158 THE OLD RED SANDSTONE. 
two feet and a half in length, exclusive of the tail, which ts 
wanting; but the armor in which it is cased might have 
served a crocodile or alligator of five times the size. It lies 
on its back, on a mass of red sandstone; and the scales and 
plates still retain their bony color, slightly tinged with red, 
like the skeleton of some animal that had lain for years in 2 
bed of ferruginous marl or clay. The outline of the occipi- 
tal portion of the specimen forms a low Gothic arch, of an 
intermediate style between the round Saxon and the pointed 
Norman. This arch is filled by two angular, pane-like plates, 
separated by a vertical line, that represents, if I may use the 
figure, the dividing astragal of the window; and the under 
jaw, with its two sweeping arcs, or branches, constitutes the 
frame. All of the head which appears is that under portion 
of it which extends from the upper part of the belly to the 
snout. The belly itself is thickly covered by huge carved 
scales, that, from their massiveness and regular arrangement, 
remind one of the flags of an ancient stone roof. The carv- 
ing varies, as they descend towards the tail, being more in 
the ridged style below, and more in the tubercled style above. 
So fairly does the creature lie on its back, that the ventral 
fins have fallen equally, one on each side, and, from their 
semicircular form, remind one of the two pouch holes ina 
lady’s apron, with their laced flaps. The entire outline of 
the fossil is that of an elongated ellipsis, or rather spindle, a 
little drawn out towards the caudal extremity. The places 
of all the fins are not indicated, but, as shown by other speci- 
mens, they seem to have been crowded together towards the 
lower extremity, like those of the Glyptolepis, an ichthyolite 
which, in more than one respect, the Holoptychius must have 
resembled, and which, from this peculiarity, presents a brush- 
like appearance — the head and shoulders representing the 
