218 
FOREIGN EQUIVALENTS, 
the Middle Pliocene and the Upper Pliocene. Dr. Ch. Depdret, 
however, treats them as belonging to one zone, and adopts a 
classification similar to that used for the marine deposits. He 
classes the fauna of Mont Perrier, and that of certain neighbour¬ 
ing deposits, evidently of the same age, as the first Upper 
Pliocene fauna, correlating it with that of the Val d^Arno and 
with the Norwich Crag. The fauna of Montpellier he considers 
to be somewhat older, and to belong to the true Middle Pliocene. 
This classification accords well with -that used for the British 
Pliocene deposits, for though there is a great resemblance 
between the Auvergne fauna and that of the Nodule Bed, yet 
when we take into account the difierence of latitude, it is more 
with the Norwich Crag that we ought, I think, to compare it. 
At present we must await the discovery of more mammalia in 
the English Crag. The only point that seems quite clear, is 
that the strata of Pardines must be somewhat older than those at 
Saint-Prest and Cromer, and newer than the Astian at Mont¬ 
pellier, with its apes and hipparions. Among the fossils at 
Pardines we find mastodon and tapir, but the occurrence of 
elephant is doubtful. This would seem to indicate that the 
strata of the Val d’Arno, containing Elephas meridionalis and 
Equus Stenonis, may include a somewhat higher zone, approach¬ 
ing more nearly to the Cromer Forest-bed, 
The occurrence of freshwater deposits of Pliocene age, scattered 
over a considerable poidion of France, seems to indicate that this 
period was essentially a continental one, and that if it were not 
for the difierence of latitude we might expect to find a close 
approach to the fauna of England. A number of the free-roaming 
mammals are common to England and France, but it is curious 
that out of about 15 species of deer from the Cromer Forest-bed, 
only three or four have also been discovered in France, and two 
of these range as far as the Val d'Arno. The Forest-bed con¬ 
tains more species of deer than any other deposit yet known. 
The only freshwater strata in southern Europe that can with 
any advantage be compared with the British Pliocene are those 
of the Upper Val d’Arno. A short distance above Florence the 
valley of the Arno narrows into a rocky gorge, beyond which 
the marine Sub-Apennine strata do not pass. Above this gorge 
the valley expands into a wide plain, known as the Val d’Arno 
Suj)eriore, stretching in a south-easterly direction nearly as far 
as Arezzo, and having a width of several miles. If we stand on 
one of the spurs of the Apennines and look down on this plain, 
we see it to end abruptly against the hills on the further side, 
its lake-like appearance and conspicuous shore-line being very 
marked. When we approach nearer, or descend to it, we find 
the plain to be cut up into separate flat-topped blocks, or 
ploughed into by narrow gorges and canons, so that the district 
has a singular resemblance, on a small scale, to the canon region 
of the Colorado. The gorges are often one or two hundred feet 
deep, and so steep that no vegetation can grow on their sides. 
