322 PROFESSOR OWEN ON THE GENUS DINORNIS. 



In the femur of the robust variety of Dinornis ingens from the Middle Island, the upper 

 tuberosity of the two posterior ones is nearer the lower than the upper end of the bone ; 

 in the femur of the Din. ingens from the North Island it is nearer the middle of the shaft. 

 In the Din. ingens from the Middle Island the inner contour of the femur descending 

 from the head is less concave : the outer expanded surface of the proximal end of the 

 bone forms an obtuse angle with the posterior surface, not a right angle, as in the Din. 

 ingens from the North Island. In the Din. ingens from the Middle Island the great tro- 

 chanterian ridge extends more boldly out, its contour is more convex, and it is relatively 

 larger. The same may be observed with regard to the antero external prominence of 

 the outer condyle : the length of shaft included between the lower end of the trochan- 

 terian prominence and the upper end of the external condyloid prominence is four inches 

 nine lines in the robust variety, and five inches five lines in the femur from the North 

 Island. 



The proportions of the tarso-metatarsal bone of the Dinornis ingens, as exemplified in 

 the bone (PI. XLVIII. fig. 1) sent by Mr. Colenso from the North Island, are nearly those 

 of the Din. struthoides. In the tarso-metatarsal bone of Din. giganteus the antero-poste- 

 rior thickness of the shaft is greater. The anterior surface of the upper half of the 

 shaft, below the perforated depression, shows a slight longitudinal concavity in Din. 

 ingens. Towards the inner side of the posterior part of the lower half of the shaft there 

 is a rough tract of three inches in length, and at its lower end a rough oval depression 

 {ib. d), about one inch by nine lines. The surface in the tarso-metatarsal bone of the 

 Apteryx for the attachment of the back-toe occupies the corresponding place : the 

 Dinornis ingens therefore, by this mark of resemblance to the Apteryx, may belong to 

 a genus (Palapteryx) distinct from Dinornis. The accuracy of the reference of the tarso- 

 metatarsal bone, m 2, in the former Memoir (p. 244) to a young individual of the Di- 

 nornis giganteus, is well-illustrated by the present bone, in which the shaft, from the 

 perforated proximal anterior depression to the beginning of the clefts of the distal arti- 

 cular trochlea, is precisely the same as in m 2 ; the tarso-metatarsal in the Dinornis ingens 

 manifesting all the characters of age, by complete confluence of its primitively distinct 

 elements, as well as by the strong and rough lateral ridges for ligamentous and aponeu- 

 rotic attachments ; whilst m 2, with the same length of shaft, shows, as described in the 

 former Memoir, the still open fissures between the proximal ends of the three constituent 

 metatarsals. 



The species, which I have called Dinornis casuarinus, is most satisfactorily determined 

 by ten femora, five of the left and five of the right leg ; by eleven tibise, five of the left 

 and six of the right leg ; and by six tarso-metatarsal bones, most of which bones have been 

 obtained from the Middle Island, at the locality and turbary deposit near Waikawaite. 



I had already figured one of the bones of this species from the North Island in my 

 former Memoir, viz. a mutilated femur (Plate XXIII. fig. 1), which I then regarded as 

 belonging to a young individual of the Dinornis struthoides. The acquisition of so many 



