HADROSAURUS. 79 
measured at the side, averages about three inches and a half in length, and below 
is slightly shorter. In front they measure about thirty-eight lines in height, and 
forty lines in width. The articular ends have the same outline as in the former 
specimen. 
The articular convexity of the more anterior pair of specimens, Figs. 5, 6, which 
are slightly longer than the others, is irregular, presenting the appearance of an 
expanded mass that has collapsed. In the succeeding pair of specimens, Figs. 7, 8, 
the articular convexity is more uniform, and is defined from the lower border of the 
body by a crescentoid lip prolonged below. ‘The border of the articular concavities, 
in the four specimens, is bevelled off and prolonged inferiorly. 
The spinal foramen is subcordate. In the anterior pair of specimens it is about 
fifteen lines in height and width ; in the posterior pair about fourteen lines in height 
and width. 
The articular facet for the head of the rib is observed in the four specimens to 
rise successively higher on the sides of the vertebral arch, and as in the former 
specimen described, it is a vertically elliptical concavity. From the relative posi- 
tion of these articular facets, the four vertebrae have been placed in the succession 
designated, otherwise I should have been induced to place the hinder pair in advance 
from the more uniform anterior convexity of their body, and their slightly less 
length. 
In the posterior pair of specimens, Figs. 7, 8, the articular processes of the arch 
are preserved, and in one of them part of the spinous process. The length of the 
vertebre between the anterior and posterior articular processes is five inches and a 
half. The processes are elliptical planes with their long diameter nearly parallel 
with the axis of the vertebrae. Those anterior look towards each other with a slight 
inclination upward; those posterior of course have an opposite direction. 
A transverse process, on the right side of the specimen, Fig. 7, apparently 
unbroken, is of robust proportions, extends outwardly, backward, and upward, and 
terminates in a rounded end without enlargement. 
Two posterior dorsal vertebra, represented in Figs. 9-11, Plate II, have the same 
general form of body as those just described. It is, however, shorter, but broader 
and deeper. Thus the smaller of the two specimens has the extreme length of the 
body at the sides forty-one lines; the width and depth anteriorly forty-five lines. 
The larger specimen has its body forty lines long, and four inches wide and deep 
anteriorly. The sides of the body, as in the preceding vertebra, are longitudinally 
concave, and terminate below in a rather sharp saddle-like ridge expanding towards 
the articular borders. 
The articular ends, Fig. 11, are cordiform in outline, with the lateral and inferior 
- borders strongly everted and convex. The posterior end is moderately concave with 
wide everted margins. The depth of the concavity at its centre is about five lines. 
The anterior articular end, Fig. 11, presents a crescentoid depressed or sub-concave 
surface below, including a sub-convex prominence extending from the centre to the 
upper border of the articular surface. 
The spinal foramen is cordiform, rather wider than high, being about fifteen lines 
transversely, and thirteen vertically. ‘The abutments of the vertebral arch are 
