41 B Sir E, Home’s description of the 
The jaws and teeth form the most remarkable characters 
of this species of delphinus, and a description of them will 
not only interest the naturalist and comparative anatomist, 
but will enable the geologist, when fossil teeth are found of 
this shape, readily to determine the species of animal to which 
they had belonged. 
These teeth, as is common in those of the whale tribe, have 
the first rudiments formed in the gum, from which the tooth 
grows in both directions, upwards through the gum in the form 
of the point of a flattened cone which is coated with enamel, 
and downwards towards the jaw, increasing considerably in 
breadth but not in thickness, till it is at last embedded in 
the substance of the jaw itself ; the lower portion has no 
enamel. 
The appearance the teeth put on, as well as the mode of 
growth, will be seen in the annexed drawing ; [PI. xx.] the 
change that takes place in the form of the tooth as it wears 
away from long use, is more remarkable than in most other 
teeth ; for the perfect tooth has a tolerably sharp enamelled 
point, while the half worn one has a curved blunted cutting 
edge. The teeth in front of the jaw are more like the inci- 
sores in other animals. The whole number in both jaws is 120, 
which exactly corresponds with that given by Dr. Roxburgh, 
and identifies these jaws as belonging to the animal which 
he has described. 
