G16 REPORT UNITED STATES GEOLOGICAL SURVEY. 



Agnostus joscpha, Hall. 



Conocoryphe (several species). 



Bathyurellus (Asaphiscus) bradleyi Meek. 



Bathyurus saffordi Billings. 



Bathyurus or Dikeloceplialus. 



Bathyurellus (Bihelocephalus) (?) truncatus Meek. 



Asaphus (Mcgalaspii;) (?) gonioccrcus Meek. 



Tiie fossils collected by us during - the season of 1877 have not been 

 carefully studied as yet, so that the list following is not complete. It 

 is probable that many of them are identical with some collected by Pro- 

 fessor Bradley. 



List of Silurian fossils. 



Bathyurus and other ob- ) Head of the middle canon of Bear River at the 

 obscure Silurian forms. ] South end of Gentile Valley. 



Biscina sp. ? Canon east of Smithfield. 



OrtMs like 0. plicatella ") 



Orthis like 0. testudinata. \ Forks of Logan River, in canon near Sta- 

 Several species of trilo- j tion 125. 

 bites. } 



Conocoryphe sp. ? ~) 



Bikelocephalus sp. % I station 133 between Marsh and Cottonwood 



nSSSTSL*? SP [ Creeks, north of Cache Valley. 



Oholella sp. 1 

 Biscina sp.? 



Bathyurus sp.? ~\ Mouth of Weston Creek Canon on west side 



BTyolithes sp. % ! of the Cache Valley, at the south end of the 



Acrotreta. sp. % j northern portion of Malade Range, near sta- 



BiscinaspA \ tion 130. 



Orthis si). ? 



) Head of Station Creek, west of Bear River 

 ) Range. 



CARBONIFEROUS. 



In the eastern and middle portions of the district the Carboniferous 

 formation occupies a prominent and important position, the outcrops 

 representing the important ranges, into whose structure they largely 

 enter, sometimes making up whole ranges. They are the lowest rocks 

 exposed in the Wyoming and Salt River Ranges. In the Bear River 

 Range the Carboniferous limestones overlie conformably the Silurian, 

 and we do not have the entire upward extension of the beds shown. 

 I shall now briefly recapitulate the most important exposures of the 

 Carboniferous. 



Labarge Mountain. — At this locality we have two isolated masses of 

 Carboniferous rocks. The most prominent was named after the stream 

 just south of it and is a monoclinal ridge surrounded by Tertiary strata. 

 There are between 400 and 500 feet of limestones exposed on the eastern 

 face of the mountain, and a few indistinct fossils of Carboniferous aspect 

 were seen in the beds on the siunmit. Whether this mountain and the 

 northern smaller mass are the remnants of an anticlinal, or whether they 



