S6 THE ZOOLOGIST. 



head of the Sedge-Warbler, a careful inspection of the latter 

 species when immature shows it is present ; furthermore, the black 

 stripe immediately above the buff-coloured eye-stripe (superciliary 

 stripe) is practically as well marked as in the Aquatic Warbler. 

 This black stripe is also present in the head of the adult Sedge- 

 Warbler in spring and autumn garb, but as the lighter mark- 

 ings of the crown of the head are considerably darker than in 

 the immature bird, this dark stripe is much less conspicuous. 

 All the same, it is quite definite. Hence this stripe and the 

 lighter eye-stripe form no absolutely distinguishing character 

 of the Aquatic Warbler. The black stripe in the Aquatic 

 Warbler's head looks more conspicuous because the buff stripe 

 is broad, light, and clear in colour, and forms a stronger 

 contrast than do the markings on the crown of the head in the 

 Sedge-Warbler. 



If one were to examine quite casually the crown of the 

 head of an immature Sedge-Warbler when the feathers were 

 not lying absolutely in their proper position, one might 

 get the impression that the head was speckled or at the 

 most irregularly streaked with buff and brownish black mark- 

 ings. Such, however, does not represent the true pattern of the 

 head plumage as it exists in life, or in the dead bird when the 

 feathers are carefully re-arranged. In reality the plumage 

 pattern of the head in the Sedge-Warbler (best seen in the 

 immature bird) is made up of a narrow medial buff stripe, on 

 either side of which are narrow alternating dark and light 

 stripes, longitudinally directed, and disposed in a bilaterally 

 symmetrical manner. The essentials of this pattern appear to 

 be represented also in the head of the Aquatic Warbler, but 

 while the stripes are of almost equal thickness in the Sedge- 

 Warbler, we find that one of the buff stripes is remarkably thick 

 and another is extremely thin in the case of the Aquatic 

 Warbler. The thin, hair-like buff streak separates the broad 

 black streak immediately over the buff eye-streak into two black 

 bands, both of which are present in the head of the Sedge- 

 Warbler and are separated by a stripe of buff. In the head of 

 the Sedge- Warbler and in that of the Aquatic Warbler we find 

 markings which, for the purpose of description, I propose to 

 designate as follows:— A stripe of buff running along the 



