8 Ilesozoic and Ccenozoic Geology and Paloiontology. 



fortified by the organic remains which had been collected at that time, 

 as well as by the mineral character of the rocks. He described the 

 rocks as micaceous sandstone, variegated sandstone, brecciated sand- 

 stone, shales, argillaceous slate and limestones. He discussed the dip, 

 direction and thickness of the strata, and the occurrence of valuable 

 minerals. 



In 1836,* he described, from Massachusetts, Omitliichnites giyanteus, 

 now Brontozoum giganteum, 0. tuberosus, and 0. tuberosus, var. du- 

 bius, now B. loxonyx, and B. sillimanium, O. ingens, now Tridentipes 

 ingens. 0. diversus, now Tridentipes elegans, O. minimus, now Argo- 

 zoum minimum, 0. i^nlniatus^ and 0. tetradactylus. 



In 1839, Prof H. D. Rogersf described the Red Sandstone of Penn- 

 sylvania, which stretches through the central and northern portions 

 in a long and irregular tract, from New Jersey to Maryland. It is 

 found in the vicinit}' of Reading, and near the Potomac river, from 

 which place is quarried the famous Red Sandstone used in Wash- 

 ington city. Prof Rogers proposed to call this the " Middle Sec- 

 ondary Red Sandstone formation," because it is higher than the Coal 

 Measures, and below the Cretaceous Green Sand of New Jersey. 



In 1841, W. C. Redfield+ described, from the Connecticut Valley, Fal- 

 (BonisGus macropterus, now Ischyjyterus macropterus, P. agassizi, P. 

 ovatiis, Catopterus anguilliformis, C. parvulus, and C. macrurus, now 

 Dictyopyge macrura. 



In the same year. Prof Hitchcock§ said the New Red Sandstone, 

 extending from New Haven to the north line of Mass., in Northfield, 

 o.ccupies a narrow synclinal trough, having a width of about 20 miles, 

 from East Hampton, in Massachusetts, to the Sound at New Haven; 

 but from East Hampton to Northfield a width of only 6 or 7 miles. He 

 described Fucoides connectiGutensis, F. shepardi, SauroidiGhnites 

 barratti, S. heteroclitus, now Ancyropus heteroGliius, 8. minitans^ now 

 Plectropterna minitans, S. longipes, S. palmatus, and S. iyolemarchus, 

 now Polemarchus gigas. He used the word Sauroidichnites as a gen- 

 eric name, but described it as the name of a sub-order under the class 

 Ichnolite. He also described Ornithoidichnites as a sub-order, and 

 used it as a generic name, and described numerous species under it. 

 These names have, however, been abandoned, and the species have 

 also been abandoned or referred to genera properly defined. The 



=■■■ Am. Jour. Sci. and Arts, vol. xxis. 

 t 3d Ann. Rep., Pa, 

 J Am. Jour. Sci. and Arts, vol. xli. 

 i Geo. of Mass. 



