Mesozoic and Cmnozoic Geology and Palceontology. 15 



mediately above the trap, with very few exceptions, that the organic re- 

 mains — the fishes, the tracks, and plants — are found. His sections 

 show the thickness of the sandstone above and below the trap, as 

 follows: 



Feet. 



Turner's Falls section, above 4,190 



below 7,788 



Mettawampe section, above 1,584 



below 5,283 



Mount Tom section, above 8,102 



" below 5.115 



Agawara and Chicopee or Springfield section, above. . .11,500 

 " " " " " " below. . . 8,li8 



The rock below the trap seems, from the evidences adduced, to be of 

 Triassic Age. He argues that the strata of sandstone were not depos- 

 ited in their present inclined position, and subsequently elevated, and 

 that the sandstone was not elevated or tilted up by the eruption of the 

 trap rock; but, on the contrar}', that the lower beds of sandstone were 

 deposited, and perhaps somewhat tilted up, when the trap was ejected 

 from beneath, and spread over the upper part of the strata, and that 

 afterward the work of depositing the sandstone was resumed, and that 

 which lies above the trap laid down. New outbursts of the trap, how- 

 ever, occurred at subsequent periods, but less in quantity, as if the 

 eruptive force were dying out. This is followed by a very learned essay 

 upon the constant and distinctive characters in the feet of animals, 

 and the application of the rules laid down, to the footmarks, which he 

 described and illustrated. He called these tracks Lithichnozoa — stone- 

 track animals; or animals made known by their tracks in stone. 



The longest trough, and greatest exposure, in the Eastern States, be- 

 gins at Stony Point, on the Hudson, and extending across New Jer- 

 sey, Pennsylvania and Maryland, reaches Culpepper county, in Vir- 

 ginia. It has a length of about 350 miles, and though frequently nar- 

 rowing to a breadth of four or five miles, it expands, in New Jersey, to 

 a width of about thirty six miles. The character ot the deposit very 

 much resembles that of the Connecticut valley. The other Virginia 

 deposit exists iu Henry, Pittsylvania, Halifax, Prince Edward and 

 Buckingham counties. 



Prof. Emmons first ascertained the extent and general character of 

 the two basins of Triassic strata, in North Carolina. One is iu Stokes 

 and Rockingham counties, bordering on Virginia. It begins at Leaks- 

 ville, and runs about thirty miles southwest to Germantown, and is 

 from four to six miles wide. The other commences six miles south of 

 Oxford, in Granville countj', and runs southwest through a part of 



