14 



the lower figure of the humerus in Pkte XX. of Hunter's Memoir, Phil, 

 Trans., 1794. 



51 1 . The left humerus of a large and old specimen of the Polar Bear (Ursus 

 maritimus). The upper figure of the humerus in the plate above quoted, 

 closely corresponds with this specimen, and was probably engraved in 

 order to illustrate the differences between the recent and fossil species. 

 As the present bone was placed in the same drawer with the two pre- 

 ceding humeri of the Cave Bear, which it exceeds in size, it is most pro- 

 bable that they are the identical specimens alluded to in the following 

 passage of Hunter's Memoir : — " There are two ossa humeri rather of 

 less size than those of the recent White Bear." Hunter does not allude 

 in the text to any other differences, but some of these are illustrated by 

 the figures. These accurately show, for example, that the humerus of the 

 White Bear is broader at both extremities, and thicker in proportion to 

 its length than in the Cave Bear : the supinator ridge forms an angle in- 

 stead of being continued downwards in a gentle convex curve ; the 

 internal condyle is much thicker and stronger where it bounds the 

 olecranal cavity, and it extends inwards to a greater distance from the 

 articular surface ; the deltoidal ridge reaches lower down in the White 

 Bear ; the antero-posterior diameter of the proximal third part of the 

 bone of the White Bear exceeds in a marked degree that of the extinct 

 species. 



The decease of Hunter took place before the observations on the fossil 

 cave-bones, which he had communicated to the Royal Society, were read, 

 and the individual to whom the task of superintending the printing- of 

 the paper was entrusted, ascribed, in the explanation of the Plates, both 

 figures of the humeri to the fossil species. Cuvier, who did not perceive 

 the resemblance of the upper figure to the humerus of the White Bear, 

 and who therefore did not recognise the mistake, avails himself of that 

 figure to illustrate his opinions respecting the specific distinction of his 

 Ursus spelceus and Ursus arctotdeus. 



There is preserved in the Parisian Collection a humerus of one of the 

 great Cave Bears, the internal condyle of which is perforated, as in the 



