143 ON A SKELETON OF A WHALE IN THE 



In discussing individual vertebrae, many of the resem- 

 blances and differences existing between them have been 

 noticed. A few additional points may be mentioned. 



The centra vary slightly from vertebra to vertebra. This 

 may be seen in plates III and IV, if different figures are com- 

 pared. It will be seen that the form changes as we pass from 

 the anterior dorsals back. This is better seen if the table of 

 measurements be examined. Here it will be found that the 

 length of the body increases from the. beginning back to the 13th ? 

 of the series as given in plate II. The great diminution between 

 the 13th and 14th indicates that several bones are lacking, but 

 from the 13th the length of the body decreases rapidly, and had 

 we the final caudals, the shortening of the bodies would be still 

 more apparent. The width of the centra increase up to the same 

 vertebra, while the height increases beyond to the last but one, 

 and from here is a rapid decrease. That is to say, the centrum 

 of each vertebra is wider than high to and including the 14th of 

 the fossil series. In the next vertebra the width is considerably 

 less than the height, and so remains in the rest of the series. 



The neural canal is largest at the beginning, top figure, plate 

 III. Here it is broadly oval, much wider than high, but in c, 

 which, unfortunately, is the only other vertebra in which both 

 height and breadth can be measured, until we go back nearly to 

 the end of the caudals, the width is reduced to from 73mm. to 

 57mm., and the height 73mm. to 38mm., and so on until in the 

 last caudal we have it only 4mm. wide and about the same in 

 height. 



Sternum. This bone is very thick and large, and, in the 

 fossil, spongy in texture. As plate I shows, its general out- 

 line is triangular. The segments are entirely anchylosed so 

 that 110 trace of sutures remains. Although the bone is not 

 perfect, as will readily be seen, still enough remains to supply 

 a fair indication of its complete form. Articular surfaces for 



