346 



SYLYIIDJE. 



Fig. 110. Acrocephalus stentoreus. 



Family SYLVIIDJE. 



The intrinsic muscles of the syrinx fixed to the ends of the 

 bronchial semi-rings ; the edges of both mandibles smooth or the 

 upper one with a single simple notch ; hinder aspect of tarsus 

 smooth, composed of two entire longitudinal laminaB ; wing with 

 ten primaries ; tongue non-tubular ; nostrils always clear of the 

 line of the forehead, the space between the nostril and the edge of 

 the mandible less than the space between the nostril and the culmen ; 

 plumage of the nestling like that of the adult female, but brighter ; 

 rectrices ten or twelve ; sexes generally alike ; a partial or com- 

 plete spring moult in addition to the complete autumn moult. 



The Sylviidw, or Warblers, comprise a large number of birds of 

 small size and, with few exceptions, of plain plumage. 



Many of them have a complete spring moult, which not only 

 causes a change in the colour of the plumage, but also a change in 

 the shape and length of the tail. In some the spring moult is 



