XXVIII REPORT UNITED STATES GEOLOGICAL SURVEY. 



leveled off and obscured by soil debris that they can nowhere be recog- 

 nized or distinguished from each other except by their fossils. Chance 

 exposures at long intervals, and the sinking of occasional wells, have re- 

 vealed the peculiar fossils of that coal-bearing formation at points as far 

 out on the jjlains as Western Kansas, and it is reasonable to infer that 

 the formation has a still wider range than is thus indicated by such facts 

 at present known. It i^ therefore reasonable to expect to find coal over 

 a large region far out on those plains which is wholly destitute of all 

 other kinds of fuel. Important districts within that region will thus be 

 rendered profitably habitable, which would otherwise be worthless. 



The Survey is under great obligations to Dr. Elliott Coues for his 

 continuous and able superintendence of the publications of the past 

 year. He was so fully occupied that he could not perform any extended 

 zoological work in the field. A synopsis of the numerous publications 

 of the Survey will be prepared by him for the Annual Eeport for 1878. 



The thanks of the Survey are also due to Mr. James Stevenson, ex- 

 ecutive officer, for his able management both in the field and in the office. 



y 



Very respectfully, your obedient servant. 



United States Geologist 

 To the Secretary of the Interior. 



F. V. HAYDEN, 



