526 



University of California Publications in Geology [Vol. 10 



tively large size of M T suggest affinity with the Pliocene genus Ischyro- 

 smilus represented in the Ricardo and in heds referred to the Tulare, 

 of California. Machaerodus palaeindicus of the Siwalik beds differs 

 from all of these forms in possession of a two-rooted Pg. 



While it is true that Pg may be well developed in adult individuals 

 of Smilodon calif ornicus as in the Idaho specimen, this occurrence is 

 so exceptional that the chance of having this tooth occur in an isolated 

 individual would be very small. 



So far as the evidence of this sabre-tooth is concerned, it might 

 be presumed to suggest a somewhat earlier geologic stage than that of 

 8. calif ornicus. It should also be noted that the Idaho form is much 

 larger than the specimens from the Ricardo and the Tulare and might 

 therefore be later than the horizons represented by the Ricardo and 

 Tulare faunas. 



Comparative Measurements 











S. Cali- 











fornicus 





r. 



ischyrus 



I. osborni 



No. 22180 





No. 22343 : 



STo. 8140 



No. 19476 



Raneho 





Idaho 



Tulare 



Ricardo 



La Brea 



Height of mandible below anterior end of Pj.. 



49 mm. 



41.2 



34.7 



40.3 



Thickness of mandible below anterior end 











of P 5 



00 







18.3 



Height of mandible below anterior end of P5.. 



52 



41.4 



36 



37 



Length anterior side inferior canine to pos- 















107 



81 



134.2 



Length anterior side P5 to posterior side 











of Mi 



71.6 



61.7 





65.5 



Length of diastema 



46.4 



33.5 



26.5 



51.5 



C, anteroposterior diameter 



19 2 



14.5 



nlO 



16.2 



P5, anteroposterior diameter 



10 



7 



a6.4 



9.9? 



Pj, anteroposterior diameter 



23.7 



20 



16.7 



25 



Mi, anteroposterior diameter 



33.2 



28.5 



24 



30 



Mj, greatest transverse diameter 



13.5 



15 



11 



15 



a, approximate. All measurements of teeth approximate on neck or base of crown. 



NEOTKAGOCERUS LINDGRENI, n. sp. 



Type specimen, a horn-core, no. 3941, collection of U. S. Geological Survey 

 assembled by W. Lindgren. Found three miles east of Boise, Idaho, by Edward 

 S. White. Occurrence doubtfully in Idaho beds. 



The horn-core (figs. 2a to 2c) obtained by Lindgren from the 

 Boise region represents an antelope of the Tragocerus type and ap- 

 proaching the characters of the Snake Creek Pliocene form described 

 as Neotragoccrus improvisus by Matthew and Cook. 3 



3 Matthew, W. D., and Cook, H. J., Bull. Amer. Mus. Nat. Hist., vol. 26, 

 p. 413, 1909. 



