152 Cincinnati Society of Natural History. 



overflowed. The Sandstone contains no valuable nilueials, and no 

 fossils had then been detected in it. 



In ] 853, Isaac Lea* described, from the Triassic of Lehigh county, 

 Pennsylvania, Clepsysaurus pennsylvanicus. 



In 1854, Dr. Joseph Leidyf described, from the Triassic of Prince 

 Edward Island, Bathygnatlius borealis. 



In 1855, Prof. J. W. Dawson described Prince Edward Island, 

 which stretches for 125 miles along the northern coast of Nova Scotia 

 and New Brunswick, has everywhere a low, undulating surface, and 

 consists almost entirely of soft red sandstone and arenaceous shale, 

 much resembling the new red of Nova Scotia, and like it having the 

 component particles of the rock united by a calcareous cement. In 

 some places the calcareous matter has been in sufficient abundance 

 to form bands of impure limestone, usually thin and arenaceous. Over 

 the greater part of the island these beds dip at small angles to the 

 northward, with, however, large undulations to the south, which prob- 

 ably cause the same beds to be repeated in the sections on the opposite 

 sides of the island. 



In the same year, Dr. E. Hitchcock, jr.;]; described Clathroitteris rec- 

 tiusculus, from the sandstone of Mt. Tom, in Eastharapton, Mass., of 

 the age of the lower Jurassic. 



In L856, Prof. E. Emmons§ described, from the Lower Triassic of the 

 Deep and Dan river beds of North Carolina, Chondrites gracilis, C. 

 interruptiis, C. ramosus, Gymnocaulus alternatus, Equisetum column- 

 aroides, Dictuocaidus striatus, liutiodon carolinensis, Clepsysaurus 

 leai, Palmosaurus carolinensis, P. sulcatns and Posidonia ovalis, now 

 referred to the genus Esther ia^ and from the Upper Triassic of the 

 Deep and Dan river beds, Strattfjerites obliquus, Acrostichites oblongus, 

 Pecopteris carolinensis, P. falcata, Pterozamites decussatus, Cyca- 

 dites actitus, C. longifoUus, Zamites graminioides, Podozamites 

 lanceolatus, P. longifolius, Lepacyclotes circrilaris, L. ellipticiis, 

 Walchia diffusa^ W. longifolia, Calamites disjimctus, Sphenoglossum 

 quadrifolium, and Posidonia nudticostata, and P. triangularis, which 

 are now regarded as svnonyms or varieties only of Estheria oralis. 



And in 1857|| he described, from North Carolina, Calamites pnnc- 

 tatus, Walchia angustifolia, W. variabilis, W. brevifolia, W. gracilis, 

 Sphenopteris egyptiaca, Cyclopteris obscura, Odontopteris tenuifolia, 



* Jour. Acad. Nat. Sci., 2d Ser., vol. ii. 

 t Jour. Acad. Nat. Sci., 2d Ser. vol. ii. 



I Am. Jour. Sci. and Arts, 2d Ser., vol. xx. 

 i N. Carolina Sur. 



II Am. Geo., pt. 6. 



