12 



afterwards witli forty-two and fifty- one respectively. In 1770, 

 Eoberfcson described cue cast ashore at Leith, with forty-six 

 teeth. But such early naturalists were not very accurate ob- 

 servers of specific distinctions, and it is even supposed that more 

 than one of them may have taken other Getacea, particularly the 

 genus Hyperoodon, for true Catodontidce, or spenn whales. How- 

 ever, this may have been, Beale positively describes the Yorkshire 

 sperm whale as having in the lowerjaw forty-eight teeth, twenty- 

 four on each side. Cuvier does not mention the number he 

 found in his Audierne specimen, but on examining his figures we 

 see that a supposed young cachalot, of which the under jaw is 

 preserved in the Parisian Cabinet d'Anatomie Comparee, has 

 twenty on each side. Cuvier himself, however, is inclined to 

 think that this last jaw may have belonged to an adult animal 

 distinct from the sperm whale, and he says that his London 

 specimen of true cachalot — his typical Physeter macrocepJialus — 

 has fifty -four teeth in the under jaw. Our Sydney specimen has 

 only forty-two teeth, so that although we may, with the cele- 

 brated John Hunter, imagine it very possible that sperm whales, 

 according to age and other circumstances, vary in the number of 

 their teeth, we need not preclude ourselves from supposing that 

 these remarkable differences may also in some degree have their 

 origin in the species being distinct. 



The Sydney Museum is in possession of two other under jaws 

 of Pacific Ocean sperm whales, besides the one appertaining to 

 the complete skeleton under examination. One of these is 

 fifteen feet long, and to be in proportion with our whale, must 

 have belonged to a skeleton sixty feet long, or more, without the 

 intervertebral cartilages. This under jaw, as far its dilapidated 

 state will allow us to ascertain, had only forty-two teeth, and 

 must, by the following proportions, have belonged to a species 

 distinct both from Cuvier's London and from the Yorkshire whales. 

 The other under jaw has also forty-two teeth, and is thirteen 

 feet two inches long. I subjoin a table of the pi'oportions of 

 these three under jaws assumed to belong to the same species, 

 that is, Cafadon Australis. 



