314 ANNUAL OF SCIENTIFIC DISCOVERY. 



colored sandstone, variable in thickness, but attaining a maximum of one 

 thousand two hundred feet. Above this is another belt of conglomerate, 

 marking the commencement of another era. Above this, again, is another 

 plant bed, entirely without animal remains, consisting mainly of ferns and 

 Cy cades. One of these is a true Cycas, and the first, he thought, which had 

 been found in the United States, though it existed as a living species in 

 New Holland. He mentioned also specimens of Yoltzia and Walchia. Next 

 comes another sandstone, in color red, and containing Posidoma, and at the 

 top some very remarkable bones, which he exhibited, but which he was 

 unable to name. With these bones were found coprolites, containing scales 

 of fishes. This sandstone is eight hundred or one thousand feet thick, and 

 was referred by him to the age of the Keuper of Europe. A bone was also 

 exhibited encased in rock, from a position below the plant bed. He spoke 

 of the difficulty of making out all these strata, owing to the great quantity 

 of debris ; but he trusted that he had proved that the upper conglomerate is 

 separate from the lower, and should be recognized as different, both for paleon- 

 tological and lithological reasons. The new red sandstone of Connecticut, 

 New Jersey, and Pennsylvania probably belongs to one of these series, and that 

 the upper, for the lower sandstone he could prove disappears upon advancing 

 north, while the upper can be traced. Thus the Richmond coal field is 

 separated from that of Deep River in North Carolina, which he considers as 

 of the Permian age, while that at Richmond he refers to the Triassic. 



Professor Agassiz said that there was not in any of our geological cabinets 

 a series of fossils so important as that laid before them by Professor Emmons. 

 His conclusions were formed from but a few moments' examination, but cer- 

 tainly we had here fossils all the way from the Upper Jura to the Lower 

 Triassic. He did not see anything which he could refer to the Perniians. 

 There were fossils here which he recognized as occurring only in Portland 

 stone and on the Purbeck beds. He had found also a well authenticated 

 Labyrinthodon. 



ON THE ORIGIN AND ACCUMULATION OF PROTO-CARBONATE OF 

 IRON IN THE COAL MEASURES GENERALLY. 



The following paper on the above subject, has been presented to the Boston 

 Soc. Nat. History, by Prof. "W. B. Rogers : 



This compound of iron, as we know, where mined in the coal measures, 

 presents itself in courses of lenticular nodules and interrupted plates, usually 

 included in the carbonaceous shales and in the fire-clays which underlie the 

 seams of coal, and in such cases it often forms a heavy ore, containing but 

 little earthy or organic matter, mixed with proto-carbonate. But it is also 

 frequently met with in a diffused condition, pervading thick strata of shale 

 and shaly sandstone, and causing these rocks to present in their different 

 layers, all the gradations of composition from a poor argillaceous and sandy 

 ore, to beds of sandstone and shale, with little more than a trace of the ferru- 

 ginous compound. 



On comparing the different subdivisions of a s}*stem of coal measures, we 



