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University of California Publications in Geology [Vol.9 



HIPPARION CONDONI, n. sp. 

 In the collections of Professor Thomas Condon, formerly of the 

 University of Oregon, there are two specimens representing a proto- 

 hippine horse of Hipparion type obtained from sedimentary deposits 

 of eastern Washington. The Ellensburg formation, in which these 

 remains were found, has generally been considered as Miocene on 

 the basis of its flora and is commonly correlated with the middle 

 Miocene Mascall formation of the John Day basin in eastern Oregon. 

 The material obtained by Professor Condon is of unusual interest, as 

 it represents the only available mammalian remains from the Ellens- 

 burg beds. 



Fig. 4. Hipparion condoni, n. sp. P 4 and M„ no. 672, Univ. Oreg. Col. Type 

 specimen, natural size. Outer and occlusal views. Ellensburg, Washington. 



Fig. 5. Hipparion condoni? n. sp. Lower incisors, no. 668, Univ. Oreg. Col. 

 Natural size. Ellensburg, Washington. 



Of the two specimens from Ellensburg one (fig. 4) consists of two 

 lower cheek-teeth (no. 672, Univ. Oregon), the other is the anterior 

 portion of a lower jaw with five incisors (fig. 5) (no. 668, Univ. 

 Oregon). Both specimens are partly covered with a matrix consisting 

 of moderately coarse, gray sandstone. It is to be presumed that both 

 specimens are from the same locality. 



The lower cheek-teeth represent P 4 and M r The teeth are hypso- 

 dont, but appear to be considerably worn. In their present stage of 

 wear, they are not longer than the crowns of some of the advanced 

 Merychippus forms from the late Miocene. In an unworn state they 



