416 PROCEEDINGS OF THE ACADEMY OF 



cana. The fish had been caught in the Suscjuehanna River, at 

 Duncannon, Pa. In the stomach there was found a large shell of 

 Lingula jiyramidata, which heretofore had not been discovered 

 inliabiting our coast further north than North Carolina. The 

 yellow Pike-perch was generally considered to be altogether a 

 fresh-water fish. The presence of the lingula in the stomach 

 would indicate that it was at least a visitor to the sea, and in the 

 case of the present fish, probably as far down as the North Carolina 

 coast. 



December 16. 



Dr. Carson, Vice-President, in the chair. 

 Twent3'-four members present. 



Bemarks on Fossil Elephant Teeth. Prof. Leidy observed that 

 the fossil elephant teeth, presented this evening by Mr. Richard 

 Peters, were obtained b}' him in Mexico. In appearance the fossils 

 resemble some others, obtained in New Mexico and Chihuahua, 

 referred to in his recent work, " Contributions to the Extinct 

 Vertebrate Fauna of the Western Territories." All appear to have 

 pertained to the coarse-plated variet}' of molars referred to a 

 species by Dr. Falconer with the name of Elcphas Golunibi. Some 

 of the specimens had been found in association with remains of 

 the Mastodon, the extinct and near relative of the elephant. 



The two genera were cotemporaneous, and were represented by 

 many species during the middle and later tertiary' periods, but no 

 remains of either have 3'et been discovered in the early tertiarj^ 

 deposits. It is probable that both are successors from a common 

 stock which existed at a period intermediate to that in which were 

 formed the known eocene and miocene deposits. The elephant has 

 survived the mastodon, as represented in the living species of 

 Asia and Africa to-day. In this countiy, the comparative abun- 

 dance and excellent state of preservation of remains of the mastodon 

 in post-tertiary deposits, would apparently indicate that it had 

 survived the elephant. The mastodon had the outward form and 

 the general construction of the living elephant. Like it, it was a 

 bulky, five-toed animal, with a long prehensile proboscis, and with 

 long tusks to the upper jaw. 



Tlie molar teeth in the two genera differ in a striking manner, 

 and so widely, that early observers thought those of the mastodon 

 were adapted to a carnivorous habit. The actual number of 

 molars is the same in both, but generally those of the functional 

 series, or those in use at any one time, are more numerous in the 

 mastodon than in the elephant. In this the molars are bulky, 

 laminated masses inserted in the jaws without fangs. In the 

 former the molars have distinct crowns, with prominent transverse 

 lobes, inserted with long, strong fangs. 



