PROFESSOR OWEN ON THE GENUS DINORNIS. 143 



in. lin. 



The length of this bone is 22 



The breadth of the proximal extremit)' . . 5 6 

 The breadth of the distal extremity .... 32 

 The circumference of the middle of the shaft . 5 



The fibular ridge extends down 10 



This ridge begins, as in the tibiae 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 (PI. 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 tibiae 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, I no 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. 



Length 110 



Breadth of proximal end in the axis of the neck . 3 8 



Breadth transverse of distal end 4 



Circumference of middle of shaft 4 8 



y 2 



