336 
AimODACTYLA. 
deep. On the inner side of the anterior face, just above the condyle, is a 
shallow excavation for contact with the head of the radius on flexion. The 
intertrochlear ridge is an obtuse angle. 
The coossified ulna and radius form a slender bone, with a slight con¬ 
vexity of the inner border at the proximal fourth, but otherwise nearly 
straight. The proximal end of the ulna is much compressed and subacute 
below. The humeral cotylus is narrowed backward from the radius, and 
is equally divided by a strong longitudinal keel. The olecranon descends 
immediately from the coronoid process. A very narrow fossa (perhaps a 
foramen) separates the extremity of the ulna, and a groove bounds the nar¬ 
row epiphysis of the same on the inner side. The three distal facets are 
all distinct, the lunar being a little the narrowest. The ligamentous groove 
of the superior (anterior) face is wide and smooth. The external side of 
the extremity presents a shallow fossa; above the internal extremity, the 
inner border is protuberant. The metacarpals still exhibit a trace of the 
common suture throughout the length, but there is no groove on the ante¬ 
rior face. The posterior face is concave for tlie proximal two-thirds. There 
are no faces for rudimentary lateral metacarpals. The distal fissure is deep, 
and the condylar carinse large, but obtuse, and extending only on the pos¬ 
terior half of the condyle. The proximal interosseous foramen is minute, if 
present. 
In comparing the scapula and fore limb of the Procamelus occidentalis 
with that of the AucJienia lama, the following relations are noticeable:—The 
bones are of the same length, but those of the extinct species are more 
slender. The portion of the scapula of the latter preserved resembles that 
of the Llama much, but the glenoid cavity is narrower. The humerus dif¬ 
fers much in its proximal portion. The great tuberosity of the Llama is far 
less prominent in all respects, while the lesser and intermediate tuberosities 
are more so, the three together forming a much wider mass than in the P. 
occidentalis. The deltoid crest is curved backward in the Llama, which it is 
not in the fossil species. The condyles are much more robust in the Llama. 
In the ulno-radius, it is to be observed that the carina of the humeral coty¬ 
lus is much less prominent in the Llama, and the olecranon does not descend 
so steeply from the coronoid process. The proximal interosseous foramen 
