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In this series of deposits, we hardly ever meet with limestone strata, comparable to those of older date; there are sometimes about the accumulations such considerable marks of local violence of water, as to render it doubtful whether the bones and shells have not been drifted from other situations. The löss beds of the Rhine probably belong to this period.

In the newer pleiocene deposits of the valley of the Elsa in Tuscany, which consist of several hundred feet of marl, and shelly t raver tins disposed horizontally, six living species of testacea were recognised by M. Deshayes: viz. Paludina impura, Neritina fluviatilis, Succinea amphibia, Limnæa auricularis, L. peregra, and Planorbis carinatus. (Lyell, book iv. ch. xi.)

The upper Val d'Arno has yielded in its insulated freshwater deposits a few apparently lacustrine shells (anodon, paludina, neritina), and a vast number of mammalia: of which the following is a list (principally taken from Mr. Pentland's communication to Mr. Lyell):—