_Tribonyx roberti Andrews_, Ibis 1897, p. 356, pl. IX, figs 4-7.
This bird is described from an imperfect pelvis, a perfect left
tibio-tarsus and a femur. The pelvis differs from that of _T. mortieri_ in
not having the deep depression in the ilia in front of the acetabulum and
above the pectineal process. It also differs in having a rather wider
pelvic escutcheon and wider renal fossal, and the supra-acetabular ridges
of the ilia are smaller than in the Australian bird. The
beautifully-preserved left tibia differs from that of _T. mortieri_ in
having the intercondylar groove wider and shallower, the inner condyle less
massive, thus making the difference between the inner and outer condyle
more marked; _T. roberti_ also has the shaft immediately above the extensor
bridge wider, the bridge itself less oblique, and the fibular crest is
longer.