324 BIRDS FROM YEZO, JAPAN—STEJNEGER. 
(i. e., the adult male) has generally the rump striped with blackish, and 
on the lining of the wing the white predominates. In Eastern birds the 
rump is in most cases unspotted, and black predominates on the under 
wing-coverts. These characters are now generally admitted. It may 
be added that the brown margins to the feathers on the upper surface 
in British examples are much darker than in Indian, Chinese, Korean, 
and Japanese specimens, and that the under surface is also deeper 
colored. But there is a character, hitherto apparently overlooked, 
which, so far as my experience goes (thirty-eight specimens), trench- 
antly separates the two species. On comparison it will be found that 
the European birds have the bill much narrower at the base than the 
birds from the East. Even the young in the first plumage can be easily 
told apart by this character. Considering this fact and the many 
points in which the two forms disagree, I refuse to adopt a trinominal 
appellation for the Eastern birds, the more since it seems as if the 
breeding habitats of the two species are separated by a belt of country 
about 600 miles wide. (Cf. Severzow, Journ. f. Orn., 1873, p. 360, foot- 
note.) 
Now, concerning the latter, it may be said that Maj. Biddulph 
(Ibis, 1882, pp. 272-276; Stray Feath., x, 1882, pp. 263-266) has made 
out a pretty strong case for those gentlemen, headed by Mr. W. E. 
Brooks, who insist upon the existence in India of two forms of Stone- 
chats, both with unspotted rumps. He states that he was able to sep- 
arate his birds in two series. In series A the males are characterized by 
absence of white on the nape concomitant with larger size (wing 2.70 
inches to 3 inches = 68.6™™ to 76™™), the females by brighter colors 
and larger size (wing 2.55 to 2.70 inches = 64.8" to 68.6™™); the 
males of series B have the white patch on the sides of the neck ex- 
tending “round to the back, meeting the white from the other side, so 
as to form a complete demicollar when viewed from above,” their wings 
varying between 2.52 and 2.75 inches (= 64™™ and 69.8™™); the 
females of the latter form are “ altogether of a much darker tone,” with 
the length of the wing 2.35 to 2.60 inches (= 59.9™™ to 66™™). Five 
specimens of somewhat intermediate size he was “ unable to separate 
by differences of color.” Then he concludes as follows: ‘ Now, it can 
not be denied that these measurements overlap considerably, especially 
among the females; but the fact remains that, after separating forty- 
three specimens solely by color and markings (omitting the last five 
undetermined), those of one form average considerably larger than those 
of the other, and that the greatest divergence in color is shown between 
those which differ most in size. It may be that the specimens that 
overlap in measurement are to be accounted for by hybridism—an ex- 
planation that no ornithologist can affect totally to ignore when treat- 
ing of two very closely allied species found in the same locality; or it 
may be that some of those classed as females would have been found 
by more careful examination to be males that had not got rid of female | 
