Vol. 5] Bovard.— Quaternary Felidae from California. 161 



are very close in their general aspects, they can be readily dis- 

 tinguished by the posterior position of the posterior nares and 

 the shorter face of 8. californicus, and possibly by the ridges on 

 the palate. It is probable that if the lower jaw of 8. floridanus 

 were known, the two species would be still more widely separated. 



Smilodon neogaeus is a larger species than 8. californicus, 

 but in general has the same proportions. The main differences 

 are. the greater anteroposterior diameter of the upper canine, 

 the possession of a single-rooted P 3 , the greater length of the 

 inferior diastema, or the posterior position of P 4 and M x on the 

 mandible, and the smaller size of M 1 in 8. neogaeus, and the 

 heavier character of the jaw and small flange of 8. californicus. 



The measurements of the cranium of 8. neogaeus are in the 

 main larger than in 8. californicus, with the exception that the 

 canine has a greater anteroposterior diameter and a somewhat 

 less transverse diameter. The most interesting comparison is 

 drawn between the mandibles of these species. It will be noticed 

 that depth of each mandible is the same, while the length in 8. 

 neogaeus is greater by 30 mm. The difference in form and size 

 is almost solely in increased length of the region of the diastema 

 in neogaeus. 8. californicus was evidently a much shorter faced 

 form than the South American cat. The coronoid process is also 

 farther forward, but is broader. P 3 is absent in californicus, but 

 is in some cases represented by a single-rooted tooth in neogaeus. 

 The character of the symphysial region is also different, that of 

 the South American form slanting backward at a considerable 

 angle and lengthening the region of contact, while in the Cali- 

 fornia specimen the slant downward and backward is not so 

 marked and the region of contact forms a large oval surface 

 extending considerably below the ramus. 



Smilodon necator Lund 8 is of the same size as neogaeus, but 

 differs from it in the breadth and length of face and the greater 

 size of teeth, except the superior canine, which is smaller. 8. 

 californicus agrees with 8. necator in the dental formula, but 

 outside of this character it shows no resemblances other than 

 those of 8. neogaeus. 



8 K. Danske. Vidensk. Selskabs. AfhancU. lx, pp. 137-208, Pis. XXVIII- 

 XXXVIII. 



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