562 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 8, 
Such is the general character of this peculiar scaly armature. 
Not much, however, of the external surface is seen; but a portion of 
two or three rows of the scales is well displayed at the anterior ex- 
tremity of the ribs on the right slab, or that on which the coronal 
portion of the cranium is preserved. This patch of the scaly covering 
of course belongs really to the left side of the animal ; it overlies the 
ribs, and in part covers the bony mass, which we suppose may be 
the remains of the shoulder-girdle. Other two considerable patches 
are observed overlying the ribs near the centre of the body, and several 
smaller patches are scattered over the specimen. All these patches 
exhibit. the minute striation of the surface, and that in front 
displays also the ribbed structure; and the casts of all of them can 
be traced on the left slab. That of the anterior patch is well 
marked, and is of considerable extent, showing both the ridges and 
the minute striation of the surface. 
Upon the left slab, too, the under surface of the scales is well 
seen, particularly a belt of a portion of four or five rows about an inch 
wide, that stretches along by the side of the vertebral column. And 
towards the posterior extremity of the specimen, the rows of scales 
are seen in their whole length (7,7) extending in parallel order from the 
ventral to the dorsal margin, sloping forwards, and crossed by the 
ribs which incline in the opposite direction. The inside of the rows 
of the scales is equally well displayed on the right slab. 
The scales themselves (fig. 3) are rhombiform, with the angles 
slightly rounded, and having projecting from the lower anterior angle 
a strong, pointed conical process, which is overlapped by the dorsal 
margin of the scale next below. They are transversely elongated, 
and measure in this direction an inch and three-quarters, length- 
wise, or from the anterior to the posterior margin, five-eighths of an 
inch. We shall, however, merely for the sake of convenience, con- 
sider the long measurement as that of the length, the short as that 
of the width. 
The ends, then, of the scales are truncated diagonally from above 
downwards and backwards; they (the scutes) are rather stout, but 
gradually thin out to the margins, which are very fine, and have a 
widish, thick ridge extending the whole length, much nearer to the 
front than the posterior margin, and parallel to it. This ridge is 
smooth and rounded below, where it is seen to be continued into the 
projecting process; above, on the outer surface, it forms an obtuse 
ridge the entire length of the scale. The anterior part of the outer 
surface is smooth as far back as this ridge, and is bevelled or sloped to 
the margin; the posterior portion is twice as wide as the smooth 
anterior border, and slopes or inclines in the opposite direction or 
backwards, so that the longitudinal carina is like the ridge of a very 
low-pitched roof with one of the slopes much shorter than the 
other. The wide posterior slope is minutely and closely striated, 
the striz being raised, sharply defined, and slightly diagonal 
from above downwards and backwards, and are somewhat broken 
and tortuous. 
The scales imbricate backwards, the anterior overlapping the 
