338 THE ZOOLOGIST. 



the able article, " On Anser erythropus and its Allies," in the 

 current issue of the ' Ibis' (cf. ' Ibis,' 1902, pp. 269-275). 



On studying this subject later, I found that there was much 

 diversity of opinion amongst authorities as to the specific validity 

 of Anser gambeli, the bird having been separated from A. albifrons, 

 and so named by Hartlaub as far back as 1852; and, although 

 his diagnosis has been questioned by several ornithologists, there 

 appears to have been no real effort made to settle the point 

 during all these fifty years. 



I must confess that when I first examined the series of skins 

 at South Kensington I was much puzzled, and felt that, with 

 such a series, it would be extremely difficult to discriminate 

 between the two species. I may here say that I consider the 

 series in the National Collection to be inadequate and not a 

 representative one, there being but very few specimens, mostly, 

 if not all, in the winter condition of plumage. Although I have 

 examined the series of both birds twice, they have afforded me 

 very little assistance. 



Later, I got together my entire series of White-fronted Geese, 

 and have devoted the bulk of the past winter season to a study 

 of this subject. I have been lucky in securing many examples 

 to fill gaps in my series, and have now sixteen carefully selected 

 specimens to work upon, these providing ample material in my 

 judgment for proving two important facts, viz. the specific validity 

 of A. gambeli — it must not be regarded as a subspecies — and its 

 frequent occurrence as a British bird ; the whole of my sixteen 

 specimens of the two species having been received from the west 

 coast of Ireland at different times. 



Most authorities agree that the chief distinguishing charac- 

 teristics between A. albifrons and A. gambeli are, the larger and 

 heavier bill, and darker under parts of the latter. I have found 

 other characters which I will state later ; but, taking this longer, 

 broader, and generally heavier-built bill as my guide, I could 

 easily separate the two birds, and make a series of ten A. gambeli 

 and six A. albifrons. 



Unfortunately, I lack some of the connecting links in the 

 latter bird ; I have seen them in years past, and remember them 

 well, but did not secure them, not knowing at the time that I 

 was collecting two species of birds. I shall meet with those 



