There is a matchless suite of fossil Echinidæ in the British Museum, which has been arranged and named by Mr. S. P. Woodward, and is now the most instructive and interesting collection extant. It contains examples of the following genera, viz., Ananchytes, Echinocorys, Echinolampas, Holaster, Galerites, Cidaris, Diadema, Acrosalenia, Glypticus, Disaster, Pygurus, Clypeaster, Scutella, Salmasis, Echinocyanus, &c. There is also a good series of echinital spines.


[CHAPTER X.]

FOSSIL FORAMINIFERA—MICROSCOPICAL EXAMINATION OF CHALK AND FLINT.


"Where is the dust that has not been alive?"

Young.


That those infinitesimal forms of animal existence which swarm throughout the waters of the ocean, but whose presence can only be made manifest by the aid of the microscope, are preserved in a fossil state,—that their durable remains constitute mountain ranges, and form the subsoil of extensive regions,—and that the most stupendous monuments erected by man are constructed of the petrified relics of beings invisible to the unassisted eye,—are facts not the least astounding of those which modern Geology has revealed.