﻿LEIDY'S DESCRIPTION OF REMAINS OF EXTINCT MAMMALIA. 



169 



The slight variations indicated in the fossils might be considered as insufficient to 

 characterise them as having belonged to a distinct species from the grizzly bear, but 

 when we reflect upon the equally slight variations which exist in the homologous 

 parts to the fossils in certain recent species of the genus, and recollect that the fossils 

 in question were found in association with remains of the Megalonyx, &c, in a country 

 never known to have been inhabited by the grizzly bear, we cannot help inclining to 

 the belief that they belonged to a species distinct from the recent ones. 



The comparative dimensions of the fossils are as follows : 



Depth of lower jaw below the last molar, 

 Antero-posterior diameter of the last lower molar, . 

 Transverse do. do. do. 



Antero-posterior diameter of the upper penultimate molar, 

 Transverse do. do. do. do. 



U. americanus. 

 15 to 18 lines 

 8 " 



5| « 

 8£ 

 6* « 



U. ferox. 

 18 to 25 lines. 

 11 " 



lh " 

 11 " 



I', amplidens. 



17 



lines. 



91 



it 



7 



it 



10 



u 



7 ' 



ti 



1 z 





Plate 17, fig. 13. — Outer view of the fragment of the lower jaw of Ursus amplidens. 



fig. 14. — Triturating surface of the last molar contained in the same specimen, 

 fig. 15. — Outer view of a left upper penultimate molar, 

 fig. 16. — Triturating surface of the same specimen. 



Ursus americanus fossilis. 



Remains of the common black bear ( Ursus americanus) have on several occasions 

 been discovered in association with those of extinct animals. Dr. Harlan* mentions 

 an inferior maxilla, which was found in Big-bone Cave, Tennessee, in association with 

 remains of the Megalonyx. The specimen, which is preserved in the collection of the 

 Academy, contains none of the teeth, and it is unchanged from the original texture, 

 except that it has lost a small portion of its gelatin. It is not improbable that the 

 specimen may be of much later date than the Megalonyx remains with which it was 

 found. 



Another specimen preserved in the cabinet of the Academy, consists of the left 

 half of the lower jaw containing the canine and anterior two molar teeth of a species 

 of bear, discovered in a ravine in the vicinity of Natchez, Mississippi, in association 

 with remains of Megalonyx, Mylodon, Ursus amplidens, Equus americanus, Bison lati- 

 frons, Cervus, &c. The specimen corresponds closely in its anatomical characters 

 with its homologue of the common black bear. The bone is exceedingly friable, and 

 is enveloped in a thick layer of compact peroxide of iron, in the same manner as the 

 specimen upon which was established the Felis atrox,~\ and which was found in the 

 same locality. 



Procyon priscus, Le Conte. Amer. Jour. Sc\ and Arts, 2d s. v, lOfi. 

 This species of extinct raccoon was first indicated by Dr. John L. Le Conte, from 

 some specimens which were found in association with remains of several animals of 



* Journ. Acad. Nat. Sc, vi, 2G9. Med. and Phys. Res., 329, pi. xiv, fig. 26. 



| Traas. Am. Phil. Soc, 2d ser. s, pi. 34. 



