1884, | 507 [ Cope. 
for the succeeding pairs of nerves perforating the neural arches. The atlas 
is not very elongate. The base of the diapophysis has a perforating canal, , 
which issues in a large inferior fossa. The vertebrarterial canal then per- 
forates the diapophysis upwards anterior to the middle of the base, and 
then soon enters the neural canal just posterior to the superior margin of 
the cotylus of the occipital condyle. 
The centra succeeding the cervicals increase gradually in length poste- 
riorly. Those of the anterior part of the dorsal series are quite depressed, 
but the vertical diameter rapidly increases, so as ta be equal to the trans- 
verse in some of the lumbars. <A trace of the opisthocoelous articulation 
exists throughout the dorsals but is very little marked in the posterior 
centra, There are no hypapophyses on the dorsals, but on one of them, 
probably the third, the inferior and lateral faces are separated by a strong 
angle, which is strongest anteriorly, giving the articular face a subquadrate 
outline. The rib-bearing diapophyses are robust. On the posterior dor- 
sals the capitular and tubercular surfaces are confluent, forming a narrow 
facet on the anterior face of the diapophysis, in a manner not seen in 
Cervus elaphus or Sus seropha. The centra of the lumbars, after lengthen- 
ing, become shorter immediately in front of the sacrum. The vertical 
diameter of one or two posterior ones is less than that of the anterior 
ones. The greater number of the lumbars display a small compressed 
hypapophysis at their anterior extremity ; but this is wanting on the 
posterior ones. The neural arches of the dorsal and lumbar vertebrae are 
nowhere perforated for the spinal nerves. 
The lumbar prezygapophyses embrace the articular faces of the poste- 
rior ones, which have a section of one side (below), the end (external), 
and a half the other side (above), of a transverse ellipse. The superior 
recurved surface does not appear. 
The sacrum consists of five vertebre, with very depressed centra. The 
ilium is attached to the diapophysis of the first, and a small anterior por- 
tion of that of the second. That of the fourth is flat and free. The an- 
terior zygapophysis of the first displays a slight degree of the superior 
incurvature general in Artiodactyla. The caudal vertebree were numerous, 
forming a long tail. The proximal ones are moderately depressed, while 
more distal ones with wide diapophysis and complete neural arch, are sub- 
cylindric, and more elongate. The number of vertebra preserved in the 
most complete of my specimens, is as follows : 
Cv. Dy L. 5 Cd 
O. culbertsoni ad......... fg 5 6 4 4 
O. culbertsont juv.......+ 5 8 6 2 1 
GieGrOnieviiueb evi cue: 4 5 3 * * 
O. g. coloradoénsts....... i 8 6 5 3 
An anterior, perhaps second, sternal segment is flat and subquadrate in 
outline, with large hemal articular face of the lateral margin anteriorly, 
and a small one posteriorly. No inferior carina. 
