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 ot a single series of fasciculi. Intestine short and 

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

 no casea; rectum short, with a large globular dilatation."— Macgilliveat. 



Plerylographical characters. "Inner branch on the jugular part distinct but short; 

 outer branch entirely free. Dorsal portion of the spinal tract usually long."* (Nitzsch.) 

 Contour- feathers with attershafts. Lumbar tract present. Eemigcs, 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- 

 vus, but when compared closely, the two are found to possess no 

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

 Nauderus riocoiiri, 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 forficatus (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. 



Fdlco forficatus Link. S. N. ed. 10, i, 175S, 89. 

 Nauderus forficatus Bidgw. 1870^B. B. & K. Hist. N. Am. B. iii, 1874, 192.— CouES, B. N. 



W. 1874,332. 

 Elanoides forficatus CouBS,Proc. Acad. Nat. Soi. Phil. 1875,345; 2d Check List, 1883, 



No. 493.— EiDGW. 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,flg3. 1,3.— 



AUD. B. Am. fol. ed. 1831, pi. 72; Orn. Biog. i, 1830 368; v,1839, 37L 

 Nauderus furcatus ViG. 1835.— AuD. B. Am. i, 1840, 78, pi. 18; Synop. 1839. 14.— Cass, in 



Baird"s B. N. Am. 1858,36.- BAiiiD,Cat. N. Am. B. 1859, No. 34.— CouES, Key, 1872,211; 



Cheek List, 1874, No. 337. 



Hab. Whole ot tropical and subtropical America, except Westlndies; 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 AUeghanies. 



Sp. Chak. Wing, 15.40-17.70; tail, 12.50-14.50; culmen, .70-. 80; tarsus, 1.00-1.30; 

 middle toe, 1.00-1,20. Head, neck, entire lower parts (including lining ot the wing and 

 basal lialf ot the secondaries underneath), and band across the rump iiure white. Back, 



* Nitzsch gives tlie above eliaracters of a group in which ho includes Milvus regalis, 

 M. (iter, and Elanoides forficatus. 



