1916] Merriam: Mammalian Remains from the Tejon Hills 



125 



PROTOHIPPUS TEHONENSIS Merriam 



P. tehonensis Merriam, Univ. Calif. Publ. Bull. Dept. Geol., vol. 9, p. 52, figs. 

 4a and 4i) and 4c, 1915. 



This species is represented by a single upper molar, no. 21779, the 

 type specimen of the species (figs. 14a to 14c), found at locality 

 2751 in the Chanac formation of the Tejon Hills at the southern end 

 of the Great Valley of California. 



The West- American types to which Protohippus tehonensis shows 

 closest resemblances are a form referred to Pliohippus or Protohippus 

 from the lower portion of the Jacalitos-Etche- 

 goin section of the North Coalinga" region, and 

 a species near Protohippus represented by speci- 

 men 21423 from the Barstow Upper Miocene of 

 the Mohave Desert. No teeth from the North 

 Coalinga form have yet been obtained which 

 correspond in position in the jaw to the type of 

 P. tehonensis, so that a close comparison is not 

 possible. The Barstow species is near the Tejon 

 Hills form in many respects, but seems speci- 

 fically distinct. 



A lower cheek-tooth, no. 21484 (fig. 15) col- 

 lected at Comanche Creek in the Tejon Hills by 

 R. C. Stoner has a short metaconid-metastylid 



Fig. 15. — Protohippus column with the valleys anterior and posterior 

 or Merychippus. Pr"?, , ,, . , . — . 



outer and occlusal views to this column narrower than m Barstow Mio- 



no. 21484, natural size. eene species which have been considered as very 

 Chanac formation, Com- 

 anche Creek, southern advanced Merychippus. In the first discussion 



Valley, Calif omfa° aqUin of the Te j° n Hills faunal ° the writer assumed 

 that the species represented by this tooth might 

 be more progressive than the most advanced Barstow form, and spe- 

 cifically distinct from it. This tooth may represent a Protohippus 

 differing from the Barstow Miocene forms to much the same degree 

 as the upper cheek-tooth in the type of Protohippus tehonensis differs 

 from them. It is possible that the specimen represents P. tehonensis. 

 The proof of this will require more and better material than that now 

 available. 



11 See Merriam, J. C, Tertiary Vertebrate Faunas of the North Coalinga 

 Region, Trans. Amer. Phil. Soc. N.S., vol. 22, part 3, p. 27, figs. 28a and 286, 1915. 

 io Merriam, J. C, Univ. Calif. Publ., Bull. Dept. Geol., vol. 8, p. 287, 1915. 



