Peterson: Osi i'i)i,(i(;v ok Owdactvlus. 437 



ing the greater, and the crown lance-shaped ; while the canine in 

 OxyJticfy/i/s loin:^ipes is a strong, slightly recurved, and perfectly 

 caniniforni tooth. This latter character seems already to have been 

 present in Protomeryx the successor of /Wyvv'/Z/d-/-//////. There is in O. 

 lon^ipcs a short diastema in front and a long one back of the canine. 

 The first premolar is strongly two-rooted, somewhat compressed lat- 

 erally and has a simple subconical crown. The tooth is compara- 

 tively as strong as is that in Protoinciyx. In Oxydactylus, as in all 

 other genera known from the Oligocene and the T.oup Fork, the first 

 premolar is separated by diastemata from the canine and the second 

 premolar. The second and third premolars are trenchant, laterally 

 compressed, and are very similar to one another in character. The 

 third has a more distinct anterior basal cusp and a small pit on the 

 triturating face near the posterior edge. The fourth premolar has the 

 antero-internal cusp less developed than in Poebrothcriuin. This tooth 

 is widest posteriorly, the internal ridge extending backward from the 

 apex of the median cusp, thus forming with the external wall a shal- 

 low valley. This tooth on one side of the jaw differs from that on 

 the other, as described above, in having the apex of the median cusp 

 interrupted by two strong ridges, extending well down on the internal 

 face of the tooth. The posterior valley is also less apparent. There 

 is a gradual increase in length antero-posteriorly from pm. y the short- 

 est to m.g which is the longest tooth in the mandible. 



The inferior molars like the superior are long and narrow, and have 

 a general resemblance to the molars in the recent camel and the llama, 

 with the important exception that the basal pillars are entirely absent 

 in O. longipes. The fifth crescent of the third molar varies in size in 

 different individuals as has been observed in other genera of this 

 family. 



The Cranium. — The exceptionally well preserved skull and lower 

 jaws of the type (No. 918), PI. IV, Figs, i, 2 and 3, deserve a rather 

 complete and detailed description. 



For the most part the sutures are distinguishable and the skull is 

 otherwise quite complete. The extreme posterior part of the sagittal 

 crest and the superior region of the supra-occipitals were missing when 

 collected. 



The cranium is comparatively small, elongate, and narrow. The 

 facial region is especially long. The orbit is small in comparison 

 with that of the llama and more ovate in shape, the greatest diameter 



