HOLLAND AND PETERSON: OSTEOLOGY OF THE CHALICOTHEROIDEA. 299 
The spine in this vertebra is of practically the same height as in the vertebra 
preceding and following it. It is compressed and flattened out in its upper half, 
viewed laterally, the posterior margin being very strongly produced backward and 
the anterior margin being strongly produced forward. Its upper extremity and 
the backward enlargement above are thickened and roughened in order to support 
a : Ngee” 2 
Fig. 60. Fourteenth dorsal of M, elatus (No. Fig. 61. Fourteenth dorsal of M. petersani (No. 1703C). 
1604). xX. <4. 1, lateral view; 2, posterior view. 
strong ligamentary attachments. This is very noticeable in specimens No. 1604 
and No. 1703C. The prezygapophyses are reduced in size in specimen No. 1604, 
looking upward and strongly forward, their anterior extremities separated from 
the upper margin of the centrum by a shallow groove. In the other two specimens 
the anterior extremities of the prezygapophyses are much more widely separated 
from the anterior margin of the centrum. The postzygapophyses in all three 
specimens look backward, downward, slightly inward, and are supported upon 
peduncular backward prolongations formed at the point of union of the laminze 
and the contiguous portion of the radix. From these peduncular projections an 
elevated ridge of bone runs directly forward, and at about its middle the apophysis 
rises upward pointing slightly forward and outward. The height of the meta- 
pophysis in this vertebra is fully twice that of the height of the corresponding 
process in the 13th dorsal. Between the origin of the spine and the metapophysis 
there is a deep depression. The transverse process extends outward and back- 
ward, viewed laterally, having its outward extremity somewhat lunate in form. 
There is no articulating surface upon this process, the tubercle of the fourteenth 
rib being only indicated by aslight swelling. The articulating faces for the heads 
