428 BIRDS OF ILLINOIS. 



Of the foregoing groups ouly two have representatives in North 

 America ; the Falconece, with several members, and the Polyhorece 

 with a single tropical species coming just within our border. 



The Falconece are represented in North America by apparently a 

 single genus, Falco, although it may ultimately prove necessary to 

 raise one or more of the supposed subgeneric divisions to fuU 

 generic rank. 



Genus FALCO Lnraffius. 



Chab. Bill strong. Its breadth at the base equal to or exceeding its length; nrpor 

 outline of the cere on a level with, or rather lower than, the base of the culmen; gonys 

 very convex, the chord of the curve about half that of the culmen. Maxillary tomium 

 ■with a very prominent "tooth," and mandibular tomium with a corresponding deep 

 notch; the end of the mandible being truncated and the tip of the maxilla compressed 

 and produced into a sti-ongly hooked tip. Nostrils small, circular, and with a conspicuous 

 central bony tubercle. Orbital region bare; projecting superciliary shield bare and 

 conspicuous, though not very prominent. Tail shorter than the wing, more or less 

 rounded, the feathers rather hard. Primaries very strong, elongated, never more than 

 two having their inner webs emarginated, the emargination angular and near the end of 

 the quill. Tiirsus never with a single continuous row of transverse scutellaB. either in 

 front or behind. Middle toe very long— never much shorter, and sometimes longer than 

 the tarsus. 



The above diagnosis includes the essential characters of all the 

 true Falcons, which apparently constitute a single genus, with, how- 

 ever, a number of more or less strongly marked subgeneric chvisions. 

 What are probably distinct genera of FalconincE are Spizapteryx, 

 Kaup (South America), and lerax Vigors (Indian). The latter in- 

 cludes the smallest of the Accipitres, some species being no larger 

 than the European House Sparrow {Passer domestictis). 



The following groups of North American Falcons are pretty well 

 characterized, and some of them (especially Tinnunculus) may be 

 entitled to generic rank : 



A. Only the first primary with inner web emarginated. First or second quill longest, 

 the first longer than the fourth. Sexes essentially alike in coloration, but young 

 very different from .adults. 



1. Hierofaloo. Tarsus longer than middle toe, and feathered far below the knee. 

 First quill shorter than the third. Size large to Largest of the family. 



2. BJiynchodon. T.arsus shorter th.an middle toe and scarcely feathered below the 

 knee. First quill equal to, or longer than, the third. Size large to medium. 



B. Two outer primaries with inner webs emarginated. Second or third quill longest, 



the first shorter than the fourth. 

 a. Basal joint ot toes without transverse scutell.'B. Tarsus about equal to the mid- 

 dle toe. 



