( 11 ) 



30. Demiegretta sacra (Gm.) (Wiglesworth No. 337 p. 07). 



Rather common. Local uame " Soppu " and " Kao-Kao." There are slate- 

 coloured and white individuals, and many two-coloured ones. These do not change 

 from a slate-coloured to a white or from a white to a slate-coloured dress, but 

 have white and slaty feathers at the same time and get them again by moult. 



31. Ardetta sinensis (Gm.) (VViglesworth No. 339 p. 68). 



Rather common on Ruk Island (Cf. Nov. Zool. V. p. 65). Local name 



" Lioh." 



The nests, containing one and two eggs, were found in May and June, among 

 reeds. The eggs are of the palest green, almost white, and measure 336 : 26, 

 38 : 24-8, 38-5 : 34-3, 308 : 245, 31 : 24-2, 35-5 : 25-5, 35 : 245, 34-3 : 24-3 mm. 



Finsch, in his list of Ruk birds in the Froc. Zool. Soc. Lond., 1880, pp. 574-77, 

 enumerates twenty-nine species, of which he had examined specimens of fifteen 

 species, the others being inserted on the authority of Kubary. The following are 

 uot in my list. 



32. CoUocalia vanicorensis (= faciphaga Cat. B. Brit. Mas. XVI., p. 500). 

 It is strange that our collectors did not come across this bird. 



33. Phaethon rubricauda (Bodd.) 



34. Tachypetes aquila (= Fregata aquila). 



35. Dysporus sula (= Sula sula). 



Thus we know thirty-five species of birds to occur on Ruk. We may with 

 certainty suppose that no more land-birds are to be discovered, bnt that sea-birds 

 will occasionally visit the islands, which were not hitherto observed. The only fact 

 of first-rate interest yet to be discovered, is the breeding and the eggs of Tephras 

 ruki, which were uot found this time. Poor as the ornis of Ruk is, the land-birds 

 are of great interest. The beautiful Metabolus ruyensis, Myiagra oceanica, and 

 Tephras ruki, are, as far as we know at present, only found on Ruk Island. 



The absence of all Alcer/inic/cir, of which species are found on all the neigh- 

 bouring groups of islands, the Pelew and Marianne Islands, and on the other 

 Carolines, of hawks, owls and of Rhipiditrae on Rnk is remarkable. 



