334 
ARTIODACTYLA. 
axis is elongate. Its odontoid process is only reverted at the sides near its 
base. In its distal lialf, the superior face is plane or convex, with a sub¬ 
acute margin all round. The articular faces of the centra of the other cer- 
vicals are plano-convex, the anterior ball being a good deal flattened. 
There is a sharp hypapophysial angle, which terminates behind in a short 
tuberosity. The transverse processes extend the entire length of the cen¬ 
trum, and are greatly expanded, forming a broad lamina, with concave 
inferior face, and produced downward and outward in front. Above this, 
the sides of the vertebra are concave, the open groove being bounded 
above by a strong obtuse angle, connecting the zygapophysis. The neural 
spine is represented by a low ridge, Avhich extends between two angles or 
ridges of the surface, which come together a little behind the border of the 
neural canal, obliterating the median keel. The posterior dorsals, with the 
diapophysis low down, are rounded below. The zygapophyses are embrac¬ 
ing, and the neural spine is rather high. The anterior lumbars have a 
median inferior angulate keel, while more posterior lumbars have an addi¬ 
tional angle on each side of the median one. 
nearly plane. 
Measurements, 
The articular extremities are 
M. 
Length of the atlas on the median line above. .. 
Length of the atlas on the lateral border.. 
Width of the atlas in front. 
Depth of the atlas in front.. 
Diameter of the neural canal behind f y^^hcal. 
( transverse ... 
Transverse extent of atlas behind. 
Transverse extent of axis anteriorly. . 
Length of the odontoid process. 
Length of an anterior cervical (belowj. . 
Diameter of the anterior ball 1 '®^^hcal .. 
\ transverse . 
Expanse of the anterior zygapophyses.. 
Least external width of the neural arch above.. 
Length of a more posterior cervical below... 
Width of the same between the diapophyses in front 
0.035 
0.069 
0. 051 
0. 027 
0.020 
0. 026 
0. 072 
0. 046 
0. 016 
0. 082 
0.019 
0. 021 
0. 040 
0. 021 
0, 080 
0. 076 
Width of the same between the diapophyses behind 
Length of the centrum of the posterior dorsal. 
Diameter of the same posteriorly | . 
' ( transverse. 
Height of the neural arch 
0. 060 
0. 035 
0. 019 
0. 028 
0. on 
