23 



tendons wliicli appear to have the same object of uniting strength 

 with perfect mobility of this part of the spine. 



The last eleven of the caudal vertebrae are without processes 

 of any kind, and rapidly diminish in size down to the terminal 

 bone of tail, which is nearly globular, and scarcely one inch in 

 diameter. 



Now taking the two most perfect sperm skeletons hitherto 

 described, namely, Cuvier's London, and Beale's Yorkshire, we 

 find that the last has forty-four vertebrae, like our Sydney 

 specimen ; but that the first has fifty-five vertebrse, accounting 

 the six last cervical vertebra? to be anchylosed into one. The 

 following table will show the differences more clearly : — 



If Cuvier's London skeleton really has the number of vertebra) 

 he assigns to it,* the animal must have been thoroughly distinct, 

 not merely from the Yorkshire whale, but from our Sydney whale 

 also ; which last, however, in this respect agrees remarkably 

 with, the one described by Beale, so far at least as we can make out 

 from that author's description. In all three whales I believe the 

 foramen for the passage of the spinal cord to be widest as it 

 passes through the atlas and other cervical vertebra?, from which 

 it tapers away until it terminates about the commencement of 

 the caudal vertebrte. 



* There is no doubt that the number of vertebrte in different species of 

 Cetacea varies much. Right whales and Rorquals generally have more than 

 fifty, and in fact forty -four is upon the whole a small number of vertebra? 

 for a cetacean animal. 



