in the Plumage of Zosterops cterulescens. 327 



when the breeding-season with the species is virtually over, 

 the throat is slightly paler than in the spring, and this livery 

 is retained until the beginning of March. The flanks then 

 become darker, increasing in intensity of colour from that 

 time forward, the yellow feathers on the throat also disap- 

 pearing and passing into grey until the autumn livery is 

 again fully assumed by the end of April. 



Of six specimens obtained at Table Cape, Tasmania, 

 during April 1894, three have the throat grey, the remainder 

 faintly washed with yellow, and in all of them the flanks are 

 of a deeper tawny buff than in Australian examples. 



The distinguishing characters in the seasonal changes of 

 the plumage of the under surface of Z. ccerulescens may be 

 briefly summarized as follows : — 



Spring plumage. — Throat bright olive-yellow ; chest and 

 breast ashy grey, passing into dull white on the abdomen ; 

 flanks very pale tawny brown ; under tail-coverts dull white, 

 in some specimens washed with yellow. 



Summer plumage. — Similar to the spring, but the throat 

 slightly duller in colour. 



Autumn plumage. — Throat faintly washed with olive- 

 yellow or gradually passing into grey ; flanks tawny buff. 



Winter plumage. — Chin and sides of the throat dull olive- 

 yellow ; centre of the throat, the chest, and breast ashy ; 

 flanks deep tawny buff; abdomen and under tail-coverts dull 

 white, the latter in some specimens washed with yellow. 



Transition from ivinter to spring plumage. — Throat 

 greyish white, faintly washed with olive-yellow ; flanks pale 

 tawny buff; under tail-coverts dull white, slightly tinged 

 with yellow. 



Cbs. — The average measurements of examples obtained 

 during winter and in summer are alike. All through the 

 year some specimens are found with the under tail-coverts 

 tinged or washed with yellow. This does not appear to be a 

 sexual character, although from the specimens examined the 

 yellowish wash on the under tail-coverts predominates 

 among the males. As a rule, however, the dull white or 

 white under tail-coverts are found in birds obtained during 

 the winter. 



Under the synonymy of Z. westernensis Dr. Sharpe includes 



