no 



REMARKS ON THE GENUS SULA. 



ments we have from 2'94 to 3*3, and Hartlaub gives the mid 

 toe and claw at 41 1 to 4*2. 



If we contrast the recorded colours of the soft parts, we shall 

 find even more striking differences : — 



Y. Heuglin 



Gould 

 Bonapte. 

 Hart), and 

 Heuglin. 



Schlegel 

 Shelley 



Bill. 



Olivaceous 



yellow. 



Yellow 

 Greenish yellow 



Pale yellow 



Yellow 



Bare Slcin of 

 Face and Chin. 



Deep black 



Bluish black ... 

 Blackish blue ... 

 Black 



Feet. 



Irides. 



Pale 



black, 



Dusky, webs al- Yellow. 



most black. 

 Greenish blue ... Yellow. 

 Plumbeous. 

 Bluish plum- Reddish yellow. 



beous, webs 



dusker. 

 Greenish. 



verging on 

 violet or blue. 



Slate colour ... Slaty grey 



Finsch and Pale greenish Dull bluish 



Hart. yellow. 



Sundcv. (young Basal half blue, Blue 



Greenish 



Yellow. 

 Yellow. 



female). 



» 



Graffe 

 Butler 



terminal por- 

 tion olive. 



Horny greenish Blackish, 

 grey. 



Bluish green ... Bluish green 



Olive, webs dark Deep, (?) bright, 

 yellow. 



Pale bluish 

 horny. 



Slate colour 



Dirty green .. 

 Lavender blue 



Greenish 

 yellow. 

 Pale green. 



It has been suggested that the colouration may vary with sex 

 as well as age, but in the present case, Captain Butler's speci- 

 mens, male and female (both apparently in exactly the same 

 stage of plumage,) differed in no single respect in the colours 

 of the soft parts ; it has further been said that the females are 

 smaller, but this idea also receives no confirmation from Captain 

 Butler's specimens. 



It will have been noticed that, while Gould and Finsch give 

 only the tips of central tail feathers as dark, others give the 

 whole of these feathers thus : 



Taking the record, judicially, I think it very probable that, 

 instead of one species, there will prove to be three. The true 

 cyanops from the Atlantic, melanops from the Red Sea and the 

 north-east coast of Africa, and personata from North Australia, 

 New Guinea, and Central Polynesia. It seems probable that 

 the specimens from the Keeling, or Cocos Islands, and Straits 

 of Sunda are identical with these latter. 



Even if the evidence were .not in the highest degree dis- 

 crepant, it should not be everlooked that probabilities are some- 

 what in favour of the distinctness of species inhabiting as 

 permanent residents, and breeding in these three very different 

 localities, the Atlantic, the Red Sea, the Straits of Torres and 

 Central Polynesia, and not occurring so far as we yet know 



