^"I'sgt'^l Oberholser Oil a New Marsh Wren. IC)1 



feathers, and in its generally barred upper and lower tail-coverts. 

 Though none of these characters are entirely constant, they 

 nevertheless furnish good average distinctions. The first men- 

 tioned prevails in 67 per cent ; that of barred upper tail-coverts in 

 7 1 per cent ; and the lower tail-coverts are transversely marked 

 in 90 per cent of the specimens examined, although in many cases 

 the barring, while perfectly evident, is not blackish, but buff. The 

 lower parts in C. p. plesius are commonly rather grayer and less 

 purely white than in palustris. The bill averages considerably 

 shorter, the wings and tail somewhat longer. The flanks and 

 upper parts, incklding the sides of neck and head, are much paler 

 and usually somewhat more grayish, this affecting chiefly the 

 brown portions of the plumage. In the shade of these parts fall 

 specimens of plesius are very close to some spring and summer 

 examples oi palitsfris^ but can usually by the other characters be 

 easily distinguished. Comparison of specimens taken at corre- 

 sponding seasons, however, makes at once evident the differences 

 between the two forms. The lighter brown of the central portion 

 of the pileum averages much paler and more extensive in plesius 

 than in palustris. There are among the specimens examined none 

 of the latter which have the lighter brown so pale or so extensive 

 as seen in some of the former ; and none of this western race have 

 the dark lateral stripes so intense in color as have many examples 

 of the eastern bird. 



The most noticeable character which separates C. p. plesius from 

 paludicola is the much paler color of both the upper and lower 

 parts, this difference being usually most apparent o'n the flanks, 

 upper surface of the wings, scapulars, lower back and rump. The 

 wings, tail and bill average somewhat longer ; and the total 

 length of culmen is decidedly longer than middle toe without claw, 

 which is not the case with paludicola. So far as is indicated by 

 the specimens examined, the bars on the middle rectrices oi plesius 

 average broader and somewhat more regular than in paludicola. 

 The area of light brown on the crown averages very much more 

 extensive than m. paludicola, often reducing to mere lateral stripes 

 the dark brown or blackish color. This difference, as well as the 

 paler general color of the birds from the western interior, was 



