1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 291 



formation. The strata are specially characterized by as oft, cal- 

 careous yellow sandstone, arranged in large concretionary shapes, 

 which here and there passes into limestone and calc grit, but in 

 many parts disintegrates into fine yellow sand, in which caverns have 

 been excavated. It is this rock which has afforded the numerous 

 Lenticulites and other foraminifera described in the works of Sol- 

 dani and Targioni-Tozzetti. They are accompanied by a very minute 

 Terebratula, to which M. Pilla particularly directed my attention, 

 and which at first sight had much the aspect of forms known only 

 in palaeozoic rocks*. 



There can be no doubt that the foraminiferous rock of S*^ Frediana 

 is of miocene age, but as it has here been brought up through the 

 subapennine strata, along one of those lines of fracture so common 

 in the adjacent region of the Maremma, we naturally miss the links, 

 stratigraphical and zoological, which connect the miocene and plio- 

 cene in the Monferrato of Turin and in the Lower Apennines of 

 Bologna. 



Further southward, and in entering the Tuscan Maremma, rocks 

 of this miocene age re-occur, overlying the ridges of alberese and 

 macigno which there rise up, and in one place, Botro di Laspa near 

 Pomaja, ^. e. in the direct road from Pisa to the Maremma, con- 

 tain the same small Terebratula as at Frediana. I examined the 

 flanks of the lateral valley through which that route passes, and 

 where the miocene contains large masses of gypsum. Traversing the 

 hills from Castellini to the copper-mines of Monte Catini'f, I thence 

 made an excursion into the heart of the Tuscan Maremma to explore 

 the relations of the coal beds of that tract which have been so largely 

 opened out, and would, doubtless, have been rendered useful, had not 

 revolutionary agitation checked all public and private expenditure. 



* See " Osservazioui sopra 1' eta della pietra lenticolare di Casciano nelle colline 

 Pisane, di Leopoldo Pilla." In this notice, published after a joint examination 

 which I made with him, Professor Pilla corrects a first sketch, in which he had 

 considered this lenticular limestone as of subapennine age, and shows that at S*^ 

 Frediana and Parlascio it constituted islets or reefs of rock of miocene age in a 

 sea of subapennine age. The corals, Lenticulites, Echini, Terebratulae, &c., are 

 supposed to be miocenic, whilst certain Ostreae and Pectens are presumed to be 

 pliocenic. It does not, however, appear that the latter are identical with known 

 subapennine species. My lamented friend Professor Pilla had formed an opinion 

 respecting the usual horizontality of subapennine strata, as contrasted with the 

 inclination of all beds of miocenic age, in which I cannot participate. In this 

 case I believe that the oldest tertiary of this part of the basin has been heaved 

 up through the overlying strata on lines from north to south ; and I cannot agree 

 with him, that these older masses ever formed ancient islets, around which the 

 younger were accumulated. On the contraiy, I am convinced that here, as in 

 the Monferrato, the whole submarine tertiary series was originally deposited suc- 

 cessively and without a break. 



t At Monte Catini, where I was hospitably received by Mr. Sloane, the intelli- 

 gent proprietor of the mines, and in other places, I examined the serpentine, 

 gabbro, and other eruptive or unstratified rocks, into the consideration of which I 

 shall not enter in this memoir, the object of which points exclusively to sedimen- 

 tary succession. The chief phfenomena have been already described by Mr. W. 

 Hamilton, Journ. Geol. Soc. London, vol. i. p. 291, and have been copiously dwelt 

 upon by Savi, Pilla, and others. 



