52 



ON THE EXTINCT MAMMALIA OF 



Length of first lower true molar, 



Breadth of second *• " 



Length of " 



Breadth of lower sectorial molar, 



Length anteriorly of lower sectorial molar, 



Length posteriorly of " " 



Length of upper canine, 



Breadth of " 



Thickness of " 



Length of lower canine, 



Breadth of " 



Thickness of " 



FELID^. 



PSEUD^LURUS. 



The genus Reudcelurus was proposed by M. Gervais, in the Zoologie et Pal6on- 

 tologie Francaises, volume I, page 127, on some remains of a feline animal from the 

 miocene formation of Sansan, Gers, France. It was distinguished from the genua 

 Felis by the single character of possessing an additional inferior premolar in advance 

 of the others. The only species described, the P. quadridentaius, was previously 

 indicated by De Blainville, in his Osteographie, under the names of Fells quadriden- 

 taius and F. tetraodon. 



PSEUD^LUEUS INTREPIDUS. 



A second species of PseudaiJurus to which the above name has been given, 

 appears to have been a member of the ancient fauna of Nebraska. It is indicated by 

 a well-preserved specimen of the lower jaw, discovered by Dr. Hayden in the sanda 

 of the Niobrara River. One side of the specimen, the left ramus, is represented in 

 figure 8, plate I. It contains the sectorial molar, the two premolars in advance, the 

 canine tooth, and the lateral incisor. The right ramus contains the same teeth with 

 the addition of the second incisor, but the canine tooth and lateral incisor are much 

 mutilated. In both rami the premolar, considered as the chief character of the genus, 

 is absent, but its alveolus remains midway in the hiatus back of the canine tooth. 



The jaw is intermediate in size with that of the Panther, Felis concolor, and that of 

 the Lynx, Felis canadensis. The form of the jaw and of the teeth is the same as in 

 the cats generally. 



In its details of form and proportions, the jaw resembles that of the Lynx more 

 nearly than that of the Panther. The summit of the coronoid process is obtusely 



