84 BULLETIN OF THE 



smooth and here and there furrowed surface, a texture which, as Schlosser has 

 remarked, is very different from that of a deer antler. The burr is very large 

 and prominent, but a vertical section shows that the beam passes into the 

 pedicel without any perceptible break or change in the tissue. In Cosoryx the 

 burr is very variable, as may be seen from Cope's figures. In this collection 

 are some specimens without any burr, others with a single burr, and some with 

 two or three. They can hardly be regarded as an evidence that the antler was 

 deciduous. 



The Skeleton. 



The vertebrce, so far as they are preserved, resemble very much those of Anti- 

 locajjra. Owing to the fact that only the posterior part of the column is pre- 

 served in the specimen, it will be most convenient to describe them from behind 

 forwards. The only caudal represented is like the second of the prong-buck, 

 but a little more complete, and clearly shows that the tail was short, as may 

 also be inferred from the sacrum. This caudal is short and narrow, especially 

 in front, with short wide transverse processes near the posterior end. There are 

 a pair of rudimentary prezygapophyses, and an exceedingly minute neural canal, 

 which will just allow the passage of a needle, and a corresponding neural spine. 

 In the prong-buck the second caudal has neither canal nor spine, and the trans- 

 verse processes are wider. 



The sacrum consists of four completely ankylosed vertebrae. The first has a 

 broad depressed centrum, well developed prezygapophyses, and much enlarged 

 pleurapophyses, which occupy most of the sacral surfaces of the ilia. The spine 

 is coalesced with the others into a high and arched ridge. In the prong-buck 

 the spines are more distinct. The other sacrals have expanded pleurapophyses, 

 but only the second has any contact with the ilium. The centra decrease rap- 

 idly in size from the first posteriorly, and that of the last is exceedingly depressed 

 and thin. The whole sacrum is quite strongly arched from before backwards. 

 The lumbar region is quite long, and consists of six vertebra?, which are slen- 

 derly constructed ; the centra are anteriorly comparatively narrow and trihe- 

 dral in section, posteriorly they are broader and more depressed. The spines 

 are low and comparatively broad, and are inclined well forward, with concave 

 anterior borders. The transverse processes on the first lumbar are short, de- 

 pressed, but comparatively broad ; these processes lengthen as we pass backwards, 

 but are very slender as compared w T ith those of Antilocapra, and the neural 

 spines are lower than in that genus. The zygapophyses are of the interlocking 

 cylindrical type usual among artiodactyles, and there are no metapophyses. 

 We may infer with considerable confidence that the number of dorsal vertebrae 

 was thirteen ; on this assumption, the most anterior dorsal of this specimen is 

 the ninth. In this the centrum is short and trihedral in section, with the infe- 

 rior border sharp and arched from before backwards ; the spine is rather short, 

 and directed very obliquely backwards; the transverse processes are short and 

 slender, and have well marked facets for the tubercles of the ribs ; the prezyga- 

 pophyses are flat and placed on the pedicels of the neural arch, and, separated 



