Neornithes Gadow, 1893 - living birds
   Neognathae Pycraft 1900 see Cohort Neognathae Pycraft, 1900
     Neoaves Sibley et al. 1988 see Subcohort Neoaves Sibley et al., 1988
       [Order] Passeriformes Linnaeus, 1758
         oscines see Suborder Oscines
           Passerida - passeridans see Parvorder Passerida (C. Linnaeus, 1758) Sibley et al., 1988
             Muscicapoidea
               Family Polioptilidae Baird, 1858 - gnatcatchers
                 Genus Polioptila P.L. Sclater, 1855
                   01 Polioptila caerulea (C. Linnaeus, 1766) - blue-gray gnatcatcher
                   02 Polioptila melanura Lawrence, 1857 - black-tailed gnatcatcher
                   03 Polioptila californica Brewster, 1881
                   04 Polioptila lembeyei (Gundlach, 1858)
                   05 Polioptila albiloris Sclater & Salvin, 1860
                   06 Polioptila nigriceps S.F. Baird, 1864 - black-capped gnatcatcher
                   07 Polioptila plumbea (J.F. Gmelin, 1788)
                   08 Polioptila lactea Sharpe, 1885
                   09 Polioptila guianensis Todd, 1920
                   10 Polioptila schistaceigula E. Hartert, 1898
                   11 Polioptila dumicola (Vieillot, 1817)