150 PROFESSOR OWEN ON THE GENUS DINORNIS. 
Femur of Dinornis elephantopus. 
Commencing with the femur, I shall premise the following Table of admeasurements 
of that bone in the three above-named species of Dinornis. 
Dimensions of the Femur in 
D.robustus. D.elephantopus. D. crassus. 
in. lines. in. lines. in. lines. 
JWantalil apacoenonD JOGO uoOo sue Ope unt ias 14 2 13 O 11 10 
Transverse breadth of proximal end.......... 6 40 5 10 4 5 
Fore-and-aft breadth of ditto ............-- Stel 4 5 3 9 
Transverse breadth of distal end ...........- 6 O iy abs 4 7 
Fore-and-aft breadth of ditto .............. Cre} Bie) Bye 5) 
Circumference (least) of shaft .............- der 0) ae!) 6 O 
The above comparative dimensions bring out the characteristic proportions of the 
femur of Dinornis elephantopus (Pl. XLIII. fig. 1), as shown by its greater thickness 
and strength. Compared with the femur of Din. robustus, this character is remark- 
ably exemplified in the articular extremities (Pl. XLIII. figs. 2 & 3). Had these 
parts alone of Din. elephantopus been preserved and submitted to me, I should have 
scarcely ventured upon a conclusion as to their specific distinction from D. giganteus, 
or its representative on the Middle Island, D. robustus, the correspondence of con- 
figuration being so close and the difference of size so slight. 
The articular surface is continued from the head upon the upper part of the neck 
(Pl. XLII. fig. 2), expanding as it approaches the great trochanter, along the summit of 
which it is terminated by a ridge. In both species the surface for attachment of the 
ligamentum teres is formed, as it were, by a portion of the inner and back part of the 
hemispheric head, having been cut off obliquely with a slight excavation. The corre- 
sponding ligamentous surface in the head of the femur of Din. crassus is relatively 
smaller, less depressed and less defined. The upper and fore part of the trochanter is 
less produced relatively to the breadth of the supra-trochanterian articular surface in 
Dinornis elephantopus. In this species the subcircular rough surface for the attachment 
of the iliacus internus muscle (fig. 1, 7) is relatively nearer to the head of the bone than 
in Dinornis robustus: the rugged and thick fore part of the great trochanter descends 
lower upon the shaft ; indeed the shortness of the entire bone seems to depend chiefly 
on the shaft being relatively shorter in Din. elephantopus than in D. giganteus or robustus. 
The intermuscular ridge continued from the trochanterian one down the fore part of the 
shaft bifurcates sooner in Din..elephantopus. ‘The depression behind the trochanterian 
ridge is less deep in Din. elephantopus. 
The oblique rotular channel is relatively as wide and deep as in Din. robustus, but 
the inner boundary formed by the fore part of the inner condyle is shorter in Din. 
elephantopus. At the back part of the shaft of the femur the medullo-arterial foramen 
