Sao BIRDS FROM YEZO, JAPAN—-STEJNEGER. 
drawn from this collection are particularly valuable, as the preparation 
is excellent, the labeling full and exact, and the sex ascertained in 
every instance by dissection. 
An examination of all the material before me gives some general re- 
sults: 
(1) The amount of white at the base of the tail-feathers is not entirely 
due to age, and is subject to an endless individual variation, hardly 
two individuals being alike. Jouy’s No. 1592, Fusan, May 2, 1886, has 
very little white on the inner webs and scarcely any on the outer web 
of the outer pair, and yet itis a fullplumaged male with the whole 
upper surface black; and among the males with olive back there are 
many with the white in the inner web developed up to the maximum 
of black-backed ones. 
(2) In Mr. Jouy’s series twenty-one specimens are marked as males, 
some are black-backed, others olive-backed, but all have white at base 
of tail-feathers; fourteen specimens are females, all of which are olive- 
backed, and all without trace of white at base of tail feathers. The 
females have also the color on fore neck and breast considerably paler and 
duller. The great number shows that this coincidence is not due to 
an accident, but that we have here expressed the true sexual difference 
in this species, viz, males have white on tail, and throat rich orange- 
tawny; females have no trace of white on tail, and throat dull orange- 
ochraceous. Against the above series it counts very little that Hen- 
son’s No. 240 is marked “ 2 ,” though having white on the outer webs of 
the tail feathers and a rich orange-tawny breast and throat; it is a 
young bird, as evidenced by the two broad light cross bands on the 
wings, and there is every probability of a mistake in sexing. The same 
remark applies to Swinhoe’s description of a young bird as male, but 
without white on the tail (Ibis, 1862, p. 305, as M. hylocharis!). As 
far as the coloration of the tail is concerned the sexual difference in 
this species seems to be the same as in Cyanoptila belia (= cyanomelana). 
(3) This sexual difference in the coloration of the tail holds appar- 
ently good even in the first plumage, when the bird is leaving the nest, 
for Von Schrenck describes and figures a young bird in this plumage 
(Reis. Amur-L., 1, p. 375, pl.xiii, figs. 1, 2), which has the rectrices white 
in basal third of outer webs, while a young bird in Mr. Henson’s collec- 
tion (No. 1522), labeled female, and still showing traces of the nestling 
plumage, has no white at all on tail. 
(4) There is a considerable difference in the color of the spring and 
fall plumages of the adult males. After the autumnal molt they are of 
a bluish slate gray above, somewhat darker on the middle of the back, 
and the feathers more or less distinctly tipped with olivaceous. When 
they return in spring, however, the whole upper surface is glossy black, 
The young males are olive backed, and Swinhoe was consequently in 
error when considering this stage to represent the winter plumage of 
the adults, 
