Or NORTH-EASTERN CACHAR. 11 



41 bis. — Polioaetus plumbeus, Hodgs. 



" This Fishing Eagle is to be found on all the rivers ; it is 

 very common all the year. — J. I." 



An old adult of this species with a wing 17, and without 

 any trace of white on the upper surface of the tail, but with 

 the lower surface of the basal two-thirds of the tail greyish 

 white mottled with dark brown. 



No one who has compared a series of these two species 

 can doubt their distinctness. Ichthyaetus must wei^h near- 

 ly double what plumbeus does. 



51— Circus macrurus, S. G. Gmel. — C. Swainsoni, 

 Smith. 



" The Pale Harrier is not common. It is found on the banks 

 of rivers and some times scouring the rice fields. I have only 

 seen it between December and March. — J. I." 



53.— Circus melanoleucus, Gm. 



" This pretty Harrier is extremely common from September 

 to April. I have not seen it during the hot weather. — J. I." 



Numerous specimens sent from Cachar shew that this spe- 

 cies is very common in that district. Amongst them are 

 several young birds, which, I am sorry to say, do not greatly 

 assist in elucidating the complicated question of the change 

 of plumage in this species. 



And first as to whether the female ever assumes the per- 

 fectly black and white plumage of the adult male. On this 

 point, I see that Mr. Gurney accepts my view, that if the 

 female ever does assume this plumage it is only quite excep- 

 tionally, and not as a normal stage of plumage. It is not 

 merely that out of more than fifty specimens dissected b^v various 

 Indian observers during the last i'ew years, not one female 

 has yet been detected in the black and white garb; but there 

 is an independent argument derived from the fact that the 

 tarsi and wings of the black and white birds average consi- 

 derably smaller than those of what I take to be adult, and nearly 

 adult females. Clearly, if these latter afterwards passed into 

 the black and white plumage, we ought to find a fair propor- 

 tion of black and white birds as big, if not bigger, than these 

 supposed immature birds. The fact that nearly the whole of 

 these are bigger than almost che whole of the black and white 

 birds, appears to me a conclusive argument against these so- 

 called immature females ever putting on the black and white 

 garb. 



