140 University of Kansas Geological Survey. 



indications of it can be seen, before the middle of the series. 

 The transverse processes reach their maximum in the first tho- 

 racic vertebra. On the anterior cervicals, the articular surface 

 is nearly rectangular and the two arms of nearly equal length, 

 the anterior one reaching nearly to the rirn of the cup, the 

 other thicker, vertical and uniting near its upper end with the 

 stout, rounded ridge from the anterior zygapophysis. In the pos- 

 terior cervicals the anterior arm assumes a more oblique 

 position, the included angle being more obtuse ; it is shorter 

 and does not reach as near to the rim of the cup. In the first 

 thoracic the vertical branch is nearly twice the length of the 

 other. In the third or fourth the anterior arm has become a 

 short, curved, pointed projection, directed more downwards than 

 forwards. The upper posterior angle is curved backward in the 

 whole series to a moderate extent, giving, in the anterior dor- 

 sals a curved articular surface resembling the italic letter S. 

 The zygapophyses have nearly the same position throughout. 

 They are much the stoutest and the longest in the cervical and 

 anterior dorsal region, showing evidently a greater range of 

 downward curvature in this region. They immediately become 

 shorter, and the oblique ridge connecting them with the upper 

 part of the transverse process is weaker and more slender. 



In the most anterior thoracic vertebree the plane of the articu- 

 lar surface for the transverse process lies only a little exterior to 

 the outer border of the zygapophyses, but posteriorly the process 

 stands widely beyond the zygapophyses, being absolutely and 

 relatively longer, and the transverse process is somewhat con- 

 stricted before the end. The spinous processes increase very 

 slightly in length and breadth, and are only slightly and nearly 

 uniformly oblique throughout. The centra increase very slightly 

 in length to beyond the middle of the series, the posterior ones 

 being distinctly more slender, and, as already stated, have more 

 protuberant transverse processes. The vertical diameter of the 

 ball increases slightly, while the transverse diameter remains 

 more nearly the same. 



