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thicker in the fossil, and the jaw does not swell out so much on the 

 outside of the alveolus of the last molar; there is also a longitudinal 

 indentation on the outside of the alveolar processes of the anterior mo- 

 lars. The present fossil, therefore, indicates either an extinct species 

 of the size of the existing Macropus laniger, or it may have belonged to 

 a female of a third gigantic extinct species. 



From the alluvial or newer tertiary deposits in the bed of the Conda- 

 mine River, west of Moreton Bay, Australia. 



Presented by Lieut. -Col. Sir T. L. Mitchell, C.B. 



\b'2b. The shaft of the right humerus of a Kangaroo, probably the Macropus 

 Atlas : it differs from that bone in the recent species in the greater 

 anterior production of the deltoidal process, in the grejiter lateral com- 

 pression of the upper half of the shaft of the bone, and in the absence of 

 the ridge which projects from the outer side of that part of the shaft of 

 the humerus in the existing Kangaroos. A considerable part of the 

 boundary of the perforation above the internal condyle is preserved ; the 

 commencement of the external or supinator ridge is visible on the oppo- 

 site side of the bone, but not in the form of the hook curving upwards, 

 as in the recent Kangaroos. The length of this fragment is five inches 

 and a half ; its circumference below the deltoidal ridge is three inches. 

 There is no trace of a medullary cavity at either of the fractured ends, 

 but the minute canal for the medullary artery may be seen, directed up- 

 wards, above the internal condyloid perforation. 



From the alluvial or newer tertiary deposits in the bed of the Conda- 

 mine River, west of Moreton Bay, Australia. 



Presented by Lieut. -Col. Sir T. L. Mitchell, C.B. 



1 526. The distal half of the right humerus of another large species of Kangaroo, 

 probably the Macropus Titan. It demonstrates the perforation above the 

 inner condyle for the median nerve and brachial artery, and shows that 

 the supinator ridge commenced higher up than in the preceding specimen. 

 The circumference of the shaft of the present humerus below the deltoidal 

 ridge is three inches and a half. There is no trace of a medullary cavity 

 at the fractured end of the bone at this part, which displays only a close 



2 u 



