GIGANTIC BIKD FEOM LOWER EOCENE BEDS. 149 



One of the most marked peculiarities of this bone is seen when it is viewed from the 

 front (PI. XXIX. fig. 13), namely, the head stands well above the trochanter, and it 

 is evident this was more obvious when the parts were perfect. In this front view the 

 superior articular surface (s.art) is seen to extend obliquely downwards and outwards 

 from the head to the trochanter, presenting only a slight concavity, and this chiefly at 

 its inner end, where it curves up to the rounded head {a./i). The outer part of this 

 articular surface also curves slightly upwards, showing that the trochanter (tr), when 

 perfect, projected a little above this surface, as well as outwards beyond the general 

 direction of the shaft. The superior articular surface is slightly convex from before 

 backwards, and overhangs the hinder part of the shaft as a distinctly rounded tuberosity 

 (PI. XXIX. fig. 15, p.t). Just below this, on the back of the bone, there is a depres- 

 sion, partly due to the crushing of the bone in this region. Anteriorly the trochanter 

 is continued into a very prominent crest (a.c), which is best seen in the end view of the 

 bone (PI. XXIX. fig. 15). This crest is continued along the front of the shaft, so 

 far as this io preserved, and consequently, at the point where the bone is broken, the 

 transverse section (PJ. XXIX. fig. 13 a) shows the antero-posterior diameter to be 

 greater than that from side to side. The second piece of this femur (PI. XXIX. 

 fig. 14) most probably held the position indicated in figures 13, 14; the cross 

 section of its proximal end (fig. 14 a) is more rounded than the lower end of the 

 proximal piece, to which it is opposed in the figure, although the crest at its outer 

 edge is still seen. The distal end of this piece is nearly quadrate in cross section, and 

 seems to indicate a flattening of the bone previous to its expansion into the condyles. 

 The bony walls of the shaft in the middle region are very thick, varying in different 

 parts of the circumference from 8 to 13 millimetres. 



Measurements of femur hi millimetres. 

 Width from head to outer tuberosity of trochanter {a.Ji-tr, PL XXIX. 



figs- 13, 15) : 115 



Width from front to back in same region (fig. 15, a.c-jjt) 104 



Greatest diameter of section of shaft (fig. 13 a) 66 



Least diameter of section of shaft (fig. 13 a) 46 



Greatest diameter of section of shaft (fig. 14 «) 58 



Least diameter of section of shaft (fig. 14 «) 48 



This femur is provisionally regarded as belonging to the same species as the large 

 tibio-tarsi ; but there is no direct proof tliat such is the case, beyond their agreement in 

 size, and being found in the same place. 



It will be seen from the above description that the six specimens of birds' bones from 

 the Park-Hill cutting represent at least four different individuals, and as they were 

 all from a comparatively small area, they seem to indicate that these large birds were 



