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1504. The proximal half of the shaft of the right femur of a quadruped as large 

 as that to which teeth of the Diprctodon australis, Nos. 1490 to 1497 

 inclusive, and the femur No. 1503, belonged. 



This fragment measures eleven inches in length, and three inches in 

 breadth at the distal fractured end, where the circumference is seven 

 inches and nine lines, the femur there not having begun to enlarge for 

 the formation of the distal condyles. The long and narrow trochanter 

 minor is developed from the posterior angle of the inner border of the 

 upper expanded part of the fragment, and resembles in form that of the 

 gigantic femur No. 1489, though it is more posterior in position: the 

 base of the trochanter major begins to swell outwards and forwards from 

 the anterior angle of the opposite border and encroaches upon the ante- 

 rior part of the shaft : it is relatively lower and swells out more abruptly 

 than in the femur No. 1489; there is no trace of a third trochanter. 

 The post-trochanterian depression resembles that in No. 1489. The 

 shaft of the present fossil is more flattened anteriorly than in No. 1503 : 

 this antero-posterior compression gives it the same resemblance to the 

 femur of the Mastodon and Elephant as has been pointed out in the 

 description of No. 1489. The large extinct phyllophagous Edentata 

 manifest this character in an exaggerated degree : the Rhinoceros is the 

 only genus amongst the ordinary Pachyderms in which the femur is flat- 

 tened as in the great extinct Australian quadrupeds, but the third tro- 

 chanter effectually distinguishes that bone in the Rhinoceros. It is evi- 

 dent, from the differences above detailed between the present femur and 

 No. 1503, that they belong to distinct though perhaps to nearly allied 

 species. The form of the transverse section of the shaft is more regu- 

 larly elliptical, and the anterior surface more flattened, in the present 

 fragment than in No. 1503, which, from its closer resemblance with No. 

 1489, might well have belonged to a young individual of the same species. 



The present fossil was detached by Count Strzelecki from the bone- 

 breccia of one of the caves in Wellington Valley, Australia : the peculiar 

 red ferruginous matter of the breccia still adheres to parts of the exterior 

 and fills the interior cavity of the bone. 



Presented by Count Strzelecki. 

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