UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 9, No. 4, pp. 49-58, 12 text figures Issued November 22, 1915 



NEW HORSES FROM THE MIOCENE AND 

 PLIOCENE OF CALIFORNIA 



BY 



JOHN C. MERRIAM 



CONTENTS 



PAGE 



Introduction 49 



Merychippus sumani, n. sp 49 



Merychippus intermontanus, n. sp 50 



Protohippus tehonensis, n. sp 52 



Hipparion mohavense callodonte, n. var 54 



PlioHppus fairbanksi, n. sp 55 



Equus or Pliohippus, probably new ofi 



INTRODUCTION 



In a study of the Tertiary mammalian faunas of California several 

 new species of protohippine horses have appeared. The designation 

 of these forms is desirable at this time in order that reference to the 

 species may be possible in publications which will appear in advance 

 of the papers including detailed descriptions of the new forms. 



MERYCHIPPUS SUMANI, n. sp. 

 Merychippus, near calamarius. Merriam, J. C, Univ. Calif. Publ. Bull. 

 Dept. Geol., vol. 6, p. 168, pi. 29, figs, la to lc, 1911. 



Type specimen, no. 21422. Barstow Upper Miocene, Mohave Desert, Cali- 

 fornia. 



Upper cheek-teeth much smaller than in typical Merychippus calamarius or 

 in M. intermontanus. Crowns of cheek-teeth considerably elongated, markedly 

 curved, and well cemented; height of the crowns often equal approximately to 

 twice their width. Protocone round, tending toward circular form in cross- 

 section, and discrete up to a stage of very advanced wear. Enamel bordering 

 the fossettes commonly more complicated than in any of the larger Merychippus 

 forms of the Barstow Miocene. 



