180 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DcC. 13, 



from the overlying neoeomian and cretaceous rocks on the other. 

 In ascending from Pedescala, in the valley of the Astico, to the 

 plateau of the Setti Communi, we passed first over the edges of a 

 great mass chiefly in the state of dolomite, probably representing 

 the lias and inferior oolite, and then over rubbly yellowish earthy 

 limestone ; next over other courses of greyish limestone containing 

 Turritellee, followed by limestone of deep red colour, which from the 

 quantity of ammonites found in it has obtained the name of " Ammo- 

 nitico rosso." This last is surmounted by the white neoeomian 

 limestone. In traversing the lofty plateau of the Setti Communi 

 from Castel Bello by Rotzo and Roana*, we had numerous exhibi- 

 tions of an ascending order, from grey earthy limestone, vdth some 

 sandy beds, up into the same red ammonite limestones, and thence 

 into the white neoeomian, which is here a purely white indurated 

 rock, and as much loaded with flints as our chalk of Antrim, which 

 it much resembles. Without dwelling on any details, I will simply 

 enumerate the succession of the strata of this tract, as proved from 

 difl'erent sections which exhibit the strata more or less inclined, but 

 all conformable, and in this ascending order : — 



1 . Dolomite, &c., of great thickness, probably representing lias. 

 2. Compact brecciated marls. 3. Beds of fine oolite, alternating 

 with yellowish marly limestone, containing shells, including Di- 

 ceras, Gryphsea, &c. 4. Thin-bedded limestone with Nerinsea 

 and univalves. 5. Thin-bedded, dark grey, sandy limestone, 

 with Neuropteris and other plants. 6. " Lumachello grigio," 

 grey mottled limestone with marl, yellow marly beds and grey 

 lumachello with sections of large bivalves. 7. "Ammonitico 

 rosso." This rock is invariably the summit of all the Jurassic 

 strata in this region, and clearly represents the Oxford formation. 

 Although seldom more than fifty or sixty feet thick, it is an 

 excellent horizon, since it contains Ammonites athleta (PhilL), 

 A.anceps (Reinecke), A.Hor?ie?'i (D'Orb.), A.Tatricus (Pusch), 

 A. viator (D'Orb.), with Terebratida diphi/a and T. triangulata, 

 8. " Biancone," or neoeomian with Ci'ioceras Duvalli (Leym.), 

 Belemnites latus (Blainv.), Ammonites asterianus, A. incertus 

 and A. semistriatus (D'Orb.), -with some forms in the upper- 

 most beds resembling those of gault, such as A. Royerianus 

 (D'Orb.). In all, this group contains fifteen species of Am- 

 monites, five or six species of Crioceras with Ancyloceras, 

 Aptychus of two species, &c. 9. "Lower Scaglia," of grey 

 colours with fucoids, — lower chalk. 10. "Upper Scaglia," of 

 red and white colours, — upper chalk, &c. 11. Nummulite lime- 

 stone and grit, with Cerithium giganteum and Nummulites of 

 the same lower tertiary age as in the same position at Bassano ; 

 of which and of all the series from the neoeomian upwards I 

 shall treat hereafter. 



In other parts of the South Tyrol, and notably at Trent, M. von 



* This is the wild country of the ancient Cirari, and the people still talk a lan- 

 guage unknown in any other part of the Alps. 



