I. StJLA. 431 



Sula raelaiiops, Hmgl. Ibis, 1859, p. 351, pi. x. figs. 2, 3 [Bur-da- 

 Kebschi, Somali Coast]. 



? Sula piscatrix, Hume, Str. F. iv. p. 483 (1876) [Laccadives]. 



Sula abbotti, Ridgiv. P. U.S. Nat. Mm. xvi. p. 599 (1893) [As- 

 sumption I., Ind. Ocean]. 



Adult. Pure white, except the primaries, secondaries and their 

 coverts, as well as the tail-feathers, which are brownish black ; the 

 quills and coverts, however, have the basal part of the inner web 

 mostly white, and the basal part of the tail-feathers is white. The 

 chin and upper part of the throat entirely naked ; feathers termi- 

 nating in a nearly straight line across the throat. Tail composed 

 of 16 or occasionally 18 feathers. Iris yellow ; bill horn-colour, 

 greenish grey, or greenish yellow ; naked skin round the eyes and 

 on the throat dark slate to bluish black ; legs and feet slate-grey, 

 brownish grey, bluish grey, or greenish yellow ; webs darker.* 

 Total length about 36 inches, culmen from feathers on forehead 

 4-3-4-4, wing 17-5-17-8, tail 7-1-7-6, tarsus 2-3. 



Nestling covered with -white down. 



hi the youngest examples which I have examined the head, neck, 

 and upper parts are mostly smoky brown, mixed here and there with 

 white, or partly white feathers ; between the base of the neck and 

 upper back a rather marked zone of whitish feathers ; chest, 

 breast, and underparts pure white ; under wing-coverts almost pure 

 white, one or two of the outermost feathers mixed with brown. 



In nearlg adult specimens the lesser wing-coverts, lower back, 

 and rump are mixed with the brown feathers of the immature ; 

 otherwise the plumage is like that of the adult. " Iris pale green ; 

 gular skin slate ; bill pale bluish horu ; legs and feet lavender-blue " 

 {E. A. Butler). 



Hah. Tropical seas throughout the world. 



a-c. Ad. et pull. Ascension I., Dec. {Dr. D. Gill). Dr. Frank Penrose 



sk. [P.]. 



d. Imm. sk. At sea, off the Cape of Good E. M. Langworthy, 



Hope. Esq. [P.]. 



e,/. J^vixad. Mekran Coast, May 14 (£". A. Hume Coll. 



sk. Butler). 



g. Imm sk. Tenasserim. J. D. C. Packman, 



Esq. [P.]. 



h, i. $ ad. sk. Raine Island, N.E. Australia. 'Challenger' Exped. 



k. Ad. sk. Norfolk Island. E. Saunders [C.]. 



I, m. Ad. sk. Norfolk Island. Seebohm Coll. 



n. Juv. sk. Curtis Island, Kermadec Group, Miss E. Eastwood 



Feb. 13. [P.]. 



* Judging from the descriptions published by various authors, the colours 

 of the soft parts in S. cyanops vary greatly [cf. Hume, Str. F. v. p. 310 (1877)]. 

 Too much importance must not, however, be attached to these differences, for 

 alter making allowance for the changes of colour caused by age, season, and sex, 

 it must be borne in mind that some of the records are probably taken from 

 birds some hours after death, when the colours of the gular pouch and legs are 

 entirely altered, while some descriptions are taken from dry skins. 



