1871.] 377 [Maynard. 



this is not so quickly given as the se wicB of E. minimus, and is 

 somewhat harsher. There is, perhaps, thirty seconds interval be- 

 tween each ke wink'. The birds while singing were perched on the 

 tops of a low alder. It appears to frequent these thickets generally 

 by the side of streams, for Mr. Brewster has repeatedly observed it 

 in similar localities at Gorham, where it has the same song and hab- 

 its. When the bird is freshly killed, the bill bears a striking resem- 

 blance to that of E. flaviventris, being somewhat broader than E. 

 minimus, and having a yellow under mandible delicately veined with 

 purple. But in the dried skin, this yellow fades into brown and 

 loses its veining. The whole bird then appears much like the 

 larger and darker types of E. minimus. Indeed, were it not for the 

 slightly larger and broader bill, generally olivaceous, or greenish yel- 

 low of the strip at the base of the upper mandible and sides of the 

 head of E. Traillii, it would be difficult to determine skins of the two 

 species. Although these species approach each other so closely that 

 without a sufficient number of skins for comparisons, they are in 

 great danger of being confounded, two intermediate species have 

 been formed, Acadicus and pusillus. The only difference between 

 Traillii and the former, are the feathers on the crown of Acadicus 

 lack the darker centres of those of Traillii and a few other (seem- 

 ingly to me), inconsistent characters. The latter (pusillus) is also 

 described as quite like Traillii, but different from it in being browner, 

 and having a less amount of white on the wings, with a few other 

 characters that I have repeatedly proved (to my mind), to be ex- 

 ceedingly variable and inconstant. Although I have never seen a 

 sufficiently large series of these three species (pusillus, Traillii and 

 acadicus), to prove conclusively that they are one, I have seen 

 enough to cause grave doubts in my mind, as to the validity of the 

 characters used in separating them. Indeed, I have been unable to 

 find any decided difference between the specimens of pusillus and 

 Acadicus, labelled by competent authorities, that I have examined 

 and compared with quite a large series of Traillii taken north. 



In connection with these observations, which have induced me to 

 advance the hypothesis that these three so-called species are one, I 

 have been strengthened in my opinions by the experience gained by 

 studying the individual variations of birds. One of the first and 

 simplest lessons we can learn in this study, is that such characters as 

 intensity and paleness of color are subject to wide individual differ- 

 ences, and should be used with extreme caution in determining spe- 



