230 Zoological Society. 



tain lO-i- quarts, or the contents of nearly 6 eggs of the Ostrich, or 

 16 of the Cassowary, or 148 of the Hen, or 50,000 of the Humming 

 Bird. The portions of bones of which casts were exhibited consist 

 of the lower end of the right and left metatarsal bones and the upper 

 end of the right fibula. These are nearly equal in size to the cor- 

 responding parts of the skeleton of the Dinornis, as the following di- 

 mensions demonstrate : — 



In neither Dinornis nor Mpyornis is the metatarsus perforated, as 

 in Casiiarius and many other birds, above the interspace between the 

 two outer condyles : that interspace is simply deeper, or curved 

 higher in both. The outer trochlea, which is entire in both portions 

 of the metatarsi in j^pyornis, is, in a marked degree, smaller than 

 in Dinornis, 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 Mpyornis, 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 j:Epyornis 

 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 jEpyornis 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 Cassowary, how- 

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

 trochlese 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 



* One-third the length of the entire bone in Dinornis giganteus. 



