APPENDIX 



RIDGWAY, ROBERT. Nomenclature of North 

 American Birds chiefly contained in the United States 

 Museum. 



RIDGWAY, ROBERT. Notes upon American 

 Water Birds. 



RHOADES, SAMUEL N. Probable Causes of 

 Polygamy among Birds. 



RYDER, JOHN A. The Mechanical Genesis of 

 the Form of the Fowls' Egg. Illustrated. 



SHUFELDT, R. W. Progress in American Or- 

 nithology, I 886- I 895. 



STONE, WITMER. A Study of the Type Speci- 

 mens of Birds in the Collection of the Academy ol 

 Natural Sciences of Philadelphia, with a Brief History 

 of the Collection. 



STONE, WITMER. The Genus Sturnella. 



STONE, WITMER. Proper Name for the Western 

 Horned Owl of North America. 



STREETS, THOMAS H. A Study of the Imma- 

 ture Plumage of the North American Shrikes to show 

 their Descent from a Common Progenitor. 



TOWNSEND, C. H. Description of a New Eagle 

 from Alaska and a New Squirrel from Lower Cali- 

 fornia. 



TRIPPE, T. MARTIN. The Migration of Birds. 



TROWBRIDGE, W. C. A Discovery Regarding 

 the Purpose of the Emargination in the Primary Wing- 

 Feathers of Certain Birds. Illustrated. New York 

 Academy of Sciences. 



TROWBRIDGE, W. C. Mechanism of Flight in 

 Soaring Birds. 



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