1921] Frick: Faunas of Bautista Creek and San Timoteo Cafion 381 



comparison with elk-like forms though no such cervid is yet known 

 from so early an American horizon. 



The lower molar (no. 23408, figs. 97a-97c) is of long-crowned, 

 antelopine form, resembling a tooth from Thousand Creek which has 

 been tentatively referred to Sphenophalos Merriam.°* Anteroposter- 

 iorly it is longer than the Nevada tooth, and the corresponding teeth 

 of the living antelope, but transversely is somewhat narrower. Other 

 slight differences between the specimens and teeth of Antilocapra are 

 the somewhat greater development of the styles, and the absence of the 

 strong backward inflection of the inner tooth lobes. 



Comparative Measurements of Teeth No. 12604 



referred to 

 Sphenophalos 



No. 23408 Antilocapra* or Ilingoceros* 

 M5, anteroposterior diameter of crown.... 16.4 mm. 14. 4 mm. 14.5 mm. 



Mj, transverse diameter of crown 7.3 7.7 7 



* Teeth are but slightly worn and the measurements are taken at the middle of the crown. 



Though the anterior crescent of the third upper molar (no. 23407. 

 fig. 100) has disappeared, and only a trace of the posterior crescent 

 remains, the tooth is still noticeably long-crowned. The specimen is 

 of the same relative proportions as no. 23408 (figs. 97a-97c) and is 

 believed to represent the same species. The inner lobes, in a more 

 modified degree than in specimen 23408, are less angular and less 

 forwardly directed than those of the otherwise very similar la.st 

 superior molars of Antilocapra. 



Comparative Mea.surements 



Mature male 



antelope Old 



Univ. Calif, specimen 



Mus. Vert. Univ. Calif. 



Zool. Coll. Vert. 



No. 23407 no. 8298 Pal. no. 19231 



M2, anteroposterior diameter 20.3 mm. 20 ram. 19.5 mm. 



M.-, transverse diameter 10 10 10 



The portion of an upper molar, no. 23406 (figs. 98a-98c), and the 

 shell of a second, no. 23780 (fig. 99), from Univ. Calif, loc. 3266, are 

 long-crowned and of the general relative proportions of the former 

 teeth and may represent the same species. Tooth no. 23406 is con- 

 siderably worn and in size lies intermediate between two specimens 

 from Thousand Creek. The styles project less than in the present day 

 pronghorn. 



5* Merriam, John C. Tertiary Mammal Beds of Virgin Valley and Thousand 

 Creek of Northwestern Nevada. Univ. Calif. Publ., Bull. Dept. Geol., vol. 6, 

 pp. 285-292, 1911. 



