ARTIODAOTYLA. 
335 
Height of the neural spine above the arch 
Length of a posterior lumbar. 
Diameter of the centrum behind / J^’^tical 
(transverse 
Expanse of the posterior zygapophyses. 
Length of the base of diapophysis. 
0. 042 
0.039 
0.017 
0. 027 
0. 022 
0. 016 
The atlas, as compared with that of Auchenia lama, is similar in size, 
but the neural canal is smaller, its diameter in the Llama being 0.028 behind. 
The foramina are relatively still larger in the Llama. In the axis, it is note¬ 
worthy that the odontoid process is not so extensively excavated on the 
superior surface. The other cervicals are-relatively and absolutely smaller 
than in the Llama, and the transverse processes are more widely expanded, 
especially along the middle of the centrum. The low neural spine of the 
recent species is wanting in the extinct one. The lateral angles of the infe¬ 
rior aspect of the centrum of the lumbar vertebrae of the P. occidentalis are 
wanting in the Llama. 
The entire fore limb, with the exception of the two distal pairs of pha¬ 
langes, is preserved with the proximal part of the scapula. The glenoid 
cavity of the latter is nearly semicircular in outline. The coracoid process 
is a thick protuberance, extending in the long axis of the glenoid cavity, 
which, toward its extremity, sends inward, at right angles, a flat hook, con¬ 
cave on the posterior side. The spine rises abruptly at its origin, and is con¬ 
tinuous for a short distance with the anterior border of the scapula. The 
humerus is rather slender, and is characterized by the large size of the tuber¬ 
osities. They are connected at their bases, the connecting mass inclosing 
a deep fossa with the head, or condyle. The greater tuberosity is produced 
much beyond the head proximally, but not much beyond the line of the an¬ 
terior border of the shaft. Its extremity is curved inward and upward. 
The lesser tuberosity is parallel with the external face of the greater, and 
nearly with the long axis of the head, and only projects beyond the con¬ 
necting mass by a keel. A tuberosity divides the bicipital sinus into two 
grooves. Not far below the head, the anterior border of the shaft presents 
a rather compressed protuberance. The condjdes are compressed, and with 
a trace of epicondylar tuberosity on the outer side only. The olecranar 
fossa is deep and narrow, and the radial fossa is contracted and not very 
