128 THE OLD RED SANDSTONE. 
powerful tail, it may be regarded either as an arrow or javelin 
flung with tremendous force, or as a knight speeding to the 
encounter with his lance in rest. Now there are missiles 
employed in Eastern warfare, which, instead of being pointed 
like the arrow or javelin, are edged somewhat like the 
crooked falchion or saddler’s cutting-knife, and which are 
capable of being cast with such force, that they have been 
known to sever a horse’s leg through the bone; and if the 
sword-fish may be properly compared to an arrow or javelin, 
the combative powers of the Cephalaspis may be illustrated, 
it is probable, by a weapon of this kind — the head all around 
its elliptical margin presenting a sharp edge, like that of a 
cutting-knife, or falchion. Its impetus, however, must have 
been comparatively small, for its organs of motion were so: 
it was a bolt carefully fashioned, but a bolt cast from a feeble 
bow. But if weak in the assault, it must have been formida- 
ble when assailed. ‘The pointed horns of the crescent,” 
said Agassiz to the writer, “‘seem to have served a similar 
purpose with the spear-like wings of the Pterichthys,” — the 
sole difference consisting in the circumstance, that the spears 
of the one could be elevated or depressed at pleasure, where- 
as those of the other were ever fixed in the warlike attitude. 
And such was the Cephalaspis of the Cornstones — not only 
the most characteristic, but in England and Wales almost 
the sole organism of the formation. (See Note F.) 
Now of this curious ichthyolite we find no trace among 
the fossils of the Lower Old Red Sandstone. It occurs neither 
in Orkney nor Cromarty, Caithness nor Gamrie, Nairnshire 
nor the inferior ichthyolite beds of Moray. Neither in Eng- 
land nor in Scotland is it to be found in the Tilestone forma- 
tion, or its equivalent. It is common, however, in the Olé 
Red Sandstone of Forfarshire ; and it occurs at Balruddery 
