100 
BULLETIN OF THE NUT TALL. 
always described the bird with all the lateral rectrices narrow, and 
destitute of any notch. 
I have not said anything, in comparing the species, about the 
color of the back, as I consider this is not altogether a satisfactory 
character by which to distinguish the birds, though Mr. Henshaw 
makes it one of his principal ones. Latham, in his original descrip- 
tion, states that the “ crown ” was “ glossy green,” and also that there 
,was a “greenish gloss between the wings.” In the first place, the 
females of both are entirely green in their upper surface, and this is 
not always pure green, as I have specimens now before me, collected 
by Boucard at Oaxaca, Mexico, in which the back is a yellowish- 
bronze, precisely like young males in my collection from California 
of the other form, collected by Dr. Heermann. Again, I have 
young males, also collected by Boucard at Oaxaca, which have the 
back of such a curious reddish-cinnamon that it is difficult to say 
what color it exactly is ; and Mr. Henshaw says, in his article 
(p. 55), that “ in California, however, where the S. rufus occurs in 
its typical condition, that is, with an unmixed rufous back, specimens 
are not uncommonly found which exhibit a strong approach to the colora- 
tion of S. alleni ” ; although, as he farther says, “ they never apppear 
to pass beyond a certain point.”.. It is, however, indisputable, that the 
two species do vary in the amount of green upon their upper sur- 
face, and also that at times they approach each other in coloration 
so nearly that, were there no other differences existing, it would be 
impossible to separate them. For this reason I do not place much 
reliance upon the amount of green on the back as a specific charac- 
ter. But there are other differences, I think, not mentioned by Mr. 
Henshaw, to be observed in the females, by which this sex of the 
two species can be distinguished. The female of the Mexican * 
species has the rectrices broad. 
In addition to the superior width of its rectrices, the Mexican 
bird has the lateral tail-feathers, for more than a third of their 
length in the central portion, jet black, the base light rufous, and 
the tips white, so that when the tail is closed, and looked at from 
* I use the terms Mexican and Californian to designate the birds with broad 
and narrow rectrices respectively, for the term rufous has been so misapplied that 
I cannot employ it at present without risk of adding to the confusion. At the 
same time the bird called alleni is not restricted to California, as I have al- 
ready shown, but goes as far north at least as Nootka Sound, and may in winter 
pass into Lower California, perhaps into Mexico. 
