6 Proceedings of the Boyal Society of Victoria. 



Essendon, Victoria, is thought to be stocked with G. leuconota 

 alone, yet the specimen marked J is a nearly mature female of a 

 bird that could only be doubtfully marked G. tibicen, and pre- 

 ferably G. leuconota. It has a narrow "saddle" with a diameter 

 of 0-9 inch, and carries the leading characters of two species, i.e., 

 the female back of G. leuconota and the female saddle of G. tibi- 

 cen. There is nothing whatever to say it is not G. leuconota in 

 the reversional stage. The dimensions are: culmen, 1-8 in.; wing, 

 lOin.; tail, 6in.; tarsus, 2*25in. 



Mr. A. McGregor, to whom I am indebted for the Murtoa 

 skins, has shot the pure "white-backs" among the flocks of 

 "black-backs." This tends partly to the theory of hybridism, 

 but it does not support it by the results noted at Essendon, 

 Morwell and Somerville, where an isolation of species appears to 

 exist. 



G. HYPEELEUCA, Gld. 



all Adult J and $. British Mus- 

 eum - . - - - 



^11 Sk. $. National Museum - 



Tarsus. 



inches. 



2-] 

 2 



Specimens in the Australian Museum led Dr. Ramsay to con- 

 sider this bird not a good species (Tab. Hist. Aust. Birds, 1888). 



Mr. Campbell' gives the measurement of the longest culmen as 

 2-31 inches. 



The bird referred to by Gould in his Tabular List (Folio, Bds. 

 Austr.) as a doubtful specimen of G. tibicen doubtless is an 



1 Proe. Roy. Soc. Vict., N.S., vol. vii., 1S95. 



