Mr. W. E. Brooks on the Genus Acautliis. 361 



forms closely allied, but nevertlieless sufficiently segregated 

 to rank as distinct species.'' Compared with my statements 

 above, we seem to be of very opposite views in this case ; 

 but I think I can offer a satisfactory explanation. By com- 

 paring summer specimens of the so-called A. holboeUi from 

 Greenland and more southern winter birds with the ordinary 

 form occurring in Europe and America under that name, I 

 was at once struck by the great differences. The Green- 

 land bird is evidently considerably larger, its bill much 

 stouter and somewhat differently shaped — not so pointed — 

 besides being on the average a trifle shorter. As to colour, I 

 thought they were rather darker and heavier-streaked below. 

 I was very soon convinced that these birds were different 

 from the common A. holboelli, being in fact the form originally 

 described by Coues as A. rostratus, but afterwards given up by 

 him. It was also clear that the specimens examined and 

 described by Brewster were the winter plumage of the same 

 form. The Redpolls are rather difficult to determine from 

 descriptions, but if the latter were all so clear and thorough 

 as those of Mr. Brewster, there would have been less confusion 

 in this group of birds. His statement that the specimens 

 from New England ' will be found to difler from the ordinary 

 type {A. linaria) in being very much larger, with stouter, less 

 acute bills, generally darker coloring, and especially darker, 

 coarser streaking beneath,' will apply to A. rostrata, as 

 distinguished not only from A. linaria but also from true A. 

 holboelli. Nevertheless, I do agree with him in regarding 

 Acanthis rostrata as a Slistinct species.' The conclusion of 

 Mr. Brewster is easily explained, he probably having only the 

 short-billed A. linaria for comparison ; but as the measure- 

 ments given below show there is a regular intergradation, and 

 tfce Greenland bird cannot be justly designated except as con- 

 specific with the other forms. It will therefore, after the 

 common usage of American writers, stand as A. linaria 

 rostrata." [Stejneger, I. s. c.) 



With this last conclusion of Dr. Stejneger's I cannot 

 agree, and I go entirely with Mr. Brewster as to complete 

 specific distinctness. Apart from its gigantic size for a 



SER. V. — VOL. IV. 2 c 



