VI . INTEODUCTORY. 



present, in connected form, your labors in the field of ornithology, but 

 would illustrate more clearly the ornithological characteristics of the 

 region in question, by aftbrding the means of comparing and contrasting 

 the distribution of species iu the several special areas. The specimens 

 collected on these Expeditions having been incorporated by Prof. S. F. 

 iiaird* iu his general Report upon the Ornithology of the various Pacific 

 liailroad Explorations, in 1858, and having been made the subject of a 

 Report, with field-notes, by yourself, t in 1861, are not tabulated iu the 

 Xiresent volume, but will be found catalogued by the National Museum 

 number, with indication of locality where obtained. 



At a second interval of five years, namely, iu 1872, you intimated to 

 me your desire to publish a treatise on the Ornithology of the Western 

 Territories you had then explored, suggesting that the still unpublished 

 report I had long since made to you might be avaikible in substance for 

 this purpose, in connection with an elaboration I was desired to make of 

 the material collected under your direction iu various parts of the West, 

 during 1870| and 1872, § by Mr. J. Stevenson, Mr. H. D. Smith, and Mr. 

 C. H. Merriam. Without instituting comparisons between these collec- 

 tions, all of which proved to be of interest and importance, I know that 

 1 simply express your own convictions in alluding to the uuilagging 

 energy, zeal, and perseverance which have marked Mr. Stevenson's 

 course during his long and continuous association with you in develop- 

 ing the Zoology of the West. Having examined the collections for my 

 own information, and being then stationed, as I am now, in the region 

 under consideration, where I could supplement your results by my owu 

 personal observations, 1 willingly undertook the task. The copy now 

 furnished you for publication by the Survey is the result. It is believed 

 to be fairly abreast of the present state of the science ; and the hope is 

 indulged that, during its passage througb the press, opportunity may 

 offer of bringing it up to the very date of issue, by incorporation of 

 the latest published items bearing on the subject in hand. 



* Reports of Explorations aud Surveys to ascertain the most practicable and econ- 

 omical Route for a Railroad from tbe Mississippi River to the Pacific Ocean. Made 

 under direction of tbe Secretary of War, in 1853-'56, according to acts of Congress of 

 March 8, 1853, May 31, 1854, and August 5, 1854. Vol. IX. Birds : By Spencer F. Baird, 

 Assistant Secretary Smithsonian Institution, with the co-operation of John Cassiu aud 

 George N. Lawrence. Washington, D. C, 1858. [Quoted in tbe present volume as 

 "Bd., B. N. J."] 



t Ou tbe Geology aud Natural History of the Upper Missouri, being the substance of 

 a Report made to Lieutenant G. K. Warren, T. E., U. S. A. By Dr. F. V. Hayden, Sur- 

 geon and Geologist of the Expedition to the Upper Missouri and Yellowstone, imder 

 command of Lieut. Warren. — Transactions of the American Philosophical Society, Vol. 

 XII, Art. i, pt. iii, Cb.ap. xvi, pp. 151-17(j. 4to. Philadelphia, 1862. [Quoted in the 

 present volume as " Hayd. 7?<'jj."] 



{ A List of Mammals and Birds collected in Wyoming Territory by Mr. II. D. Smith 

 and Mr. James Stevenson, during the Expedition of 1870. < Rep. U. S. Geol. Surv. 

 Ter. 1870, pp. 4()l-466. 8vo. Washington, 1871. 



§ Report on Mammals and Birds of tbe Expedition [of 1872]. By C. H. Merriam. 

 < Sixth Ann. Rep. U. S. Geol. Surv. Ter. 1872, pp. G131-715. 8vo. W^isbiugtou, 1873. 



