230 THE DESEADO FORMATION OF PATAGONIA 
The humerus has a large head but is considerably flat- 
tened 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 Pelecyornts. 
The coracoid is a decidedly stout bone, with a wide dis- 
tal 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 approxt- 
mately cylindrical in section and fairly heavy. ‘The distal 
end is missing, but if I have associated correctly the speci- 
men 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 
