34 



E. M. MUSEUM MEMOIRS. 



half the length. The neck of this animal resembled that of Elephas, or was even 

 shorter. 



The description of the skeleton is now continued mostly from the Uintathe- 

 rium remains. As in the description of the skull, the writer passes from one 

 genus to another, according to the nature of the materials. In the case of the 

 skeleton this course is justified in many instances by the close likeness of struc- 

 ture. Wherever variations exist, they are pointed out. 



UlNTATHERIUM — VERTEBRAL COLUMN. 



The special characters of the cervical region are not known. The neck, 

 judging from a single cervical the measurements of which are given above with 

 those of Loxolophodon, was probably about the same length in each genus. The 

 dorsal vertebrae also agree closely, as far as our material admits of comparing 

 them. It is safe to conjecture, as will be shown in the Restoration, that the gen- 

 eral features of the vertebral columns were similar. The following description 

 is in part an extract from the first Bulletin from the Museum. It is based 

 upon nine dorsals and two lumbar vertebrae of Uintatherium. 



Dorso-lumbar Scries. The Centra are large, sub-triangular ; slightly opisthocoe- 

 lous, but less so than in the Proboscidia. They compare bone for bone in length, 

 but not in height, with those of a mastodon of medium size in the museum col- 

 lection ; increasing in length regularly backwards, at the same time becoming 

 narrower and higher. The Costal Surfaees anteriorly are large and deep ; in 

 the middle dorsal region they almost meet, as in Elephas. Behind they are 

 reduced to thin lozenge-shaped projections of the centra. The Neural Spines 

 are markedly smaller than those in the Proboscidians and Rhinoceros. Those 

 placed about sixth and seventh in the Restoration have about the same angle as 

 in Mastodon ; in the last dorsals they are wide, straight, and very thin ; in the 

 lumbar region short, stout, and tuberous. The metapophyses of the last lumbar 

 vertebrae are very characteristic ; they are high, parallel with the column, form- 

 ing deeply concave pre-zygopophysial faces on their inner sides. Into these 

 are mortised the post-zygapophyses, forming a very close union between the 

 successive vertebras. This recalls the arrangement of these parts among the 

 primates rather than the loose articulation on the laminae of mastodon or tapir. 

 The transverse processes present unique features. In the anterior region they 

 are long, wide, and rugose, and in the same plane with the laminae, sending 

 out wide projections curving downwards. In the middle region they lose these 

 projections, assume a sub-trihedral shape, supporting a large facet for the rib. 

 The pedicles throughout are deeply notched behind. 



Sacral Region. The sacrum is composed of four vertebras, three true and 



