BIRDS OK NORTH AND MIDDLE AMERICA. 715 



i. Wiiifi; avfrajfin",' 4S.4, tail 52.4; iiioro wliitc dii lateral n ■(■trices. 

 (Eastern lirazil. ) 



Polioptila leucogastra, ailiilt male (extraliiiiital > « 

 re. Head without iiny l)Uu-k.'' 



(/. <iray of i)iieiiiii not darkeniiif; towani auriciiiar rcirioii. 



t\ No white superciliary stripe; tail loiijijer (averaj^in^' more than 48). 

 /. Auricular re<i;ioii with at least upper half pale <;ray, not consj)icuuiisly 

 different from darker gray of occiput, and fadiiii: ^n-adnally into paler 

 gray or grayish white of lower portion. 

 g. 1V\]\ smaller (exposed culmen averaging less than 10.5); outermost 

 primary nmch smaller, much less than half as long as next (ninth). 

 /(. Larger, with smaller bill (wing averaging more than 50, exposed 

 culmen less than 10). 

 i. r.lack at base of lateral rect rices more restricted; gi-ay of upper 

 jiarts clearer, white of under jiarts less grayish. 



Polioptila caerulea caerulea adult female I p. 717) 

 ?/. r>lack at l)ase of lateral rectrices more extendeil; giay of upper 

 parts tluUer, white of under ])arts grayer. 



Polioptila caerulea obscura, adult female (p. 720) 

 ///(. Smaller, with larger bill (wing averaging less than 48, culmen 

 averaging 10 or more). 

 i. Smaller and paler (in coloration like /'. r. crrulra): wing averag- 

 ing 45.:^, tail 43.5, tarsus 1().5. 



Polioptila caerulea niexicana, adult female (j). 722) 



a. Larger and darker; wing averaging 47 or more, tail more than 



50, tarsus 17 or more. 



j. Upper parts bluer slate-gray; under j>arts pale bluish gray 



(white oidy on alidomen, anal region, and under tiul-coverts) . 



Polioptila caerulea caesiogastra, adult female (p. 723) 



jj. l^pper parts (hiller slate-gray; under parts white medially. 



Polioptila nelsoni, adult female (p. 724) 

 g(j. IV\\\ larger (exposed culmen averaging more than 11); outermost 

 jtrimary nmch larger, at least half as long as tlie next (ninth). 



Polioptila nigriceps, adult female (p. 729) 

 ff. Auricular region white, or grayish white, abruptly and strongly con- 

 trasted with a dusky jiostocular streak, above which is a narrow 

 white or whitish streak. 



",S'[///r/((] IcncogaMrii Maxinniian, Beitr. Naturg. P.ras., iii, pt. 2, 1S31, 710 (Province 

 of r>ahia, e. Brazil; t\\)e in coll. Am. Mus. Nat. Hist.). — Polioptila h'Hco(j(tslra Sclater, 

 I'roc. Z<ioi. Soc. Loud., 1855, 12, part ( Bahia; Montevideo?); Sharpe, Cat. Birds 

 I>rit. .Mus., X, 1885, 440 (Bahia and Pernand)uco, Brazil). — I'[olioj)lil(t'] Icncogaiilrit 

 Ridgway, Proc. U. S. Nat. Mus., v, 1882, 387, 388, 389, part (Bahia; crit.); Hell- 

 iiKiyr, Novit. Zool., vii, 1900, 536, in text (crit.); viii, 1901, 3(50 (diagnosis); Tier- 

 nicii, 18 Lief., 1903, 25. — Calicirord ittrlcdpillii Swainson, Zool. Illustr., new ser., ii, 

 18:!1, 1)1.57 (no locality mentioned). — [Cnlirirord] (hiiiiirola (not Sglrin ihiiitiroln 

 Vieillot) Bonaparte, Consp. Av., i, 1850, 31(), part; (\nlinmrit'] diuiiicoln Cabanis 

 Mus. Hein., i, 1850, 34. 



''In the adult females of /'. liKi-dj/ns/nt and /'. /ihimlilcjis (proluibly also /'. (uitmru- 

 laris, which, however, 1 have not seen i tlie deep slate-gray or slate color of the 

 pileum grailually darkens into nearly lilacU on the ujiper jyortion of the auricular 

 region: but there is no distinct, sharply delined iilack mark or " hood " as in section r. 



