16 
ANNALS OF THE QUEENSLAND MUSEUM. 
half its length. Placed in the attitude proper to it with its dorsum 
in view (PI. iii, fig. 6), the contraction of its distal end is in striking 
contrast with its expansion at its opposite end, a contrast duplicated 
by the sharp relief of its distal features. The trochlear groove is 
here deeply incised, and its convex sides rise into ridges which, con- 
tinuing beyond the groove, converge and meet together on the mid 
point of the dorsum. Between the ridges and immediately proximad 
of the articulating convexities the surface for the insertion of the 
dorsal ligament is sunken, roughened, and pitted. The left side of 
the bone, as it lies, is broader than the right one ; it begins to expand 
gently from its distal end to about the middle of its length, then 
rapidly until it approaches the proximal border to join which it 
suddenly contracts. On the right side it begins to dilate about the 
middle of its length, whence it extends widely outwards to reach the 
proximal border, which on that side is tumid. The proximal troch- 
lear excavation (PI. iii, fig. 4) is on its upper edge almost semicircular; 
its surface trends downwards, inwards, and laterally from the right 
to the left side, and reaching the plantar surface encroaches upon 
it to the extent of one-fourth of its length ; below the upper edge 
and following its transverse curve is the surface specialised for 
adaptation to that of a preceding bone, a smooth uninterrupted 
band dilated and curled upwards at its right extremity, less broad and 
directed inferolaterally at its left. Within the curve of this surface 
is a large and deep pit whose surface shows that it was the seat of 
ligamentous insertion. The plantar surface (PI. iii, fig. 5) is simply 
a broad and deep trough formed by the rise from it of a ridge on 
each side. 
A bone of this description must necessarily be a basal phalanx, 
and it is almost needless to add the basal phalanx of a first toe. Its 
bilateral dilatation, narrow transverse articulating facette, inferior 
ligament, and provision for the defence of a powerful flexor tendon, 
are a concourse of characters which leads to no other than the latter 
conclusion. 
The inevitable inquiry, To what bird did it belong ? cannot be 
so readily answered. After elimination of the families of birds 
which have either no hind toe or one in a rudimentary condition, 
or are so elongate and slender as to bring its toe joints entirely out 
of parallel with the fossil, there followed a strict comparison of the 
