350 



latter bone, of a large species of Dinornis. The fragment has belonged 

 to a pelvis intermediate in size between Nos. ] 559 and 1561, but is nearer 

 the former. From this it differs in the concavity of the upper boundary 

 of the ischiadic notch, and the descending process forming its posterior 

 boundary, which almost touches the pubis. The posterior margin of the 

 wall of the acetabulum is straight, and ascends at a right angle with the 

 horizontal ischium. In the larger pelvis, No. 1559, as in the smaller one, 

 No. 1561, this margin curves back at less than a right angle. The 

 ischium is thinner and less convex internally. 



1561. The almost entire pelvis of a smaller species of Dinornis, probably 

 Dinornis dromioides, Owen. It seems to include all the sacral vertebrae, 

 which are eighteen in number : seven anterior ones with the lower trans- 

 verse processes, four without those processes, and seven in which they 

 reappear, extending obliquely outwards and backwards to the line of 

 junction of the ilia with the broad posterior part of the sacrum. The 

 most important feature in the present pelvis is the demonstration of what 

 was obscurely indicated in the foregoing specimen, viz. that the ilia do 

 not, as in existing Struthious birds, including the Apteryx, approximate 

 one another along the whole length of the sharp and narrow ridge 

 formed by the spines of the sacrum, but that they diverge above the 

 acetabula, to give place to a broad horizontal expanse of bone developed 

 from the posterior sacral spines, as in the Bustard and most other birds. 

 This surface forms a smooth shallow concavity, perforated as usual by 

 two lateral series of small foramina. From the pelvis of the Bustard 

 that of the Dinornis differs in the greater relative depth and verticality of 

 the anterior plates of the ilia, which meet above to form a ridge, as in 

 the existing Struthionidce : the posterior expanded part of the pelvis is 

 relatively shorter than in the Bustard, and the difference is extreme which 

 this part of the pelvis of the Dinornis presents, as compared with that 

 of the Apteryx, the Ostrich, the Emeu, and a fortiori the Rhea, in which 

 the ischiadic bones meet, and are united for a considerable extent below 

 the posterior part of the sacrum, which there becomes almost obliterated. 

 The acetabula are relatively nearer to each other than in the Bustard, 

 but further apart than in the Ostrich, Emeu, and relatively than in the 



