42 



probably marks the place o£ the bottom of the sockets, which 

 are formed deep in the gum of the upper jaw, for the purpose of 

 receiving the points of the teeth of the under jaw. 



The palatines are small and quadrilateral. The pterygoideans 

 very large, form two angular apophyses behind, separated fi'om 

 each other by a deep emargination of an elliptical form. 



The lower jaw is a singular contrast to the upper ; the former 

 being as slight and fragile as the latter is massive and strong. 

 So weak is the connection of this under jaw with the skull, that 

 the articulating condyles arc scarcely to be detected. The 

 broad branches are nearly as thin as paper, and although the 

 sides are reflexed inwardly, as in dolphins, the doubling, so as to 

 form the hollow tube, does not occur as in them, near the base 

 of the jaw, but within three inches of the symphysis. Each 

 triangular branch, which at the articulating base is semicircular 

 and about four inches high, and convex on the outside, is, from 

 its extreme thinness, almost transparent. The symphysis, 

 which is short in comparison to that of the genus Catodon, is 

 boat shaped and carinated. From its sides project horizontally 

 about thirteen teeth, curved gently upwards on each side. The 

 longest of these is situated about the middle of the symphysis, 

 and is about one and a quarter inch long. They have all single 

 roots implanted in single sockets. They are all about half 

 hollow, as in the true sperm whales, but being so much longer, 

 thinner, and sharper in proportion, give the animal a quite 

 different asj)ect, and perhaps a more ferocious one. "Neverthe- 

 less, so extremely feeble an under jaw demonstrates that the 

 long sharp teeth serve merely for the purpose of retaining the 

 weak mollusca which, no doubt, form this creature's prey. 



