364 Dr. R. W. Shufeldt on cases of 



of that useful work^ those authors say: — "The crus, which is 

 much longer and more extensive [than the femur], is chiefly 

 composed of the tibia, the fibula being quite rudimentary and 

 represented by a styliform bone on the outer side of the 

 tibia." So much, then, for many authorities prior to 1890, 

 as well as before and after the fact had been published in 

 1885 by Dr. Baur and myself that there were existing 

 carinate birds with complete fibulse. Subsequent to 1890, 

 or even at the present time, the opinions of anatomists still 

 appear to be conflicting with regard to this interesting point 

 in the structure of birds. Even so careful and observant 

 a morphologist as my friend Dr. Hans Gadow, in Newton^s 

 ' Dictionary of Birds,'' not yet entirely through the press 

 (1893), gives the definition for the avian fibula in part I. of 

 that work as '^ the bone on the outer side of the Tibia, 

 thick at its proximal end, but very slender and pointed 

 towards the ankle-joint, which, however, is never normally 

 reached, the distal portion of the fibula being already defi- 

 cient in the embryo '' {op. cit. p. 249) . 



With this before us, I shall now proceed to give a few 

 examples of the leg-bones of birds, wherein we not only find 

 a complete fibula, but wherein it does normally reach the 

 ankle-joint. Pandion and Colymbus have already been suffi- 

 ciently dwelt upon elsewhere, and in concluding this article 

 it gives me pleasure to call attention to the leg-bones as 

 they are found in another avian group. I refer to the 

 Steganopodes. 



In the Snake-bird {Plotus anhinga), for example, the 

 fibula is not only thoroughly ossified, but also complete, and 

 reaches quite down to the tarsal epiphysis of the tibio-tarsus. 

 Its extreme distal end is the only part that fuses with the 

 tibio-tarsus, and it appears to slightly overlap the tarsal 

 element co-ossified at its extremity. To satisfy any doubt 

 upon this latter point, however, embryo birds of this species 

 must be examined. This, up to the present time, I have 

 not done. My drawing (fig. 1) shows the leg-bones of the 

 Snake-bird so well that further explanation seems to be un- 

 necessary. It will be as well to add, however, that although 



