172 Zoological Society : — 



tinued from the procnemial plate is interrupted as in the Binornis 

 elephantopus . The fore part of the tibia internal to the procnemial 

 ridge is impressed by irregular vascular grooves. The fibular ridge 

 is interrupted by a smooth tract, in or near which is the orifice of 

 the canal for the obliquely descending medullary artery in all the 

 species of Binornis. The upper division of the ridge is shorter in 

 the Binornis elephantopus than in the Binornis robustus, and rela- 

 tively shorter than in the Binornis crassus. The surface between 

 the fibular ridge and the inner border of the shaft at the back part 

 is concave transversely in Binornis elephantopus^ not merely flat as 

 in Binornis robustus and Binornis crassus, and, as it descends, it 

 continues longer a flat surface before it changes gradually to a convex 

 one. The oblong rough insertional surface above the inner condyle 

 is relatively shorter and better defined in the Binornis elephantopus 

 than in the Binornis robustus. On the characteristic fore part of 

 the lower end of the tibia, that bone in the Binornis ele^ihantopus 

 repeats all the modifications ascribed to the Binornis in my memoir 

 on the Gastornisy or large fossil bird from the Paris eocene*. 



The tendinal canal inclines obliquely inwards parallel with the 

 inner border of the expanding end, near which it is placed ; the bony 

 bridge spans across it from a flattened tubercle developed from the 

 lower part of the outer pier. The outlet of the canal is as wide as 

 in the Binornis robustus ; its aspect is obliquely forwards and down- 

 wards. External to the tubercle is an oblique rough depression, 

 relatively narrower and better defined than in the Binornis robustus. 

 The inner condyle is relatively narrower and more produced forwards 

 than in the Binornis robustus, resembling more the proportions of 

 that part in the Binornis crassus. The general form and oblique 

 direction of the wide distal trochlear articulation are closely repeated 

 in all the species, the canal being rather more sharply defined behind 

 in the Binornis elephantopus than in the Binornis robustus. The 

 depression on the entocondyloid surface is less deep in the Binornis 

 elephantopus than in the Binornis robustus. 



The above-specified difl"erences, as well as all that I have noticed in 

 the tibiae of other species of Binornis, are so inferior in degree to 

 those which I have found in closely allied genera, and even in dif- 

 ferent 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 

 affinity of the species which I have referred to Binornis and Pal- 

 apteryx, and which species have been divided, with a more liberal 

 imposition of terms, by Dr. Reich enbach into the nominal genera 

 Anomalopteryx, Movia, Emeus, Syornis, &c., no additional facts or 

 characters being given by that nomenclator than are to be found in 

 the pages or plates of my own memoirs. 



The fibula of the Binornis elephantopus remains, as in other 



Binornithes, and as in the existing Struthious genera, permanently 



distinct from the tibia ; as a general rule in birds, it soon becomes 



anchylosed to that bone. In the species now defined it is a straight 



* ' Proceedings of the Geological Society.' 



