14o ON A SKKLETOX OF A WHALK IN IHK 



In (liscnssing iadividnal vcrtebne, many of the ro:^eni- 

 blances and differences existinji' between them have bwn 

 noticed. A few additional })oints may be mcntidned. 



The centi-a vary slig-litly from vci'tebra to vertebra. This 

 may be seen in ])lates III and IV, if different liunres are com- 

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

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

 measurements be examined. Here it will l)e found that the 

 length of the l>ody increases from the beg;inning back to the 13th, 

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

 the loth 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 woidd 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 wddth is considerably 

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



The neural canal is largest at the l)eginning, top figure, plate 

 III. Here it is broadly oval, much wider than high, hut in a, 

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

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

 the end of the caudals, the width is rciluced to fi'oni 73mm. to 

 57mm., and the hcjight 73mm. to -'jSuim., and so o.i until in the 

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

 height. 



titcrunrn. — This bone is very thick and large, and, in the 

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

 line is trian,gular. The segments are entirely anchylosed so 

 that no trace of sutures remains. Although tlie bone is not 

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

 a fair indication of its complete form. Articular surfaces for 



