1913] Merriam: Fauna of Orindan and Siestan 



375 



EQUIDAB 



Remains of early horses have been found at two localities in 

 the Orindan beds. No specimens representing this group are 

 certainly known from the Siestan. It is stated that bones of a 

 horse were found in a shaft sunk in Siestan beds on Frowning 

 Ridge near the upper end of Telegraph Canon, but the writer 

 has been unable to obtain any definite information as to this 

 occurrence. Two teeth representing species near Neoliipparion, 

 and an astragalus that may well represent a horse of Miocene 

 age have been obtained near Bolinger Canon. A single tooth 

 was obtained by Mr. J. P. Buwalda from Mr. Williams, who 

 discovered it in extensive Orindan exposures about two and one- 

 half miles from the mouth of Tassajara Canon, on the southwest 

 side of Mount Diablo. The specimen from Tassajara Canon and 



Figs, la to lc. Neohipparion, sp. Upper premolar. No. 19830, natural 

 size. Orindan beds, southwest of Mount Diablo. 



Fig. 2. Neohipparion or Merychippus. Upper premolar. No. 1323, 

 natural size. Orindan?, west of Bolinger Canon. 



Figs. 3a and 3b. Hipparionf ? ) or Neohipparion. Upper cheek-tooth. 

 No. 1324, natural size. Orindan?, near Bolinger Canon. 



