152 PROFESSOR OWEN ON THE GENUS DINORNIS. 



is the orifice of the canal for the obhquely descending medullary artery, in all the 

 species of Dinornis. The upper division of the ridge is shorter in Dinornis elephan- 

 topus than in Din. robustus, and relatively shorter than in Din. crassus. The sur- 

 face between the fibular ridge and the inner border of the shaft, at the back part, is 

 concave transversely in Din. elephantopus, not merely flat as in Din. robustus and Din. 

 crassus; and, as it descends, it continues longer a flat surface before it changes gra- 

 dually to a convex one. The oblong rough insertional surface above the inner condyle 

 is relatively shorter and better defined in Din. elephantopus than in Din. robustus. On 

 the characteristic fore part of the lower end of the tibia, that bone in Din. elephantopus 

 repeats all the modifications ascribed to the genus Dinornis in my Memoir on the Gas- 

 tornis, or large fossil bird from the Paris eocene'. 



The tendinal canal inclines obliquely inward, parallel with the inner border of the 

 expanding end, near which it is placed (PI. XLIII. fig. 4,/) : the bony bridge spans across 

 it from a flattened tubercle developed from the lower part of the outer pier. The out- 

 let of the canal is as wide as in Din. robustus ; its aspect is obliquely forward and 

 downward. External to the tubercle is an oblique rough depression, relatively narrower 

 and better defined than in Dinornis robustus. The inner condyle, a, is relatively 

 narrower and more produced forward than in Din. robustus, resembling more the pro- 

 portions of that part in Din. crassus. The general form and oblique direction of the 

 wide distal trochlear articulation of the tibia are closely repeated in all the species ; 

 the concavity being rather more sharply defined behind in Din. elephantopus than in Din. 

 robustus. The depression on the entocondyloid surface is less deep in Din. elephantopus 

 than in the Din. robustus. 



The above specific differences, as well as all that I have noticed in the tibiae of other 

 species of Dinornis, are so inferior in degree to those which I have found in closely allied 

 genera, and even in different species of the same genus, of other large land- and wading- 

 birds, as e. g. in species of Ciconia, and in the existing Struthious genera, as to leave a 

 strong impression on my mind of the generic afiinity of the species of wingless birds of 

 New Zealand which I have referred to Dinornis and Palapteryx, and which species have 

 been divided, with a more liberal imposition of terms, by Dr. Reichenbach, into the 

 nominal genera Anomalopteryx, Movia, Emeus, Syornis, &c. ; no other facts or characters 

 being assigned for that multiplication of generic names than those which are to be found 

 in the pages or plates of the Memoirs in the Zoological Transactions. 



Fibula of Dinornis elephantopus. 



The fibula of Dinornis elephantopus remains, as in other Dinornithes, and as in the 

 existing Struthious genera, permanently distinct from the tibia. As a general rule 

 in Birds, the fibula soon becomes anchylosed to the tibia. In the species now defined, 

 it is a straight styliform bone, 14 inches 6 lines in length (PI. XLIII. fig. 6). The head is 



' Quarterly Journal of the Geological Society, 1856, vol. xii. p. 210. pi. 3. fig. 2. 



