98 A MANUAL OF THE BIRDS OF AUSTRALIA. _ 
Adult in winter-plumage—Similar to the adult in breeding-plumage, but lores 
and the crown of the head mottled with white. 
Immature male—Wings dark brown; entire back ash-brown, the feathers 
edged with white ; upper tail-coverts paler with no white edges ; middle tail-feathers 
similar, slightly fringed with white on the inner webs, outermost pair of feathers 
white at the base and fringed with white at the tip on the outer webs ; fore-head and 
lores white, the latter with a few dark dots which indicate the black of the adult ; 
head black with white margins to the feathers, which imparts a streaked appearance ; 
hind-neck very pale grey ; entire under-surface pure white. 
Immature (first plumage) —Uniform brown above, the scapulars, secondaries and 
upper wing-coverts buff tipped ; sometimes the whole of the feathers of the upper 
back have bright buff tips ; sometimes the tips are almost absent ; the feathers of 
the top of the head have white tips, the eye-stripe being indicated by a lighter streak, 
the loral patch being darker ; the back of the neck darker than the head or back, 
and the under-surface white with a dirty grey wash varying in intensity. 
Nestling —Brownish al] over above, the down with a mixture of white, obsolete 
darker patches being indistinctly seen ; throat and chest as back ; abdomen dirty 
white. With age the down appears lighter and the first feathers show with rufous 
tips. 
Nest.—A fissure of a rock close to the water’s edge, without any nest, or well 
concealed under a tussock of grass. 
Egg—Clutch, one; ground-colour stone, spotted all over with rich chestnut, 
and smaller spots of grey ; axis 44 mm., diameter 31-32. 
Breeding-season.—October to December. 
Distribution and forms—Throughout the tropical seas of the world, breeding 
on isolated islets. Mathews separated five forms and two have since been added, 
thus: M. a. anethetus (Scopoli) from the Philippine Islands and the China Sea ; 
M. a. novehollandie (Stephens) from East Australia, separable by its greyer neck, 
darker brown upper coloration, larger size and different tail coloration ; the West 
Australian W/. a. rogersi Mathews is similar but much darker ; MW. a. antarctica (Lesson) 
from the Seychelles, Mauritius and Laccadives is a smaller race than the preceding, 
which it resembles in coloration ; M. a. fuligula (Lichtenstein) from the Red Sea is 
larger than above and has less white on inner web of the primaries and more white 
ontthe tail-feathers ; I. a. recognita Mathews, from Hast America, breeding on the 
Bahamas, is generally lighter above, especially on the tail, and obsolete grey wash on 
under-surface and different tail coloration ; and WM. a. nelsoni (Ridgway) from Pacific 
Coast of Mexico and Central America, larger than preceding with relatively longer or 
more slender bill and under parts of body tinged with pale grey. 
Genus ONYCHOPRION. 
Onychoprion Wagler, Isis, 1832, heft 3, col. 277, March. Type (by monotypy): Sterna 
serrata Wagler = S. fuscata Linné. 
Planetis Wagler, Isis, 1832, heft 11, col. 1222, Nov. Type (by monotypy): S. guttaia ex 
Forster MS. = S. fuscaia Linné. ii 
Haliplana Wagler, Isis, 1832, heft 11, col. 1224, Nov. Type (by monotypy): Sterna fuliginosa 
Gmelin = S. fuscata Linné. 
Thalassipora Riippell, Syst. Uebers. Végel Nord-ost Afrika, p. 140, 1845. Type (by mono- 
typy): S. infuscata Lichtenstein = S. fuscata Linné. 
Dipsaleon Gistel, Naturg. Thierr. Schul., p. 10, 1848 (pref. Easter 1847). New name for 
Planetis Wagler. 
Medium-sized Terns with comparatively short stout bills, short legs, long 
wings and very long tails. The culmen is a little longer than the head, and much 
longer than the tarsus. The nature of the nostrils shows an approach to that seen 
in the Noddies. The toes are comparatively short and fully webbed. The streamers 
are well developed, making the tail more than half the length of the wing. 
