138 



more than one half of which seem to he identical with the species 

 found in the Calcaire grossier and London clay. 



A nummulite limestone forms the base of the above series, and is 

 shown to be conformable to the scaglia, or rock containing ammo- 

 nites, belemnites, and flints (the equivalent of the chalk), which rising 

 into the Alps, passes into a dolomitic limestone charged with casts of 

 fossils of the oolitic series. No rocks of igneous origin interfere, in 

 this district, with the above order of superposition ; but they are largely 

 developed to the west of the Brenta, where they cut through the re- 

 gular deposits. In illustration of the above, two transverse sections 

 from S. to N. are then detailed. 



1st. — From Asolo to Possagno, exhibiting the youngest group or 

 conglomerate rising to the height of from 700 to 800 feet above the 

 Adriatic, and dipping S.S.E. at angles increasing from 25° to 40°. 



The dip and direction are the same in the succeeding strata of marl 

 and limestone, for the space of five miles, and near Possagno they 

 range conformably to the scaglia ; with which, however, the lowest 

 members of the tertiary series are there not seen in contact, owing to 

 a denudation in the Val d'Urgana. 



2d. — From Bassano to Campese in the Canal di Brenta. This 

 section, owing to the much higher inclination of the beds, exhibits all 

 the above members of the tertiary and secondary series in the short 

 space of two miles. At Sarzon the marls of the Calcaire grossier 

 inclined at 70° to 80°, are succeeded by a compact nummulite lime- 

 stone, absolutely vertical ; forming piers on each bank of the Brenta. 

 This vertical nummulite rock is in positive and conformable contact 

 with the scaglia, or ammonite rock, and they rise together to peaks 

 of considerable height. The scaglia passes conformably into a dolo- 

 mitic limestone, with remains of the oolitic series which forms the 

 principal mass of this and the higher regions of the neighbouring 

 Alps. 



From the preceding facts, the author infers that some of the last 

 expansive forces by which the secondary strata of the Tyrolese Alps 

 have been set on edge, have also raised the tertiary deposits into their 

 present vertical positions. Such forces, he presumes, found their issue 

 in the adjoining basaltic and trap-rocks west of the Brenta. He next 

 points to the above sections, as proofs that unconformability is not 

 an invariable test of the distinction (if any such there be) between 

 secondary and tertiary formations ; and in describing the entire ab- 

 sence of the plastic clay in this district, he further remarks that it 

 would be in vain to seek here for those various subdivisions of the 

 tertiary series which exist in certain parts of Europe, and which some 

 geologists would desire to establish as general types of these forma- 

 tions. 



April 3. — J. S. Upton, Esq., M.A., of Trinity College, Cambridge ; 

 Edward Wynn Pendarves, Esq., M.P., of Pendarves, Cornwall, and of 

 39, Grosvenor-street ; the Rev. John Lodge, M. A., Fellow of Mag- 

 dalen College, Cambridge, and principal Librarian of the University 

 of Cambridge ; the Rev. John Brown, M.A., Fellow of Trinity Col- 

 lege, Cambridge j Captain John Franklin, R.N., F.R.S., &c. Com- 



