1870. ] HANCOCK AND HOWSE—LEPIDOTOSAURUS. 561 
tudinal line. They are for the most part broken down, merely 
tubercular scars marking their position ; but near to the centre of 
the left maxilla they are quite perfect, and are seen projecting into 
the adherent matrix, having much the appearance of minute teeth. 
The largest are one-sixteenth of an inch in length, and are rather 
obtusely pointed; several of them are coated with a thin layer of 
transparent glass-like enamel. Their resemblance to teeth is still 
further shown by a large pulp-cavity and thick dentine-like walls, 
which have a white milky hue, and are very tender, being evidently 
much changed by fossilization. They are, however, apparently pro- 
cesses of the bone from which they project; no distinct anchylosis can 
be seen, and when broken away there is no depressed scar, but their 
bases are persistent, like rugged tubercles. 
Traces of similar tooth-like processes are found much further back 
on the sides of the skull. The palatal surface of the muzzle, so far 
as it could be explored, displays no teeth, neither does the outer or 
alveolar margin of the maxille ; but not much importance can be 
placed on these negative facts when the peculiar state of the spe- 
men is considered. Very little can be added to what has already 
been said respecting the other portions of the cranium. After care- 
fully removing the crystalline carbonate of lime from the interior of 
both portions of the skull, its walls are found distinctly lining the 
concayities in the matrix, though in places the bone is reduced to 
mere traces. And in one part the coronal wall has been thrust 
inwards, apparently by some disturbance in the matrix; and the 
general distortion is so extensive that little can be determined 
except the contour, which has been already described, and this is not 
by any means perfect (see Pl. XX XVIII. fig. 2). The crown seems 
to have been considerably elevated and arched. 
Perhaps the most interesting, and certainly the best-preserved 
feature of our strange amphibian has yet to be noticed. As it lies, 
it seems to have been covered with large, minutely striated, bony, 
imbricated scutes or scales, which extend from end -to end and 
from the dorsal to the ventral margin of the specimen. These 
scales are arranged in diagonal lines, sloping from behind forwards, 
and give to the surface of the animalastrongly ribbed appearance in 
the same direction. The inside view of the scales presents the same 
sort of ribbing as the exterior ; indeed both sides of this bony arma- 
ture remind the observer of the ridges and furrows of a tiled roof, 
only the individual scales are not distinguishable as the tiles of a 
roof are; the ridges and furrows alone are visible, and the junction 
of the rows is not perceptible. This may be partly owing to the 
pressure to which the fossil has been subjected, incorporating the 
bony scales with each other; but it undoubtedly results in a great 
measure from the character of the scales themselves, which permit 
the most close and accurate fitting. However this may be, the spe- 
cimen at present has the appearance of having been incased in a 
continuous bony shield coextensive with the trunk. No portion of 
the tail existing, it is impossible to say whether or not the scales ex- 
tended to it. 
