FALCONID^ — THE FALCONS. 131 



culmen, .45 - .58; tarsus, 1.20 - 1.55 ; middle toe, 1.15 - 1.40. Second 

 quill longest; first longer than third. Crissum uniform deep reddish- 

 rufous, rarely barred with white and dusky. Upper tail-coverts 

 obsoletely barred with plumbeous. 



Adult. Above plumbeous-black, the feathers lightening into plumbeous- 

 blue on the edges and ends, and showing obscure bars on the posterior 

 portions. Throat and jugulum ochraceous-white, the ochraceous tinge 

 deepest posteriorly and without any streaks. Young. Above plum- 

 beous-black, without lighter obscure bars, or with a brownish cast, and 

 with faint rusty edges to the feathers. Throat and jugulum deep soft 



jection over tlie cheeks, which are purer black. All the leathers above darker centrally, but the 

 obscure spots so formed mostly concealed ; shafts of the feathers inconspicuously black ; uytper 

 tail-coverts each with two broad transverse spots of black. Secondaries, primary coverts, and 

 })rimaries uniform dull black ; the former, and inner feathers of the latter, very narrowly ashy- 

 whitish on terminal border, — the coverts with a bluish shade terminally. Tail black (dull light 

 brown at apical margin), crossed with about six obsolete narrow bands of plumbeous, tliese 

 changing to nari'ower white bars on the inner webs. Chin, base of maxillce, throat, sides of the 

 neck, and jugulum, ochraceous-white, the ochraceous tinge deepest posteriorly ; breast (bro.adly 

 across) and sides black, with numerous nai-row transverse bars of reddish-white, becoming more 

 ashy posteriorly ; abdomen, anal region, tibiffi, femorals, and lower tail-coverts uniform deep, 

 almost castaneous, rufous. Lining of the wing dull black, with circular ochraceous-white spots, 

 but former predominating ; whole under surface of primaries and secondaries a similar blackish - 

 dusky, the former with narrow transverse elliptical spots of white, of which there are eight (the 

 first and last merely indicated) on the longest quill. Wing-formula, 2-1-3. Wing, 7.70; 

 tail, 3.95 ; tarsus, 1.20 ; middle toe, 1.20. Tail slightly emarginated ; second and third feathers 

 longest (counting from exterior). 



9 (5,218, Mazatlan ; Colonel Grayson). Almost precisely similar to the male ; less contrast 

 between blackish-plumbeous of the nape, and more bluish of the back ; bands on tail five in 

 number; bars on black beneath more reddish. Wing-formula same. Wing, 8.80; tail, 4.40; 

 tarsus, 1.30 ; middle toe, 1.30. 



Jhv. (Bryant Coll. 1,531, Orizaba, Mex.). Above continuous dull black, without bluish cast 

 or concealed spots ; tail-bands narrower, purer white ; black beneath duller, transverse bars 

 more obsolete, broader, and pale rusty ; chestnut-rufous of posterior lower portions lighter and 

 less uniform ; lower tail-covei"ts with broad transverse spots of plumbeous-black. Wing-fornuila 

 as in adult. Wing, 8.75 ; tail, 4.40. 



Two young males from Tehuantepec, Mexico (Nos. 613 and 613, May 16, 1871 ; F. Sumichrast), 

 differ from that described above in some remarkable respects : the upper parts are in one black, 

 but without the ru.sty margins to the feathers ; in the other, almost exactly as in the adult plu- 

 mage described. The lower parts, however, are most different ; thethroat and jugular are uniform 

 deep .soft ochraceous, with a few longitudinal streaks of black near the black abdominal patch ; 

 the bars in this last are deep rufous, and the terminal band of the tail is also deep rufous. The 

 weak bill, and soft, blended character of the plumage, indicate unmistakably the very young 

 age of these specimens, which are also marked " very young " by M. Sumichrast. 



In colors, as well as in size and form, this very handsome little Falcon closely resembles the 

 F. sevcriis, Horsf., of Manilla and the neighboring East Indian Islands ; the main difference is 

 tliat in that species the lower surface is wholly deep rufous, instead of jjartly black. 



List of Specimciis examined. — National Museum, 11 ; Boston Society, 6; Philadelphia 

 Academy, 7 ; New York Museum, 3 ; G. N. Lawrence, 3 ; R. Ridgway, 2. Total, 32. 



Measurements. — ^. Wing, 7.20-8.80; tail, 4.20-5.10; culmen, .45-. 55; tarsus, 1.25- 

 1.50; middle toe, 1.15-1.30. Specimens, 13. ?. Wing, 8.50-9.00; tail, 5.00-5.50; 

 culmen, .58 ; tarsus, 1.48-1.55 ; middle toe, 1.30-1.40. Specimens, 8. 



Hab. Tropical America, northward through Central America and Mexico almost to southern 

 border of United States. 



Localities: Veragua, Sol. & S.\lv. 1869, 252. 



