EXPLANATION TO PLATE IV. 



Figs. 1. 3. Corvus oorax sinuatus, Wagler. American Raven. 



Fig. 3. CorvTis corax principalis, Ridgway. Northern Raven. 



Figs. 4, 5, 6, 7. Oorvus cryptoleucus, Couch. White-necked Raven. 



Figs. 8, 9, 10, 11, 13. Corvus amerioanus, Audubon. American Crow.' 

 Figs. 13, 14. Corvus americanus floridanus, Baird. Florida Crow. 



Fig. 15. Corvus caurinus, Baird. Northwest Crow. 



Figs. Id, 17. Corvus ossifragus, Wilson, Fish Crow. 



'Pigs. 31, 32. Corvus americanus, Audubon. See Plate V. 



