Ch. Xni.] SUBAPENNINE STRATA. 209 



added, some species of fossil shells which are found in these deposits 

 throughout the whole of Italy. 



"We have now, however, satisfactory evidence that the Subapennine 

 •beds of Brocchi, although chiefly composed of Older Pliocene strata, 

 belong nevertheless, in part, both to older and newer members of the 

 tertiary series. The strata, for example, of the Superga, near Turin, 

 are Miocene ; those of Asti and Parma Older Pliocene, as is the blue 

 marl of Sienna ; while the shells of the incumbent yellow sand of the 

 same territory approach more nearly to the recent fauna of the Medi- 

 terranean, and may be Newer Pliocene. 



We have seen that most of the fossil shells of the Older Pliocene 

 strata of Suffolk which are of recent species are identical with te"sta- 

 cea now living in British seas, yet some of them belong to Mediterra- 

 nean species, and a few even of the genera are those of warmer cli- 

 mates. We might therefore expect, in studying the fossils of corre- 

 sponding age in countries bordering the Mediterranean, to find among 

 them some species and genera of warmer latitudes. Accordingly, in 

 the marls belonging to this period at Asti, Parma, Sienna, and parts 

 of the Tuscan and Roman territories, we observe the genera Conns, 

 Cyprcea, jS trombus, Pyrula, Mitra, Fasciolaria, Sigaretus, Delphi- 

 nula, Ancillaria, Oliva, Terebellum, Terebra, Perna, Plicatula, and 

 Corbis, some characteristic of tropical seas, others represented by 

 species more numerous or of larger size than those now proper to the 

 Mediterranean. 



The proportion borne by the recent to the extinct species varies in 

 the same district, as Professor Ponzi pointed out to me, in 1857, in 

 the neighborhood of Rome, according to the place in the series occu- 

 pied by different sets of superimposed marls and sands. 



The classification of these several members of the Pliocene period, 

 and the separation of them from the Miocene, is a task the accom- 

 plishment of which will task the skill and industry of the Italian 

 geologists for many years to come. 



I have already alluded to the Newer Pliocene deposits of the 

 Upper Yal d'Arno above Florence, and stated that below those sands 

 and conglomerates, containing the remains of the Elephas meridionalis 

 and other associated quadrupeds, lie an older horizontal and conform- 

 able series of beds, which may be classed as Older Pliocene. They 

 consist of blue clays with some subordinate layers of lignite, and 

 exhibit a richer flora than the overlying Newer Pliocene beds, and 

 one receding farther from the existing vegetation of Europe. They 

 also Comprise more species common to the antecedent Miocene period. 

 Among the genera of flowering plants M. Gaudin enumerates Pinus, 

 Glyptostrobus, Taxodium, Sequoia, Ilex, Quercus, Prunus, Platanus, 

 Alnus, Ulmus, Ficus, Laurus, Per sea, Oreodaphne (fig. 161), Cinna- 

 momum, Cassia, Acer, Juglans, Betula, Rhamnus, Carya, Rhas, Smi- 

 lax, Sassafras, Psoralea, and some others. 



This- assemblage of plants indicates a warm climate, but not so 

 14 



