222 ALLEN'S NATURALIST'S LIBRARY. 



THE AQUATIC WARBLER. ACROCEPHALUS AQUATICUS. 



Motacilla aquatica, Gm., Syst. Nat., i., p. 953 (1788). 



Acrocephalus aquaticus, Newt. ed. Yarn, i., p. 380 (1873); 

 Dresser, B. Eur., ii., p. 591, pi. 89 (1876); Seeb., Cat. B. 

 Brit. Mus., v., p. 89 (1881); id. Hist. Br. B., i., p. 357 

 (1883); B. O. U. List Br. B., p. 20 (1883); Lilford, 

 Col. Fig. Br. B., pt. ix. (1888); Saunders, Man., p. 79 

 (1889). 



Adult Male. General colour above tawny-buff, becoming 

 clearer on the lower back, rump, and upper tail-coverts, the 

 whole of the upper parts broadly streaked with black centres 

 to the feathers, less distinct on the rump and upper tail-coverts ; 

 wing-coverts blackish, edged with pale tawny-buff, the inner- 

 most secondaries similarly coloured ; primary-coverts and quills 

 dark brown, with narrow tawny-brown margins, broader on the 

 secondaries, which appear more uniformly rufous near the 

 bases ; tail-feathers dark brown, with narrow tawny edges ; 

 crown of head pale tawny-buff in the centre, with a broad 

 black streak along each side of the crown, followed by a broad 

 eye-brow of pale buff; cheeks and under surface of body light 

 tawny-buff, a little whiter on the throat and abdomen, and 

 deeper on the sides of the body and under tail-coverts ; under 

 wing-coverts and axillaries whitish, slightly tinged with buff; 

 bill very slender, dark brown above, paler on the lower man- 

 dible ; feet pale clay-yellow ; iris hazel. Total length, 5 inches ; 

 culmen, 0-55; wing, 2*4; tail, 2*0; tarsus, 0-85. 



In Summer Plumage there are some narrow blackish streaks on 

 the fore-neck and sides of the body. This is rather an unusual 

 circumstance with a Warbler, the possession of streaks on 

 the under parts being generally considered to be a sign of 

 immaturity. 



NOTE. The Aquatic Warbler can only be mistaken for the Sedge- 

 Warbler in this country, and from this bird it is easily recognised by the 

 broad mesial streak on the crown, flanked by the two black bands which 

 extend above the pale eyebrow for the whole length of the crown. The 

 bird is hardly a true Acroccphalus, for its bill is small and weak, and more 

 like that of the Grasshopper Warbler. The first, or bastard, primary is 

 very small, and does not reach to the end of the primary-coverts. The 

 second and third primary-coverts are equal and longer than the fourth. 



Range in Great Britain. An accidental visitor, but one which 



