19G 
PROFESSOR H. G. SEELEY OX THE STRUCTURE, ORGAHIZATIOX, 
such as is seen in Crocodiles and Lizards, but the great oblong plate which extends 
outward to the quadrate bone must have been attached along much of the length of 
that bone. 
The quadrate hone. —Posterior to the pterygoid bone is a much stronger bone, 
imperfect at both ends, which I regard as the quadrate bone. As preserved, it is 
L4 centim. long. It is somewhat compressed, constricted in the middle, and expands 
proximally to a width of 4 millims. It has an internal expansion which is not fully 
seen, which is wide, thin, and oblique, and appears to be the pterygoid process. The 
surfaces of the quadrate bone are smooth, and concave in length in every direction in 
which exposed. 
The loioer jaw. —The lower jaw has its constituent bones displaced. As preserved, 
it is about 9 centims. long, and measures 8'5 centims. from the articulation for the 
quadrate bone to the extremity of the dentary bone. There is no indication of a 
coronoid process. It is long and narrow, increasing a little in depth as it extends 
backward, but becomes less deep again towards the posterior articulation. The out¬ 
line is straight along the dentary border, and slightly convex below. Both dentary 
bones are present, and show that they had only a narrow union at the extremity of 
the jaw, and were not anchylosed together. The extreme length of the dentary bone 
was probably about 6 ‘5 centims. The angular and surangular were both elongated 
bones. The splenial bone appears to have lapped along the inner side of the jaw and 
extended forward to near the extremity of the dentary bone. The articular bone is 
lunate, 8 millims. long; not unlike this bone in the Crocodile, with a transverse concave 
articulation. The bone, though now exposed, was probably imbedded. Twenty-seven 
teeth can be counted apparently anchylosed to the dentary bone, extending along a 
border of more than 4 centims. Other teeth may have been present further back. 
Hyoid hones. —Between the articular end of the lower jaw and the displaced 
quadrate and pterygoid bones are slender, delicate, straight, cylindrical bones, very 
imperfectly displayed, which are jointed. Their slenderness and position are suggestive 
of the hyoid elements. The length exposed is 2 - 2 centims. The structure apparently 
consists of a rod measuring 1'8 centim. and two short joints of about 2 millims. each. 
The terminal joint is conical. 
The vertebral column. —The vertebras extend in a continuous curve, with the neck 
bent round so as almost to meet the sacrum ; beyond which the tail extends, at first 
gently curved, and then almost straight. About 59 centims. of the vertebral column 
are preserved, but a portion of the tail, of unknown length, is lost. 
The cervical vertebrae. —The cervical vertebrae are conspicuously elongated (Plate 14, 
2-7). Six are preserved in connected sequence. Measured round the curve, they 
have an aggregate length of 13 centims. The Atlas does not appear to be preserved, 
or, if preserved, is broken, and tire fragment out of position and imbedded in matrix. 
As the first of the series is the short Atlas, this animal appears to have had seven 
cervical vertebrae. Being in close union by means of the several articular processes, 
