FALCONID-E DIURNAL RAPTORES. 459 



object of its pursuit so suddenly as to render hopeless any attempt 

 to escape. It has frequently been known to seize and kill a bird 

 so large that it was unable to carry it, and had to drop to the 

 ground. 



"In nearly every instance the nest of this Hawk has been con- 

 structed in trees. It is usually large in proportion to the size of 

 the bird, and its materials are somewhat elaborately put together; 

 it is composed chiefly of large sticks and twigs, and the whole 

 platform is covered with a thin lining of dry leaves, mosses, grass, 

 etc. Mr. John Krider, of Philadelphia, found a nest in New Jer- 

 sey, in the vicinity of that city, which was built on the edge of a 

 high rock." 



SUBGENTJS Astur LACEPEDE. 



Astur LACEP. Menag. Mus. Hist. Nat 1815, 505. Type, Falco palumbarius LINN. 



Notwithstanding the vast difference in size between the typical 

 species of Astur and those of Accipiter, the details of structure are 

 essentially the same, the greatest differences between them being 

 very nearly bridged over by species of intermediate size and struc- 

 ture. 



North America possesses a single species of the subgenus Astur, 

 and this is a near relative of A. palumbarius, but sufficiently dis- 

 tinct, having the plumage of the lower parts much more delicately 

 penciled and the color of the upper parts more bluish than in the 

 European species. 



Accipiter atricapillus (Wils.) 



AMERICAN GOSHAWK. 



Popular synonyms. Blue Hen Hawk or Chicken Hawk. 

 Falco atricapillus WILS. Am. Orn. ii, 1808, 284, pi. 52. flg. 3. 



Astur atricapillus BP. 1830. NUTT. Man. 1833, 85. CASS. in Baird's B. N. Am. 1858. 15. 

 BAIBD, Cat N. Am. B. 1859. No. 14.-CouES, Key. 1872. 218; Check List. 1874. No. 340; 

 2d ed. 1882. No. 496; B. N. W. 1874, 338,-RiDOW. Norn. N. Am. B. 1881, No. 433. 

 Astur palumbarius var. atricapillus B. B. & R. Hist N. Am. B. iii, 1874, 237. 

 Falco palumbarius "LiNN." AUD. B. Am.pl. 141; Orn. Biog. ii, 1834, 241 (nee LINN.). 

 Astur palumbarius AUD. Synop. 1839,18; B. Am. i. 1840, 95. pi. 23. 

 Accipiter (Astur) palumbarius Sw. & RICH. F. B.-A. ii, 1831, 39, j>l. 26. 



