PROFESSOK OWEN ON THE GENUS DINOENIS. 249 



the cavity of the shaft and the expanse of the distal end of the femur are dinor- 

 nithic. 



In carrying out comparisons with previously determined species of the genus, I find 

 that, the least diameter of the shaft being one seventh the length of the femur in 

 1). parvus, the entire bone is relatively less thick than in Binornis gerano'ides^, and the 

 distal end is relatively less expanded than in Binornis didiformis^. The trochanter 

 (PI. LVI. figs. 1, 2, c) shows rather less relative height than in B. didiformis, but 

 presents equal breadth. The distal end has greater relative breadth, especially of 

 the rotular concavity (ib. fig. 1, r), compared with the length of the femur and the 

 diameter of the shaft, than in Binornis geranoides. The muscular ridges are as 

 strongly developed on the hinder or popliteal aspect of the shaft (fig. 2), and the 

 popliteal space (ib. figs. 2 & 6, «) is as deeply excavated, as in any other species 

 of Moa. 



The rough, deep, oval depression (ib. fig. 2, g) reappears at the same part above the 

 outer condyle {e). The outer surface of the great trochanter (fig. 4, c) shows a broad 

 longitudinal angular depression, beneath which the distal part of the narrowing 

 trochanter is indented by a narrower and shallower longitudinal one (fig. 4, h). From 

 the fore border of this depression is continued the intermuscular ridge (fig. 1, i), which 

 runs straight down the middle of the fore part of the shaft to within one third of the 

 distal end of the bone. 



The full, oval, flat, rough surface (fig. 1, d) on the fore part of the femur, midway 

 between the head of the bone and the trochanter for the insertion of the 'iliacus 

 intemus ' muscle, is well defined ; it is nearer the middle of that part of the bone than 

 in the femur of Binornis elcphantopus. The oblong rough surface at the hind part 

 of the base of the great trochanter for the insertion of the strong tendon of the ' obtu- 

 rator internus ' is also well marked '. From this a linear rising or ridge (ib. fig. 2) 

 descends along the inner side of the shaft parallel with the anterior ridge. On the 

 outer and back part of the trochanterian enlargement are two oblique parallel ridges 

 extending downward and backward; the lower one is the strongest and longest. Two 

 linear ridges extend down the back of the femoral shaft, converging, and terminating 

 in a single ridge at about one third of the length of the femur from the distal end. 



The medullarterial canal (fig. 2, k) opens, as in other Moas, between the hinder 

 ridges a little way above their confluence, at the mid length of the bone. 



In the femur of Binornis ingens and in that of B. struthioides, at the middle of the 

 back of the neck of the femur, a seemingly vascular foramen, bigger than the rest 

 thereabouts is figured. A foramen in the corresponding position is relatively larger, 

 more marked, in B. parvus (fig. 2); it might be taken for a 'foramen pneumaticum,' 



' Trans. Zool. Soc. vol. v. 186.5, p. 400, pi. Ixv. " Ibid. vol. iii. 1843, p. 249, pi. xxiv. 



' The musclea in relation to the above femoral characters are determined from the analogy of Ajittrux 

 att^tralis. See Trans. Zool. Soc. vol. iii. 1842, p. 291, pis. xxxii., xxxiii. 



VOL. XI. — PART VIII. No. 3. — Januari/, 1883. 2q 



