1851.] 171 



molar measures antero-posteriorly 4J inches, the sixth molar 3j, and 

 the fifth molar has been about 3J inches. The angle of the jaw is 

 eight inches behind the posterior molar. The lower jaw has been full 

 two and a half feet long, and belonged to an animal three times the 

 size of the Pahieotherium magnum of Cuvier. 



Prof. Bairdhas also sent three fossil Tortoises from the same locality, 

 one of which Dr. Leidy oelieved to be a new genus. 



Mr. Lea stated that he had examined the fossil bones of a reptilian quadruped , 

 which Dr. J. Y. Shelley had sent to the Academy in Nov., 1847, from Upper 

 Milford, Lehigh Co., Pa., on Hassac's Creek, a tributary to the Perkiomen. 

 The notice of Dr. Shelley's donation, published in No. 7, Vol. 5, of the Proceed- 

 ings, as part of the Annual Report of the Recording Secretary, had not met Mr. 

 Lea's view until within a few days, it being there remarked, that these remains 

 were from a formation probably anterior to the coal. 



The great interest which attaches to all these sauroid remains, induced Mr. 

 Lea to examine the specimens in the Cabinet of the Academy, when he was per- 

 fectly satisfied by the lithological characters of the nr.atrix, and by the geogra- 

 phical position of the locality, that the epoch of the existence of this reptilian 

 quadruped had been misapprehended. The matrix was found to be carbonate of 

 lime, in the form of a conglomerate, and the locality near to the range of the 

 trappean hills, known as the "Conewago Hills" in Pennsylvania, and as the 

 Blue Mountains in Virginia. On the south of these intruded rocks, lies the 

 formation known by the geologists of the United States, generally, as the New 

 Red S%7idstone, although Elie de Boumont, and Dr. Jackson, of Boston, are not 

 of the opinion that it is the equivalent of the Trias or upper new red sandstone, 

 or the Permian or lower new red sandstone of Europe. Certain it is, however, 

 that this red sandstone formation, which stretches in a long and narrovi^ band, 

 from South Carolina to the Connecticut yver, and exists probably at Truro 

 in Nova Scotia, sometimes with considerable interruptions, has been found 

 to contain the foot prints of numerous genera and species of birds, and of 

 reptiles, as well as a large number of fishes. These have been chiefly ob- 

 served on the Connecticut river. But until now there had not been found in 

 this formation in the United States, so far as he knew, any hones of the ani- 

 mals which then inhabited its shores. It is well ascertained, that this calcareous 

 conglomerate forms the upper portion of the so-called new red sandstone forma- 

 tion, and lies on its northern border, appearing at various points : in the N. E. 

 part of New Jersey at Pompton, westwardly at Germantown in the same State, 

 and it is found crossing the Delaware at Spring Mills about 15 miles below 

 Easton. It is recognised at the locality, where these bones were found, in the 

 S. E. corner of Lehigh county, and in the same line south-westward, below 

 Reading, about one mile, where it exists in very large masses, the line of the 

 Philadelphia and Reading railroad making a deep cut through it. It there ex- 

 hibits its structure as a very coarse calcareous conglomerate of various colors. 

 In the same direction it is found on the Potomac river, and is known there as the 

 Potomac marble, of which the columns of the Halls of Congress are made. 



Mr. Lea remarked that it was greatly to be regretted, that all the bones of this 

 specimen had not been obtained, but it was due to Dr. Shelley to say that he 



