THE MARSH-WARBLER. 343 



moult in Aug.-Sept., but insufficient material is available to make 

 certain. Summer. A complete moult (including wings and tail) 

 takes place apparently Feb.-Mar., but insufficient material is avail- 

 able to make certain. New plumage as winter but upper-parts 

 rather more olivaceous. Abrasion makes upper-parts considerably 

 paler and more greyish and rump pale earth-brown tinged oliva- 

 ceous. In worn plumage more distinctly different from Reed- 

 Warbler which does not become so greyish and is always rusty on 

 rump. 



Nestling. (Not examined.) 



Juvenile. Specimens considered by their collectors to be of 

 this species appear to be indistinguishable from juvenile Reed- 

 Warblers. 



First winter. Apparently like adult, but no specimen in 

 moult examined. 



Measurements and structure. $ wing 66-72 mm., tail 51-56, 

 tarsus 22-24, bill from skull 14-16 (12 measured). $ wing 64-72. 

 Primaries : 1st equal to, or 1-5 mm. shorter or 1-2 longer than, 

 primary-coverts, 3rd longest, 2nd 1-2 shorter (exceptionally 

 equal to 3rd, usually equal to and very occasionally .5-1 shorter 

 than 4th, always longer than 5th), 4th 1-2.5 shorter, 5th 4-5 shorter, 

 6th 6-9 shorter ; 3rd emarginated outer web, no emargination on 

 4th ; 2nd with a notch on inner web falling between tips of 6th and 

 8th and exceptionally 9th primaries. Outer tail-feathers 5-8 mm. 

 shorter than central. Tips of tail-feathers inclined to be pointed. 

 Bill rather wide and fiat at base, compressed and thin at tip. 

 Otherwise as A. a. arundinaceus. 



Soft parts. Bill : upper -mandible dark brown, under-mandible 

 flesh ; inside mouth yellow ; legs and feet brownish-flesh or 

 yellowish-flesh ; iris olive-brown. 



CHARACTERS. No subspecies. Differs from A. s. scirpaceus in 

 coloration and in 2nd primary being usually slightly longer com- 

 paratively and notch on inner web of 2nd primary usually nearer 

 tip of feather. Differs from A. dumetorum chiefly in slightly longer 

 wing and tail and in several details of wing-formula (cf. " Measure- 

 ments and structure ") chief of which are : A. palustris 2nd 

 primary longer, 4th and 5th shorter, 3rd only emarginated not 4th 

 or 5th, 2nd only with notch on inner web and this is much nearer 

 tip of feather. 



FIELD-CHARACTERS. Bears close resemblance to Reed-Warbler 

 and is often found in similar localities, but has a different carriage. 

 Pale flesh-coloured tarsus of Marsh-Warbler is much lighter than 

 slate-brown of Reed, and upper-parts are a colder more olive brown. 

 By far the best field-character, however, is striking and melodious 

 song of male, which differs widely from the well-known jerky song 

 of Reed-Warbler, being infinitely superior, taken in quick time and 

 including imitations of many other species (F.C.R.J.). 



