444 BIRDS OF ILLINOIS. 



gus of nearly uniform width, being destitute of crop, and thus resembling that of the 

 owls; its walls extremely thin; stomach very large, round, slightly compressed, its mus- 

 cular coat very thin, and composed of a single series of fasciculi. Intestine short and 

 rather wide; pylorus with three knobs, duodenum forming a loop in the usual manner; 

 no ca3ca; rectum short, with a large globular dilatation." MACGILLIVRAY. 



Pterylographical cliaraoters . "Inner branch on the jugular part distinct but short; 

 niter branch entirely free. Dorsal portion of the spinal tract usually long."* (NrrzscH.)_ 

 Contour-feathers with aftershat'ts. Lumbar tract present. Eemiges, 23. 



Apparently more nearly related to Pernis, Leptodon, Regerhinus, 

 and allied forms than to any other genera, the genus Elanoides yet 

 stands isolated from these by the absence of many characters com- 

 mon to them, and by the possession of features peculiarly its own. 

 In general external form, it approaches quite nearly the genus Mil- 

 i- us, but when compared closely, the two are found to possess no 

 real affinities of structure. The same is true of its relationship to 

 X ancients riocouri, usually placed in the same genus, but which is 

 more intimately related to Ictinia, Elanus, and their affines. 



The genus contains but a single species, the E. forficatus, which 

 is peculiar to America, belonging to the tropical and subtropical 

 portions on both sides of the equator. The species is noted for the 

 elegance of its form and the beauty of its plumage, as well as for 

 the unsurpassed easy gracefulness of its flight. 



Elanoides forncatus (Linn.) 



SWALLOW-TAILED KITE. 



Popular synonyms. Swallow-tailed Hawk; Fish-tail Hawk; Snake Hawk; Fork-tail 

 Snake Hawk; Mackerel- tail Hawk; White-headed Swallow Kite. 



Falco forficatus LINN. S. N. ed. 10, i, 1758, 89. 

 Nauclerus forficalus RIDGW. 1870, B. B. & R. Hist. N. Am. B. iii, 1874, 192,-CouES, B. N. 



W. 1874,332. 

 Elanoides forficatus CouEs.Proc. Acad. Nat. Sci. Phil. 1875,345; 2d Check List, 1882. 



No. 493. KIDGW. Nom. N. Am. B. 1881, No. 426. 

 Falco furcatus LINN. S. N. ed. 12, i, 1766, 129. WILS. Am. Orn. vi, 1812, 70, pi. 51,flgs. 1,3. 



AUD. B. Am. fol. ed. 1831, pi. 72; Orn. Biog. i. 1830 368; v,1839, 371. 

 Naucierus furcatus VIG. 1835. AUD. B. Am. i, 1840, 78, pi. 18; Synop. 1839, 14. CASS. in 



Baird's B. N. Am. 1858,36.-BAiKD,Cat. N. Am. B. 1859, No. 34.-CouES, Key, 1872,211; 



Check List, 1874, No. 337. 



H AB . Whole of tropical and subtropical America, except West Indies ; north, casually 

 to Massachusetts and Michigan, more regularly to Maryland, Illinois, Iowa, Minnesota, 

 etc. Much more numerous in the Mississippi Valley than east of the Alleghanies. 



SP. CHAR. Wing, 15.40-17.70; tail, 12.50-14.50; culmen, .70-. 81); tarsus, 1.00-1.30; 

 middle toe, 1.00-1.20. Head, neck, entire lower parts (including lining of the wing and 

 basal half of the secondaries underneath), and band across the rump pure white. Back, 



* NITZSCH gives the above characters of a group in which he includes Milvus regalis, 

 .. ater, and Elanoides forficatus. 



