42 NORTH AMERICAN OOLOGY. PART I. 



illustrate the egg of this Hawk. The specimen represented in my drawing was 

 taken in Louisiana by Dr. James Trudeau, to whom I am indebted for the copy. 

 It measures, length, lj\ inches; breadth, 1| inches. Its ground color is a greenish- 

 white, and the egg is thickly marked over its entire surface by irregular blotches 

 of oli^e-brown, dark slate-green, and purplish-drab colors. 



CIRCUS HUDSONICUS. 



Falco hudsonicus, Linn. Syst. Nat. I, 1766, 128. 

 Faico uliginosus, Gmelin, Syst. Nat. I, 1788, 278. 



WiLS. Am. Orn. VI, 1812, 67, pi. li, fig. 2, 

 Faico ajancus, Bonap. Am. Orn. II, 30. 



" " NuTTALL, Manual, I, 1832, 109. 



AuD. Orn. Biog. IV, 1838, 396, pi. ccclvi. 

 Buteo cyaneus. Rich. & Swains. F. B. A. II, 1831, 55. 

 Strigiceps uliginosus, Bonap. Geog. and Comp. List, 1838, p. 5. 

 Circus cyaneus, Aud. Synopsis, 1839, p. 19. 



" " " Birds of America, I, 1840. 



Falco europogisius, Daudin, Traite, II, 110. 

 Circus hudsonicus, Cassin, Syn. N. A. Birds (Illust. Birds of Cal.), 1854, p. 108. 



VoLG. — The Marsh-Hawk. American Hen- Harrier. The Common Hen-Hawk. 



This Hawk is one of the most widely distributed birds of Xortli America, breed- 

 ing from the fur regions around Hudson's Bay to Galveston, Texas, and from Mas- 

 sachusetts to Oregon and California. It is abundant everywhere, with the exception 

 of the southeastern portion of the United States. Sir John Richardson speaks of 

 it as so common on the plains of the Saskatchewan, that seldom less than five or 

 six are in sight at a time (in latitude 65°). Mr. Townsend found it on the plains of 

 the Columbia River and on the prairies bordering on the Missouri. The Viacennes 

 Exploring Expedition obtained specimens in Oregon. Dr. Gambel speaks of it as 

 common in California, and Dr. Heermann also found it abundant in that State. Dr. 

 Sucldey's party obtained specimens in Minnesota ; Captain Beckwith's, in Utah ; Cap- 

 tain Pope, Lieutenant AVhipple, and Dr. Henry, in New Mexico ; and Lieutenant 

 Couch, in Tamaidipas, Mexico. Dr. Woodhouse met with it abundantly from the 

 Mississippi River to the Pacific Ocean, throughout the summer, showing conclu- 

 sively that it breeds in those different sections of country. De la Sagra, Lembeye, 

 and Dr. Gundlach all give it as a bird of Cuba, but not as breeding there. 



Richardson (Fauna Boreali- Americana, p. 55) states that all the nests of this Hawk 

 observed by him were built on the ground by the side of small lakes, of moss, grass, 

 feathers, and hair, and contained from three to five eggs, of a bluish-white color, and 

 unspotted. They measured an inch and three quarters in length, and were an inch 

 across where widest. In regard to the position and manner of constructing the nest, 



