SULID^ — THE GANNETS — SULA. 177 



(No. 67316, Christmas I. ; Dr. T. H. Streets) : Head, neck, and upper parts generally, dark 

 grayish brown ; lower neck and entire lower parts white, the flanks streaked with grayish ; middle 

 of the back, and upper part of rump, streaked with white. Okler (No. 68361, Calhio, Peru, July 

 15, 1870 ; Dr. L. Kedtenbacher) : Head, neck, and lower parts, white ; upper parts dark gray- 

 ish brown, the feathers (except reniiges and rectrices) narrowly tipped with white ; middle tail- 

 feathers hoary white toward base. Bill purplish, the ma.xilla pale grayish horn-color ; feet dusky 

 (in dried skin). Wing, 14.60 inches ; tail, 7.75 ; culmen, 3.60 ; depth of bill through base, 1.20 ; 

 tarsus, 1.75 ; middle toe, 2.35. 



In the adult plumage this species presents a quite close resemblance to the mature stage of 

 S. bassana ; but the very different form of the bill and bare skin about the face will serve readily 

 to distinguish it. The coloration seems to be much more constant in this species than in either 

 S. leucogastra or S. jnscator, the four adults before us not presenting any appreciable differences. 



The immature specimen from Callao, Peru, described above, differs slightly from others in the 

 bill being more slender, and of a more purplish hue. It is labelled "S. variegata, TscH. ;" but 

 .whether really variegata or not, tliere can be little doubt that it is referable to S. cyanops. 



This species was procured by Dr. Bryant at the Bahamas. It was about the size 

 of the Sula leucogastra, but was heavier, and more muscular. He found about twenty 

 pairs breeding at Santo Domingo Key. They apparently lay their eggs later than 

 the Booby ; and the largest of the young, found early in April, were not more than 

 half grown, and the eggs of several had been freshly laid. As in the case of the 

 Booby, the number of the eggs is always two. The eggs are whiter than those of the 

 Booby, the chalky covering being much thicker, and do not differ much in size and 

 proportions, the two extremes measuring 2.60 by 1.67 inches, and 2.45 by 1.73. 

 These Gannets did not associate with the other species. The young birds and eggs 

 were all in one part of the island. When half fledged they were very pretty, the 

 snowy white down with which they were covered forming a striking contrast to the 

 dark brown of the tail and wings, then just appearing. Their habits were precisely 

 the same as those of the Boobies, and their internal structure presented no appreciable 

 difference. 



The Sida personata of Gould is identical with the Bahama species. It was noticed 

 at sea by Dr. Pickering, between the Sandwich Islands and our Avestern coast, in 

 long. 167° 30' W. As this locality is the nearest to the coast of IS^orth America of 

 any given by the naturalists of the Wilkes Expedition, this species may be looked 

 for as an inhabitant of the Pacific coast of the United States. It was also observed 

 in other localities in large numbers by the naturalists of that Expedition. It Avas 

 found most abundant at Honden Island and Enderby's Island, in both of which it 

 was engaged in the duties of incubation. So far as is known, it inhabits the Pacific 

 Ocean as far to the southwest as ISTorthern Australia, and is more abundant in the 

 northern and eastern portion of its range during the season devoted to the rearing 

 of its young. 



Mr. Peale states that these birds Avere first seen on the 20th of Jiily, lat. 13° 

 30' 28" S., long. 89° 25' W\ One month afterward they were found in great num- 

 bers at Honden Island, one of the Paumotu Group, Avhere they Avere sitting on a 

 single Qgg each, one bird having only tAvo eggs. They had no nest Avhatever, not even 

 a cavity scratched in the sand. Flat dry sandy beaches Avere selected on the shores 

 of the lagoons, the female laying her egg on the bare ground, the male assisting in 

 the duties of incubation. They remained very gravely at their stations, regardless 

 even of man. Many Avere pushed off their nests Avitli the muzzles of the guns ; they 



9.10, 4.15, 1 .60, 2.15, 3.10 — a specimen from the Paumotu Islands being the largest. The smallest is the 

 Peruvian specimen described above. 

 VOL. 11. — 23 



