FALCONID.E — THE FALCONS. 



2G7 



the (1'isky sufl'iisinp; tlic lores. Whole oral rc^rion scarcely vaiieiriilcil pale yi'llowisii ; 

 whole ehiu and tliroat iimimeiilate. 



Prevailing tint above, Ijlaekish-lirowii, liecoininir iiinplish-ljlack on juiinaiit's ; wliole 

 outei- sni'liice of winiT jilaiii, Iml interscapular rcj;ion soiiiewliat varietratcd wilh piirlially 

 concealeil, iri'eLrular lilotches oC ileeper oehraeeous than the lowei' parts: iijipcr tail-cuv- 

 erts with paiis of inilistini-l white spots. Tail j;i'ayish-lirown (while at exlicme Imsc). 

 crossed wilh ahont ten narrow, indistinct, but i-e^nilar liands ol' dusky. I-ininjr of llie 

 wings yellowish-white, wilh sparse cordate s()ols ol' lilackish, this lint pi-evailin.u: over the 

 under primary coverts; under siirfuee of the primaries pure pui-plish-lilaek afler their 

 einarirination, but anteriorly plain hoary brown, growing paler basally. On inner webs 





12117. 





Biiteo oiijpterus (Mazatlnn). 



an. very indistinct transverse spots of dusky, touching neither the edge nor shaft of the 

 feather, and entirely concealed when the wing is closed. Shafts of i)riniaries pure white 

 on under side; on outer, dark brown. Wing-fornnila, 3-4-2-5-0-7-1,8. Three 

 outer primaries emarginated on iimer webs; second, third, and li)urth, siiniated on outer. 

 AVing, 13.70; tail, 7.00; tarsus, U.IO; middle toe, 1.35. Primaries project beyond sec- 

 ondaries, 5.50. (Cassin's type.) 



Young female (:iS,')Oii, San Jose. Costa Ilica; .T. Cariniol). Differs from the type chiefly 

 in lighter colors. The whole forehead very broadly innnaculale dull wliilc. this contiini- 

 ing back to the occi]iut in a broad unstreaked superciliary stri|ic ; along ihc upper edge 

 of the ear-coverts is a rusty sufl'usion. with condensed, line dusky streaks, forming an 

 indistinct stripe separating th(> wholly white ear-coverts from the supraoral stripe; the 

 " mustache " is very conspicuous ; the breast lias a few large tear-.sliaped siiots of clear 

 blacki.sh-brown, and the sides have very .sparse, irregular, and more sagittate spots of the 

 .same ; the whole posterior jiarts arc iumiaculate. The upper parts are more viuiegatcd with 

 paler, the wing-coverts and runi]) having the feathers irregularly boi'dered wilh whitish. 

 The upper tail-coverts are white, barred with dark brown. Tail, hoaiy lirown, crossed 

 by nine or ten nearly i)l)solete, narrow b;uids of du.sky. Whole lining of the wii'gs ini- 

 maeulate, except the cons])icuous jiatch on the primary coverts. The whole imder snrlhce 

 of the primaries is uniform slaty, gradually deepening into black towards ends. Wiiig- 

 fonnnla, ;]-4-2 - 5-0-7, 1. Wing, 15.00; tail, S.Ol) ; tarsus, 2.15 ; middle toe, 1.55. 

 Priinai'ies project Iteyond sccondm-ies, 0.00. 



TTab. Tropical America, from the southern border of the United States to Buenos .Vyres. 



The iiielaiiistic specimen describefl above agree.s perfectly with Mv. Scla- 

 ter'.s excellent fi<];ure of hi.s B. fuliginosus above cited, and the only di.scre- 

 pancy in the description is in the measurements, — those "iven for the j5. 

 fullf/liiosiis being, wing 12.00, tail G..")!!, and tarsus 2.00. This difference — 

 certainly not great — very likely indicates tlie jiroportions of the sexes, 

 while tiie discrepancy as regards the length of the tarsus, it is jirobable, 

 results from a difl'erent mode of measurement. 



