VERTEBRATE REMAINS, PORT KENNEDY BONE DEPOSIT. 245 



of that epoch, than the more conic teeth of the large cats of the present age. 

 The latter were represented, as we shall see, by a contemporary species, Uncia 

 inexpcctaia. 



Smilodon mercerii Cope (PI. XX, figs. 2-2r). [Type No. 50, Mus. Acad. Nat. Sci.] 

 Uncia mercerii Cope, Proc. Acad. Nat. Sci. Phil., 1895, p. 448. 



This saber-tooth is represented in the Academy's collection by two premolar teeth 

 from the upper and lower series, found near by at the same time and place ; and by 

 two mandibular rami of a second individual found together by Mr. W. H. Witte, 

 Mr. Mercer's assistant. The premolar teeth are the specimens on which the exist- 

 ence of the species was inferred. They are quite similar to the pm^ and pm T of 

 6". gracilis, differing chief!}" in their smaller size. The discovery of the mandible 

 enables me to ascertain the characters which distinguish the species from 5". gracilis. 

 These are : The different proportions which hold between the inferior molar and the 

 premolars ; the two-rooted pm f ; and the smaller size. The species is not so special- 

 ized in the sectorial direction as S. gracilis. Thus, the pm T in the two species 

 differ but little in size, and the pm^ is larger, though the jaw is smaller, and the 

 m T , or sectorial, is considerably smaller proportionately to the reduced size of the 

 jaw in S. mercerii. These characters are brought out in the measurements. In 

 further detail I observe that the posterior cutting lobe of the pin -% is more distinct 

 from the heel, and is more compressed than in S. gracilis, and that the anterior 

 base of the pm T is less produced anteriorly. 



But two incisors on each side are preserved, but the surface of the alveolar wall 

 on one side preserves indication of the alveolus of the I. 1. The forms of the 

 crowns of the other incisors and of the canine are as in 6". gracilis. The symphysis 

 is deep, and its anterior face transversely concave. The inferior projection of the 

 flange is moderate, but greater than the anterior projection. Its edges are thin both 

 anteriorly and inferiorly. The ramus is not deeper at the pm^ than behind the m T . 

 The coronoid process is low as in other Smilodon s, with sloping anterior and slightly 

 concave posterior border. The masseteric fossa is strongly marked, especially by 

 the strong horizontally prominent inferior edge of the ramus. Anteriorly it fades 

 out below the last true molar. The inferior border of the ramus is very greatly 

 convex. The condyle and angle are broken off. There are two well-separated 

 mental foramina ; the posterior below the anterior root of the pm^, and the anterior 

 below the middle of the diastema. There are three subequal foramina on the 

 anterior face of the symphysis ; one immediately below the incisor teeth ; one a 

 little above the inferior line of the symphysis ; and one a little nearer to it 

 than to the superior foramen and in line with it. The dental foramen is very large 

 and enters the ramus below the middle, and posterior to the vertical line of the 

 posterior border of the sectorial. 



