561. Thalasseus Pelecanoïdes Vol. VII. Pl. 23. 562. Thalasseus poliocercus, _Gould_ Vol. VII. Pl. 24. 563. Thalasseus Torresii, _Gould_ Vol. VII. Pl. 25. Since my account of this species was printed I have seen adult specimens from Southern India, which country is in all probability its true habitat. Genus STERNA, _Linn._ The members of this genus, as now restricted, enjoy so wide a range over the globe, that they may be said to be universally dispersed: three species are found in Australia. 564. Sterna melanorhyncha, _Gould_ Vol. VII. Pl. 26. 565. Sterna gracilis, _Gould_ Vol. VII. Pl. 27. 566. Sterna melanauchen, _Temm._ Vol. VII. Pl. 28. “This beautiful bird,” says Mr. M’Gillivray, “is very local in its breeding-places, the only one known to me being one of the ‘three sand-banks’ near Sir Charles Hardy’s Islands. The eggs are two in number, deposited in a slight hollow in the sand. I have seen this bird on another neighbouring sand-bank, also on Solitary Island, near Cape York, and in Endeavour Straits, but was unable to procure a specimen from any of the three last-mentioned localities, on account of its excessive shyness. It is one of the most noisy of the Terns, and I generally saw it in small parties of half-a-dozen, or thereabouts. The fully-fledged young of the year differs from the adult in having the black on the head dark brown mottled with white, and the whole of the upper surface and wings variegated with dark brownish grey.” Genus STERNULA, _Boie_. Europe and Australia are both tenanted by little Terns, the specific distinctness of which cannot be questioned, however much that of the large Terns (genus _Sylochelidon_) may be: ought we not then to infer that some peculiar law prevails, and that if one be distinct the other is also? However that may be, it is certain that birds regarded as identically the same, because no external difference is perceptible, breed at opposite seasons in the two hemispheres, and that if the birds of one hemisphere be brought and retained in the other, they continue to moult their feathers and to breed at the same period that they would have done had they remained in their native country. 567. Sternula Nereis, _Gould_ Vol. VII. Pl. 29. Genus GELOCHELIDON, _Brehm_. It would be strange if this form did not exist in Australia, when all the other European genera of Terns are found there; still I have no other evidence of such being the case, than that of a specimen in the collection of King’s College, London, which is said to be from Van Diemen’s Land, and to which in the year 1837 I gave the name of _Sterna macrotarsa_. 568. Gelochelidon macrotarsus, _Gould_.