92 THE CHICAGO ACADEMY OF SCIENCES. 



ica. It is much more common in the interior of the United States 

 and is only a casual visitant east of the AUeghanies. Its breed- 

 ing range is quite coincident with its geographical distributions 

 in the United States. 



Genus CIRCUS Lacep&de,"1801. 



Circus hudsonius (Linnaeus). Marsh Hawk. 



Falco hudsonius LiNN^us, S. N., ed. 12, I, 1766, 128. 



Circus hudsonius Vieillot, Ois. Am. Sept., I, 1807, pi. 9. 



Circus cyaneus var. hudsonius Cotjes, Key, 1872, 210. 



Circus cyaneus of some authors. 



Popular synonyms : Haeriek. Maesh Harbieb. R1Q-TAII.ED Hab- 



BIEE. AmEBICAN HaBBIEB. 



The Marsh Hawk is a resident species but is much more 

 common during its migrations than in other seasons. About two- 

 thirds of the birds observed within our limits are in the young 

 or reddish phase of plumage. As its name would indicate, it is 

 usually seen on marshes and on prairies. Its migrations usually 

 take place during the latter half of March and first half of April, 

 and in October and November. 



The range of this species includes the whole of North Amer- 

 ica, south in winter to Panama and Cuba. Its breeding range is 

 practically coincident with its geographical distribution, though 

 it nests quite sparingly in the eastern United States south of the 

 parallel of 40°. 



Genus ACCIPITER Brisson, 1760. 



Accipiter velox (Wilson). Sharp-shinned Hawk. 



Falco fuscus Gmelin, S. N., I, 1788, 280 {nee Fabricius, 1780). 

 Accipiter fuscus Bonapabte, Comp. List, 1838, 5. 

 Astur fuscus Audubon, Syn. 1839, 18. 

 Nisus fuscus Kaup., Mon. Falc. Cont. Orn., 1850, 64. 

 Falco velox Wilson, Amer. Orn., V, 1812, 116, pi. 45, fig. 1. 

 Accipiter velox Vigors, Zool. Journ., I, 1824, 338. 

 Popular synonyms: Little Swift Hawk. Pigeon Hawk. Bullet 

 Hawk. Slate-colobed Hawk. , 



This species is a variable and at times an abundant migrant. 

 Although these hawks are occasionally seen within our limits 

 throughout the summer, I h^ve no records of their having nested 

 here. They arrive early in March and depart late in October. 

 Mr. B. T. Gault informs me that on two occasions a Sharp-shinned 



