MARSH-TIT. 



477 



is found whichj were it not probable that intermediate forms occur, might 

 fairly be considered specifically distinct. The tail is rounded, slightly 

 shorter than that of the East-Siberian birds ; the upper parts are sandy 

 white, and the flanks pure white. This bird may be looked upon as the 

 extreme arctic form. Southwards, in Japan the Marsh-Tit, to which I 

 have given the name of P. japonicus *, has the tail, although rounded, still 

 further decreased in length, and the colour of the upper parts is only 

 slightly paler than in South-European examples ; but the flanks are only 

 faintly suffused with brown. In North China the Marsh-Tit of South- 

 west Europe (P. palustris) reappears : the tail is nearly even, and equal in 

 length to that of its European ally ; and the only perceptible difference is 

 that it is a trifle paler on the upper parts than examples from the British 

 Islands f. The Marsh-Tit of Turkestan, P. songarus, is apparently speci- 



* To better and more clearly express the dift'erences found in the Marsh-Tit, I have 

 drawn up the following Table : — 



+ Dresser, ' Birds of Europe,' iii. p. 1 20, is in en-or in saying that the Chinese form most 

 nearly resembles P. borealis. 



