254 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



square miles. The surface of the summit is undulating, pre- 

 senting on the south side a steep face, several hundred feet 

 in height, covered with debris^ rendering it almost inaccessi- 

 ble. This plateau is covered with excellent grass, and gives 

 origin to numerous springs, all of which dry up within a 

 short distance of their source. As a whole, this district is 

 very arid, and almost destitute of tree vegetation. 



The total number of stations made by Mr. Bechler, in the 

 district assigned to him, w^as forty, and the entire area about 

 3000 square miles. Barometric observations were made when- 

 ever needed, and about 2000 angles of elevation and depres- 

 sion with fore and back sights, so that the material for ob- 

 taining the correct altitudes is abundant. 



The rocks of this district embrace all the sedimentary for- 

 mations yet recognized by the investigators who have studied 

 the resfion that lies between the Park Rancfe and the Great 

 Salt Lake, namely, from the Uintah quartzite (which under- 

 lies the carboniferous) to the group or latest tertiary, in- 

 clusive. Not only have the geographical distributions of 

 these formations been mapped, but all the displacements of 

 the strata have been traced and delineated, the latest-named 

 investigations bringing out some interesting and important 

 facts in relation to the orographic geology of the region, 

 especially as regards the eastern termination of the great 

 Uintah uplift, and the blending of its vanishing primary 

 and accessory displacements with those of the north and 

 south range above mentioned. Much information was also 

 obtained concerning the distribution of the local drift of that 

 region, the extent and geological date of outflow of trap, etc. 



The brackish water-beds at the base of the tertiary series 

 containing the characteristic fossils were discovered in the 

 valley of the Yampah. They are thus shown to be exactly 

 equivalent with those now so w^ell known in the valley of 

 Bitter Creek, Wyoming Territory. These last-named local- 

 ities were also visited at the close of the season's work, and 

 from the strata of this horizon at Black Buttes station three 

 new species of Unio were obtained, making six clearly dis- 

 tinct species in all that have been obtained, associated to- 

 gether in one stratum, at that locality. They are all of either 

 distinctively American types or closely related to species 

 now living in American fresh waters. They represent, by 



