Vol. 4] Merriam. — A New Sabre-tooth from California. 



173 



damaged, but there appears to have been neither metaconid nor 

 heel present. The transverse diameter is relatively large and the 

 tooth considerably heavier than in Smilodon ncogaeus. 



Of the North American species Machaerodus gracilis Cope, 

 from the Port Kennedy Fissure, resembles the California!) species 

 in the form of P.,, while the heel of Mj has almost disappeared. 

 M. ischyrus differs from this species particularly in the short- 

 ness of the diastema and probably of the whole jaw, in the 

 absence of a posterior basal cusp on P 4 , and in the complete 

 reduction of the heel of M P Judging' from Cope's figure* of 

 the type of M. gracilis the mandibular flange is not as prom- 

 inent and the jaw as a whole somewhat weaker than in M. 

 ischyrus. 



Smilodon fatal is Leidy, f rom the Quaternary of Texas, known 

 only from the dentition of the upper jaw, if a typical Smilodon 

 as it appears to be, would differ in the structure of P 4 , as also 

 of the mandible in general. 



Dinobastis scrus Cope, from the Texas Quaternary, does not 

 differ from M. ischyrus greatly in size and had large external 

 incisors with a. moderately elongated superior canine. The 

 superior sectorial has a large protostyle, but the basal cusp 

 anterior to this is rudimentary. This means that, as in Hoplo- 

 phoneus, the posterior part of P 4 opposing it was probably rel- 

 atively shorter than in Smilodon. The characters mentioned all 

 suggest correlation with M. ischyrus, although there would at 

 present be no justification for considering them identical. 



Felis imperialis Leidy, from the Quaternary of Middle Cali- 

 fornia, is known only from a fragment of the upper jaw with the 

 third premolar. It is evidently also a short-faced form but seems 

 to have been, as far as can be determined, of the true Felis type. 



Machaerodus catocopis Cope, from the Loup Fork of Kansas, 

 has a relatively larger inferior canine, a deeper mandibular 

 flange, and is much narrower across the symphysis. 



Machaerodus palaeindicus Bose, from the Siwalik beds of 

 India, very closely resembles this species in size, in shortness 

 of the diastema, and in the form of the anterior portion of the 



*E. D. Cope. Jouv. Philad. Acad. Nat. Sc., 2nd Ser., Vol. 11, PI. 

 20, fig. 1. 



