“Tree-Ducks” of the genus Dendrocygna. 55 
of the tibio-tarsus of Dendrocygna autumnalis (454) to the lowest 
point on the inner condyle at the distal end of the shaft, this bone 
of the leg is seen to have an extreme length of 114 mm, while the 
fibula has a length of but 60 mm. 
The tibio-tarsus is nearly straight from end to end, the 
shaft between the extremities being subeylindrical in form, and 
somewhat compressed antero-posteriorly. Proximally, the cnemial 
processes are very conspicuous, the entocnemial one being a 
broad lamina of bone, reared above the shaft’s summit, and projecting 
directly forwards. On the other hand, the ectocnemial process 
is triangular, smaller, and with convex, thickened, free superior 
border projects directly inwards, towards the median plane, the 
pelvic limb being articulated as in life. This process, or rather 
its inner angle, stands directly in front of the head of the fibula 
in the articulated skeleton. The summit of the shaft presents the 
usual concavities for the condyles of the femur, and the fibular 
ridge is prominent on the outer side of the shaft for rather more 
than its superior third. At the lower part of the shaft in front, 
we find the usual “tendinal canal”, which is deep distally, where it 
is spanned by a bridgelet of bone, which in life hold certain tendons 
in the aforesaid channel (Fig. 82, Pl. 11). 
The condyles are of about equal size, the outer one being some- 
what more eircular in outline than the inner, the latter being 
kidney-shaped. Both anteriorly and posteriorly they are well 
separated from each other by the intercondylar space or groove. 
At a short distance below the fibular ridge on the outer aspect 
of the tibio-tarsal shaft, the very slender distal moiety of the fibula 
meets the latter, to have its extremity fuse with it. This takes 
place at a point about at the junction of middle and lower thirds, 
below which point no trace of the fibula is to be seen. 
At its proximal end, the head of the fibula is rather large, 
comparatively speaking, with respect to the balance of the bone, 
and compressed from side to side. On the posterior aspect of its 
shaft, at a point about opposite the middle of the fibular ridge on 
the tibiotarsus, we find the usual tubercle for the insertion of the 
tendons of the biceps flexor ceruris (No. 99, Myology of the 
Raven). 
In Branta canadensis the fibula may be traced as far as the 
ankle-joint; though from the middle of the shaft of the tibio-tarsus 
it is thoroughly fused with the shaft of that bone. Distally, it 
