FALCONID^ — DIURNAL RAPTORES. 447 



Young female (No. 48,826, Santiago, Chili, May, 1866: Dr. Piiilippi). Occiput and nape 

 thickly markecl with broad streaks of dusky, tinged with rusty; scapulars umber-brown, 

 tipped with rusty; all the feathers of the wings narrowly tipped with white; tail-feathers 

 with a subterminal irregular bar of dark ashy; breast tinged with rufous, and with badly 

 defined cuneate spots of deeper rusty. Wing, 12.25; tail, 7.50. 



An adult female, obtained at San Francisco, California, Febru- 

 ary 11, 1868, had the "bill black, eyes orange-red, tarsi and toes 

 yellow." Total length 16^ inches, extent 42 inches. 



As to the occurrence of this species in Illinois, we have Uttle infor- 

 mation, the only record being that of the writer's previous lists, 

 based on a pair observed near the river at Mt. Carmel during the 

 summer of 1863 or 1864. It is very likely of not uncommon occur- 

 rence during summer in suitable places in the extreme southern 

 counties of the State. 



Genus ICTINIA Vieillot. 



Je(i)i!» ViElLL. Analyse, 1816, 24. Type, Falco mississippiensis WrLS. 

 Nertus BoiB, Isis, 1828, 314. Type, Falco phtmbeus Gmel. 



Gen. Chae. Form falcon-like; the neck short, shoulders broad, wings long and 

 pointed, the rectrices strong and stiff, claws strongly curved and acute, and general or- 

 ganization robust. Bill short and deep, "bulged" laterally, the terminal hook abruptly 

 compressed; tomia irregularly toothed and notched; gonys very convex, ascending ter- 

 minally. Cere narrow; nostril very small, roundish. Feet small but robust, the tarsus 

 about equal to the middle toe; outer toe decidedly longer than the inner, which is equal 

 to the hallux; web between it and the middle toe well developed; tarsus with a distinct 

 frontal series of broad transverse scutellfe ; claws short, but strongly curved, very sharp, 

 grooved beneath. Third quill longest; first of variable proportion with the rest; outer 

 two with inner webs siniiated. Tail a little more than half the wing, emarginated, or 

 nearly even, the feathers broad, with nearly truncated, though rounded, ends. 



Structurally, Ictinia seems to be most nearly related to Harpagus, 

 a tropical American genus, which, however, differs much in gen- 

 eral appearance, being of decidedly hawk-like aspect. The struc- 

 tural differences between the two genera may be tabulated as fol- 

 lows : 



Ictinia, Tomial tooth simple. Tarsus nearly equal to, or but little longer than, the 

 middle toe; posterior toe equal to the outer. Wing very long, reaching to or beyond 

 end of the tail, the primaries greatly developed, almost twice the length of the second- 

 aries. Tail about one half the wing, even, or slightly emarginated. 



» 



Harpagua. Tomial tooth double. Tarsus about one and a half times the middle 

 toe; posterior toe decidedly shorter than the outer. Wing short, reaching only to about 

 the middle of the tail, the primaries only moderately developed, less than one and a half 

 times the secondaries. Tail nearly equal to wing, slightly rounded. 



