REPORT ON THE BIRDS — TONGA, THE FIJIS, API, AND TAHITI. 



39 



No. 20. Tongatabu. Female, young. 



[Common on the reefs at low water; also met with in the woods through the island. 

 Shot July 21.] 



No. 22. Tongatabu. Male. Shot July 22. 



No. 19 is white, assuming the slate-coloured dress from below and on the back ; slate- 

 blue appanage in full development. 



No. 20. Slate-blue, with white chin-stripe ; the scapular appanage in beginning of 

 development. 



No. 22. White, sprinkled on the neck, back, and below with single slate-blue feathers ; 

 no development of scapular appanage visible. 



On several occasions I have shown that the white dress in this Heron is not dependent 

 upon age or sex, and that at present we are not able to explain the causes of these 

 interesting differences in coloration satisfactorily. 



9. Porphyria samoensis, Peale. 



Porphyrio samoensis et Porphyria vitiensis, Puale. 



Porphyrio vitiensis, F. and H., Ornith. Central-Polyn., p. 172, torn. xii. fig. 3. 



Porphyrio indicus, Cass, (nee Horsf., nee F. and H.). 



Porphyrio vitiensis, F. and H., Journ. f. Ornith., 1870, p. 135 (Tonga); H. and F., Proc. Zool. 



Soc, 1871, p. 27 (Savai). 

 Porphyrio samoensis, Finsch, Journ. f. Ornith., 1872, p. 55; Proc. Zool. Soc.', 1877, p. 726. 

 Porphyrio vitiensis, Layard, Proc. Zool. Soc, 1875, p. 439 (Fiji) ; ibid. 1876, p. 497 (Navigators'), 



-and 1876, p. 503 (Tonga). 

 Porphyrio indicus, Whitmee (nee Horsf.), Ibis 1875, p. 446 (Samoa). 

 Porphyrio calvus, Elliot, Stray Feath., vol. vii. p. 16. 



No. 



22.] 



21. Tongatabu. Female. [Eyes red. The only specimen seen. Shot Jul)- 



I have already explained (Proc. Zool. Soc, 1871, p. 27) that Porphyrio indicus, 

 Horsf., does not occur in Polynesia, as has been stated by Mr Cassin, but that the 

 Central-Polynesian Islands (Fiji, Navigators' and Friendly group) possess only one 

 species; Porphyrio samoensis, Peale. The description in the Ornithology of Central- 

 Polynesia, p. 170, taken from a Javan specimen of the true Porphyrio indicus, Horsf., 



should therefore be cancelled altogether. 



