Vermivoreæ. Bill without a distinct notch, or lacking it
entirely; rictal bristles wanting, or very minute; culmen and
gonys nearly straight; bill only very moderately compressed.
_a._ Middle toe and claw about equal to tarsus.
Bill not acute; culmen and gonys decidedly convex; notch
just perceptible; bristles apparent … _Protonotaria._
Bill moderately acute, robust; no notch; culmen straight,
its base elevated and slightly arched; bristles not
apparent … _Helinaia._
Bill moderately acute; robust; no notch; culmen convex, its
base not elevated; bristles apparent … _Helmitherus._
_b._ Middle toe and claw considerably shorter than tarsus.
Bill very acute, its outlines nearly straight; notch not
perceptible; bristles not apparent … _Helminthophaga._
Bill very acute, its outlines nearly straight; notch just
perceptible; bristles strong … _Parula._
Sylvicoleæ. Bill distinctly notched; rictal bristles strong;
outlines generally slightly curved.