102 THE EXTINCT PECCARY OF NORTH AMERICA. 
of the fossil species just named. The premolars of the series under examination, fig. 12, 
pl. 37, resemble more closely those of the cave head than of the Iowa fossil, except the first 
tooth, which differs from the corresponding one of both these fossils in being smaller and’ 
in possessing but a single large conical lobe. 
Figures 14, 15, pl. 37, vol. X., represent another imperfect series of isolated upper mo- 
lars, formerly referred to Platygonus compressus, and these teeth nearly resemble the 
corresponding ones indicated in the former figures and those of the cave head. 
Figure 11, pl. 37, further represents a series of unworn premolars contained in a frag- 
ment of a skull, formerly also referred to P. compressus, and these resemble the isolated ones 
of fig. 12, pl. 37, but unworn. 
In figures 7, 8, plate 37, is given a representation of the inferior right series of molars 
of the cave head above referred to, in which the same striking increase in development 
of the principal lobes is observable, in comparison with their condition in the recent pec- 
caries, as in the case of the upper molars. 
In figure 3, pl. 6, we have a representation of a corresponding series of teeth, to that 
just indicated, from one of the lowa fossils, in possession of Prof. Wyman. The teeth 
of this fossil are slightly more robust than those of the cave head, and the premolars are 
less square or are more laterally compressed, a variation which is frequent in different in- 
dividuals of the recent Dicotyles torquatus. In the last true molar, the contiguous sides 
of the anterior pair of lobes are much less concave than in the cave head, and the unsym- 
metrical lobe is almost simple, while it is subdivided in the latter. 
In an inferior series of molars, contained in a fossil fragment, from Galena, presented by 
Dr. Edward Kittoe, the teeth are considerably smaller than in either of the corresponding 
series just dispensed with, and the transverse valleys of the true molars appear rather more 
open in consequence of a less proportionate degree of development of the lateral offsets 
of the inner lobes. In the last molar the unsymmetrical lobe forms a single large conical 
tubercle. . 
Figure 10, plate 37, represents two inferior back molars, contained in the fragment of 
a lower jaw, formerly attributed to Platygonus compressus. The teeth pretty closely re- 
semble the corresponding ones of the series last indicated in a more worn condition; and 
in the open transverse valleys, they bear much likeness to the opposing upper teeth of fig. 
13, which accompanied them. 
We further possess two isolated, slightly worn, back inferior molars, from Galena, one 
of which presents a variation from the more common condition in having its unsymmetrical 
lobe diminished in size and enclosed by a thick basal ridge. 
Figure 18, plate 57, represents the fragment of a back inferior molar, formerly viewed 
