246 



REMARABLE INTERMIXTURE OF ORGANIC 



cies, and probably existed under conditions of temperature, &c. sim- 

 ilar to what these latitudes are now subjected to. Approaching the 

 northern termination of the sub-Apennine range at Sienna, Parma, 

 and Asti, (according to Mr. Lyell,) the proportion of species identi- 

 fiable with those now living in the Mediterranean is still considerable; 

 but it no longer predominates (as in the south of Italy) over the un- 

 known species. 



As these sub-Apennine hills, resting on each side of the Apennine 

 range, were formed under the sea, they must have been elevated to- 

 gether with the Apennine range, subsequently to their deposition. 

 Before this period, the Apennines were consequently much lower, 

 and formed a narrow mountainous peninsula extending into the Med- 

 iterranean. Their sides were probably clothed with forests, and af- 

 forded food and shelter to the elephants and other large mammalia, 

 that have left their bones so abundantly in some of the present val- 

 leys, particularly in the vale of Arno. These valleys, it is supposed, 

 were once the beds of ancient freshwater lakes, in which depositions 

 were forming at the time when the marine depositions which consti- 

 tute the beds of the sub-Apennine range were taking place. By the 

 observations of M. Bertrand Geslin, published in the Journal de 

 Geologie, t. iii., it would appear, that between the source of the 

 Arno and Florence, three distinct basins can be traced. The beds 

 of these basins are composed of argillaceous blue marl of consider- 

 able thickness, containing fossils* in the upper part of the marl. 

 Above this are beds of sand, containing numerous bones of large 

 mammalia. These sands are covered by beds of rolled siliceous 

 pebbles, intermixed with sand, above which there is a bed of yellow 

 argillaceous sand. The pebbles appear to have been derived from 

 the mountainous range on the north. Neither remains of marine 

 shells nor lignites occur in these depositions. The animal remains 

 in the upper valley of the Arno are those of the elephant, the 

 large hippopotamus, the rhinoceros, the tapir, the deer, the horse, 

 and the ox. There are also bones of carnivorous animals belong- 

 ing to the hyena, the bear, the fox, and some species allied to the ti- 

 ger. From the character of the animal remains we may infer, that 

 these freshwater depositions are of a comparatively recent date; 

 they were, probably, coeval with the uppermost marine beds in the 

 sub-Apennine hills. The beds, both in the sub-Apennine hills, and 

 in the valleys of the Apennines, consist principally of marl, sand, and 

 loosely adhering materials; hence they are exposed to rapid degra- 

 dation. On the north-east side of the Apennine range, in the dis- 

 trict of Placenza, there is a marine deposition deserving particular no- 

 tice, from the extraordinary mixture of animal remains which have 

 been found in it, and are at present preserved in the Museum at Milan. 



A friend of the author, S. Banfill, Esq. of Exeter, who visited the 

 Museum the last spring, obtained from the director of that institution, 

 an account of the principal organic remains from this deposition, with 

 a brief notice of the locality, of which the following is a translation : — 



