Lign. 4:—Fossil teeth of Fishes of the Shark family, in Chalk; from Lewes.
(See 'Medals of Creation.' p. 625.)
SHELLS AND FISHES IN CHALK.
But besides the fossils which are obvious to the unassisted eye, the Chalk teems with myriads of minute forms that may readily be detected with a lens of moderate power; and even when these have been extracted, the residue, which appears to be merely white calcareous earth, is found, when examined under the microscope, to consist almost wholly of bodies yet more infinitesimal—of perfect shells and corals, so minute, that a cubic inch of chalk may contain upwards of a million of these organic remains (see [Lign. 5])!
Lign. 5:—A few grains of Chalk-dust highly magnified, and shown to consist of shells, &c.
| a, a, Shells called Rotalia. |
| b, ——————- Textularia. |