And hear his anvil sound,
A deaden'd clang,—a huge dim form
Seen but, and heard, when gathering storm
And night were closing round."
But these wheel-stones were not the only geological curiosities to which this simple mode of explanation was applied. In the same storied neighbourhood there occur in considerable numbers the round whorled shells of the genus Ammonites. These were gravely set down as petrified snakes wanting the head, and their petrifaction and decapitation were alike reverently ascribed to the power of the sainted abbess of Whitby.
"They told
How of a thousand snakes each one
Was changed into a coil of stone
When holy Hilda prayed."
The stone-lily belonged to that large class of animals ranked together as Echinodermata, a name taken from one of the leading subdivisions of the group—the Echini or sea-urchins. It seems to have been one of the earliest forms of life upon our planet, its disjointed stalks occurring largely in some of the oldest Silurian limestones. In the Secondary ages it began gradually to wane, until at the present day its numerous genera appear to be represented by but the comatula and the pentacrinite, two tiny forms that float their jointed arms in the profounder depths of the sea.