the Teeth of graminivorous Quadrupeds. 249 
science, by liberally communicating to them his own knowledge 
of the subjects connected with their inquiries, is sufficiently known 
to the members of this learned Society. He identified the species 
of the genus to which the skull belonged, in the manner above 
mentioned; and, by an accurate search among the skulls of ani- 
mals deposited in the British Museum, discovered a small head 
in a dried state, which, when properly macerated and cleaned, 
proved to be that of a young Sus JEthiopicus, whose teeth were 
in a growing state, and enable me to explain all the necessary 
circumstances respecting this curious mode of dentition. 
The grinding teeth, in this young head, are distinct from 
each other, and four in number, on each side of the jaw. 
That which is most anterior is the smallest, and has a grind- 
ing surface only equal in extent to that of one of the processes 
contained in the large tooth of the full grown animal : the se- 
cond has a grinding surface equal to that of two such pro- 
cesses : the third is still larger, its surface being equal to that 
of three processes. 
These three teeth, in their general appearances, resemble 
those of the common hog ; they have also the same kind of 
fangs ; their only peculiarity is, the enamel being intermixed 
with the substance of the tooth, but without any bony matter 
surrounding it. 
The fourth or last tooth is very different from the others, and 
exactly resembles that found in the large head, only that this 
is in a growing state. It is composed of seven processes, united 
together ; these are in different stages of growth, fitting them 
to come forward in succession, similar to those of the elephant. 
The two first have their grinding surface worn smooth : the 
points of the two next have recently cut the gum ; and the 
