PROFESSOR OWEN ON THE GENUS DINORNIS. 143 
in. lin. 
" The length of this bone is . . at S22) 40 
The breadth of the proximal soo ene at SG 
The breadth of the distal extremity. . . . 3 2 
The circumference of the middle of the shaft. 5 0 
The fibular ridge extends down - . . . . 10 O 
This ridge begins, as in the tibiz of other species of Dinornis, below the expanded 
end of the tibia near the middle of its back part, inclining to its outer side. 
In its slender proportions, and the relative positions of the procnemial (p) and 
ectocnemial (e) ridges, the tibia of the Dinornis struthioides agrees with that of the 
D. dromioides. 
Description of the Bones of the Leg of the Dinornis gracilis. 
The advantage of additional specimens, as confirming, by the repetition of the same 
characters, a species previously defined, is still greater in respect of the ground which 
they afford for the discrimination of a distinct but nearly allied species. Notwith- 
standing the well-marked differences observable between the femur of the Dinornis 
struthioides (Pl. XLI. fig. 2) and the Dinornis gracilis (ibid. fig. 1), I might have 
deemed them due to differences of sex or individuals, had I not had evidence of the 
fixity of the specific characters of the Dinornis struthioides by the successive arrivals of 
additional specimens of its bones. Attending the hoped-for confirmation from such 
arrivals, it appeared to be most prudent to refrain from announcing a new species of 
the rapidly increasing family of the great wingless birds of New Zealand until further 
evidence might be obtained by corresponding differences in the tibize and metatarsi 
of the two species. 
Having had the good fortune at length to receive, through the kind contributions of 
the Rev. Richard Taylor, M.A., of Wanganui, and of W. E. Cormack, Esq., these 
additional illustrations of the Din. gracilis, Ino longer delay communicating descriptions 
and figures of them to the learned Society, in whose Transactions my former Memoirs 
have appeared and have been so liberally illustrated. 
Femur. 
The bone (PI. XLI. fig. 1) was obtained at the Bay of Opito, East Coast of the 
North Island, from beneath a sandy deposit, about three feet below the surface, by 
Mr. Cormack. 
The following are the chief dimensions of this bone :— 
in. lin. 
Weemethiy eve.) ea-nue- af 0) 
Breadth of proximal aia in ithe axis of He meplg 3 8 
Breadth transverse of distalend . . .... 4 O 
Circumference of middle of shaft 4 8 
