POLIOPTILA. 569 



branch, deeply cup-shaped, very compact, composed of plant-fibres and other 

 felted materials, lined with soft feathers, and often beautifully decorated exte- 

 riorly with variously colored lichens. Eggs 3-5, greenish or bluish white, speckled 

 with brown. 



a}. Exposed portion of outer tail-feather entirely white. 



h^. Top of head in adult males plumbeous-blue, bordered anteriorly and later- 

 ally by a black line ; in female, bluish ash-gray, not markedly different 

 from lighter gray of sides of head. 

 c\ Lower parts white medially, pale ash-gray laterally ; upper parts clear 

 grayish blue or plumbeous, deeper on top of head, decidedly paler 

 on rump; length 4.05-5.50, wing 2.00-2.20 (2.07), tail 2.05-2.20 

 (2.15). Nest always (?) beautifully decorated with lichens. Eggs 

 .56 X -43. Hab. United States, chiefly south of 42°, wintering in 

 Gulf States, western Cuba, Bahamas (occasionally), Mexico, and 



Guatemala 751. P. cserulea (Linn.). Blue-gray Gnatcatcher. 



c^ Lower parts light bluish gray, deeper laterally ; upper parts deep bluish 

 plumbeous, somewhat bluer on top of head, but scai'cely, if at all, 

 paler on rump ; about the size of P. ccerulea. Hab. Bahamas 

 (Abaco and New Providence ; resident) ; Cozumel ? 



P. cserulea caesiogaster Kidgw. Bahaman Gnatcatcher.^ 

 h"^. Top of head in adult males glossy black ; in females and young dark bluish 

 gray or plumbeous, abruptly contrasted with whitish of sides of head 

 (the latter sometimes including a distinct superciliary streak), 

 c'. Tertials broadly and conspicuously edged with pure white. 



d}. Lores partly (sometimes entirely) white ; occiput (in adult male), 

 as well as crown and forehead, glossy black; length about 

 4.00-4.25, wing 1.90-2.00, tail 1.90-2.10. Hab. Southern Mex- 

 ico (Tehuantepec, etc.), Guatemala, Salvador, and Nicaragua. 



P, albiloris Scl. & Salv. White-lored Gnatcatcher.^ 



d}. Lores entirely black in adult males, dull grayish in females and 



young. 



e^. Otherwise like P. albiloris ; length about 4.25-4.50, wing 1.85- 



2.10, tail 2.00-2.20. Hab. Brazil (Bahia, etc.) to Nicaragua. 



P. leucogastra (Max.). Maximilian's Gnatcatcher.' 



e^. Smaller, and with occiput light bluish gray, like hind-neck, 



back, etc. ; length 3.75, wing 1.85, tail 1.75. Hab. Yucatan. 



P. albiventris Lawr. Lawrence's Gnatcatcher.* 



c'. Tertials inconspicuously edged with dull grayish white or light grayish. 



d}. Lores, superciliary region, and upper half of ear-coverts glossy 



black in adult male, ash-gray in female and young; length 



1 New subspecies; seventeen specimens examined. 



2 PoliojytUa albiloris ScL. & Salt., P. Z. S. 1860, 293. 



3 Sylvia leucogastra Max., Beitr. iii. 1831, 710. Polio])tila leucogastra ScL., Cat. Am. B. 1862, 12. 

 * Polioptila albiventris Lawr., Ann. N. Y. Ac. Sci. iii. No. 9, 1885, 273. 



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