72 A MANUAL OF THE BIRDS OF AUSTRALIA. 



Genus SULA. 



Sula Brisson, Ornith., Vol. I., p. 60, Vol. VI., p. 494, 1760. Type (by tautonymy) : Sula = 



Sula leucogaster Linn6. 



Dysporus Illiger, Prodr. Mamm. et Av., p. 279, (pref. April) 1811. New name for Sula Brisson. 



Sularius Rafinesque, Analyse de la Nature, p. 72, 1815. New name for " Sula Lac." = Sula 



Brisson, cf. Auk, Vol. XXVI., p. 50, Jan. 1909. 



Abeltera Heine und Reichenow, Nomencl. Mus. Hein., p. 351. (pref. Sept.) 1890. New name 



for "Sula Reichb. 1853" = Sula Brisson. 



Hemisula Mathews, Austral Av. Rec., Vol. II., pts. 2 and 3, p. 55, Oct. 23rd, 1913. Type 



(by original designation) : Sula leucogaater rogersi Mathews. 



Small Suline birds of dark coloration above, with general characterr as in 

 Piscatrix, but with different proportions. 



The bill is a little longei, but the tail is much shorter, while the metatarsus 

 and toes are notably long. The bill is typically Suline, more than half the length 

 of the tail, but less than twice the metatarsus. The wing is long, more than twice 

 the length of the tail. The metatarsus is coarsely reticulate with small scales, the 

 scales being smaller on the hinder aspect. The toes have the posterior joints clearly 

 reticulate, the anterior ones covered with scutes more or less broken up. This 

 genus is denned by the coloration of the adult, a character differentiating it at 

 once from the rest of the Suline birds. 



The immature plumage of this bird and Piscatrix show great similarity, while 

 the adults show just as great a dissimilarity. The evolution of Piscatrix from its 

 immature whole brown plumage passes through the stage when the brown is lost 

 on the belly first. The present genus seems to show a peculiar stoppage in this 

 course, this bird showing a brown coloration throughout, save the breast and 

 abdomen, which are pure white. Though practically the same wing length is 

 developed, the tail in Piscatrix has grown much lorger, the metatarsus lengthening 

 in Sula. 



53. Sula leucogaster. BROWN GANNET (BOOBY). 



[Pelecanu* leucogaster Boddaert, Tabl. Planch. Enlum., p. 57, (pref. Dec. 1st) 1783: Cayenne. 

 Extra-limital.] 



Gould, Vol. VII., pi. 78 (pt. xxra.), June 1st, 1846. Mathews, Vol. IV., pt. 3, pi. 228, June 

 23rd, 1915. 



Pelecanus plotus Foreter, Doscr. Anim., ed. Licht., p. 278, (pref. Jan. 1st) 1844 : near New 



Caledonia. 



Sula leucogaster rogersi Mathews, Austral Av. Rec., Vol. I., p. 189, March 20th, 1913 : Bedout 



Island, mid-West Australia. 



DISTRIBUTION. Tropical Northern Australia. 



Adult male. Entire upper-parts, throat, fore-neck, and sides of breast chocolate- 

 brown, somewhat darker and more blackish on the primary-quills ; secondaries 

 white at the base of the inner webs ; under wing -coverts chocolate -brown, except 

 the median series which are white ; breast, abdomen, sides of body, axillaries, and 

 under tail-coverts pure white. Bill and skin yellow, spot in front of the eye blue ; 

 iris silver-grey ; feet pale yellow. Total length 710 mm. ; culmen 84, wing 374, 

 tail 200, tarsus 43. 



Adult female. Similar to the adult male but larger. 



Immature and young. Described by Dr. Macgillivray : The young birds are 

 hatched with eyes closed, with only an indication of down on head, back, humeral, 

 femoral, and each pectoral region. The eyes open very soon, and the birds become 

 covered with whitish down at an early stage, the beak and legs being of a pale slaty- 

 grey, much the same colour as the naked skin ; the gape also a pale slate colour. 

 They grow almost to full size before acquiring any feathers, the first to appear being 



