98 MEMOIRS OF THE CARNEGIE MUSEUM 
centrum is decidedly more concave than in the Oligocene genus. The general out- 
line of the bone, except in the matter of its deeper centrum, is quite similar to that 
of the Princeton specimen. 
Third Dorsal Vertebra.— The tip of the spine of the third dorsal is broken off, 
but it was evidently as high as that of its predecessor, and only slightly lighter. 
Fie. 48. Lateral View of Fourth Dorsal Fic. 49. Lateral View of Fifth Dorsal 
of D. hollandi Peterson. } nat. size. of D. hollandi Peterson. 4 nat. size. 
One of the most important differences between the vertebral column of Dinohyus 
and that of Archwxotheriwm is seen in the arrangement of the canals through the 
sides of the pedicles and the vertical canals through the superior portion of the 
neural arch, similar to that in Sus and Bison americanus. In Professor Scott's 
admirable memoir (87, p. 290) it is stated that the pedicles of the neural arch are not 
perforated by vertical canals as in Sus. While this is to a certain extent true, it is 
seen upon very close scrutiny of the specimen, that some of the dorsals have the 
vertical as well as the transverse canals present, although they are relatively smaller, 
are more irregular in their position, and could not have possessed the functional 
