The lower fluviatile strata, 1 to 4, are full of river shells, and bones and teeth of animals, among which those of the mammoth were incredibly abundant, its remains in Sir Antonio Brady's collection alone being estimated by Mr. Woodward to belong to more than one hundred individuals. Above these strata is a layer of clay, brick-earth, and gravel, No. 5, irregular and twisted, and folded in a very remarkable way, somewhat after the manner of the contorted drift on the Norfolk coast above mentioned. It contains pebbles of quartz, Lydian stone, sandstone, angular and waterworn flints, and fragments of grey wethers, one of which weighed 26 pounds. Some of the pebbles are imbedded with their long axes vertical, and therefore could not have been deposited by the action of water. This singular stratum, termed "loess" by Prestwich and "trail" by Fisher, bears unmistakable signs of having been accumulated by the action of ice, which has caught up the various materials of which it is formed, and deposited them on melting with the utmost irregularity. It proves that the climate at the time was more severe than that which prevailed while the mammaliferous strata below were being formed.
Above it the surface is composed of the ordinary rainwash of the district, fine red loam, No. 6, which has been accumulated under the climatal conditions of the present time. It contrasts with the bed on which it rests in its homogeneous nature.
This section is repeated with but little variation at Grays Thurrock opposite Gravesend, at a distance of about twelve miles. From the lower fluviatile strata of this locality, the most important remains which have been discovered belong to the big-nosed rhinoceros, which frequented the spot in considerable herds, both
