Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/771

 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 processes 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 maxillae ; but not much importance can be placed on these negative facts when the peculiar state of the spemen is considered. Very little can be added to what has already been said respecting the other portions of the cranium. After carefully removing the crystalline carbonate of lime from the interior of both portions of the skull, its walls are found distinctly lining the concavities 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. XXXVIII. 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 animal a strongly 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 armature 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 specimen 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 extended to it.