AUSTRALIAN BLAGK-BROWED MOLLYMAWK. 
dusky yellow, and always with a darker tip. We considered these grey-headed 
and grey-necked individuals, if the biU was broad, yellowish and darker 
tipped, to be the young of D. mdano'phrys. There was no difficulty in dis- 
tinguishing the grey-headed D. melanophrys from the grey-headed Th. chlor" 
orhynchus and Th. culminatus, since the colour of the bill in the two latter is 
much more clear cut and distinctly black and yellow than the dusky-brownish 
or yellowish bill of the immature D. melanophrys'^’’ — Wilson himself casts 
doubt upon these grey-headed birds being immature D. melanophrys as none 
were procured. It should also be observed that Wilson never notes D. cauta, 
though some of the subspecies of this bird should have been seen by him. 
That species, though somewhat larger, has a unicolored bill and is very shy, 
as noted by Wilson for his unrecognisable birds. 
The examination of long series of this bird proves the recognition of several 
races desirable, and I propose the following subspecies as separable, with the 
material available. D. melanophris was described from the Cape seas, where 
it is very abundant, and the form there found breeds in the South Atlantic. 
At various times it has been recorded as breeding on Gough Island, Tristan 
d’Acunha, and the Falkland Islands, but the last-named locality seems the 
only authentic one at the present time. 
The birds from Kerguelen Island have longer bills, and the bill-coloration 
seems paler than in the typical form ; this is a matter which seems to have 
escaped serious attention, and the various discrepant accounts of different 
observers have been lumped as seasonal or sexual features. I am inclined 
to put such down to the confusion of races, as adult birds seem to show con- 
stancy in their bill-coloration, as they certainly do in the bill-measurements. 
For the Kerguelen breeding birds, I propose to use 
Thalassarche melanophris helcheri, subsp. n. 
The New Zealand breeding birds, for which I have taken up Solander’s MS. 
name, whose diagnosis I attach, have short bills and the black in front, above 
and behind the eye is pronounced, while a strong greyish wash is noticeable 
on the lores. The Kerguelen birds lack the greyish lore-wash and the black 
in front of the eyes is not so marked, though the black behind the eye extends 
further back. 
The Australian bird (New Zealand breeding) should be, therefore, called 
Thalassarche melanophris impavida Mathews. ^ 
impavida Diomedea (alis pennatis, pedibus a’quilibribus tridactylis) rostro lutescente cera 
nigricante, capite albo ; regione oculorum nigra 
Habitat m Oceano australi Latit. austr. XXXIX 17 Longit. occid. CCIV 6 (Apr. 11, 
1770) 
Bostrum figura omnino convenit cum Diomedea exulante Lion sed pallide & sordide 
lutescens, apiee parum incarnatum, la'vigatum 
271 
