33 



The situation of the bones of the pelvis, which are the only- 

 vestiges of the hinder legs of ordinary mammals, marks the 

 place in the spinal column, from which these extremities, if 

 they had existed, would have been suspended. The deve- 

 lopment of the V bones in Cetacea probably takes its origin 

 in the total abortion of the ordinary hinder extremities of 

 other Mammalia. 



The pelvis in the sperm whale is not in immediate junc- 

 tion with the spine, but suspended in the flesh at some 

 distance from it. The antepenultimate of the lumbar 

 vertebrae in our Sydney skeleton bears towards its extremity 

 an impression which probably serves for the attachment of 

 the strong muscles that support the bones of the pelvis. 

 In the true whale of the Southern Ocean (Balcena Aus- 

 tralisj, the pelvis is composed of three pieces, a middle 

 and two more slender ones, which are articulated, one on 

 each side of the former. So also it appears to be with 

 the sperm whale, except that what answers to the middle 

 bone of the true whale appears here to be composed of 

 two arched bones. Thus, in reality, there are four bones, 

 two on each side of the sperm whale, and they lie in the 

 form of a crescent, of which the convex part is directed 

 forward. These bones are situated in front of the anus, 

 but are probably not joined together by any true articula- 

 tion. 



In Beale's Yorkshire whale, he describes a pelvis which is 

 of a very different structure from this. There, he says, the ani- 

 mal had two broad, flat, irregular and quadrilateral bones, 

 ossified at their symphysis — a structure which approaches more 

 to the pelvis of the Cape Rorqual ( Meg apt era Poeskop of 

 Gray). 



The largest of these pelvic bones in our Botany whale, is 

 curved somewhat like a rib, convex on one side, concave on 

 the other, broader at one extremity and at the other hooked, 

 back towards the convex side. The smaller bone, which perhaps 

 answers to the os ilium in more perfect mammals, is sub- 

 cylindrical, somewhat curved and thicker at the base than at 



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