Bicknell on Hylocichla alicice bicknelli. 
*57 
panion, a solitary Purple Finch occasionally alighted, and with a 
few wild fugitive notes was gone, to other mountain tops or the 
forests of the descending slopes. 
But to revert to the Thrushes. The two specimens of the new 
form which were obtained were both males, and were unques- 
tionably breeding,* though no nest known to belong to their 
species was found. 
It remains to briefly consider some facts furnished by the birds’ 
occurrence as narrated. These facts bear directly on the long 
contested question of the relationship which H. alicice and H. 
swainsoni bear to one another, and it can scarcely be denied 
that the present evidence on this point is conclusive. Not only 
have we representatives of both birds preserving their respective 
identities at the same locality, under identical conditions of en- 
vironment. but examples of each taken under these circumstan- 
ces, display, except in size, even a greater dissimilitude than 
those which occur together on their migrations. There is but 
one tenable interpretation of these facts : the birds — Hylocichla 
alicice and H. ustulata szvainsoni — are wholly and entirely dis- 
tinct. Any theory of dichromatism which might be advanced, 
aside from its extreme unlikelihood, would be shown inadequate 
by the relative differences in proportions of parts which the two 
birds exhibit. These differences, as well as those of color are 
illustrated by the Catskill birds. A specimen of H. swainsoni 
taken at the top of Slide Mountain was in every way typical of 
its species, and conspicuously unlike the examples of bicknelli 
taken at the same time. Aside from differences in the propor- 
tions of parts, the two birds were strikingly different in color, the 
decided grayish olive tinge of the superior surface of swainsoni 
contrasting strongly with the much darker brownish cast of its 
congener. One example of the latter instead of showing indica- 
tions of a bufty tinge about the sides of the head and on the breast, 
which under the circumstances we should expect to be the case, 
were it in any way specifically related to swainsoni , has ab- 
solutely no indications whatever of this shade about the sides 
of the head, and actually less on the breast than any speci- 
* Both birds were carefully examined and the evidence on this point was positive and 
unequivocal. A Thrush’s nest containing spotted eggs discovered near the top of Slide 
Mountain may have been either that of this form or of swainsoni, but as positive iden- 
tification was prevented, further allusion to it is, for the present, withheld. 
