58 
inclined but slightly from the horizontal. There is no neural spine. The 
neural arch ends in an angulation above from which two ridges diverge 
backward, one to each postzygapophysis. With this centrum both ribs 
are preserved to which reference will be made later. 
Measurements of Cervical Vertebra {distorted) of Paralyse of Edmontosaurus. 
Mm. 
Maximum length, about 175 
Maximum height, about 157 
Length of centrum 123 
Anterior height of same, about 74 
Posterior height and breadth of same, about 85 
Depth of concavity of posterior end of centrum 38 
Diameter of neural canal 37 
Anterior Dorsal Vertebra. The dorsal vertebra here described (Figure 
31) is from the paratype of Edmontosaurus and is the anterior one of two 
having much the same size and proportions. It appears to be about the 
fourth or fifth from the front in the dorsal series. Two ribs, one of which 
is well preserved in its entirety (Figure 33), evidently belong, judging from 
their proportions, to this particular vertebra. 
The centrum of this vertebra is opisthocoelous, but with the concavity 
and convexity less than in the cervical vertebra above described. It is 
longer than high, narrows downward, is pinched on the sides, and has a 
longitudinal keel below between the articulating ends. The neural arch 
is high and robust. The neural spine is short and does not rise much above 
the top of the transverse processes. It is broad in the fore-and-aft direction, 
inclined backward at an angle of about 45 degrees to the horizontal, is 
thin, and comes to a sharp edge along its anterior slope the base of which 
is vertically above the midlength of the centrum. It extends far beyond 
the posterior end of the centrum. It narrows slightly above its midheight, 
but regains its lower breadth by expanding above at the curved superior 
border which is thickened and rugose. The transverse processes are long 
and heavy, and rise upward at an angle of about 35 degrees to the vertical, 
inclining backward nearly as much as the neural spine. Anteriorly they 
come to a thin, sharp edge which is a continuation upward, with a change 
of direction outward of the narrow upper border of the prezygapophyses. 
Interno-posteriorly a thin flange is developed connecting them with the 
postzygapophyses. Externo-posteriorly a much stouter flange extends 
down to the posterior shoulder of the neural arch. Between these flanges 
a deep excavation leads downward and is separated from the corresponding 
excavation of the other side by a median lamella of bone extending up from 
the neural canal and supporting the pair of postzygapophyses from below. 
The development of flanges in the transverse processes results in their 
being subtriangular in outline in cross-section. There is an inner face, 
broad and flat, an antero-external one becoming transversely concave 
in its upper part, and a third directed almost backward also concave with 
the conca\dty rapidly increasing below. The second and third faces are 
about equal in extent and both are narrower than the inner face. 
