CORYPHODON. 
217 
The ribs are compressed for a great part of their length. The hmmal 
segments are ossified as far as the sternum, and are less compressed. Two 
sternal segments are preserved, with three haemal segments adhering to cor¬ 
responding angles. The segments are flat and subquadrate, the lateral 
borders slightly concave, and thinned by a rounded bevel from one side only. 
Anterior and posterior margins thickened, with rib-articulations at the angles. 
Meastirements. 
M. 
Transverse extent of the distal end of the humerus. ...._ 0.100 
Transverse extent of the atlas... 0.170 
Transverse extent of the neural arch of the atlas behind.... 0.094 
Transverse extent of the axial facet of the atlas behind... 0.043 
Antero-posterior length of the atlas..... 0.060 
Antero-posterior length of the base of the neural arch .. 0.045 
Antero-posterior length of the base of the transverse process.... 0. 025 
Vertical diameter of the atlas behind. 0.095 
Width of a rib a little below the tubercle . 0.023 
Width of a rib of the hsemal portion...... 0. 018 
Width of a segment of the sternum.. 0. 058 
Length of a segment of the sternum. ....... 0.055 
Thickness of a segment of the sternum in front...'..... 0.015 
But one specimen has come under my observation which I can refer 
to this species. It is about as large as an Ox, of not more than medium 
proportions. The species is well distinguished from the others with 
superior canines with triangular section, by the short, wide crowns of the 
molar teeth, and the rudimental condition of the anterior and posterior 
cingula. 
Coryphodon elephantopus, Cope. 
Plates 1, figs. 5-6; li, lii, liii, and liv, fig. 1. 
Batlmodon elephantopus, Cope, Eeport Vert. Poss. Il^ew Mexico, U. S. Geog. Survs. W. of 
100th M., 1874, p. 10; Id., Ann. Eeport U. S. Geog. Survs. W. of 100th M., 
1875, p. 95, plates v, vi. 
This species is the only one of the genus which is represented by a 
nearly perfect cranium, the corresponding parts in the C. molestus being 
injured iby pressure. This cranium was found in the hard sandstone which 
divides the Eocene on the Gallinas into two nearly equal parts, and had 
thus escaped the distortion which the more numerous specimens of C. lati- 
dens, C. molestus, etc., had suffered in the softer argillaceous rock above the 
