358 
of the bands, the thickness of the plates of enamel, the smoothness of 
their sides, and the great depth to which the notches forming the digi- 
tated processes extend. So strong, indeed, are all these characters, 
and so nearly do the upper terminations of these plates approximate 
to the protuberances on the grinders of other animals, and particularly 
of the mammoth, as to give room for the conjecture, that this tooth 
may have belonged to an animal, possessing intermediate characters 
between those of the elephant and those of the mammoth. 
The specimen, the surface of which is represented Plate XX. Fig. 
5, also varies considerably from the recent as well as from the common 
fossil teeth, in the form and arrangement of its plates This tooth, an 
upper tooth of the left side, which I purchased at the sale of Rack- 
strow’s Museum, was described in the catalogue as having been taken 
up with ballast from the bottom of the Thames. 
Of the variation which takes place in the form and arrangement of 
the plates in this tooth, it is very difficult to give a description. In the 
recent teeth, and in the common fossil teeth, the plates are continued 
straight across the tooth, the enamel being disposed in a long elliptical 
line, in which the osseous part, or the ivory of Mr. Home, is included. 
Hence, by the abstraction of the surrounding crusta petrosa, as we 
have already seen, frequently is the case with the fossil teeth, the tooth 
falls to pieces, and each flat plate is found separated. But in the 
specimen, which has been just examined, an irregularity may be ob- 
served in the third anterior row of the plates, where the two digitated 
processes of a plate passing over little more than half the width of the 
tooth are interposed between the second and fourth plate, and thrust 
a portion of the latter plate rather aside. It is an extension of this 
peculiarity of form which, in part, characterizes the present tooth, 
since very few of the plates, of which it is formed, pass directly across: 
leaving it difficult to say, how the osseous part is disposed. 
But the most characteristic peculiarity of this tooth is, the continuity 
of many of its plates, and the remarkable Daedalian line in which the 
