Jleaozoic and Ccenozolc Geology and Paloiontology. 147 



fortified by the organic remains which liad 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, Ornithichnites giganteus, 

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

 bius, now B. loxonyx, and B. sillimanimn, 0. ingens, now Tridentipes 

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

 zoum minimum, 0. palmatus^ and 0. tetradactylus. 



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

 sj'lvania, which stretches through the central and northern portions 

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

 found in the vicinity 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. RedfieldJ described, from the Connecticut Valley, Fal- 

 ceonisctis macropterus, now Ischypteims macropterus, P. agassizi^ P. 

 ovatns, Catopterus angutlliformis, C pai'vulus, and C. macrurus, now 

 Dictyopyge macrura. 



In the same 3'eai-, Prof Hitchcockg said the New Red Sandstone, 

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

 occupies 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 Fiicoides connecticiitensis, F. shepardi, Sauroidichnites 

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

 Plectropterna minitans, S. longipes, S. palmatus, and 8. polemarchus, 

 now Polemarchus gigas. He used the word 8auroidichnites as a gen- 

 eric name, but described it as the name of a suborder 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. Sei. and Arts, vol. xxix. 

 t 3d Ann. Rep., Pa, 

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

 § Geo. of Mass. 



