26 



THE MOA IN AUSTRALIA. 



which the upper outline is nearly horizontal. The saddle so 

 formed is in fact more deeply seated than in D, crassus. The 

 outer surface of the trochanter (ect. t.) is nearly flat, devoid of 

 the submarginal convexity shown in Dromceus, and the muscular 

 attachments (m) are in two shallow depressions raised above the 

 level of the bone by tubercular outgrowth, as in Dinornis, instead 

 of into two excavations from the surface, separated by a bridge, 

 as occurs in the emu. The mode of origin of the great tro- 

 chanter of the fossil strongly resembles that of the moa — it rises 

 abruptly from the shaft, and forms immediately a prominence, 

 which curves over towards the inner aspect of the bone, and 

 overlooks the markedly concave anterior surface between it and 

 the head. In the subject of Sir R. Owen's figure of Dromornis 

 the form of this surface is obscured by mutilation, but in the 

 recent Dromoeus it is comparatively flat and the trochanter 

 rises from the shaft by a gradual and smoothly rounded increment; 

 and it is only near its upper end that it forms a re-curved edge. The 

 large air channel into the interior bone of the Emu, so intimately 

 connected with the excursive habits of the typical birds, is wanting 

 in all the fossils under consideration, but in the moa and in our 

 fossil alike it is foreshadowed by three small foramina just 

 beneath the hinder edge of the neck. Commensurate with these 

 feeble means of communication with the outer air the internal 

 chamber (cav.) is but feebly developed within the substance of the 

 shaft. The linear dimensions of its section are less than a fourth 

 of those of the whole section enclosing it. In Dinornis the lesser 

 trochanter is hardly appreciable, it is represented by a mere thread 

 on the surface of the shaft ; in the Emu it is a well-developed 

 outstanding ridge. The upper part {t. mi.) of this linea aspera, as 

 it exists in the Moa, is preserved in the fossil. There is in Din- 

 ornis a large oval rugosity for muscular insertion nearly in the 

 centre of the inner and concave surface between the head and 

 the origin of the trochanter major {t.ma.) This feature also 

 is very evidently repeated in the Australian fossil, whereas in the 

 Emu we perceive but a faintly rough surface much nearer to the 

 head. In an ordinary case it would have been sufificient 

 to point out the several characters of the object under 

 review in order that we might arrive at a judgment 

 upon its systematic claims, but since those claims tend 

 to modify the experience of the most eminent of modern palaeont- 

 ologists it is expedient that we should briefly revert to the grounds 

 on which they appear to rest. The chief particulars in which 

 the femur in question differs from that of Dromornis, are a long 



