34 



DISCOVERY REPORTS 



The last sternal bone has again an uneven anterior border, the left side being in advance of the 

 right. It is without anterior notch. The posterior margin has a deep, angular notch extending nearly 

 to the middle of the bone ; in the South Australian specimen it is wide and shallow. There are three 

 facets on each side for sternal ribs, one at each antero- and postero-lateral corner and one midway 

 between these. 



The ventral surface of the bone is raised into a low, ill-defined tubercle. 



SCAPULA (Fig. lo) 



Both the scapulae of the Discovery specimen are damaged posteriorly. Anteriorly the evenly convex 

 dorsal margin meets the straight anterior margin at almost a right angle, not being broadly rounded 

 as in the South Australian specimen. The acromion, as in the latter specimen, is bent upwards and 

 inwards, the superior and inferior margins being parallel to each other and the distal margin rounded. 

 It is shorter than in the South Australian specimen. The coracoid is without the distal expansion 

 noted in the South Australian' specimen, but is otherwise similar in position and shape. 





Fig. 10. Scapula. ( x ^.) 



Fig. II. Hyoids. ( x ^.) 



HYOIDS (Fig. II) 



The thyro-hyals are not fused to the basi-hyal. The basi-hyal has a short, straight anterior margin 

 and deeply concave posterior margin. The lateral portions of the bone which are convex are rugose, 

 and are completely occupied by the facets for connexion with the thyro-hyals. 



The thyro-hyals are wing-like in shape, and stoutest at their proximal ends where there is a broad 

 area for attachment to the basi-hyal. The bones diminish in thickness from the anterior to the posterior 

 border, where the upper and lower surfaces meet in a ridge at a very acute angle. The distal tips of 

 the thyro-hyals are truncated and rugose. 



The tympano-hyals are elongate, flattened and tapering at each end to a truncated rugose tip. 

 The thickness of the bone diminishes from the front to the hinder margin, which last has a fairly 

 acute edge. 



APPENDIX 



(i) A male specimen of H. planifrons was measured and examined by Dr L. Harrison Matthews, 

 at Leith Harbour, South Georgia, on 3 January 1927. It was intended that the skeleton should be 

 preserved, but before it could be despatched to England an avalanche, which obliterated part of the 

 whaling station, buried the specimen, and it was not recovered. 



