52 SYLVIID^. 



It seldom happens that male birds with the black forehead and eye-streak are found 

 in Mexico and Guatemala; and this' fact has given rise to the supposition that the bird 

 found in these countries, for which Bonaparte gave the name P. mexicana, is a species 

 distinct from P. cmrulea. Mr. Sclater, in 1859, thought that the black marks in the 

 male were only assumed during the breeding-season. If this is really so, we know of 

 no parallel case of such a change taking place in Passerine birds ; but the suggestion 

 receives support from the fact that one of our specimens with the black frontal line was 

 shot at Lanquin in March. Dr. Gundlach, however, speaks very positively on the 

 point, stating that the character which distinguishes the male from the female is only 

 to be observed in spring shortly before the departure of the birds from Cuba for the 

 United States in April '^^- 



2. Polioptila nigriceps. 



Polioptila nigricens, Baird, Rev. Am. Birds, p. 69'; Lawr. Mem. Best. Soc. N. H. ii. p. 267^; 

 BuU. U.S. Nat. Mus. no. 4, p. 12 ^ 



P. cmrulecB similis, sed pileo toto cum loris et superciliis nitenti-nigris. Long, tota 4-3, alse 1-95, candae 2-0, 

 rostri a ricfni 0-65, tarsi 0-75. (Descr. maris ex La Union, San Salvador. Mus. nostr.) 



Hub. Mexico, Mazatlan {Xantus ^, Grayson '^), Tepic ( Grayson ^), Quiotepec (Oaxaca), 

 Tapanaand Santa Efigenia (Tehuantepec) {Sumichrast^); San Salvadoe, La Union 

 {0. S.). — Colombia; Venezuela. 



Having had, through the kindness of the authorities of the Smithsonian Institution, 

 an opportunity of examining the type specimen of Polioptila nigriceps and of comparing 

 it with Colombian and Venezuelan examples some time called P. buffoni, we were 

 unable to appreciate any tangible diflFerences between them. Both have the lores black ; 

 and in the amount of black on the outer rectrices both were almost exactly alike. We 

 are therefore obliged to acknowledge them to be of one species. The La-Union 

 specimen described above has a few white feathers in the lores, but does not otherwise 

 differ from the type of P. nigriceps. The true P. buffoni is from Guiana, and has, as stated 

 in Mr. Sclater's original description, the outer rectrix nearly wholly white. The name 

 P. nigriceps, therefore, can be used for the bird having the range indicated above. It 

 is stated by Grayson ^ to be found in North-west Mexico in low brushy woods at all 

 seasons, and by Prof. Sumichrast^ to be common almost everywhere in the west of the 

 Isthmus of Tehuantepec and in dry warm districts of the State of Oaxaca, frequenting 

 the ravines and thin woods and going almost always in pairs. 



3. PolioptUa bilineata. 



Culicivora bilineata, Bp. Consp. i. p. 316 '. 



Polioptila bilineata, Scl. P.Z. S. 1860, p. 273 'j Baird, Rev. Am. B. i. p. 72'. 



Polioptila superciliaris, Lawr. Ann. Lye. N. Y. vii. pp. 304 ^ 322', viii. p. 179°, ix. p. 92'; Sd. 



