342 CHARLES D. WALCOTT 



The strata of the lake beds section three miles up the canyon 

 are largely a fine calcareous deposit, with more or less arenaceous 

 and argillaceous matter in the form of fine sand. Some of the 

 white beds are made up almost entirely of the remains of fresh- 

 water shells of the following genera, as identified by Dr. W. H. 

 Dall : Valvata, Planorbis, Pisidium ?, and possibly Amnicola and 

 Pampholyx. The species are undetermined, but resemble Val- 



FiG. 2. View of Waucobi embayment from the foothills of the Sierra Nevada. 

 a Lake beds at the level of Ovi^en's Valley ; b, contact of lake beds with the Cambrian 

 quartzites ; c, point above the highest exposure of the lake beds in Waucobi Canyon ; 

 d, point of Inyo Range overlooking Deep Spring Valley on the east ; e, Waucobi 

 Mountain south of Waucobi Canyon. 



vata siiicera Say and Planorbis parvus Gld. "Any of them might 

 be recent or Pliocene ; my impression from the mass is that they 

 are Pleistocene." 



As the beds approach the steeper slope of the mountain, 

 about ten miles above the mouth of Waucobi Canyon, the sedi- 

 ments become coarser and coarser, and brown arenaceous beds 

 predominate over the drab and light gray sediments. Near the 

 contact with the quartzites, a little below Devils Gate, bowlders 

 of the quartzite a foot or more in diameter occur in the coarse 

 sediments, and the contact of the lake beds and the Cambrian 

 quartzites is finely shown on the south side of the canyon. 



At a point about two miles above Devils Gate, and 3000 feet 

 above the lowest lake bed observed in Owens Valley, there is a 



