Bill rather long, being nearly of the same length as the head, straight, or slightly decurved, tapering to a very acute point, much compressed; the upper mandible with the ridge distinct, the sides declinate and flat at the base, the edges somewhat inflected beyond the middle, the notch obsolete; lower mandible with the dorsal line straight, the edges involute, the tip extremely acute. Nostrils oblong; exposed. Feet of moderate length; tarsus about equal to the middle toe and claw, slender, much compressed, with the upper scutella blended; toes slender; claws rather long, moderately arched, slender, much compressed, laterally grooved, extremely acute, plumage soft and blended. Bristles obsolete. Wings rather long, somewhat pointed, the outer three nearly equal, the second longest. Tail of moderate length, nearly even.--Name from [Greek: Helos], a swamp, and [Greek: Naiô], to inhabit. 104. 1. Helinaia Swainsonii, Aud. Swainson's Swamp-Warbler. Plate CXCVIII. Male. Bill as long as the head, much compressed; wings rather long, second and third quills equal and longest; tail even; upper parts olive-brown, the head strongly tinged with red; lower parts and a band over the eye pale yellowish-grey, the feathers on the cheeks tipped with brown, the sides of the neck and body more grey, the abdomen whitish. _Male_, 5-1/4, 8-1/2. South Carolina to Massachusetts. Very rare. Migratory. Swainson's Warbler, Sylvia Swainsonii, Aud. Orn. Biog. v. ii. p. 568; v. v. p. 462. 105. 2. Helinaia vermivora, Lath. Worm-eating Swamp-Warbler. Plate XXXIV. Male and Female. Bill nearly as long as the head, less compressed than in the last; wings rather long, second quill longest, first and third equal; tail very slightly rounded. Upper parts light olive-green; head and lower parts pale brownish-yellow, the former with four longitudinal black bands; throat and abdomen nearly white. _Male_, 5-1/2, 8-1/2. From Texas northwards, and in the interior to the Missouri. Not very abundant. Migratory. Worm-eating Warbler, Sylvia vermivora, Wils. Amer. Orn. v. iii. p. 74. Sylvia vermivora, Bonap. Syn. p. 86. Worm-eating Warbler, Sylvia vermivora, Aud. Orn. Biog. v. i. p. 177; v. v. p. 460. 106. 3. Helinaia Protonotarius, Lath. Prothonotary Swamp-Warbler. Plate III. Male and Female. Bill nearly as long as the head; first quill longest; tail even. Male with the head, neck, breast, and sides rich yellow, abdomen and lower tail-coverts white; hind neck and fore part of back greenish-yellow, rump, tail-coverts, smaller wing-coverts and margin of the quills and tail-feathers light greyish-blue; the latter, except the middle, having the greater part of their inner webs white. _Male_, 5-1/2, 8-1/2. From Texas eastward to Nova Scotia. In the interior to Kentucky. Saskatchewan. Rather rare. Migratory. Prothonotary Warbler, Sylvia Protonotarius, Wils. Amer. Orn. v. iii. p. 72.