TRANSACTIONS OF WAGNER 

 UINTA SELENODONTS 



III. The Vertebral Cobiuin, and especially the cervical region, is but im- 

 perfectly represented in any of the specimens. The only cervical vertebra which 

 I have seen is a somewhat imperfect atlas. This, so far as it is preserved, 

 is quite like that of Poebrotherium; it is short and broad and has a very con- 

 vex neural arch, with hardly any more than an indication of the neural spine. 

 The arch is perforated by foramina for the first pair of spinal nerves. Ante- 

 riorly the transverse processes extend out more widely from the sides of the 

 vertebra than they do in Poebrotherhun, but whether they are carried so far 

 backward as in the latter I am unable to say. 



The Princeton collection contains no thoracic vertebrse, and I shall there- 

 fore quote Wortman's account of them : " The vertebrae resemble those of 

 the modern llamas closely in their general proportions. The bodies of the 

 anterior dorsals are but moderately keeled, and towards the posterior end of 

 the series strongly keeled; they increase gradually in size from before back- 

 ward. The neural spine of the fifth is long and recurved, those of the suc- 

 ceeding dorsals decreasing in length posteriorly. The neural spines of the 

 last two are considerably shorter and broader, having an almost vertical direc- 

 tion. The rib facets in the anterior region have their usual relations and 

 positions, the ribs articulating with the vertebrae by two distinct facets, but in 

 the last two the capitular and tubercular facets appear to be fused together as 

 in these dorsals of the llama." ('98, pp. 107-8.) 



The lumbars, which, according to Wortman, are seven in number, are 

 relatively large. The first three have rather short but progressively elongat- 

 ing centra; those of the next three (4th, 5th, 6th) are of nearly the same size 

 and shape ; they are long, narrow, and depressed, with prominent ventral keels. 

 The centrum of the last lumbar is shorter, broader, and more depressed than 



