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rable, I must now follow other authors in referring both this and the preceding species to the 

 larger and better-defined genus Larus. Finding that the above title had already been bestowed 

 on another member of the genus, by Temminck, Captain Hutton has done me the honour to 

 associate my name with the present species, which is now figured for the first time. 



Another local naturalist, Mr. T. H. Potts, whose name is of frequent occurrence in the 

 course of this work, has paid me a similar compliment in proposing the name of Larus bulleri 

 for a Yellow-billed Gull, which he considers distinct. While I take this opportunity of ex- 

 pressing my acknowledgments, I am unable at present to recognize the supposed specific distinc- 

 tion. On a careful comparison of the two birds, I find that they correspond exactly in size, in 

 the form of the bill, and in the colours of the plumage, even the eccentric markings on the pri- 

 mary quills being the same in both. The only difference, therefore, is in the colour of the bill 

 and legs ; and as it is well known that several members of this group undergo a seasonal change 

 in this respect, the distinction cannot be accepted as having any specific value till it be sbown 

 that the difference of colour is constant in both birds all the year round. As opposed to the 

 latter view, I may mention that in the autumn of 1871 I shot a specimen, on the sand-banks at 

 Hokitika, in which the bill was pale coral-red in its basal portion, and brownish black beyond 

 the nostrils, indicating, as it appears to me, a transition to the black bill characteristic of the full 

 winter plumage. 



Dr. Finsch, to whom I forwarded skins of both for examination, concurs in this opinion ; 

 but he also goes further, and refers the species to Larus pomare of Bruch (supposed to be from 

 the Sandwich Islands), although he complains of the extreme confusion and insufficiency of all 

 Bruch's descriptions. While I attach great weight to the opinion of so careful an ornithologist 

 as Dr. Finsch, I am unable to adopt his view in the present case ; for having visited the Museum 

 at Mayence and examined the type of Lams pomare for myself, I find that it has a more robust 

 bill than our bird, and more black on the primaries ; while the young, in addition to the spotted 

 markings on the back and wings, which appear to be common to the whole group, has dark ear- 

 coverts, and a brown terminal band across the tail. 



The specimens on which Mr. Potts founded his description of Larus bulleri were obtained 

 near the mouth of the Waimakariri river ; and, as already mentioned, I met with the same bird 

 on the west coast ; so that, assuming my identification to be correct, the Black-billed Gull is not 

 confined to the inland lakes, as was hitherto supposed, but also frequents the mouths of rivers 

 and estuaries, where it appears to mingle freely with the flocks of Larus scopulinus, Sterna fron- 

 talis, and other birds having a community of interest. 



On the habits of this species, as observed by Mr. W. T. L. Travers on Lake Guyon, in the 

 Province of Nelson, I have much pleasure in quoting the following account from the pen of that 

 gentleman : — 



" The Black-billed Gull breeds on the main river-bed; and one or more pairs usually frequent 



the lake after the breeding-season is over. On one occasion a pair of these birds, having by 



some means or other lost their own brood, returned to the lake earlier than usual. I brought up 



a young bird belonging to another brood, and placed it on the lake ; and the bereaved parents at 



once took to it, tending it with the greatest care and solicitude. It is extremely interesting to 



watch these birds in their ordinary search for food during windy weather. The prevalent winds 



2o 

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