LOWER LIAS. 
25 
with a slight concavity to the upper ridge, which has been broken off in each, so 
that its height is conjectural. Other evidences of dermal bones on the under part 
of this slab are too fragmentary and scattered to throw any light upon their natural 
arrangement. On the right side (Tab. II), overlying the ends of the ribs, about 
ten inches distant from the vertebrae, are preserved three of a series of flattened, 
sub-ovate, dermal scutes {da,da)^ about 3 inches by 2 inches in the long and cross 
diameters, and from 2 to 4 lines in thickness. The outer surface exhibits the 
same character of sculpturing as do the dermal bones of the tail ; the inner surface 
is smooth. 
In the block containing the second and third cervical vertebrae the pair of 
lateral, unsyrametrical, dermal bones have been preserved nearly in their natural 
position. They are three-sided ; the shortest is directed towards the intervening 
vertebrae ; the side next in length looks downward ; the outer surface, directed 
upward and outward, is the most extensive. These scutes have been fractured 
through their centre. They show an external, very compact, layer of bone, 
thickest on the outer or peripheral side. The rest of the bone shows a rather 
close cancellous structure. Above these, but slightly displaced, is a pair of wedge- 
shaped bones, which are probably dermo-neurals, indicative of a parial arrange- 
ment of these along the nape, contrasting with their single series above the tail- 
Each of these dermal bones are somewhat unsymmetrical in form, 2 inches 9 lines 
in the length of the base, 1 inch 9 lines in breadth, with the median surface more 
extensive than the outer, and both converging to a ridged summit, but which is 
broken away. 
The anterior pair of nuchal scutes is preserved in connection with the occiput, 
overlapping the atlas (Tab. I, fig. 1, dn, r)- They are similar in shape, but smaller 
in dimensions, than those last described, and have been broken across. 
From the sura of the foregoing observations, it may be inferred that the surface 
of the Scelidosaur was defended by several longitudinal series of massive dermal 
bones, those occupying the median and upper surface being arranged in pairs upon 
the nape and singly along the tail. External to these were a lateral series, at least 
two in number but probably more, on each side the trunk, having the same wedged 
and ridged shape as the dermo-neurals. Beneath these wei e flattened, ovate scutes 
along the lower lateral part of the thoracic-abdominal region. In the tail we have 
more decisive evidence of a single median row of large, symmetrical, cuneiform, 
hollow-based, superiorly ridged dermo-neurals, with dimensions making three 
occupy the space of five vertebrae along the base of the tail, and nearly seven 
vertebrae along the hinder half of the tail. There was a corresponding median 
series of smaller and less vertically extended dermo-haemal bones, and also a single 
series of dermo-laterals, of more depressed and fuller ovate form, on each side. 
The accidents attending the decomposition of the carcass of this reptile seem 
4 
