DR. J. VON HAAST ON A NEW SPECIES OE DIXORNIS. 177 



greater in comparison with their length than in Di7iorms jJCU'vus. This is doubtless 

 owing to the more pachydermal character of the species under review. Thus, while 

 the breadth of the sacral centrum is 0"81 inch, in the fifth it has increased to 114 

 inch, and it only diminishes to 0-97 inch in the eighth, retaining the same breadth 

 in the eleventh, and being still O'SO inch in the fourteenth. 



The ischium, broken off on both sides before its expansion in breadth, is also more 

 massive in comparison to the size of the species than the corresponding part in JJinoruis 

 parvus. Only a small portion of the pubis exists, but sufficient to show that the 

 obturator foramen was well developed. 



Femue. 



Measurements. inches. 



Length 5-65 



Middle of shaft 0-87 



Proximal end of shaft 1'95 



Distal end of shaft 1-90 



This bone, though so verj small, in its general character closely agrees with that of 

 the Dinornithidse (Dinornis maximus included), and thus is quite different from the 

 femur ot Mefjalapteri/x as previously described. The head of the bone has a well- 

 defined neck, though not so restricted as in Dinornis parvus. The trochanterian 

 articular surface is broader than in most of the Dinornithidse, the curve of its anterior 

 boundary being more rounded, but the slope towards the great trochanter is less, so 

 that the latter scarcely rises above the head of the femur. The well-defined ecto- 

 trochanterian ridge, div iding the posttrochanterian from the anterior or pretrochanterian 

 surface, is very sharp and prominent, so that the former appears far more excavated 

 than in any other of the Dinornithidse, the more so as also the posterior edge of the 

 articular trochanterian surface is a little overlapping. This feature also distinguishes 

 it from JJinonds curtus, which in this respect closely agrees with the larger species of 

 the Dinornithidse. The rough depressions for muscular insertions on the post- 

 trochanterian surface are well excavated, showing that this species, though of small 

 size, must have possessed considerable power. 



The linear ridges are rather inconspicuous, the principal ones being those on the 

 inner side of the shaft, one beginning 60 inch below the neck. After a space of 

 about 0-50 inch it divides, the more prominent portion continuing its oblique direction 

 across the shaft and meeting another ridge, forming the boundary of the posttrochan- 

 terian surface. 



The inner portion of the first-mentioned ridge continues in its downward course 

 along the shaft to the well-indicated rough tuberosity. On this line the orifice for the 

 medullary artery is situated. The outer ridge also continues in its downward direction 



2d2 



