sternum had a moderate keel but both this and body of the bone are very thin, so much so, that in my specimen, much is broken away, giving the figure the appearance of the bone being fenestrated, which was not the case. In general the sternum is similar to Pelecyornis.
The coracoid is a decidedly stout bone, with a wide distal end for articulation of the sternum. The proximal end has a long articular facet for the scapula. This bone is heavier than the corresponding one in Pelecyornis.
The femur has a small rounded head on a short neck, the articular surface spreading over the entire proximal end of the bone. Thus the trochanter is abbreviated and does not rise above the top of the head. The shaft is of considerable length and fairly heavy.
The tibio-tarsus has a wide flaring end to receive the articulation of the femur. The bone is very long as in Pelecyornis. On the external side is a long ridge along which the fibula was attached by cartilage or by ligaments, but was not fused to the tibio-tarsus. The shaft is approximately cylindrical in section and fairly heavy. The distal end is missing, but if I have associated correctly the specimen figured by Ameghino, the condyles are flattened, the inner being the flatter, and the outer rising in a narrow margin.
[Figure 157] shows a fibula which would have occupied the position indicated along the side of the tibio-tarsus and corresponds entirely with the same bone in Pelecyornis.
The tarso-metatarsus is long and slender, almost exactly the counterpart of the same bone in Pelecyornis. The bone has a triangular upper end, with two shallow articular concavities, separated by a median spine. The shaft is rectangular in cross section, has a shallow depression on the anterior face extending from the upper end to below the middle of the shaft; while on the posterior surface is a similar furrow, which is however bounded by a higher ridge on the external margin. The distal articular condyles are almost bilaterally symmetrical, the middle one being about half again as large as the two lateral ones. Just above the cleft between the condyles for digits III and IV there is a moderate sized perforation.
Fig. 155. Femur—
½ natural size.
