(syn. Sterna Ϯ Black-naped Tern S. sumatrana) Portmanteau of genera Gygis Wagler, 1832, tern, and Sterna Linnaeus, 1758, tern; "Sterna dougallii ... Though, with a conservatism probably to be regretted, I have classed these birds under Sterna, I am not satisfied that this is the correct course, but under the present circumstances I cannot do otherwise. A monographic study by an up-to-date ornithologist would probably see this bird placed under Thalassæa Kaup, which genus was provided for it alone. With it would probably be accepted Sterna striata, which appears to be strictly congeneric, and also Sterna sumatrana kempi, though the last named is somewhat aberrant, and on account of its proportionately much stronger feet, might be given subgeneric rank under the name GYGISTERNA (nov.), the monotypic type being the above-mentioned Sterna sumatrana kempi Mathews. Many authors may consider Thalassæa to be invalid on account of the prior Thalasseus, and of course these may make use of Gygisterna for this group." (Mathews 1912).