284 On the Tertiary and Secondary Rocks forming the 



the only grounds of distinction between the two consisting in 

 the different nature of their organic remains. 



It has been mentioned, that to the west of the district 

 described, volcanic rocks are intermingled with the regular 

 deposits. I only made a short excursion in that direction, and 

 near St. Agata and Florian I observed tertiary rocks tra- 

 versed by amygdaloidal trap and the vitreous basalt of Monte 

 Gloso. These and the contiguous regions further westward 

 are fully described by Fortis and Maraschini, both of whom 

 show that igneous rocks have there burst through and alter- 

 nated with deposits of different ages. By these numerous 

 vents we may therefore presume, that the expansive forces 

 were finally elaborated, which when ronfined below may have 

 elevated the neighbouring deposits. I have therefore selected 

 these deposits as types of observation, because they are wholly 

 exempt from the confusion usually incident to any intermix- 

 ture with volcanic rocks. 



List of Organic Remains observed in a cursory Examination of 

 the Tertiary Deposits near Asolo, Possagno, Bassano, fyc. 



(Named by Mr James de C. Sowerby.) j^^ties in other Parts 



Bivalves. of Europe. 

 Ostrea. Several species, all in the "> 



younger beds above the blue marl y 

 Pectenjleuronectes and other species ; J Subapennines 



chiefly in the upper sands subor- > , f , , r 



dinate to the conglomerates . . . j ° ?' 



Chama squamaso. Min. Con. Interme- 'I •»> . ycc u. 



diate blue marls $ ' n 



Lucina concenlrica, Lam. In the higher > -p, .. « . fi 



beds of blue marl jnacemi, ash, &c. 



— — — mutabilis, Deshayes, do. do. Grignon. 



Univalves 



(chiefly in the middle and lower blue marls). 



Rostellaria sinuosa? Bourdeaux. 



Cassis diadema (of Grateloup and Bas- "I -r, j n 1 



t . x C a Bourdeaux. 



Conus stromboides (concinnus of Sower.) ^ Highgate, Barton, and 

 (See Min. Conch, t. 302. f. 2.) . . $ Paris. 



i Lowest beds of Cal- 

 Fusus longcevus. Min. Conch, t. 63 . .< cairegrossier,Lon- 



' don clay, &c 



Melanin costellata, Lam Paris basin. 



Mitra scrobiculata, ( Volula scrobiculata ) Placeniia, Sienna, 

 ofBrocchi) 5 Turin. 



