BIRDS OF NORTH AND MIDDLE AMERICA 61 



directly or indirectly desmognathous or (in genus Elanus) schizo- 

 gnathous; cervical vertebrae 13 or 14 (15 in Pandionidae) ; dorsal 

 vertebrae heterocoelous; coracoid grooves overlapping; procoracoid 

 process large; metasternum entire or with one pair of notches or foram- 

 ina (these sometimes developed on one side only) ; ischium not con- 

 tinued or produced backward as a spine; ^^ flexor tendons of type III 

 or (in Pandionidae) type XI; syrinx tracheobronchial; caeca minute 

 (except in Pandionidae) ; cervical pterylosis with lateral apteria (except 

 in Pandionidae) ; ^^ aftershaft present; secondaries aquintocubital; rec- 

 trices 12-14; young nidicolous (altricial), ptilopaedic. 



KEY TO THE FAMILIES OF FALCONES 



a. Metasternum cuneate; furcula articulating with anteroinferior angle of ster- 

 num; clavicle ankylosed with sternum at symphysis by a strong median 

 process; acrocoracoid without articular facets for furcula; postacetabular 

 portion of ilium not deflected (nor with notch indicating the two elements 

 posteriorly); basipterygoid processes present; functional; tarsom.etatarsus 

 prismatic (its anteroposterior diameter equaling or exceeding the trans- 

 verse), the posterior face with a prominent median process, terminated 

 above by an expanded cordate surface; hallux less than half as long as fourth 

 toe; femorocaudal muscle absent, accessory femorocaudal muscle present; 



myological formula BXY + Sagittariidae " (extralimital) 



aa. Metasternum subtruncate; furcula entirely separated from keel of sternum; 

 clavicle not ankylosed with sternum; acrocoracoid articulated with furcula; 

 postacetabular portion of ilium deflected; basipterygoid processes absent or 

 rudimentary; tarsometatarsus greatly flattened, with strong lateral ridges 

 (the anterior one produced and thin, and the posterior face of the proximal 

 end with two ridges, separated by a deep and wide groove) hallux much 



32 These characters contrasting with those of Cathartae. 



33 Sagittariidae. — Gypogeranidae Stephens, in Shaw's Gen. Zool., xiii, pt. 2, 

 1826, 4; Bonaparte, Saggio Distr. Anim. Vertebr., 1831, 36; Rev. Mag. Zool., 

 1850, 478; Consp. Gen. Av., i, 1850, 12; Kaup, in Jardine's Contr. Orn., 1849, 119; 

 Huxley, Proc. Zool. Soc. London, 1867, 465; Carmus, Handb. Zool., i, 1868-75, 310; 

 Barrows, Stand. Nat. Hist., iv, 1884,263, 264, in text; Fiirbringer, Unters. Morph. 

 Syst. Vog., ii, 1888, 1294, 1565, 1580; Gadow, Classif. Vertebr., 1898, 33.— Serpen- 

 tariidae Sclater, Ibis, 1880, 404; Gurney, Cat. Birds Prey, 1894, 16; Sclater, 

 Birds South Africa, iii, 1903, 402; Reichenow, Die Vogel, i, 1913, 366.— Oestu- 

 chomorphae Cams, Handb. Zool., Wirbelth., i, 1868, 75, 310.— Serpen tarii See- 

 bohm, Classif. Birds, 1891, 78; Sharpe, Rev. Rec. Att. Classif. Birds, 1891, 78; 

 Hand-list, i, 1899, xx, 241; Pycraft, Proc. Zool. Soc. London, 1902, 318, 319; 

 Swann, Synopt. List Accip., pt. 1, 1919, 3. — Gypogerani Knowlton, Birds of the 

 World, 1909, 48, 209. — Sagitariidae Sclater, Syst. Av. Ethiopicarum, pt. 1, 1924, 

 46; Swann, Monogr. Birds of Prey, i, pt. 2, 1925, 63; Bannerman, Birds Trop. 

 West Africa, i, 1930, 165. — Sagittarinae Finsch and Hartlaub, Vog. Ost-Afr,, in 

 Von der Decken's Reise, iv, 1870, 93.— Sagittarioidea Peters, Check-Hst Birds of 

 World, i, 1931, 192. 



A very distinct and remarkable family comprising a single genus {Sagittarius 

 Herman) represented by one species, peculiar to Africa. (An extinct species 

 from the Lower Miocene of France.) 



