Lesley.] 40 fi [November 6. 



Among the earliest acts of the founders of the Academy of 

 Natural Sciences of Philadelphia, was a resolution that its 

 origin should date from the 21st day of March, A. D., 1812. 

 The Anniversarj' of this day in 1854, was a marked occasion; 

 because of the desire that the members felt to celebrate the 

 erection of their New Hall. Members, Correspondents and 

 their guests assembled at a sumptuous dinner in the Musical 

 Fund Hall. On the evening previous a discourse was pronounced 

 by Mr. Foulke before au audience assembled in the Hall of the 



paper in the Proceedings of tlie Academy of Natural Sciences of Philadelphia, 

 read June 9, 1868). Kight species of Unio and two species of Anodonta were 

 found by Mr. Cope. Mv. Conrad refers the lilue clay to an ancient water-course 

 of the Delaware river, which there is some reason to Ijelieve crossed middle 

 New Jersej' in a direct line to the sea shore. If this blue clay be indeed 

 above the Hadrosaurus Green Sands, then the remarks above, in the text, on 

 the invalidity of fossil determinations of age between widely separated re- 

 gions receive additional force ; for the fresh-water Wealden, with its Iguano- 

 don remains underlies the Green Sand of England. On the other hand, Messrs. 

 Meek and Hayden have found extensive fresh-water deposits at the mouth of 

 the Judith river in the Central basin of the North American Continent, and 

 consider tliem as constituting tlie bottom subdivision (No. 1) of the Middle 

 Cretaceous. Such deposits can hardly have relationships of time with one 

 another as marine deposits have. They are the local phenomena of all ages. 

 The Delaware river has flowed in about the same channel which it now occu- 

 pies ever since the close of the New Red, Norristown, or Connecticut River 

 Sand Stone era ; a channel determined by the topograpliical features of the 

 Baltimore-Philadelphia Lower Silurian (Quebec Group?) liills, on whicli Ger- 

 mantown, ))ack of Philadelpbia, is situated, and terminating in a promontory 

 at Trenton. Tliis range of hill land must have been higher in the air before 

 the close of the New Red era than now, because it has sutfered immense ero- 

 sion since then. But apart from that consideration, it must have been carried 

 bodily upward to a still higher general level, by tliat rise of the Conlinent, 

 which not only dried the New Red estuary basin, but elevated the New Red 

 sediments many hundred feet, forming the Pennsj'lvania and New Jerse5' New 

 Red hill countrj' of the present day. But this elevation could not have been 

 efl'ected without the production either of hill country, low plains, or subma- 

 rine shallows all along the area now occupied by Southern New Jersey, Dela- 

 ware, &c. The River Delaware may at that time have had a much longer 

 course, but in wliat direction, would be detei'mined by the nature of the 

 uplifted land. It niaj' have meandered through vast marshes, like those of 

 the Carolina sea board ; or it may even have flowed far away toward the south- 

 west into the Susquchannah river, itself prolonged. In this river channel 

 would have been deposited the fresh-water blue clay with Mr. Cope's Union- 

 idae. Subsequently, a reversed or downward movement shortened the river, 

 submerged the outside land, produced an archipelago along the coast ami 

 permitted the deposit of the Cretaceous and Tertiary formations, which, by a 

 final reelevation, have now become Soutliern New Jersey, Delaware, Kastern 

 Virginia, &c. But the more recent discovery of the bones of a postpleiocene 

 horse, by Prof. Cope, in such relations to tliis clay bed, as to make it pretty 

 certain tliat the animal was embedded in it, near its lower limit, relieves us 

 from the necessity of considering the deposit older than the Hadrosaurus 

 marl. 



