696 ZOOLOGY. 
numbering all the other birds together. It is surprising that so 
common a bird should have resisted research, as this one has, for 
thirty years. Its history is somewhat peculiar. Discovered by 
Audubon on the Yellowstone, in 1843, the original specimen, still 
preserved in the Smithsonian, has remained unique until the pres- 
ent year. It was described and figured by Audubon (Birds of 
America, vii, p. 359, pl. 500) under the name of Emberiza Bairdii, 
and in 1858 was made the subject of an elaborate article by Prof. 
Baird, who instituted for its reception the genus Centronyx. This 
name, however, is scarcely tenable, the structural peculiarities 
being so slight that the bird might very properly stand as Passer- 
culus Bairdii, if the original generic designation be considered too 
broad for present use. (The species is so much like a savanna 
sparrow that it was some days before I learned to tell the two 
apart, at gunshot range, often shooting one by mistake for the 
other.) The literature of the subject rested mainly on these two 
articles until 1869, when “ Centronyx Bairdii” came again on the 
tapis, through the announcement of its discovery in Massachusetts 
(see Maynard, Am. Nat., iii, 1869, p. 554, and Nat. Guide, p. 112: 
see also Allen, Am. Nat., iii, p. 631, and Brewster, Am. Nat., vi, 
1872, p. 307). This, however, was a mistake: the supposed Cen- 
tronyx proving to be a Passerculus, believed by Mr. Maynard to 
be new, and by him afterwards named P. princeps (Am. Nat. vi, 
1872, p. 637; see also Coues, ‘‘ Key,” pp. 135, 352). In noticing 
these points last year, in the “ Key,” as just quoted, I rather cast 
suspicion upon the true species itself, by venturing upon the gra- 
tuitous presumption that a second specimen of Centronyx would 
never be found. This was decidedly the greater blunder of the 
two —to tell how I happened to be led into it would not interest 
the general reader. So matters stood till this year, when Mr. C. 
E. Aiken took, in Colorado, a Centronyx which was considered to 
be a second new species of that genus, and was published as such 
under the name of C. ochrocephalus (Am. Nat., vii, 1873, P. 237). 
The writer of the article in question takes pains to point out cer- 
tain slight discrepancies in size and form between the type speci- 
men of C. Bairdii and the single specimen of the supposed new 
species, and lays particular stress upon a difference in the colora- 
tion of the heads of the two. Now I have not yet seen the new 
bird, and will not risk the chances of being twice mistaken about 
One species ; but this is certain : that the ascribed specific charac- 
