2S AVIFAUNA OF LAYS AN. 



p. 353 (Borneo) , Lcggc, B. Ceylon, p. 1180 (1880); Nichols. Ibis, 1882, p. 70 (Cocos b4*b) ; 

 Mflne-Edw. Ann. So. Nat. Zool. ser. vi. tab. xiii. art. no. 4, p. 30 (1882) , Seeb. B. Japan, p. 213 (1891) ; 

 Wiglesw. Abh. u. Bcr. Mus. Dresd. 1890-01, p. 72 (1802, in "Ave. Polynesia"). 

 Piscatrix piscator, G. R. Gray, Haod-1. iii. p. 120 (1871). 



Sula plumiyula, Pelz. Ibis, 1873, p. 52, ex Natt. MS. (Australia?) (type examined hy Salvador,). 

 Dhjtorm hemandezi, Gundl. J. f. O. 1878, p. 208 (Cuba) ; id. J. f. O. 1881, p. 401. 



Adult. Bill horn-colour, overspread with dull blood-red in dried skin, light blue with the 

 hare space ou the forehead and a mark near the base of lower mandible purplish red m 

 life Bare space on chin and throat black in dried skin, blue with blaekish markings 

 in life. Plumage pure white, with a more or less developed buff tinge on the top of head 

 and hind neck. Greater upper wing-coverts and quills dark greyish brown. Shafts ot 

 white tail-leathers straw-yellew. Feet purplish red in dried skins, red with purple tinge 

 i„ life. Claws horny white. Iris dark brown, with a circle of greyish and brownish hues 

 on the outer edge. Total length about 28 inches, wing 14 5 to 16"5, tail 8-8 to J o, 

 culmeii 3 to 3'5. 



Immature birds are spotted with brown above, and the young in the first plumage are 

 dark brown above and lighter smoky grey beneath, with quills and tail-feathers much 

 paler. The young birds vary extremely in coloration, and it is difficult to find several 

 specimens of exactly the same colour. 



The c-s are like those of other Gannets, covered with a chalky crust of a dull white, and the 

 shell under it is light greenish blue. They measure 2'5G by 157 inches, 2'4 by TO, 

 2-25 by 14,7, and 2 76 by 177. 



This bird resembles the Common Booby (Sula sulci, Linn.) in building its nest on the top of 

 a bush and not on the ground like Sula cyanops s Sundev. The nest is made of twigs, and 

 only one egg is laid. Its cry is loud and harsh, and it vigorously attacks anyone trying to 

 drive it off the nest. 



It is very plentiful on Laysan, and was caught and skinned at sea near Niihau, on 

 Lisiansky and Midway Islands, also often seen at sea. 



The' speeies of Sula do not intermix, and the breeding-places of the different species 

 are always separate. 



These islands are about the northernmost places where the widely-spread Sulci piscatrix (L.) 

 occurs, but in America it goes as far north as Southern Florida and Lower California. 

 This species has (I. c.) been noticed from Kauai by Stejneger. 



(Note.— The Plate given with this species is a photograph of the palm-tree mentioned 

 by Kittlitz, and which has thus been continuously used by the birds for more than 70 years.) 



