Zoology 7 1 5 



Still more important in some respects, although less re- 

 plete with startling novelties, were two volumes emanating 

 from the pen of Spencer F. Baird, then Assistant Secretary 

 of the Institution. Many new species of mammals and birds 

 had been collected by the naturalists of the Pacific Railroad 

 surveys, and the identification and correct classification of the 

 material obtained necessitated comparisons and consequent 

 studies of most of the species of the entire continent. To 

 such an extent was this the case that Baird deemed it expe- 

 dient to extend his researches to cover all the North Ameri- 

 can material described or contained in the Institution. The 

 result was the preparation and publication of two massive 

 quarto volumes comprising all that was known systematically 

 of the mammals and birds of America north of Mexico. 

 These volumes formed the eighth and ninth of the Pacific 

 Railroad Reports. 



Extra sheets of the text of both of these volumes on mam- 

 mals and birds were subsequently published in connection 

 with the plates already issued (often retouched and consider- 

 ably altered) and some new ones. Copies of the plates pub- 

 lished in connection with the reports of the United States 

 and Mexican Boundary Survey were also incorporated. 



The United States and Mexican Boundary Survey had 

 been organized for the delimitation of the boundary between 

 the United States and Mexico under the conditions provided 

 for in the treaty of 1853. Major W. H. Emory was the 

 United States commissioner, and the field work of the com- 

 mission was performed in 1854 (December) and 1855. The 

 naturalists of the survey were John H. Clark and Arthur 

 Schott. The mammals, birds, and reptiles were reported on 

 by Professor Baird, and the fishes by Doctor Girard. The 

 text in this report was less noteworthy than the plates : the 

 latter were numerous, and many of them very well executed, 



