548 BULLETIN 50, UNITED STATES NATIONAL MUSEUM 



{. Inner toe, without claw, falling short of penultimate articulation 



of middle toe; middle toe, without claw, longer than tarsus; 



hallux, without claw, more than one-third as long as tarsus. 



g. First (outermost) primary, only, with inner web emarginated; 



longest primaries exceeding distal secondaries by much more 



than half the length of wing; second primary longest, the 



first equal to or longer than third; lower portion of acrotar- 



sium without transverse scutella. (Sexes alike in coloration 



and young very different from adults). 



Falco, subgenus Falco (extralimital) 



gg. First (outermost) and second primaries emarginated on inner 



webs; longest primaries exceeding distal secondaries by very 



httle if any more than half the length of wing; third primary 



longest or else very nearly as long as second, the first not 



longer than fourth, usually shorter; lower portion of acro- 



tarsium with transverse scutella. 



h. Length of cere on top equal to more than one-third the length 



(curve) of culmen; depth of bill at base greater than distance 



from nostril to tip of maxilla; distance from bend of wing 



to tip of longest primary covert decidedly less than from 



latter point to tip of longest primary; basal phalanx of 



middle toe with transverse scutella (continuous with those 



on lower portion of tarsus) ; sexes alike in coloration, 



j^oung distinctly but not conspicuously different from 



adults Falco, subgenus Rhj^chofalco (p. 681) 



hh. Length of cere on top less than one-third the length (curve) 

 of culmen; depth of bill at base less than distance from 

 nostril to tip of maxilla; distance from bend of wing to tip 

 of longest primary covert little if any less than from same 

 point to tip of longest primary; basal phalanx of middle toe 

 with small roundish scales; sexes conspicuously different 

 in coloration, the young (of both sexes) similar to adult 



female Falco, subgenus Aesalon (p. 690) 



//. Inner toe, without claw, extending to beyond penultimate phalanx 

 of middle toe; middle toe, without claw, shorter than tarsus; 

 hallux, without claw, less than one-third as long as tarsus. 

 (Sexes very different in coloration, but young essentially like 

 adults) Falco, subgenus Tinntmculus (p. 715) 



Subfamily Herpetotherinae: Laughing Falcons 



>Herpetother8e Lesson, ficho du Monde Savant, 9« ann., vii, s^r, 2, No. 3, Jan. 



12, 1843, col. 61 (includes, besides Herpetotheres, "Phijseta," Asturina, 



Chondrohierax, Odontriorchis, Rostrhamus, Gampsonyx, Pernis, Baza, and 



Aviceda!) . 

 = Herpetotherinae Sclater and Salvin, Nom. Av. Neotr., 1873, 122. — Salvin 



and Godman, Biol. Centr.-Amer., iii, 1901, 111.— Knowlton, Birds of 



World, 1909, 212, 225, in text. 

 = Herpetothcrese Ridgway, Proc. Boston Soc. Nat. Hist., xvi, 1873, 52; Orn. 



Illinois, i, 1889, 427. 

 = Herpetotheres Ridgway, U. S. Geol. and Geogr. Surv. Terr., Bull 4, ser. 2, 



June 10, 1875, 4, 5, 6; No. 6, 1876, 452. 

 > Herpetotherinae Peteks, Check-list Birds of World, i, 1931, 276 (includes 



Micrastur) . 



