OSTEOLOGY OP THE DODO. 79 



dyle is more produced and sharper in Aptornis, the fore part of the same condyle is 

 less produced. 



The femur in Onemiornis^ and Binornis^ is much thicker, in proportion to its length, 

 than in either Aptornis or Didus. In Pezophaps the great trochanterian ridge rises 

 higher above the neck, and the shaft has a more uniform thickness, with the inner 

 contour less concave, than in Didus. 



The characters which have been noted at the proximal and distal ends of the tibia of 

 Didus are repeated in those of the tibia of the Goura. The difference in size is more 

 marked than in the femur ; the length of the tibia of Goura coronata is 4 inches 7 lines, 

 and its shaft is more slender, in proportion to its length (PI. XXIV. fig. 13), than in 

 Didus (PI. XXII.). The tendency to a trihedral form of the shaft is less marked in 

 Goura ; the anterior prominences of the distal condyles are thicker in proportion to the 

 intervening fossa. 



In the Vulture the fibular ridge is more parallel with the long axis of the shaft than 

 in Didus ; the tendinal canal is less cylindrical, has an oblique course from the middle 

 of the anterior surface towards the inner condyle ; the fore parts of both distal condyles 

 are less produced and less convex ; the distal end is narrower from before backwards in 

 proportion to its breadth ; both extremities of the bone are less expanded in proportion 

 to the shaft than in the Dodo. 



In the great Plover {(Edicnemus crepitans) the tibia, as in other Grallse, is longer in 

 proportion to its thickness than in Didus ; the epicnemial process rises higher above and 

 projects further in front of the condylar sm-faces before it divides into the pro- and 

 ectocnemial plates; and these are relatively more produced. The fibular ridge is 

 shorter in proportion to the length of the tibia, is more prominent, and more parallel 

 with the axis of the shaft. The distal condyles project further backward than in Didus. 

 The tibia in Charadrius, Otis, Tantalus, Grus, Ciconia, Mycteria, Porphyrio, opposes 

 similar or equivalent difierences to those in (Edicnemus, against the affinity of Didus to 

 any of those Grallse. 



In the comparison of the tibia of this extinct flightless bird with that of the Cnemiornis, 

 the wonderful development of the plates and processes at the proximal end of the bones 

 in the New Zealand bird is strikingly manifested. In Cnemiornis the fibular ridge runs 

 in a line with the shaft, and does not incline from above obliquely forward as in Didus 

 and the Doves ; the ridge on the outer side of the distal fourth of the bone is sti-onger 

 and sharper in Cnemiornis ; the tendinal canal is transversely elliptical, medial in 

 position, with a slight inward inclination ; the intercondyloid fossa is much wider in 

 Cnemiornis. The difierences, indeed, in all the characters of the tibia, as compared with 

 Didus, in the Vultures, Plovers, Penguins, and terrestrial flightless birds tend to render 

 more instructive and convincing the resemblances which Pigeons present in the same 

 characters to the extinct Mauritian bird. 



' Trans. Zool. Soc. vol. v. pi. 65. fig. 1. ' Ibid. fig. 5. 



