11 



in Dinoi'nis, as is also the inner trochlea, as far as one may judge 

 from the posterior part which is preserved. The interspaces of the 

 trochlese are wider posteriorly in ^pyornis, and the outer one is 

 more angular at its upper end. The middle portion of the posterior 

 surface of the lower third of the shaft of the metatarse in jEpyornis 

 is more produced than in Dinornis, and a ridge is continued from it 

 to each lateral trochlea, dividing the back part of the shaft above 

 them into three surfaces ; whereas the corresponding surface in 

 Dinornis is simply flat from side to side. Above this part in JEjjyornis 

 the posterior surface on each side of the middle prominence is con- 

 cave and meets the anterior surface at a ridge, which is narrowest at 

 the outer border of the bone. In Dinornis both borders of the lower 

 third of the shaft are thick and rounded. 



The Mpyornis does not show any trace of the rough tract for 

 attachment of a back toe, as in the Palapteryx robustus ; in this re- 

 spect it resembles the Dinornis. 



At 6 inches from the lower end, the shaft begins to be concave 

 along the middle of the fore part, the concavity deepening as it 

 ascends ; whereas in Dinornis the anterior median concavity of the 

 shaft does not begin to appear until above the upper half of the bone. 

 In this character the ^pyornis resembles the Cassowary ; but it 

 differs from the Cassowary in the much narrower or sharper lateral 

 margins of the shaft of the metatarsus. Like the Cassowarj, how- 

 ever, the breadth of the shaft is greater in proportion to that of the 

 trochleae than in the Dinornis or Palapteryx. 



It would be hazardous to conclude as to the length of the entire 

 metatarse from the breadth of the distal end ; for this is equal in 

 Dinornis giganteus and Palapteryx robustus, whilst the length of 

 the metatarse is 1 foot 6 in. in the one and 1 foot 4 in. in the other. 

 I think it more probable, however, that ^Epyornis had a shorter than 

 that it had a longer metatarse than the Dinornis giganteus. 



That its leg-bones were smaller is significantly indicated by the 



difference of size in the fibulae. 



Dinornis. jEpyomis. 



in. lin. in. lin. 



The longest diameter of the upper end ..211 29 



The shortest diameter of the upper end. .14 10 



This bone in Mpyornis shows a flat, full, oval articular facet on its 

 tibial side, of which there is no trace in Dinornis. 



Upon the whole, therefore. Prof. Owen concluded that the JEpy- 

 ornis maximus did not surpass in height or size the Dinornis gigan- 

 teus, and that it was more probably a somewhat smaller bird. 



From the obvious differences which M. Geoffroy found on com- 

 paring these fragments with the casts of the metatarsus of the 

 Dinornis giganteus, he has inferred with much probability not only 

 its specific but generic distribution, and has proposed for it the name 

 oi jEpyornis maximus*. This distinction is illustrated not only by 

 the metatarsal bones, but by the eggs themselves. Mr. Walter 



* From aiTTi'is alta, opvi^ avis. The trivial epithet is hazardous, to say the 

 least, with the results of the comparison with the above recorded. 



