GEOLOGY. 331 



these is a belt of analogous rocks in North Carolina, commencing some 

 distance south of the Virginia line, and stretching south-westwardly 

 across the State, and for a few miles beyond its limits into South Carolina. 

 This area includes the coal-bearing rocks of Deep River. The western 

 belt extends, with two considerable interruptions, entirely across Virginia, 

 being prolonged towards the south-west in the course of the Dan River in 

 North Carolina, and towards the north-east, through Maryland, Pennsyl- 

 vannia and New Jersey forming what is usually called the New Red 

 Sandstone belt. 



From an examination some twelve years ago of the fossil plants of the 

 most western of the Virginia belts designated, Prof. Rogers had been led 

 to refer this group of rocks to the Oolite series on or near the horizon of 

 the carbonaceous deposits of Whitby and Scarborough, in Yorkshire. 

 Some years later he discovered many of the same plants in the middle 

 belt of Virginia ; and in the summer of 1850 he found several of these 

 plants in the coal rocks of Deep River, in North Carolina. In each of the 

 latter districts we meet with Equisetum Columnare, Zamites, and a 

 plumose plant referred to Lycopodites, and strongly resembling L. Wil- 

 liamsonis, of the Yorkshire rocks. These are among the usual forms 

 occurring in the easternmost of the Virginia belts. 



Besides the fossil plants common to these three areas, they contain two 

 species of Posidonomya and two of Cypris. Of the Cyprida? one species 

 has a smooth, the other a beautifully granulated carapace. They are both 

 very small, seldom exceeding l-30th of an inch in length and l~70th in 

 width. Both species cf Posidonomya differ in proportions from the Pos. 

 Minuta of the European Trias, but one of them strongly resembles the P. 

 Bronnii of the Lias, although of larger dimensions. 



Prof. Rogers remarked upon the uncertainty which exists as to the true 

 nature of the small shell-like fossils, which, being assumed as mollusks, 

 have been referred to Bronn's genus Posidonomya. But whatever may 

 be their zoological affinities, the fossils now under consideration have 

 great interest, as affording further means, not only of comparing together 

 the mesozoic belts of North Carolina and Virginia before referred to, but 

 of approximating more justly than heretofore to the age of the so called 

 New Red Sandstone, or Triassic rocks, which formed the prolonged belt 

 lying farther towards the west. 



In the report of Prof. Emmons, published in the autumn of 1852, 

 mention is made of the remains of Saurians in the Deep River deposits, 

 as well of the Posidonia and Cypris, and of an Equisetites, a Lycopodites 

 and other allied forms, together with a naked, rather spinous vegetable, 

 regarded by him as a cellular cryptogamous plant. 



In view of the general identity of the fossils thus far found in the Dry 

 River and Middle Virginia belts with those of the most eastern deposit 

 in Virginia, viz., that including the coal of Chesterfield, Prof. Rogers 

 maintained that the general equivalency of these three eras may be re- 

 garded as established, and therefore the Dry Paver belt of North Carolina, 



