454 BIRDS OF ILLINOIS. 



In South Anioricn is found a third subgenus which may he dis- 

 tinguished from typical Arrijiiitr as foUows : 



Accipitcr. Five outer primaries with inner webs emarginated ; 

 fourth or fifth (|uill longest ; inner toe not reaeliing middle of second 

 joint of middle toe. 



Hicriixjiicidx. Four outer primaries with inner webs emarginated ; 

 tliird or fourth (|uills lou^'cst : iimcr toe reaching to or beyond middle 

 of second joint of middle toe. 



SuBGENi's Accipiter BnissoN. 



Arciiiifer liRiss. Orn. i. 17(i". lu. Type F»ho ni.iu.i Linn. 

 Xi.ius Cuv. Lc(;oDS Anat. Coinp. i. tnhl. ois. 1799. Siinio type 



Cooperastur lii". \if\\ I't Afiiu" ZiicM. 1S.VI, .'wW. Typr Fulm sslniilnji \vx>., = F. 

 cooperi Bp. 



The species of this subgenus are generally of small size and 

 slender form; hut, with a graceful and apparently delicate structure 

 they combine remarkable strength and unsurpassed daring. They 

 differ from the species of Aniur mainly in less robust organization. 

 The species are very numerous, and most plentiful within the tropi- 

 cal regions. The Old World possesses about thii-ty nominal species. 

 Tropical America has, so far as known, thu-teen species, two of 

 which are peculiar to Cuba. (These the reader may lind carefully 

 monographed in the Bulletin of the U. S. Geological and Geograph- 

 ical Survey of the Territories, Vol. II., No. '2, pp. 01-129.) 



The two North American species may he distinguished as follows : 



Common Chaiiacters. Adull.i. Aliove bluish «liitc or pliinibootis, the tail with 

 darlcer cross-bands and imrro>yly lipped witli whitish; lower parts whiti-, barred or 

 transversely spotted with pinliish nifous or liclit brownish, the erissiini plain while. 

 Young. Above Krnylsh brown, the feathers bordered, more or less diBtinelly. with 

 rusty, and scapulars with hirge white spots, mostly concealed, however; tail-bands 

 more distinct than in the adults, the spaces between them browner; lower imrls white, 

 somolinies tinged with bulT (especially in younger individuals), longitudinally striped 

 with brciwiiish or dusky. 



1. A. cooperi. Size large, the wing more than 8.50 inches. Tall decidedly rounded. 

 Male: Wi ng. «.)«•>. to ; tail.7.8(> S.30. Female: Wiivr. 10.00-11.00; tail, 10.00-10.50. 



2. A. veloz. Size smaller, the wing usually less than » inches. Tail even, or (In adult 

 malisi slightly cniaiginated. Male; Wing. 11. 10 7.10; tail. 5, SO 0.10. Female: Wing. 

 7.S0-S.80; tail,0.C0'S.2O. 



