220 NORTH AMERICAN BIRDS. 



blotches were large and well marked ; iii the others, less strongly traced, but 

 quite distinct. 



The nest was found in a tract of low land, covered with clumps of sedge, 

 on one of which it had been constructed. It is descriljed as about the size 

 of a i)eck basket, circular, and couijiosed entirely of small dry sticks, " fin- 

 ished off or topped out with small Ijunehes of pine boughs." There was 

 very little depth to the nest, or not enough to cover the eggs from view in 

 taking a sight across it. " No feathers were found in or about it. It was 

 simply made of small dry sticks, about sbc inches tliick, with about one inch 

 of pine boughs for finishing off the nest." The eggs were found about the 

 20th of jMay. They contained young at least two weeks advanced, showing 

 that the bird began to lay in the latter part of April, and to sit upon her 

 eggs early in the following month. 



It will be tlms seen that the eggs of this Hawk vary greatly in size and shape, 

 and in the presence or absence of marking, varying in length from 1.75 to 

 2.00 inches, and in breadth from 1.25 to 1.50, and in shape from an almost 

 gobular egg to an elongated oval. Some are wholly spotless, and others are 

 very strongly and generally blotched with well-defined purplish-brown. 



This Hawk was found breeding in the Humboldt Valley by Mr. C. S. 

 M'L'arthy, on the Yellowstone by ^Ir. Hayden, at Fort Benton by Lieutenant 

 MuUan, at Fort Eesolution by Mr. Keunicott, at Fort Eae and at Fort Simp- 

 son by Mr. Ross, at La Pierre House by Lockhart, and on the Lower Ander- 

 son by Mr. ^MacFarlane. 



Genus NISUS, Cuvier. 



Accipitcr, Bris.s. 1760. (Type, Falco nisus, LiXN.) 



Nisus, Crv. 1799. (Same tj^ie.) 



Astur, L.^CKP. 1801. (Type, Fako palumbarius, Lisx. ) 



Diedolion, Savig. 1809. (Same type.) 



Dcedalium, Agass. (Same type.) 



Sparvius, ViEiLL. 1816. (Same type.) 



Jcrax, Leach, 1816. (Same type. ) 



Aster, Swains. 1837. (Same tj-pe.) 



Micrmiisus, Gray, 1840. (Type, Falco gabar, Daud.) 



Phabotypus, Glog. 1842. (Same type.) 



Hicrnspiza, 1844, Jcntspiza, 1851, and Tcraspiza, 1867, Kacp. (Type, Falco Hnus, 



Latham.) 

 Hieracospiza, Agas. (Same type.) 

 Nisaslur, Blas. 1844. (Same type.) 

 Urospiza, 1845, Urospizia, 1848, and Uraspiza, 1867, Kaup. (Type, Sparniis cirrJiocepha- 



lus, ViEILL.) 

 Leucoapiza, Kaup, 1851. (Type, Falco iioi-cE-liollaiidim, Gmel.) 

 Cooperaslur, BoNAP. 1854. (Type, Accipitcr cooperi, Bosap.) 

 Frythrospiza, Kavp, 1867. (Type, A. trinolalus Temm.? not of Boxap. 1830 !) 



Gen. Char. Form slender, the tail long, tho wings short and rounded, the feet slender, 

 the head small, and hill rather weak. Bill nearly as high through the base as the length 



