126 
In the Emeu (Dromaius) the sternum (ib. fig. 7), with the same general form as in 
the Cassowary, further differs from that of the Dinornis in the approximation of the 
coracoid grooves (ib. c, c) so as to come into actual contact at the middle of the anterior 
border. 
Of the sternum of the Dodo we as yet unfortunately know nothing, although we may 
as reasonably expect the osseous remains of that extinct bird to reward the search of 
naturalists and collectors in the islands of Mauritius and Rodriguez, as the similar quest 
in New Zealand has been followed by the recovery of the bones of the Dinornis. 
In the Apteryv however we find a sternum (ib. fig. 8), which, with the same general 
Struthious characters, very closely corresponds with the particular modifications of that 
of the Dinornis, It has the same small proportional size to the body ; nearly the same 
superior breadth as compared with the length, the same slight degree of convexity, and 
the same characteristic expansion and marginal configuration posteriorly. In the sternum 
of the Apteryx described at p. 34 and figured in Pl. LX. figg. 2 & 3, two small subcir- 
cular spaces remained unossified in the body of the sternum ; in two more mature speci- 
mens which I have subsequently received, ossification has obliterated these spaces, where 
however the bone is thin and diaphanous, and the sternum presents only the two deep 
posterior emarginations, bounded by a middle xiphoid prolongation and the two angular 
elongated processes (p, p), as in the Dinornis. These processes in the Apteryx are 
relatively broader, thinner, and are subincurved: in the Dinornis they seem, from the 
remains of the one on the left side, to be straight, and become thicker and narrower, 
The costal articular surface occupies a greater proportion of the lateral margin of the 
sternum in the Apteryx than in the Dinornis, though it is less than in the Ostrich. The 
coracoid groove has the same relative position and size in the Apteryx as in the Dinornis, 
but has a different form: in the small existing wingless bird it is an oblique notch, 
formed by a small process projecting upward and forward from the outer surface of the 
sternum near the antero-external angle: in the Dinornis (id. fig. 2, c) it is an oblique 
depression, as if the end of the thumb had been pressed into the same part of the bone 
when soft. ‘The anterior and lower border of the depression is not produced beyond the 
level of the bone; but in the example before me it is notched, as if for the passage of 
vessels to the joint. 
Whether the antero-external angle (a) is prolonged so far in Dinornis as in Apteryz, 
the fracture of that part i the present specimen does not allow to be determined. The 
anterior margin between the coracoid articulations in the Apteryx is deeply excavated, 
whilst in the present species of Dinornis it is almost straight. Four smooth depressions 
with three well-marked rough surfaces (r, 7’, 7") for the attachment of sternal ribs, cha- 
racterise the anterior two-thirds of each lateral border in the Dinornis. The outer sur- 
face of the sternum in the Dinornis shows the impressions of the decussating bands and 
fibres of the aponeurotic periosteum, with which it was covered when recent. 
A part of a young Apteryx, kindly transmitted to me by Dr, Robert Hunter, demon- 
strates that the sternum is developed, as in other Struthionide, from two lateral centres, 

