BIBLIOGKAPHY. 13 



cation of the second volume of the Fortieth Parallel Survey by Hague and Emmons, 

 setting forth the descriptive geology of the territory' examined by that organization. 

 Such portions of this work as relate to the Carboniferous of Colorado are discussed 

 below; but the volume by Clarence King on the systematic geology (Vol. I), which 

 was published the year following, is more advantageous in its arrangement 

 and comparisons. The brief discussion by Peale and Stevenson as to the age of the 

 Rocky Mountains is included in my bibliography, because, while not directly bearing 

 u23on the historical geolog}^ of the Paleozoic, it deals with factors which determine 

 the distribution and characteristics of sediments and faunas. 



In 1878 appeared the tenth annual report of the Haj'den survey — the fourth and 

 last volume dealing particularly with the geologj^ of Colorado. It contains reports 

 by Peale, Endlich, White, and Holmes, which, so far as they pertain to my subject, 

 are discussed in the resume. The same year was published the volume on system- 

 atic geology of the Fortieth Parallel Surve3\ In this volume King has assembled 

 with industry and discussed with judgment the facts available from many sources at 

 the time of his writing. The arrangement is such as to make it more convenient for 

 my purpose than the individual accounts upon which it is based, and these, therefore, 

 1 have as a rule laid aside in favor of King's more correlated work. 



In 1879 was published a preliminary report b}^ Stevenson on operations in Colo- 

 rado and New Mexico. In Colorado the only Carboniferous area touched on is. that 

 on the east side of the Sangre de Cristo Range, from Spanish Peaks to Costillo Peak. 

 The facts upon which this report is based are given in greater detail in a publication 

 which appeai'ed in 1881, and I have not, therefore, given it special consideration. The 

 paper by Henrich on the ore deposits of Leadville, which appeared this year, is the 

 first of the numerous series of short articles relating especially to the economic geol- 

 ogy of this great mining camp which were published for some time preceding and 

 immediately following the publication of Emmons's Leadville monograph. I will 

 include these in the bibliography, but not I'efer to them individuall}'. 



In 1880 Dutton issued a publication on the Permian of North America, in which 

 . he refers part of the Red Beds of Colorado, etc., to the Permian, the upper poition 

 being Triassic. Hayden expressed somewhat the same view the same year, in 

 describing the Twin Lakes and Teoealli Mountain. 



The most important work relating to this subject which appeared in 1881 was 

 Stevenson's report upon examinations in southern Colorado and northern New Mex- 

 ico, a preliminary account of which was published in 1879. The onh' Carboniferous 

 area in Colorado discussed in this paper is that along the east side of the Sangre de 

 Cristo Range from Spanish Peaks to Costillo Peak. 



A pajDer which appeared in 1883, "Notes on the geology and mineralogy of San 

 Juan County, Colo.," by T. B. Comstock, so far as it concerns m_v subject, is lai"gely 



