Rick \ EI. I. o)i Hvlocichla aJiciiE bickmlli. I57 



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 weie 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. aliclce and H. 

 sivainsoni bear to one another, and it can scarcely be denied 

 that the pi'esent 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 

 aliciiB and H. ustiilata sivainsoni — 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 exhilMt. These differences, as well as those of color are 

 illustrated b}- the Catskill birds. A specimen of H. s%uai)iso7ii 

 taken at the top of Slide Mountain was in every way typical of 

 its species, and conspicuousK' unlike the examples of bick)ielli 

 taken at tlie same time. Aside from differences in the propor- 

 tions of parts, the two birds were strikingly diflerent in color, the 

 decided grayish olive tinge of the superior surface of sivainsoni 

 contrasting strongK' with the much darker brownish cast of its 

 congener. One example of the latter instead of showing indica- 

 tions of a buffy 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 an\- way specifically related to swainsoni. has ab- 

 solutely no indications v\ hatever of this shade about the sides 

 of the head, and actually less on the breast than an\- 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 swahisoni, but as positive iden- 

 tification was prevented, further allusion to it is, for the present, withheld. 



