114 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. II. 



Sternum. Portions of several large sternal bones have been 

 obtained. The most perfect example is that figured in 

 Zool. Trans. Vol. iv. PL IV. It is of a shield-like form, 

 entirely destitute of a keel, and very slightly convex : it is 

 remarkable for its breadth ; the anterior border from one costal 

 angle to the other is seven inches ; it has a broad median 

 process, and two very long diverging lateral ones. As these 

 characters resemble those of the Apteryx, this sternum is 

 referred to Palapteryx rather than to Dinornis. 1 



Pelvis. There are in the wall-cases portions of pelves of 

 great size, and which in all probability are referable to the 

 most colossal species of Dinornis or Palapteryx. In respect 

 to this part of the skeleton the extinct birds approach nearer 

 to the tridactyle Grallce than to the living Struthionidce. 



In the table-cases there are several delicate pelves of birds 

 of small size, belonging to several genera; they are ex- 

 tremely fragile, and were broken to pieces during their long- 

 transport, and have been repaired with much trouble. Some 

 of them belong to the genus Apteryx ; apparently the exist- 

 ing species : others to the bustard-like bird, the Aptornis. 

 There are many specimens of the coalesced pubis andischium 

 of different kinds of birds. 



Femur or thigh-lone. Table-Case 15. The femur of the 

 Dinornis is remarkable for its great strength. The trochanter 

 is very broad, thick, and elevated ; the distal extremity is of 

 great size, and the rotular cavity very broad. The shaft is 

 rounded, and the muscular ridges and tuberosities are more 

 strongly developed than in any other birds. There is no 

 aperture for the admission of air into the interior of the shaft 

 of the bone ; and both the weight and cancellous structure 

 prove the accuracy of Prof. Owen's original statement in his 

 description of Mr. Rule's fragment of the shaft, that the 

 Dinornis at all ages retained the medullary contents of the 

 cavities of the femur, as in the Apteryx ; the only other ex- 

 ample of a terrestrial bird in which the air is not admitted 

 into any of the bones of the extremities. 



The absence of the pneumatic foramen and canal, the great 

 thickness of the dense osseous wall of the medullary cavity of 

 the shaft, the great size of the distal end of the bone, and the 



1 See "Zool. Trans." vol. iv. p. 17. 



