Eaton — John Day Felidce in Marsh Collection. 451 



trace of any of these teeth being the nearly closed 

 alveolus of P 2 on the right side. Jnst how much reliance 

 can be placed on the diameters of the superior canines, 

 as specific characters, is uncertain ; still, attention should 

 be called here to the fact that, in the diametral indices of 

 the superior canines, the three specimens, Nos. 10044, 

 10045, and 10517, agree much more closely with the types 



Fig. 11. 



Fig. 11.— Nimravus debilis (Cope). Cat. No. 10045, Y. P. M. X % 



of N. debilis and N. debilis major than with N. gompho- 

 dus; and the same may be said with reference to the 

 height index of the anterior zygomatic pedicle. 



The fourth skull, No. 10046, Y. P. M. (fLg. 12), whose 

 measurements and indices are given under the genus 

 Nimravus, is much smaller than the threa last enumer- 

 ated, being in fact even smaller than the type of N. debilis. 

 The superior canines are relatively longer than in that 

 type, yet their measured diameters are almost exactly 

 equal to those of N. debilis. The postcanine diastemata 

 are short; and in the reduction of the premolar teeth, 

 as well as in the slight development of the infracar- 

 nassial exostoses, this specimen differs from the type of 



