1848.] MURCHISON ON THE STRUCTURE OF THE ALPS. 225 



In resuming the consideration of the deposits which in the Vicentine 

 and adjacent countries overUe the scagUa or chalk, I may add that they 

 sometimes consist of strata, more or less sandy, which alternate with 

 marls and graduate up into sandier bands of greenish calcareous grit. 



In some tracts so much green earth is disseminated in this series, 

 that near Schio where such is the case, and where the strata have been 

 inverted, as before said, by the porphyry, this band was considered 

 by the older geologists to be the secondary or cretaceous greensand. 

 Professor Catullo has shown, in a recent publication, to what a great 

 extension this zone attains in the Friuli. There it is characterized 

 by a Pholadomya, which is scarcely to be distinguished from the 

 P. margaritacea of the London clay*. Passing over for the present 

 all the next overlying strata in this section, which the palaeontologists 

 of our party believed would prove to be of miocene age when fully 

 examined, I have here only to repeat what I stated in my former 

 memoir of the year 1829, that the highest deposits of the whole series 

 contain many true subapennine shells, and that the beds in which they 

 lie are apparently linked on to those we are now considering. 



In regard to Monte Bolca, near Verona, so famous for its fossil 

 fishes, I unhesitatingly affirm that it is of true lower tertiary age. In 

 company with Sir C. Lyell I made sections of it and of the adjacent 

 Monte Postale in 1828, which leave no sort of doubt that the strata 

 are simply continuations of the eocene deposits of the adjacent Vicen- 

 tine. Marly, whitish and yellowish limestones, occasionally mottled 

 with bluish grey and brown colours, are on the whole subordinate 

 to bands or mounds of peperino, and are also distinctly traversed by 

 dykes of the igneous and basaltic rocks described by Brongniart. 



AVhilst the latter are certainly posterior, and have in many cases 

 altered the contiguous limestone, the peperino must, I conceive, be 

 viewed as the result of submarine volcanic dejections contemporaneous 

 with the other deposits, the heat attending the evolution of which 

 may have destroyed the fishes of a former well-tenanted bay of the 

 sea, just as on a recent occasion shoals of them were killed on the 

 coast of Sicily when Graham's island arose from the deep. Notwith- 

 standing this abundance of eruptive matter, quite enough, however, 

 of the original sedimentary deposit remains to show, that it is entirely 

 distinct in lithological and zoological characters from any portion of 

 the scaglia or chalk which flanks it on the north. Thus, lignite coal 

 here occurs in the same position as cited in previous pages in the 

 Savoy and Swiss Alps, and at Val d'Agno and Monte Viale in the 

 adjacent Vicentine ; whilst the plants, including dicotyledonous trees, 

 palms, cocoa-nuts, and certain aquatic forms, are pronounced by Dr. 

 linger to be eocene types f. Nummulites, indeed, occur between 

 the lower and upper fish-quarries, among which I collected the small 

 N. globulus and the N. millecaputy and with these are associated 



* I have mislaid the note which I made concerning the other fossils of this 

 lower tertiary greensand, but besides Ostrese, I apprehend that it contains a 

 peculiar Gryphaea, like the G. colwnba ? ? of Brongn. of Montecchio Maggiore. 



t See also M. Adolphe Brongniart's description of some of the plants collected 

 by his father (IMern. du Mus. d'Hist. Nat. vol. viii. p. 313). 



