NATURAL SCIENCES OF PHILADELPHIA. 157 



was noticed some years ago by him under the name of Ossite. A 

 similar material has been found near Charleston, S. C, in a post- 

 pliocene formation. 



E. D. Cope gave an account of his discovery of tlae fresli-water origin of 

 certain deposits of sand and clays in west New Jersey, whicli he found to con- 

 tain leaves of dicotyledonous trees, ctenoid fish scales, and numerous Unionidje 

 in a tolerably good state of preservation. The most important part of the 

 deposit consisted of a heavy black clay, which is used for making brick, which 

 rests on a bed of hard laminated clay, with a thin layer of iron-stone between. 

 The clay bed, at one place examined, is 25 feet in thickness, and at from one 

 to three feet from its bottom occurs a bed of fresh water mussels. These are 

 Unios and Anodontas of si.x; species, all of them, as pointed out to him by Dr. 

 Lea, hitherto undescribed, and having some analogy with those of the Wealden, 

 procured by Dr. Mantell in England. The beds are from tlie top of the clay 

 down, conformable, and have a dip of about 2.5° to the soutli-east. The upper 

 surface of the clay is worn into holes, which are filled by the material of abed 

 of coarse gravel of little depth, which covers the whole. Above this is a bed 

 of fine sand, varying from six to fifteen feet in thickness to the soil. The point 

 at which the section is visible is in New Jersey, ou the banks of the Delaware, 

 about six miles above Camden, N. J. 



These deposits belong to Meek and Hayden's Earlier Cretaceous, No. 1, 

 which contains abundant remains of leaves on the Raritan River, but no 

 animal fossils. Their age has been heretofore quite uncertain ; they have been 

 stated by Meek and Hayden to be the earlier division of the later Cretaceous of 

 the general geologic series. They extend across the States of Delaware, Mary- 

 land and Virginia. In Maryland they are stated by Ducatel to contain the 

 important deposits of carbonate of iron ; and Philip Tyson, State Geologist, 

 informs me that these beds lie upon the red and blue clays, forming hills, 

 which have been produced by erosion of tlie valleys to the beds below. These 

 iron clays contain several species of Cycadaceous plants, whence Tyson infers 

 the age of the clays to be Jurassic, and not Cretaceous. 



There are in the Museum of the Smithsonian Institution, Washington, several 

 specimens of fossil Unios, from a ferruginous clay which crops out at some 

 elevation on the banks of the Potomac. These species are identical with those 

 which have been found in the New Jersey clays, and the deposit is doubtless 

 the same as that which traverses the State of Maryland. 



Indurated grey clays on the Rappahannock River have been examined by my 

 friend Philip R. Uhler, of Baltimore, who has obtained from them leaves and 

 stems of some six species of plants, in beautiful preservation, of the orders 

 Cycadacete, ? Gnetacea; and Filices. The position and character of this bed 

 renders it exceedingly probable that it is a continuation of those of Maryland 

 and Alexandria. 



The vvhole formation indicates the existence of an extended body of fresh 

 water, having a direction and outline similar to that in which were deposited 

 the red sandstones and shales of the Triassic belt, which extends parallel to its 

 north-west margin throughout the States in which it occurs, separated, except 

 in New Jersey, by a broad band of Gneiss, and Potsdam rocks. The carbonate 

 of iron was no doubt deposited in a bog or bogs along its margin or in its 

 shallows, as the bottom became elevated, as suggested by Tyson, — though not 

 in a salt-water swamp, as supposed by him. The cycads and dicotyledonous 

 trees grew in the swamps and on the shores, while terrestrial reptiles of large 

 size no doubt haunted their sliades. 



These beds appear to dip conformably beneath the lower Cretaceous marine 

 beds in New Jersey, in which, at a distance of a few miles from their border, 

 occurred the remains of the Hadrosaurus ; and it is therefore not probable that 

 they were cotemporary with these, as is the case with the Wealden of Kent 



1868.] 



