EXPLANATION TO PLATE IV. 



Figs. 1. 2. Corvus corax sinuatus, Wagler. American Raven. 



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



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



Figs. 8, 9, 10, 11, 12. Corvus americanus, Audubon. American Crow. 1 



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



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



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



■Figs. 21, 33. Corvus americanus, Audubon. See Plate V. 



