SILVER GULL. 
Light coral bill and in the immature a light bill though not clear coral ; the 
first three primaries all with mirrors, but somewhat elongate in shape 
(c/. figure). 
BrucJhigavia novcB-hollandice gouldi (Bonaparte) ; North Australia. 
Larger, with a deeper bill and usually lacking the mirror on third primary. 
Bruchigavia novce-hollandice forsteri, subsp. n. ; New Caledonia. 
Smaller than the preceding and larger than the next ; no mirror on the third 
primary, and the first two primary-mirrors intermediate between those of these 
two. Culmen (exp.) 37-41 mm. ; wing 293-300 ; tarsus 49-50. 
Bruchigavia novce-hollandice scopulinus (Forster) ; New Zealand. 
Smaller than the former, with square-cut primaries as figured by Saunders 
in the Cat. Birds Brit. Mus., Vol. XXV., p. 239. The bill is not such a deep 
red as in the typical form, and the primaries have hold white tips ; in some of 
the Australian forms small white tips are seen on the primaries ; these white 
tips are, however, quickly worn away. 
Bruchigavia novce-hollandice gunni (Mathews) ; Tasmania ; Victoria. 
Cannot be confused with any other form on account of the whiteness of the 
third primary (c/. figure). 
Bruchigavia novce-hollandice ethelce (Mathews) ; South Australia. 
Recalling B. n. novce-hollandice from which it differs in its larger size, and from 
B. n. longirostris in the presence of a mirror on the third primary. 
Bruchigavia novce-hollandice longirostris Masters ; South-west Australia. 
Differs in its large size, longer biU, longer legs, deeper-coloured biU (when it 
is red), and the absence (generally) of a mirror on the third primary. 
Bruchigavia novce-hollandice hartlauhi (Bruch) ; Cape of Good Hope 
must be included under this species-heading. 
Hull {ante, p. 451) has noted that the movements of the Montagu Island 
birds incite speculation, and puts forward two theories, inclining to the latter. 
In view of my experience of the species, the former is not worth considering 
and the latter 7nust be the solution. 
A criticism of the primary-coloration would cause more speculation as 
the Tasmanian bird has the mirrors more extensive than any other, and has 
smaller mirrored birds on each side— -South Australian and New Sou^h Wales. 
The South Australian bird seems to be closer to the New South Wales and 
West Australian than it is to the Tasmanian, while the Torres Strait bird 
is quite close to those from West Australia, but differs at sight in the colour of 
the bill ; the New Caledonian form seems quite a connecting link between 
the New Zealand and the Torres Strait forms. 
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