132 ON AN OVERLOOKED SPECIES OF REGULOIDES. 



him. A mere opinion won't do. He must satisfactorily 

 dispose of all the facts noted in this paper. I was extremely 

 puzzled by Mandelli never sending me a bird that correspond- 

 ed with my brown-headed North-West ones, but now the 

 reason is clear. His R. proregulus, on the other hand, agreed 

 perfectly with North- West Himalayan examples, which to my 

 mind disposes of Mr. Hume's argument as to the habitual 

 greater intensity of colouring in individuals obtained in moister 

 localities. The exact geographical distribution of the two 

 closely-affined Reguloides is an interesting question, and of 

 this we may know more hereafter. 



Although the two birds are close to each other in general 

 appearance, the three Erythrosterm — parva, albicilla, and 

 hyperytlira — are even closer. I could cite many other species 

 with slighter differences than those existing between the two 

 Reguloides under consideration. 



I have heard the call note of each, and I cannot say they 

 are different : but we have apparent identity of note in many 

 species where there is the most marked distinction. A distinct 

 note is, however, conclusive. 



Since the above paper was written I have examined a selec- 

 tion of the two birds from Mr. Hume's museum. 



As regards darkness of head, R. superciliosus, or the greener 

 bird, is very variable, some having the top of the head green 

 without any blackish markings. It is most probable that the 

 very green and yellow birds, without the dark trochiloides-like 

 head coloration, are those in first or nestling plumage, and 

 that the dark colour is not acquired till after the first moult. 

 The converse of this would hardly be likely. I know that young 

 Willow Wrens (P. trochilus) are of lighter tone, and immeasur- 

 ably more yellow than the old birds. In fact, the old bird cannot 

 be called yellow in comparison. This rule is, I believe, pretty 

 general as regards these little birds ; and R. superciliosus, in spite 

 of its wing bars, is wonderfully close to P. trochilus. They are 

 both Willow Wrens, and have similar call-notes, nests, and eggs. 



The upper figure on the plate of R. superciliosus in Mr. Dres- 

 ser's "Birds of Europe," shot at Darasun, 29th August, I take 

 to be a nestling bird in first brilliant green and yellow plumage. 

 It precisely agrees with Mr. Hume's specimen procured at 

 Mergui in Tenasserim, on the 6th November 1874. On the 

 other hand, the lower figure of the plate is well represented by 

 some of the January Burmese examples of the old bird, some- 

 what faded. I don't think much, if any, of the blackish olive 

 head coloration would be left by the middle of summer. Traces 

 of it are visible on two birds I shot near Calcutta about 

 Christmas time last year. I decidedly think that these dark- 

 headed birds are the old ones after their autumnal moult; and 



