320 PROFESSOR OWEN ON THE GENUS DINORNIS. 



having been swept away by storm-waves a short time before Mr. Earl's arrival, the black 

 bed of peat was exposed, to which Mr. Earl's attention was attracted by observing some 

 bones projecting from its surface. These and many other bones, obtained by digging 

 close to the surface, or at a moderate depth in the peat, all belonged to species of 

 Dinornis. 



Commencing with the leg-bones referable to known species, I first select for description 

 the femur of the Din. giganteus, of which hitherto only the shaft has been described ; 

 but I have now had the opportunity of examining four perfect specimens contained in 

 the collections of Dr. Mackellar and Mr. Percy Earl. 



The femur of the gigantic Dinornis closely accords with the generic characters of the 

 bone, as given in the former memoir (pp. 247, 248). The rough surface for implanta- 

 tion of a muscle at the middle of the fore-part of the proximal end is well-marked, and 

 there is an obtuse prominence from the middle of the rotular concavity (PI. XLIV. 

 fig. 2, r) above the transverse ridge which divides this from the lower inter-condyloid 

 space. The back-part of the proximal extremity of the bone is entire and imperforate, 

 as in the other species of Dinornis. Its dimensions are given in the ' Table of Admea- 

 surements ' : the length precisely accords with that conjecturally assigned to the femur 

 of the Gigantic species in the former memoir (p. 248, table, f. 1 and Note"). 



The circumference of the middle of the shaft exceeds that of the fragment there de- 

 scribed, and indicates the Gigantic Dinornis of the Middle Island to have been a stronger 

 and more robust bird than that represented by the bones from the North Island, de- 

 scribed in the former memoir. In Plate XLIV. the proximal (fig. 1 ) and distal (fig. 2) 

 extremities of this noble bone are figured of the natural size. 



Fine tibiae of Din. giganteus in both Dr. Mackellar's and Mr. Percy Earl's collections 

 supplied, by the perfect state of their articular ends, what was defective in the more 

 ancient and rolled bones from the North Island. The head of the tibia is characterized 

 in Birds by the flat or sinuous, or sometimes slightly convex articular surface (PL XLV. 

 a, a) adapted to tlie inner condyle of the femur, by the large size of the tuberosity {ib. t) 

 which divides this from the smaller sloping articular surface applied to the inner side of 

 the outer condyle, and by the ' epicnemial' ridge (6), which is commonly broad and 

 more or less produced upwards from the anterior and outer part of the proximal sur- 

 face of the tibia. From the outer, usually more or less obtuse, angle of the epicnemial 

 ridge a short ' ectocnemial ' ridge {k) is commonly continued downwards upon the outer 

 part of the shaft : a compressed prominent ' procnemial*' ridge (p) is continued further 

 down the fore-part of the shaft of the tibia. 



The proximal end of the tibia of the Gigantic Dinornis (PI. XLV. fig. 1) agrees, like that 



* To facilitate and make more intelligible the comparisons of the tibiae in the different species of Dinornis 

 and other birds, I have proposed the above names for the well-marked and constant processes and ridges ■which 

 have not before received any distinct appellations in Comparative Anatomy. 



