— 
SILVER GULL. 107 
Larus novehollandie gunni Mathews, Nov. Zool., Vol. XVIII., p. 212, Jan. 31st, 1912: 
Tasmania. 
Larus novehollandia ethele Mathews, Austral Av. Rec., Vol. I., pt. 2, p. 30, April 2nd, 1912: 
Kangaroo Island, South Australia. 
Bruchigavia novehollandie yorki Mathews, Birds Austr., Suppl. No. 1, Check List, p. 30, 
Feb. 16th, 1920: Torres Straits, Queensland. Nom. nov. for Gelastes gouldi Bonaparte, 1854. 
DistrrBuTION.—Australia generally and Tasmania. 
Adult male-—Back and wings blue-grey ; head and neck all round and entire 
under-surface of the body pure white including the axillaries and under tail-coverts ; 
upper tail-coverts and tail also white as well as the small coverts round the bend of 
the wings, both above and below; inner under wing-coverts inclining to grey ; 
bastard-wing and primary-coverts white; the first primary black with a white 
mirror towards the end which occupies both webs, slightly fringed with black on the 
inner one ; the second primary has a line of white near the base which occupies the 
shaft and a small portion each side of it, a mirror near the tip similar in shape to 
the one on the first primary but more broadly margined with black on the inner 
web; the third primary has a similar line of white from the base to beyond the 
middle of the feather, and another elongated spot on the inner web which is joined 
by the continous white shaft, also tipped with white ; the fourth quill is white on 
the outer web for the greater part of its length, towards the end it crosses on to the 
inner web: the basal portion of the inner web is greyish-brown near the shaft with 
a subapical black and white tip ; the fifth primary is white on the outer web nearly 
the whole length, dark grey and fringed with black on the inner web, with a subapical 
black band and white tip; the sixth quill is blue-grey fringed with black on the 
inner web towards the end and a narrow subapical black band and white tip; the 
seventh primary blue-grey with a very slight fringe of black on the inner web near 
the tip ; secondaries entirely blue-grey ; bill and feet red ; iris white, eyelid red. 
Total length 440 mm. ; culmen 36, wing 309, tail 120, tarsus 50. 
Adult female —Similar to the adult male but smaller. 
Immature —Difiers from the adult in having the tips of the feathers on the 
nape, hind-neck, and mantle brown; the lesser wing-coverts brown tipped with 
white and fringed on the sides more or less with ochreous-buff, the greater coverts 
grey with a subapical brown spot and white tip; bastard-wing dark brown on the 
inner web ; the secondaries grey with subapical brown marks and tipped with white ; 
the innermost secondaries brown with grey bases irregularly marked and fringed with 
white at the tips, also a slight mottling of buff; some of the scapulars similarly 
marked but paler; the feathers of the rump grey with subapical brown spots and 
fringed with buff at the tips; some of the upper tail-coverts blackish at the tip ; 
tail-feathers white with a subapical dark band mottled with buff and tipped with 
white. As the bird advances in age the brown of the upper wing-coverts seems to 
be the last to change. Iris light grey, eyelid orange, bill dark horn, legs and feet 
greyish-black. 
Immature with traces of down—Channel Rock, Torres Straits, June Ist, 1881 : 
“Tris brown, bill horn, legs and feet light brown ’’; top of the head uniform light 
brown, bases of all feathers white tipped with light brown with a penultimate bar 
of much darker brown ; these colours increase in depth on the scapulars ; rump 
white; tail-feathers with white tips, penultimate brown bar and white bases ; 
general under coloration white; primaries black with white tips, the first two 
primaries showing incipient mirrors (which are not present in first complete immature 
plumage, but reappear at a later age); greater coverts white, the outermost with 
irregular black markings, the next two fringed on outer web with darker brown. 
(These are similar in immature birds, but are pure white in adult.) 
Nestling —Heavily mottled with brown on the upper-surface ; under-surface 
white. 
Nest.—Formed of a few rushes and grasses. 
