1 889-] The Proboscidia. 209 
while in the Ilford Mammoth in the British Museum, figured 
by Leith Adams/ the length of this region equals the width. 
The skull agrees with those of the E. primigeniiis, and differs 
from those of the E. indicus in the narrower proportions of 
the posterior part of the cranium. The teeth are of the 
coarse-plated E. colnmbi type. The individual is not very 
large, though old. The diameter of the tusks at the alveolus 
is no mm. In a fragment of a huge specimen from South- 
western Texas, the diameter of the tusk at the base is 210 
As a result, it is not clear that the two American forms 
can be distinguished as yet from the Elephas primigenius or 
from each other, except as probable subspecies, E. p. coltanbi, 
and E. p. aniericanus. But more perfect material than we 
now possess may yet enable us to distinguish one or both of 
these more satisfactorily. No American species of the family 
exceeded this one in general dimensions, especially the form 
E. p. cohnnbi. 
EXPLANATION OF PLATES. 
Plate IX. 
Tetrabelodo7i campester Cope. Palate with teeth from below, 
one-fourth natural size ; from Loup Fork bed of Kansas. 
Original. 
Plate X. 
Side view of jaws of individual of Tctrabelodon campester 
represented in Plate IX., one-eighth natural size. 
Plate XI. 
Tetrabelodon angtistidens proavus Cope, mandibular ramus 
and symphysis from above and in profile, one-sixth natural 
size. Fig. A, first true inferior molar of a young animal, one- 
third natural size. Fig. B, last superior premolar of young, 
perhaps of this species, two-fifths natural size. 
.graph^a 
1879, p. 69. Monograph 
