MASKED GANNET. 75 



in the naked bases of the jaws and chin, different proportions of wings, tail, culmen, 

 etc., different number of tail-feathers and the metatarsal and toe-covering. The 

 culmen is longer than the head, more than half the length of the wing, but less than 

 twice the length of the metatarsus. The tail is wedge shaped, consisting of sixteen 

 feathers, the central feathers broader, the outside ones not so short ae in Sulita, 

 and the length less than half that of the wing. The legs are short and stout and 

 more than half the length of the culmen ; the metatarsus coarsely reticulate on the 

 front and sides, smaller scales behind but the scales not so fine as in the preceding 

 genus the toe-covering consists of reticulations which can be traced in the juveniles 

 as scutes irregularly broken up, but even in the downy young no regular scutes 

 are preserved. The toes are long, the middle claw strongly pectinated. 



This genus has a tropical distribution and would probably claim nearer relation- 

 ship to Sulita than either Piscatrix or Sula. This should demand the attention of 

 future investigators. 



55. Parasula dactylatra. MASKED GANNET. 



[Sula dactylatra Lesson, Traite d'Orn., 8 e livr., p. 601, June llth, 1831 (ex Voy Coqu., Vol. I.,- 

 p. 494, April 1828) : Ascension Island, Atlantic Ocean. Extra-limital.] 



Gould, Vol. VII., pi. 77 (pt. xxm.), June 1st, 1846. Mathews, Vol. IV., pt. 3, pi. 227, June- 

 23rd, 1915. 



Sula personata Gould, Proc. Zool. Soc. (Lond.), 1846, p. 21, May: Raine Island, North- 



Queensland. 



Sula dactylatraledouti Mathews, Austral Av. Rec., Vol. I., pt. 8, p. 189, March 20th, 1913: 



Bedout Island, mid-West Australia. 



DISTRIBUTION. Tropical Northern Australia. 



Adult male. General colour above and below pure white ; bastard-wing, 

 primary -coverts and quills chocolate-brown, somewhat paler on the secondaries ; 

 inner webs of primaries hoary or silvery-grey, becoming white on the inner webs 

 of the secondaries towards the base ; tail-feathers also chocolate-brown with white 

 shafts. Bill light yellowish -horn ; base and skin dull purplish -blue ; iris yellow ; 

 feet blue. Total length 840 mm. ; culmen 99, wing 417, tail 177, tarsus 56. 



Adult female. Similar to the adult male but larger. Total length 860 mm. ; 

 culmen 105, wing 429, tarsus 59. 



Immature. Head, neck and breast white, mottled with brown, and the wings 

 brown. 



Downy young. Pure white in colour. 



Nest. None made. 



Eggs. Almost invariably two in number ; bluish-white, covered with lime ; 

 axis 64-69 mm., diameter 44-46. 



Breeding -season. July onwards to December and later according to season 

 and locality. 



Distribution and forms. Atlantic, Indian and Pacific Oceans, throughout the 

 tropics only. Rothschild in 1915 proposed five subspecies, as follows : P. d. dactylatra 

 (Lesson) from Ascension Island and South Atlantic Coasts with bill horny blue-grey, 

 very slender, feet and legs yellow ; P. d. melanops Hartlaub, from Western Indian 

 Ocean, with bill greenish -yellow, slender, feet and legs slaty-blue to dull black ; 

 P. d. personata (Gould) from Western Pacific, with bill yellow, very stout and large, 

 feet and legs greenish-blue ; P. d. californica Rothschild, from Coasts of California 

 and Central America, with bill bright yellow, very thick, feet and legs orange ; and 

 P. d. granti Rothschild, with bill red and feet bluish-green, from Galapagos Islands. 

 To which should be added : P. d. bedouti Mathews from Bedout Island, mid-West 

 Australia, with a much smaller bill than P. d. personata Gould. 



