Adult Male. Plate CLXXV. Fig. 1.
Bill of moderate length, slender, nearly straight, acute, subtrigonal at the base, compressed towards the end; upper mandible with the dorsal outline slightly arched, the sides convex towards the end, the edges sharp, the tip narrow but rather obtuse; lower mandible also much compressed, with the dorsal line straight, the sides nearly erect and slightly rounded, the sharp edges inflected. Nostrils basal, lateral, oblong, with an arched membrane above, open and bare. Head rather compressed, neck and body short. Legs of ordinary length; tarsus compressed, anteriorly covered with six scutella, posteriorly with a long plate forming a sharp edge; toes scutellate above, the second and fourth nearly equal, the hind toe much stronger, with a much larger claw, the third and fourth united as far as the second joint; claws arched, much compressed, acute.
Plumage soft and blended. No bristly feathers about the bill. Wings short, broad, rounded, first quill about half the length of the second, which is considerably shorter than the third, fourth, and fifth, which are nearly equal, the fourth, however, being the longest. Tail of ordinary length, graduated, of twelve narrow rounded feathers.
Bill dusky above, pale brownish-yellow beneath. Iris dark hazel. Feet pale flesh-colour. The upper parts are blackish-brown, each feather with a brownish-white line along the shaft, and the outer edge towards the end reddish-brown. Wings dusky, the outer edges barred with pale yellowish-brown on the outer webs. Upper tail-coverts and tail similarly barred. Throat and central part of the breast greyish-white, the rest of the lower parts pale reddish-brown, the sides under the wings faintly barred with dusky.
Length 438 inches, extent of wings 558; bill along the ridge 4½12, along the edge 612; tarsus 8½12.
Adult Female. Plate CLXXV. Fig. 2.
The female resembles the male, and the young birds are distinguishable only by having the bill shorter, and the lower parts more tinged with red.
The Long-billed Marsh Wren is very closely allied to the present species, and the two form part of a group which Vieillot distinguishes by the name of Thyrothorus.
