WASHAKIE BASIN. 215 



in fossil remains. Some layers contain a great number of fresh-water 

 shells, both Unio and Goniohasis, and others abound in leaf-impressions, 

 among which are fragments of tropical plants of the palm species. From 

 the disintegrated material of some of the beds were obtained also a few 

 fish-vertebrae. Among the shells were recognized 



Unio teUinoides. 



Gonidbasis tenera. 



Goniobasis nodulifera. 



Goniohasis Carteri. 

 The beds are here nearly horizontal, having a dip of 2° to 3° to the 

 southward, and are overlaid by more arenaceous beds, with intercalated 

 clays, whose disintegration produces a light shifting soil, which conceals 

 most of the outcrops. 



To the south of the stage-road, west of Barrel Springs, is a narrow, east 

 and west ridge, whose irregular, serrated outline forms a striking contrast 

 to the usual level summit line of the bluff ridii^es of this reoion. It is 

 composed of greenish-drab sandstones, containing some admixture of clay, 

 which form the base of the Bridger Eocene in this region. This ridge rises 

 toward the east,, having its culminating point in Haystack Mountain, which 

 has an elevation of about 900 or 1,000 feet above the surrounding plains. 

 It is made up largely of coarse, loosely-aggregated sandstones, composed of 

 quartz grains, reaching the size of a duckshot. Interstratified with the 

 sandstones are clayey beds, which toward the base seem to predominate 

 over the arenaceous material. Along the northern base of this line of cliffs 

 are found fragments of turtles, which have been washed out of the decom- 

 posed strata. On the northern face of Haystack Mountain was found tlie 

 petrified trunk of a large coniferous tree, lying across one of the narrow 

 ravines, a length of about 15 feet being thus exposed, either end being 

 still imbedded in the sandstone. It is about 3 feet in diameter where 

 uncovered, which is probably a considerable distance above its base. The 

 woody appearance is very well preserved, the exterior being whitened, so 

 that the resemblance to the weathered trunk of a dead tree is almost 

 perfect; portions of the bark are covered with yellow spots, apparently of 

 exuding gum,- retaining their original coloring. The interior is a black. 



