Ml*. R. Swinhoe on Formosan Ornithology. 429 



176. Sternula sinensis (Gmel.). 



S. sumatrana, Raffles. 



The true Little Tern, S. minuta (L.) is not an uncommon winter 

 visitant to the south coast of China, and occasionally comes to our 

 coast during that season. But in Formosa we have a resident 

 species quite distinct, with constant dark bill and legs, and grey 

 on the upper tail. I have several skins of this species, procured 

 in summer at Taiwanfoo ; so that there can be no doubt of the 

 plumage not being matured. These I have compared with the 

 American Sternula and the Australian S. nereis, Gould, but 

 both these are much more closely allied to S. minuta. There 

 are, however, specimens in the East Indian Museum, marked S. 

 minuta, from the Indian Archipelago, which appear to me iden- 

 tical with our bird. These have been noted by Raffles as Sterna 

 sumatrana. Four adult specimens were brought to me on the 

 29th August. They all varied in the length, colour, and even 

 shape of the bill. In one the bill was a uniform blackish brown ; 

 in two others the bills were of a brownish-yellow ground-colour, 

 washed over with black ; and in the fourth the apical half was 

 blackish grey, and the basal half brownish ochre. The legs and 

 toes of this last were light reddish brown, with orange under- 

 tarsi and soles, the claws being blackish brown. The other 

 three had ochre-brown legs and toes, with more or less orange 

 on their under-surfaces. In none of my nine specimens is there 

 any mottling of immaturity, and most of them have the tail- 

 feathers much worn. The stomachs of those dissected contained 

 small shrimps and a few small fish. Intestine 12 inches long; 

 caeca situate ^y from anus, about ^^ long. Length of bird 9 in.; 

 wing 7^; tail 4, well forked, the four central rectrices being 

 short and obtuse, the four lateral on each side pointed and 

 graduated outwards, the outer one being I^q in. longer than 

 the central. Crown, nape, and loral streak black, leaving the 

 forehead, a partial eyebrow, and the moustache-streak white. 

 All the under-parts pure white. Upper parts, including rump and 

 central rectrices, pale French grey. Primary quills with white 

 shafts ; the first two black, with broad white borders to the inner 

 webs ; the next two blackish grey, with narrower borders ; the rest 

 of the same colour as the back. Secondaries tipped with white. In 



