﻿168 LEIDY'S DESCRIPTION OF REMAINS OF EXTINCT MAMMALIA. 



internally is less narrowed than in recent wolves. It is also broader in the antero- 

 posterior diameter when compared with its transverse diameter ; and its basal ridge 

 externally is a little more abrupt and is slightly crenated at the border. 



The second and third molar teeth have their basal ridge internally a little better 

 developed, which is also the case with the internal oblique ridge, descending towards 

 the cusp anteriorly. 



The principal measurements of the fossil, in comparison with those of the corres- 

 ponding part in recent wolves, are given in the following table. 



MEASUREMENTS. 



tx 

 o 



Q 



ti 



rt o 



a § 



»*, 

 . o 



03 



lines. 



3 p. 

 P. o 



as 



§ ° 



o 



a 



<s 



•a 



'5 o 



o3 

 »o 



I'S 

 o 



a a 



•a 



a 



9 



a 



o . 



*■§ 



H 



.5 o 



3 

 > 



•si' 















From base of crown of third molar to upper margin of maxilla* . 



25 



24 



21J 



24 



26 



31 



From base of crown of fourth molar to upper margin of maxilla, . 







34 



36 



30 



34 



36 



41 



From back of last molar to canine alveolus, . . x 







38 



43 



414 



424 



46 



53 



Antero-posterior diameter of first molar alveolus, 







3 



33 



n 



4 



4 



44 



Do. do. of second molar tooth, . 







5 



64 



7 



6f 



7 



7 



Do. do. of third molar, .... 







6 



8 



75 



' 4 



8 



8 



84 



Do. do. of fourth molar, .... 







91 



13 



12* 



m 



13 



16 



Do. do. of fifth molar, .... 







7 



8 



H 



8 



8 



9 



Transverse do. do. .... 







8 



10f 



11 



104 



lOf 



114 



Antero-posterior diameter of last molar, .... 







4 



4 



AS, 



*4 



4 



41 



41 



Transverse do. do. .... 







5* 



7 



7i 



* 4 



64 



7 



7 



Plate 17, fig. 11. — Outer view of the fragment of the upper jaw of Canis primcevus. 

 fig. 12. — 'Lower view of the same specimen. 



Ursus amplidens, Leidy. Proc. Acad. Nat. ScL, vi, 303. 



This species is founded upon a fragment of lower jaw and an upper molar tooth, 

 which were discovered in association with remains of Megdlonyx, Mylodqn, Ereptodon^ 

 Equus arnericauus, Cervus virginianus fossil is, and Mastodon, in a ravine in the neigh- 

 borhood of Natchez, Mississippi. 



The fragment of the jaw is of the left side; and it contains the last molar tooth, 

 It has about the same size as the corresponding portion of the jaw of the common 

 black bear [Ursus americanus), or of that of the grizzly bear ( Ursus fer ox) at an age 

 when the permanent teeth have all protruded but are not yet worn by attrition. Its 

 form also does not vary from what it is in the latter animals, except that it is more 

 convex externally. 



The last molar tooth is intermediate in size to that of the black and the grizzly 

 bear, but the form of the crown is more like that of the former than that of the latter. 



The specimen of an upper molar is the penultimate one of the left side. It has 

 very nearly the same form as in the grizzly bear, except that the small cone in front 

 of the outer pair of principal cones is almost as well developed as that behind them. 



