198 
PROFESSOR H. O. SEELEY ON THE STRUCTURE, ORGANIZATION, 
neural spine has its anterior border more vertical, but in both the posterior border is 
inclined obliquely backward, so that the spine becomes less high towards its posterior 
extremity. 
Slender cervical ribs are attached to the anterior extremities of the sides of the 
centrum. The ribs are straight, slender, pointed behind, are as long as the vertebrae 
to which they run parallel, and have thickened heads for attachment. 
Near these cervical ribs are several slender, long, tendenous ossifications, such as 
are often met with in the vertebral column in Birds and Mammals, and are common 
in the caudal region of the Bernissart Dinosaurs. 
Dorsal vertebrae. — There appear to have been sixteen dorsal vertebrae in the 
19 centims. between the neck and sacrum. None of these vertebrae are so pre¬ 
served as to be worth description. They give little information about the centrum, 
but show that the neural spines were 9 millims. high in the anterior vertebrae, vertical, 
6 millims. wide, with the anterior and posterior margins parallel, and the truncated 
superior outline convex. The ribs appear to have been attached to short transverse 
processes or tubercles given oft’ from the neural arch. The centrums appear to be 
bi-concave or flattened at the ends. 
The ribs are strong, curved, and compressed from front to back. 
Sacrum .—The sacrum appears to have included two vertebrae. They are short, 
and had well-developed transverse processes, 12 millims. long, which expanded 
externally. But the bones are too badly preserved to demonstrate any other point of 
structure. 
Caudal vertebrae. —Twenty-three caudal vertebrae are preserved. Each centrum 
is 1 centim. long. The body of the centrum is compressed from side to side, and 
rounded on the base. At about the level of the neuro-central suture transverse 
processes are developed in the earlier part of the series. Then the neural arch rises, 
and develops short zygapophyses on the level of the summit of the neural canal, and 
forms a short platform from which the high vertical neural spine rises. The measure¬ 
ment from the base of the centrum to the neural platform in the earlier caudal 
vertebras is 1 centim. ; and the height of the neural spine above the platform is 1’2 
centim. The caudal vertebrae after the first two have long spathulate chevron bones, 
which are directed obliquely backward. They are at first very long, and then become 
gradually shorter. With their development the neural spine becomes constricted at its 
base and wider at the summit, so that it gradually assumes a wedge-like form. At 
about the 14 th caudal vertebra, 11 or 12 centims. behind the sacrum, the summit ol 
the neural arch is notched. The spine after this continues to decrease in height as 
the notch increases in depth, until after about six vertebrae the neural spine is com¬ 
pletely divided into anterior and posterior parts, which have the spines obliquely 
directed backward and forward, with an increasing interval between them. As they 
are followed backward, the vertebrae diminish in all dimensions except length. And 
the neural spine decreases in height, while the transverse process, which at first is 
