of the wild Boar, and Animal incognitum . 
33i 
EXPLANATION OF THE PLATES. 
Plate XX. In this Plate are three figures of the lower jaw of 
the wild boar, in different stages of growth, to shew the mode 
in which the teeth are supplied. The figures are on a scale of 
half an inch to an inch. 
Fig. 1. Represents the first set of grinders, and the mode in 
which they are shed, by others rising up immediately under 
them : one of the second set is in its place ; another is forming 
in the substance of the jaw ; and there is a small cell behind 
it, in which were the rudiments of the succeeding tooth. 
Fig. 2. Represents the second set of teeth in their place, with 
the small cell delineated in the first figure increased to a large 
size, and containing an imperfectly formed tooth, greatly ex- 
ceeding in size any of the others. 
Fig. 3 Represents the jaw in a still more advanced stage 
of its growth, with the tooth which was only forming in the 
second figure now come to its full size, and in its proper place 
in the row of teeth ; there is also a new cell formed, for a suc- 
ceeding tooth. 
Plate XXI. Represents a view of a portion of the lower jaw 
of the animal incognitum, (on a scale of half an inch to an inch,) 
to shew the appearance of the smaller or first formed grinders, 
in their place in the jaw ; also the cavity immediately behind 
them in the substance of the jaw, in which were contained the 
rudiments of the larger grinder, which was afterwards to occupy 
the principal part of the jaw. 
Plate XXII. Represents a view of the lower jaw of the animal 
incognitum, with the large grinder, (the cavity for forming 
U u 2 
